1. Facilitating Market Access

1.1 FMA 179

Programme Title:

Trapping to determine the flight seasons for Arhopalus tristus

Programme Leader:

Dr.Max Suckling

Institution:

HortResearch

Summary

Goal:

The goal of this research programme was to help mitigate the risk and cost caused by the burnt pine longhorn as a quarantine pest of export timber.

Background

Context of project:

Arhopalus tristis attacks logs, stumps and standing, dead or damaged trees of pine species. A. tristis is frequently reported by industry workers as sheltering in export sawn timber at sawmills and in ports, and exports to Australia require fumigation when it has been found.

Approach & Outcomes

This was to be achieved by further developing promising leads involving (a) developing a bait for use in traps, (b) improving the trap design and (c) identifying the importance other factors such as trap location, to allow more precise definition of the Arhopalus flight season.

It has already been shown that A. tristis also shows an olfactory and behavioural response to fire-associated pine odours. Historically data on the flight season was combined with new data provided by AgriQuality and MAF from the National Survey of Bank and Wood Boring Beetles, and operational trapping at sawmills. Experimental trials were also conducted, using traps baited with a range of possible attractants. Two trap types were compared.

The outcome was:

Historical data from passive pane trapping at two Canterbury sawmills over three seasons (1996-1999) showed the flight season (late November-late April). A substantial data set of the 2001/02 seasonal phenology of this pest was also collected at a local timber yard in Kaiapoi and from five South Island AgriQuality monitoring sites. Seasons phenology data at two-weekly intervals was also summarised from the 360 traps operated for MAF’s national survey across 16 regions.

At present Lindgren traps are used by AgriQuality and MAF for monitoring A. tristis. Trapping trials conducted at Bottle Lake Forest Park compared a panel trap design to Lindgren traps, with various potential lures. The panel trap (corflute trap) showed equivalent or better catch than the Lindgren traps.

Field tests at the Port of Tauranga were successful at developing a lead for an improved trapping system, but some further work is required. The very large trap with a cross-vane warrants further investigation for a standardised system. The advantages of this type of system are that it is a standardised sampling unit, and it does not require costly night attendance by the trap operator, because the beetles can be counted the next day.

Gazebo-scale tests of synthetic attractants were unsuccessful. Field tests at Bottle Lake Forest Park, compared burnt bark solvent washes (water, white spirits and ethanol) as attractants, but no significant improvements resulted in catch.

More information is now available in the phenology and regional abundance of the beetle. However, a baited trapping system has not been developed, despite testing of a wide range of approaches. A large passive vane trap appears to offer the best promise for standardising catches in ports, but work is needed to develop the action threshold. Given the strong attraction of beetles to areas post-fire, and to kiln areas there still appears to be an opportunity to develop a lure for this insect, despite the lack of success with various experimental protocols tested here. Further work should focus on head-space analysis of odourants at areas near kilns, where beetles aggregate in response to strong odour strength, as well as vane trap development for the ports.

1.2 FMA 180

Programme Title:

Identification Key to Tetranychidae of New Zealand

Programme Leader:

Dr Zhi-Qiang Zhang

Institution:

Landcare Research, Auckland

Summary

This project provides a user-friendly identification key to the genera and species of the mites of Tetranychidae in New Zealand. It enables the identification of tetranychid mites in New Zealand to facilitate requests for rapid quarantine decisions from trading partners. The key was constructed through careful studies of over 2000 specimens preserved on slides, and was illustrated with figures of discriminating characters. A total of 12 genera and 46 species were included in the key, including 3 genera newly recorded for New Zealand and 16 new species. Distribution, taxonomic references, the list of specimens with host plants were provided for each species.

Goals:

To provide a user-friendly identification key to the genera and species of the mites in the families Tetranychidae occurring in New Zealand.

Background

Context and Project:

A key is required that allows identification of tetranychid mites in New Zealand to facilitate requests for rapid quarantine decisions from trading partners.

Approach & Outcomes

Existing slide-mounted specimens in NZAC, MAF NPPRL in Lincoln and Lynfield, and other available material, were collated, assessed and examined by light microscopy, and diagnostic features discriminating genera and species were identified and illustrated by line drawings. The information was collated into an illustrated dichotomous key. Unnamed species were referred to by codes. Distributional data were provided based on published records but mostly from data accompanying the specimens.

The outcome was:

About 850 slides containing over 2000 specimens of New Zealand tetranychid mites were studied. An illustrated key to 2 subfamilies, 12 genera and 46 species of the Tetranychidae was constructed. Both subfamilies of the Tetranychidae are represented in New Zealand. Among the 12 genera, three are recorded for the first time in New Zealand. Among the 46 species, over one third are new species to be described in the future. For each species, the following data are provided: full species name, list of taxonomic references; distribution data; and a list of specimens examined, with host plant and distribution information.

1.3 FMA 181

Programme Title:

Consumer/health component of quantitative risk assessment of Salmonella spp. In sheep meat produced in New Zealand

Programme Leader:

Dr Craig Thornley

Institution:

Institute of Environmental Science and Research Ltd

Summary

To determine the contribution of sheep meat consumption to the incidence of salmonellosis and Salmonella Brandenburg infection among humans in New Zealand

Background

Case identification commenced on 25 January 2002. As at Friday 28 June 2002, 84 case interviews had been completed. The response rate to case interviews has been acceptable, with 69% (84/121) of eligible cases participating in the study. Interviews have been completed with 76 control participants of a total of 148 potentially eligible persons contacted, a response rate of 51%. Sixteen eligible cases of Salmonella Brandenburg infection have been identified during the study period thus far, and ten of these have participated in the study.

Approach & Outcomes

To provide data to validate the QRA model, using information from Objective 1 and estimates of the true population incidence of human infection with: (a) all Salmonella species combined; and (b) Salmonella Brandenburg separately.

Work on this proposed objective is planned for the 2002-03 financial year, pending continuation of the contract.

The number of Salmonella Brandenburg cases included in the study thus far is still lower than expected because fewer cases have been identified than had been projected. The number of S Brandenburg cases is typically lowest during summer and autumn, so the low numbers recruited to the study so far do not necessarily mean that insufficient numbers will be recruited to the study by completion. The response rate presented in the current report is correctly based on the total number of eligible cases identified by ESR.

1.4 FMA 182

Programme Title:

Welfare and Mortality of Newborn and Young Calves in the Dairy Industry

Programme Leader:

Professor David J Mellor

Institution:

Animal Welfare Science & Bioethics Centre, Massey University

SUMMARY

The goal of this work was to determine the status of dairy calves at birth and the extent to which they experience significant welfare compromise during the first 4 days after birth. Clinical, physical, physiological and pathophysiological indices, which are well-established for ewes and lambs, were used to assess the incidences of placental insufficiency brought about by maternal underfeeding or stress during early pregnancy, premature birth, intrapartum hypoxaemia, cold exposure and starvation.

The physiological status of calves at birth was fairly uniform. Prepartum factors, namely placental insufficiency and maternal underfeeding during late pregnancy were not major problems in the calves of this study. Assistance was provided for the present cows when birth did not apparently progress for over one hour. Intrapartum hypoxaemia was subsequently evident in assisted calves and was accompanied by elevated plasma lactate concentrations and reduced calf vigour. Assisted calves did not become hypothermic but did exhibit a prolonged time to stand which may have delayed colostrum intake and interfered with intake and absorption of immunoglobulins. Other significant factors were weather, air temperature and time of day at birth. Calves that died had significantly higher birth weights and plasma lactate concentrations than calves that remained healthy. A comparison between calves that were separated from their mothers at ages younger and older than 24 hours revealed that those separated early had a higher incidence of sickness and mortality and, on average, lower colostrum intakes. We conclude that calves seem to have a good chance of survival when they are alive at birth and that factors to which calves are exposed later in life may have a greater influence on mortality rates. Early assistance during dystocia might reduce the effects of intrapartum hypoxaemia, such as inhibition of heat production, which the calf is likely to experience. Ensuring the intake of colostrum adequate to acquire passive immunity thus seems of major importance for the welfare of the newborn calf.

Goal:

Using clinical, physical, physiological and pathophysiological indices, proven in ewes and lambs, to assess the causes and animal welfare consequences of factors that predispose newborn dairy calves to death or debility up to 4 days of age.

BACKGROUND:

It has been shown that from 4 days of age the welfare of Bobby calves remains acceptable provided the Code of Recommendations and Minimum Standards for the Welfare for Bobby Calves is followed (Todd et al., 2000a, b; Stafford et al., 2000, 2001). There are also validated criteria for assessing the status of calves upon arrival at a meatworks (Stafford et al 2001). These criteria can now be used to improve the detection of calves not treated according to the Code and can thereby facilitate the necessary remedial action. Notwithstanding these positive advances, critics of the Bobby Calf trade can still claim that the situation for all calves prior to pick-up at 4 days of age is still not known, because it is only those calves that meet certain ‘fitness’ criteria defined in the Code that are allowed to be transported. Thus, there could be a significant unobserved or hidden proportion of calves where welfare compromise is substantial and calf losses great. At present no convincing argument could be mounted to counter such claims because our knowledge of the nature and cases of welfare compromise, debility and mortality of calves during the period between birth and 4 days of age is very limited.

APPROACH AND OUTCOMES

The approach was to use criteria previously well established for lambs to assess the physiological and pathophysiological status of calves at birth and during the first 4 days after birth. Major causes of death or poor performance in newborn lambs were placental insufficiency brought about by maternal underfeeding or stress during early pregnancy, premature birth, intrapartum hypoxaemia, cold exposure and starvation.

The results have shown that the physiological status of calves at birth is fairly uniform. Prepartum factors, namely placental insufficiency and maternal underfeeding during late pregnancy were not major problems in the calves of this study. Assistance was provided for the present cows when birth did not apparently progress for over one hour. Intrapartum hypoxaemia was subsequently evident in assisted calves and was accompanied by elevated plasma lactate concentrations and reduced calf vigour. Assisted calves were not observed to become hypothermic in response to intrapartum hypoxaemia, unlike newborn lambs. However, a prolonged time to stand in assisted calves may have delayed colostrum intake and may have interfered with the intake and absorption of immunoglobulins. Environmental variables such as weather, air temperature and time of day at birth did have an influence on rectal temperature, plasma glucose concentration and time to stand. There was a significant difference in plasma lactate concentrations and calf birth weight between calves that subsequently became sick and those that remained healthy, but there were no significant differences between these groups in any of the other parameters measured. Calves that died had significantly higher birth weights and plasma lactate concentrations than calves that remained healthy. A comparison between calves that were separated from their mothers at ages younger and older than 24 hours revealed that those separated early had a higher incidence of sickness and mortality. Also it was apparent that calves staying with their mother longer were likely to take in more colostrum. From these findings it can be concluded that calves seem to have a good chance of survival when they are alive at birth and that factors to which calves are exposed later in life may have a greater influence on mortality rates. Early assistance during dystocia might reduce the effects of intrapartum hypoxaemia, such as inhibition of heat produce, which the calf is likely to experience. Ensuring the intake of colostrum adequate to acquire passive immunity thus seams of major importance for the welfare of the newborn calf.

PUBLICATIONS

Diesch, T., Mellor, D.J., Stafford, K.J. and Ward, R.N. (2002). The physiological status of dairy calves at birth. In: Animal Welfare and Behaviour: From Science to Solution. National Animal Welfare Advisory Committee and International Society of Applied Ethology joint conference 27-28 June 2002, Hamilton, New Zealand, p.19.

Diesch, T.J., Mellor, D.J., Stafford, K.J. and Warn, R.N. (2002). The physiological status of newborn dairy calves between birth and four days of age. Physiological Society of New Zealand, Programme and Abstracts, Annual Meeting 4-6 December 2002, in press.

1.5 FMA 183

Programme Title:

Chronic pain in ruminants after painful husbandry practices

Programme Leader:

Assoc. Prof Kevin Stafford

Institution:

Animal Welfare Science and Bioethics Centre, Massey University, Palmerston North

Summary

To determine if the pain experienced by calves following amputation dehorning continues after 24 hours. Jaw activity was recorded for 2 days before and after amputation dehorning. Grazing activity was reduced on the day following dehorning in calves subject to amputation dehorning alone. Grazing activity did not change in control calves and in calves that were dehorned following the administration of local anaesthesia and Ketoprofen. The reduced grazing on day 2 after dehorning suggest that calves are still in pain and should receive both local and systemic analgesia before and systemic analgesia on the day following dehorning to alleviate this pain.

Goal:

Using novel equipment to assess the value of feeding and ruminating behaviour as indices of chronic pain in heifers after dehorning.

Background

A series of contracts has been completed investigating the acute pain in ruminants after husbandry procedures and our knowledge of the acute behavioural and physiological responses to husbandry procedures has advanced greatly in the last decade. However, we have a poor understanding of the duration and intensity of the chronic pain, which may be caused by these procedures. The development of an apparatus to monitor jaw activity in grazing livestock allows us to monitor feeding and ruminating behaviour of cattle during the days after dehorning and this will allow us to determine whether the pain caused by this procedure continues for several days or is complete within 24 hours of dehorning.

Approach & Outcomes

Twenty four, six month old replacement Friesian heifers were divided into three treatment groups; 

  1. dehorned by scoop dehorners, 
  2. dehorned by scoop dehorners following local anaesthesia and having a NSAID (Ketoprofen) given before dehorning and each morning for the following two days, 
  3. control calves handled as groups (1) and (2) but not dehorned.

The jaw activity of these calves was recorded for 2 days before treatment and for the two days following it. Jaw activity was not carried out during the day of treatment. Records from the jaw recorders were downloaded onto a specially developed computer software package and analysed.

There was no change in the grazing and ruminating behaviour of control calves over the four days of recording. Calves subjected to amputation dehorning grazed significantly less on the day following dehorning than on the days preceding dehorning or the second day following it. This suggests that the calves were still experiencing pain on the day following dehorning. The grazing time of calves that were dehorned but received Ketoprofen did not change during the four days, which suggests that the analgesia reduced the pain experienced by these calves.

The time spent ruminating was greater in dehorned calves and dehorned calves that received analgesia on the day following dehorning. This supports the thesis that rumination may be a form of self-analgesia.

Previous studies have shown that local anaesthetic and systematic analgesia should be used before amputation dehorning. The results of this study suggest that systematic analgesia should be maintained for at least 48 hours after amputation dehorning. The role of rumination in inducing endogenous analgesia requires further study.

1.6 FMA 184

Programme Title:

Monitoring welfare in stock presented for slaughter

Programme Leader:

Dr Jo Pollard

Institution:

AgResearch

Summary

This project developed a system of monitoring variables related to on-farm welfare standards, using stock arriving at slaughter plants, for use by MAF and NAWAC in revising codes of welfare.

Systems for assessing sheep and cattle were developed at local farms and tested at a slaughter plant. Anticipated signs of ill health and mutilations were arranged into a checklist that progressed in a sequence down the animal. At the slaughter plant, 99 prime cattle, 111 cull cows, 100 prime lambs and 100 cull ewes from multiple farm sources were assessed. The observations were carried out by two people, in group pens where the animals were held in lairage prior to slaughter, with the cattle observed from outside the pen, and the sheep examined under manual restraint. Data was recorded against checklist categories then transferred to an Excel spreadsheet, which was used to provide summary statistics.

Assessing individuals took 1-2 minutes. In cattle, readily quantified variables were the presence and deformity of horns, ear tags and notches, fullness of udders, length of the feet, length of the tail, the method of castration (entire, empty scrotum or no scrotum), and body condition score. Variables for the cattle that could not be assessed adequately in lairage pens were deformity of the tail, cleanliness and lameness. In sheep, close inspection of the sheep enabled a thorough assessment of health and mutilations. The least easily quantified variables were the number in the group lying or trembling/shivering, lameness and cleanliness. Recording efficiency would be improved by recording data directly onto a waterproof hand-held computer. Excel provided an effective system for data storage and summary. Many differences between the cattle and sheep checklists highlighted a need to create individual recording systems for different species of livestock.

Goal:

To develop a system of monitoring variables related to on-farm welfare standards using stock arriving at slaughter plants, for use by MAF and NAWAC in revising codes of welfare.

Background

New Zealand needs to demonstrate integrity in production systems that claim good standards of welfare. Some variables that reflect on-farm practices and welfare standards may be monitored effectively in stock presented for slaughter at processing plants. This project provided a system for monitoring such variables, for use by MAF and NAWAC in revising codes of welfare. The system may also be useful to processing plants wanting to demonstrate that their suppliers have good animal welfare standards. The information collected is additional to welfare-related information already collected by slaughter plants.

Approach & Outcomes

Systems for assessing sheep and cattle were developed under veterinary consultation at local farms. All parts of the animal that could be inspected visually for signs of ill thrift, disease, mutilation or abnormality, and the range of expected observations for each part of the animal, were documented. These were arranged into a checklist that progressed in a sequence, starting at the head of the animal.

The recording system was tested over five days at a slaughter plant, with the aim of assessing 10 animals from 10 sources for four stock types: prime cattle, cull cows, prime lambs and cull ewes. The observations were carried out by two people, in group pens where the animals were held in lairage prior to slaughter. One person recorded the observations against the checklist categories, or used the checklist for reference and recorded observations using a dictaphone. The cattle were observed from outside the holding pen, while sheep were observed firstly as a group and then randomly chosen individuals were examined under manual restraint. Data recorded on the dictaphone tapes and against checklist categories were transferred to an Excel spreadsheet, which was used to provide summary statistics.

For the prime cattle, 99 animals from 17 farm sources were observed, and for the culls, 111 animals from 16 farm sources were observed. It proved impractical to observe 10 animals from 10 sources, as many consignments of cattle were smaller than this. Therefore all animals in every pen were assessed. Assessing each individual tool 1-2 minutes. Readily quantified variables were the presence and deformity of horns, ear tags and notches, fullness of udders, length of the feet, length of the tail, the method of castration (entire, empty scrotum or no scrotum), and body condition score. Variables for the cattle that could not be adequately assessed in group lairage pens were deformity of the tail, cleanliness (the cattle had been washed), and lameness.

For the sheep, 10 individuals from 10 farm sources were readily available for assessment, for both prime lambs and cull ewes. Each sheep took 1-2 minutes to assess. Close visual and physical inspection of the sheep enabled a thorough assessment. The least easily quantified variables were the number in the group lying or trembling/shivering, lameness and cleanliness (the sheep had been washed).

Data from the initial implementation of the system indicated that welfare concerns relating to on-farm conditions for cattle may include thinness of cull cows, regrown horns, multiple ear-tagging and substantial ear-notching. Other concerns identified that may have arisen during transport and/or lairage, were watery discharge from the eyes and roughly circular, recent traumatic skin lesions. For sheep, welfare concerns may include very short tails, a high frequency of recent cuts, and a high incidence of separation of the horn from the wall of the foot. Additional concerns seen in cull ewes were high frequencies of low body condition and missing teeth.

Recording sheets and the dictaphone were equally effective for recording data. Efficiency would be improved by recording the information directly onto a waterproof hand-held computer. Excel provided an effective system for data storage and summary. Many differences between the cattle and sheep checklists (due to differences in practical observation techniques and expected observations) highlighted a need to create individual recording systems for different species of livestock.

1.7 FMA 185

Programme Title:

Shade: Its use by livestock and effectiveness at alleviating heat challenge

Programme Leader:

Dr Andrew Fisher

Institution:

AgResearch

Summary

The aim of the study was to quantify the use of shade by cows in hot weather, and the extent to which the provision of shade reduces body temperature and influences milk production. Lactating cows were assigned to two groups of 10, balanced for colour and age. One group was grazed in a paddock containing a shade structure (36m2), while the other group was grazed in an adjoining paddock with no shade, for 10 days, followed by a further 10-day period in which the groups were swapped. Vaginal loggers recorded body temperature, and video cameras recorded shade use. Temperature, humidity and black globe temperature were measured in and out of the shade. Both groups of cows were observed for 24-h periods where time spent grazing, standing or lying was recorded to determine cow activity patterns. Milk production and composition was measured throughout the study. Regression analysis indicated that shade use increased exponentially with increasing ambient temperature, and that cows started to use the shade when the temperature reached 25oC. Shaded cows had a lower mean body temperature during the day than unshaded cows (38.9 vs. 39.0 oC), and had a lower peak daily temperature (39.7 vs 40.1 oC). There was no difference between shaded and unshaded cows in mean 24-hour body temperature. Daily milk production was greater for shaded cows (14.3 kg) than for unshaded cows (13.9 kg).

PUBLICATIONS

Fisher, A.D., Roberts, N. and Matthews, L.R. 2002. Shade: Its use by livestock and effectiveness at alleviating heat challenge. Report to MAF Policy, June 2002.

1.8 FMA 186

Programme Title:

Performance Testing of Farm Animals

Programme Leader:

Dr Mark Fisher

Institution:

AgResearch

Summary

It is recommended that the serving capacity test not be used to identify superior beef bulls (i.e. individuals likely to produce earlier conception rates). While there is some merit in identifying unsound bulls in this way, it is further recommended that the test be re-evaluated with practical knowledge from within the New Zealand beef industry, in order to determine the most appropriate conditions (e.g. test duration). Finally, the National Animal Welfare Advisory Committee should be asked to consider whether allowing restrained, non-oestrous cows to be mounted and served several times, is a permissible harm.

Goal:

To understand the features of, and justification for, a number of tests for performance and their implications for the welfare of farm animals.

Background

Farm animals can be tested for their predisposition or susceptibility towards certain traits or characteristics. This enables breeders to retain and use animals of “superior” genetic or phenotypic merit. Such tests can have significant welfare costs to individual animals and resultant selection programmes may also have unintended consequences. It is important to consider the merit of these types of tests using accepted principles of animal welfare. For example is the test a harm which should not be imposed whatever the benefits, or is it justifiable in terms of the benefits gained outweighing the harms imposed, and are there any alternatives and/or ways of minimising any harms? Given that some tests can be rigorous, it is also important to consider whether popular usage lacking such rigour is justified.

Approach & Outcomes

Contributions in the scientific literature were used to consider a number of performance tests in farm animals. These were the serving capacity test (which assesses mating ability in beef cattle), exposing sheep to the toxin sporidesmin ( indicative of susceptibility to facial eczema) and marker-assisted selection (identifying animals with genes of superior merit). 

These tests were evaluated using three principles of animal welfare: 

  1. are the harms inflicted of a kind which ought not, under any circumstances, be inflicted; 
  2. is the harm justified in that the benefits outweigh the harms inflicted; and 
  3. can the harms be reasonably minimised.

Assessment of an animal or animals likely performances can be undertaken in a number of ways, both informally or subjectively, or more formally or objectively. They similarly vary in their costs and benefits to individual animal welfare. The beef cattle serving capacity test indicates the mating ability of a bull in the field on the basis of the number of times restrained cows are mounted and served in a yard test. 

Bulls that are more active in the yard test are deemed to be 

  1. sound for field mating programmes; and 
  2. likely to get the herd in calf earlier in the breeding season than those less active. 

However, while there may be merit in identifying reproductively unsound bulls, the value in identifying those able to enhance early conception rates is equivocal. There are some risks to the welfare of the bull and cow e.g. genital injury. However, because they are restrained, the test cows have little opportunity to express normal behaviour (usually rejecting being mounted and served when not in oestrus) representing a significant compromise to welfare. The other tests of animal performance investigated, while raising animal welfare concerns, do not have such significant ethical issues.

PUBLICATIONS

Material from this report will be presented at the National Animal Welfare Advisory Committee conference in Hamilton on 27th and 28th June 2002, under the title “Assessing libido – implications for the cow and bull”. A formal scientific publication describing and discussing the serving capacity test is also anticipated.

1.9 FMA 187

Programme Title:

Predicting risk conditions for thermal stress during livestock transport

Programme Leader:

Dr Lindsay Matthews

Institution:

AgResearch

Summary

The aim of the study was to develop a dataset for measures of thermal stress on board sheep transport vehicles, in order to identify risk conditions. Two livestock transport vehicles, operating under commercial conditions, were monitored during February and March 2002. Temperature and humidity were logged in five pens inside each vehicle, as well as on the outside of each vehicle. From these data, the temperature-humidity index (THI) was calculated. Global positioning equipment was used to determine the location of the vehicles, and when they were moving or stationary. The THI often (but not always) increased when the vehicles were laden and stationary. The highest THI values were recorded in a vehicle on an enclosed deck of a Cook Strait ferry. Regression models of the data showed that the ambient conditions, the initial pen THI, and the duration of the stationary period were all significant factors in contributing to THI increases. Some THI increases occurred in stationary vehicles despite ambient conditions being mild, suggesting that lack of airflow in the immediate locality is a critical factor.

Goal:

To reduce the risk to animal welfare during long distance transport by identifying hazardous ambient environmental conditions.

Background

Transport of livestock, in general, and on long-haul inter-island journeys, in particular, exposes animals to challenging conditions that can result in severe welfare compromise and concern. The Temperature-Humidity Index (THI) is a good measure of thermal stress, and we have observed that during stationary phases, such as when the vehicle is waiting to board or is on the ferry, the THI values on occasions can reach unacceptably high levels in some pens. Sheep and lambs appear to be particularly at risk from the environmental conditions during stationary phases of journeys. As yet, we do not have sufficient information to identify precisely the ambient conditions that lead to high risk, or conversely, those that pose little risk. Thus, the aim of this study is to develop a dataset for measures of THI in response to ambient conditions across the day and night.

Approach & Outcomes

Two livestock transport vehicles, operating under commercial conditions, were monitored during February and March 2002, in order to identify contributing factors to any thermal stress conditions for sheep and lambs on board the vehicles. Temperature and humidity were logged in five pens inside each vehicle, as well as on the outside of each vehicle. From these data, the THI was calculated. Global positioning equipment was used to determine the location of the vehicles, and when they were moving or stationary. The drivers recorded details of each journey they made, as well as the numbers and classes of livestock carried. Regression analysis was used to examine factors contributing to THI increases.

Animal stocking densities on the vehicles conformed to Animal Welfare Codes.

The THI often (but not always) increased when the vehicles were laden and stationary. The highest THI values were recorded in a vehicle on an enclosed deck of a Cook Strait ferry. However, the vehicles were placed on the outside decks of the ferries on 86% of journeys.

Regression models of the data showed that the ambient conditions, the initial pen THI, and the duration of the stationary period were all significant factors in contributing to THI increases.

Some THI increases occurred in stationary vehicles despite ambient conditions being mild, suggesting that lack of airflow in the immediate locality is a critical factor. Where airflow is minimal or absent, even an ambient temperature of 22oC can result in very high THI values in stationary laden sheep transport vehicles.

These results suggest that laden livestock transport vehicles during summer should not be placed on enclosed ferry decks where airflow is absent or minimal. Furthermore, excessive THI increases can occur on stationary laden sheep transport vehicles at most ambient temperatures during the warmer periods of the year, and that relatively mild ambient conditions are no guarantee of safety if other factors (particularly airflow) are lacking.

For a given stocking density and vehicle design, increases in pen THI are most likely to be driven by the absence of airflow in the location, and increase in proportion to the duration of the stationary period. Our results indicate that mild ambient conditions provide some protection against excessive THI increases if the duration of the stop is limited, but livestock transport operators are best advised to park their vehicle (particularly on ferries) where there is airflow, and/or to minimise the duration of stops where possible. The practice of having trucks parked up for some hours waiting to unload at abattoirs at the end of their journeys is to be discouraged.

PUBLICATIONS

Fisher, A.D., Stewart, M. Duganzich, D.M., Tacon, J. and Matthews, L.R. 2002. Predicting risk conditions for thermal stress during livestock transport. Report to MAF Policy, July 2002.

1.10 FMA 188

Programme Title:

Sheep Meat Modelling

Programme Leader:

Neil Andrews

Institution:

ABARE

Summary

The OECD Aglink world agricultural sheep meat trade model was completely redeveloped and has greater coverage, more extensive representation of sheep meat supply, trade policies, domestic support policy and trade that will allow more rigorous analysis of trade policy as it effects sheep meat. It may be used also to support projections exercises.

Goal:

To extend the OECD Aglink world agricultural trade model to incorporate detailed representation of the major sheep and sheep meat markets and the associated trade and policy linkages.

Background

The sheep meat industry and trade is influenced by a variety of protectionist measures in a number of major markets. Analysis of the implications of policy changes for sheep meat will be important for both New Zealand and Australia in the current WTO agricultural negotiations. The OECD Aglink model does not have sufficient country or policy detail for sheep meat to enable adequate analysis of policy issues.

Approach & Outcomes

The approach was to build structural models of supply, demand and trade for the main markets involved in the world sheep meat market. These were developed through rigorous testing to obtain credible estimates of responsiveness of the various agents active in the markets based on published estimates where available but predominantly on the basis of economic theory and prior knowledge of relevant characteristics of the various industries.

The original OECD AGLINK model for sheep meat was enhanced significantly by:

  • Replacing single equation representations of sheep meat, live sheep exports and wool supply with detailed structural models of Australian and New Zealand lamb, mutton and wool production based on flock inventory relationships in each country;
  • Adding models for sheep industries in European Union and the United States which also employ a system of flock inventory relationships to capture the complex dynamics of sheep meat supply;
  • Adding single representations of supply response for sheep meat in Canada, the Middle East and Central and Eastern Europe;
  • Adding representations of demand for domestically produced sheep meat in the US, Canada, the Middle East as well as Central and Eastern Europe;
  • Introducing market price determination mechanisms for New Zealand, the European Union, Middle East, Central and Eastern Europe, United States and rest of world for lamb, mutton and sheep meat where appropriate;
  • Extending the coverage of sheep meat import demand countries through the addition of individual import demand relationships for lamb, mutton and sheep meat for a number of important countries on world trade;
  • Adding representations of trade access arrangements (tariffs and tariff-quotas) in all importing countries for sheep meat which incorporates a number of bilateral trade flows;
  • Incorporating a ‘rest of world’ representation of import demand.

The parameters in the supply system developed for the EU were not estimated empirically largely because of the small data sample available (6 observations). The seemingly poor quality of the data generally but particularly for the EU also worked against the likelihood of achieving a good outcome from empirical analysis.

Two simulation experiments are reported as examples of how this tool can be used to support policy and projections analyses. The first estimates the impact of a 20 per cent expansion of European union import quotas for both New Zealand and Australian sheep meat while the second experiment looks at the effect of an expansion in demand for imported sheep meat in the Middle East.

PUBLICATION

Documentation, EXCEL spreadsheet data, trade policy, domestic support policy and model files, SIMPC code and programs for simulation and generating ‘k factors’ are provided.

1.11 FMA 151

Programme Title:

Assessment of calf castration distress

Programme Leader:

Assoc. Prof. Kevin Stratford

Institution:

Animal Welfare Science and Bioethics Centre, Massey University

Summary

The plasma cortisol response ( ICR ) and by inference the pain induced distress caused by 5 different castration techniques (rubber ring, Callicrate Bander, surgery with the spermatic cords being drawn out, surgery with the spermatic cords being cut by an emasculator, clamp) were measured in calves 2-4 months of age. The effect of local anaesthetic and a non-steroidal anti-inflammatory agent (Ketoprofen) on this response was measured over 8 hours to determine if they alleviated the pain induced distress caused by the castration.

The cortisol response to ring and band castration was similar with a peak at 90 or 60 minutes post-castration respectively. The cortisol response to both techniques returned to control values 3 hours after castration. The cortisol response was virtually eliminated by local anaesthetic either given alone or with ketoprofen.

The cortisol response to surgical (pull) castration peaked at 30 minutes and returned to control values 3.5 hours after castration. Local anaesthetic had no significant effect on the cortisol response to surgical (pull) castration but when combined with ketoprofen the response was virtually eliminated.

The cortisol response to surgical (cut) castration peaked at 2.5 hours after castration but was not significantly different from control values at any time during the 8 hours of sampling. When local anaesthetic was given before surgical (cut) castration the cortisol response was numerically greater than when it was not given but the differences were not significant. Local anaesthetic and ketoprofen given together eliminated the cortisol response.

The cortisol response to clamp castration peaked at 30 minutes and returned to control values 90 minutes after castration. Local anaesthetic had little effect on the response but when combined with ketoprofen the response was eliminated.

The integrated cortisol response for the 4.5 hours following castration decreased in the following order, band, surgical castration with traction, ring, surgical castration with the cords being cut, and clamp castration.

Wound healing was slower after ring and bander castration than surgery. Two of the thirty calves castrated by clamp became rigs which is a common occurrence with this technique despite the spermatic cord being cut across twice.

If castration is to be carried out without local anaesthetic the choice of method is problematic. Clamp castration causes the lowest ICR and by inference the least pain and distress but it is also the method most likely to fail. Surgical castration (cut) causes an intermediate ICR and the lowest cortisol peak response but these responses are quite varied between animals and the animal does respond behaviourally during the process making it less attractive. Surgery (pull) causes an ICR similar to ring and bander castration but causes a lower peak response than bander. However surgery causes definite behavioural responses during castration which reduces its appeal. Band castration causes the highest ICR and also the highest peak response and is therefore less attractive than ring, which has a lower peak response. Surgery causes the most rapid wound healing. The results suggest that surgery with the spermatic cords being cut is probably the best choice to minimise pain induced distress, have rapid wound healing and guaranteed success.

If local anaesthetic is used then at least as far as the acute cortisol response is concerned ring or bander are the preferred techniques as local completed or nearly abolishes the cortisol response to these methods but is much less effective with clamp and surgical castration. However wound healing is definitely slower with the ring bander than surgery.

If local anaesthetic and ketoprofen are to be used then surgical castration is preferred as the acute cortisol is abolished and wound healing is quicker. Castration by surgery is definite unlike clamp and ring where there is evidence of problems with rings breaking and causing problems.

These results suggest that local anaesthesia and ketoprofen should be used whenever surgical or clamp castration is carried out and that local anaesthesia should be used with ring or band castration.

BACKGROUND

A survey of beef farmers in New Zealand found that of the 2.821 respondents who castrated their calves, 85% used rings, 18% surgery and 1% a castration clamp (Burdizzo) (Stafford et al., 2000). Some used more than one method depending on the age of the cattle. Three methods of surgery were used by approximately equal proportions of respondents, the spermatic cord was broken by pulling, by clamping and cutting, or by scraping the cord and then cutting it. Local anaesthetic was used by a small % (4%) of respondents. The majority of farmers castrated calves with rings at 2 to 3 months of age and with the other methods at 4 to 5 months. Although not mentioned in the survey, a new method of castration, similar to ring castration, employing a rubber ligature (The Callicrate Bander) is being used to castrate older cattle (Knight et al., 2000).

During the 1990s research into the distress and pain caused by castration concentrated on lambs (Mellor and Stafford, 2000) or on young calves (Robertson et al., 1994; Molony et al., 1995). A number of studies looked at ways to alleviate the pain and distress caused by castration. Mellor and Stafford (2000) compared the plasma cortisol response and by inference the pain and distress caused by a wide range of castration techniques in lambs and identified those techniques likely to cause the least pain or distress in the hours following castration. They found that surgical castration of lambs caused a greater cortisol response than rubber ring castration and by inference much greater distress. Local anaesthetic virtually abolished the cortisol response to ring castration but had little impact on clamp castration. A non-steroidal anti-inflammatory agent reduced the cortisol response to ring and clamp castration

1.12 FMA 164

Programme Title:

Chronic Pain in Calves

Programme Leader:

Assoc. Prof. Kevin Stafford

Institution:

Animal Welfare & Bioethics Centre, Massey University

Summary

Dehorning and castration are two painful procedures routinely carried out on cattle worldwide. The pain caused by these two procedures and experienced by cattle in the following 8 to 12 hours has been defined in physiological and behavioural studies. However the pain experienced by cattle in the days and weeks following dehorning and castrations has not been studied and identified and there is little scientific evidence to suggest that cattle are in significant pain in the days following the procedures. A study by Stafford and Mellor (2002) in which the feeding and ruminating behaviour of cattle was monitored in the days following dehorning showed that feeding, i.e. grazing behaviour, was lower during the day after dehorning than before suggesting that cattle are still in pain 24 to 48 hours post-dehorning. This agrees with anecdotal evidence of cattle being inactive during this period.

This study used three methods to monitor calf responses in the days and weeks following dehorning and castration. 

These are:

  1. pain threshold response to a mechanical and a thermal stimulus, 
  2. overt behaviour, and 
  3. plasma cortisol and fibrinogen response. 

The responses were monitored before treatment, behaviour on day-4 and pain threshold and plasma cortisol and fibrinogen responses on day-1 and all three on days 1,2,8,15 and 22 afterwards. The dehorning and castration studies were carried out on two Manawatu farms. Both studies had four treatments. The dehorning study included a handling control (DHC), a local anaesthetic and ketoprofen control (LaKDHC), dehorning (DH), and dehorning following local anaesthesia and ketoprofen (LaKDH) groups. The castration study included a handling control (RCC), a local anaesthetic and ketoprofen control (LAKRCC), castration (RC) and castration following local anaesthesia and ketoprofen (LaKRC) groups.

The pain threshold response to thermal and mechanical stimuli was not changed significantly in DH, DHC and LaKDHC calves. In LaKDH calves the threshold to the mechanical stimulus increased in the day following treatment and the threshold to the thermal stimulus decreased. The increase is expected as the analgesic protocol would increase the threshold to the thermal stimulus decreased in all the treatments from day-1 to 1 and then remained stable. The threshold to the mechanical stimulus was stable in RC, RCC and LaKRCC calves but in the LaKRC calves it decreased until day 8. The pain threshold method may be too insensitive to detect any differences in the pain experience of calves in the days and weeks following dehorning or castration or the location of the testing, the hind limbs, may be inappropriate especially for dehorning. More frequent sampling before and in the hours and days following treatment might determine how useful the procedure is.

In the dehorning study the DH and LaKDH calves ear-flicked more and grazed and ruminated less on the day following treatment suggesting that they were experiencing some pain or distress on this day. In the castrations study there was no difference in the behaviour of calves from the four treatment groups on the day following treatment. There was little change in the behaviour of the castrated calves from before treatment and following treatment suggesting that they did not experience any significant pain on the day after castration.

The plasma cortisol increased in DH calves from day-1 to day 2 suggesting that calves were still experiencing some distress on the first and second day after dehorning. The cortisol response in the castration study decreased during the study and suggest that castration causes little pain or distress on the first and subsequent days after treatment. Plasma fibrinogens remained similar throughout both studies.

On the day following dehorning the behaviour and plasma cortisol concentrations of calves suggest that they are still experiencing some pain. This supports previous findings by Stafford and Mellor (2002). However the behaviour of calves in the days following castration suggests that they are not experiencing significant pain. The pain threshold response of calves was not altered significantly by dehorning or castration but the use of the analgesic protocol before dehorning or castration did have some effect on the threshold.

1.13 FMA 165

Programme Title:

Further strategies for alleviating the acute pain and distress associated with dehorning in calves

Programme Leader:

Prof. David J Mellor

Institution:

Animal Welfare Science & Bioethics Centre, Massey University

Summary

  • We confirmed that lignocaine local anaesthesia plus the non-steroidal anti-inflammatory drug ketoprofen, given 15-20 minutes prior to amputation dehorning, substantially reduced the 8-hour cortisol response to dehorning.
  • Xylazine, given either alone or together with lignocaine, causes a significant rise in plasma cortisol concentrations (equivalent to about half the peak response to dehorning) which lasts about 30 minutes, suggesting that the onset of sedation is itself moderately distressing.
  • Xylazine alone appears to have moderate analgesic effects, as judged by changes in plasma cortisol concentrations, which last until about 3 hours after dehorning, thus providing some pain relief during this period.
  • Lignocaine is more effective than xylazine in alleviating the pain caused immediately by horn amputation itself, and appears to provide marginally (although not significantly) better pain relief during the next 2.5 hours until its nerve blockade effects pass.
  • The overall cortisol responses of calves dehorned after prior injection of lignocaine plus xylazine or xylazine alone are similar. However, the distress experienced with xylazine alone is likely to be greater during the 0.5 hour before and the first hour after dehorning because of the distress caused initially by xylazine and the nerve blockade effects of lignocaine.
  • The effects on the cortisol response to dehorning of lognocaine alone (previous work) and lignocaine plus xylazine (present work) are similar, so that giving xylazine does not increase the pain induced distress caused by dehorning, and also may increase pre-dehorning distress (see above). When making a decision about whether or not to use xylazine, therefore, these observations need to be weighed against the benefits of immobilising the calves during dehorning.
  • The use of tolazoline to reverse the effects of xylazine is of concern. Xylazine reversal with tolazoline in the absence of dehorning added to the xylazine-induced cortisol response so that the total response by 25 min. after tolazoline was equal to the peak response after dehorning without any pain relief, and subsequently, for at least 4 hours, plasma, cortisol concentrations remained above control values. This could mean that the calves were more distressed or that tolazoline had direct stimulatory effects on the activity of the hypothalamic-pituitary-adrenal (HPA) axis. It is not clear which.
  • Likewise, when the effects of xylazine were reversed immediately after dehorning by tolazoline, high cortisol concentrations were seen throughout the subsequent 7 hours, and for most of the time the concentrations were much higher than those seen after dehorning without pain relief. As the xylazine-tolazoline calves also received lignocaine, the exceptionally high cortisol concentrations after dehorning and xylazine reversal with tolazoline suggest either that substantial psychogenic stress occurred or that tolazoline has direct stimulatory effects on the HPA axis. More work is required to clarify this.

Background

To date we have defined the acute cortisol distress responses to amputation dehorning in calves aged between 6 weeks and 6 months (Petrie et al 1996; McMeekan et al 1997, 1998a, b; Sylvester et al 1998a, b), the effects of using four different amputation methods (Sylvester et al 1998a) and the effects of causing shallow and deep amputation wounds (McMeekan et al 1997). We have also evaluated the efficacy of different alleviation strategies in reducing the acute cortisol distress response to amputation dehorning. These strategies include local anaesthesia (LA) lasting between 2 and 7 hours (Petrie et al 1996; McMeekan et al 1998b; Sylvester et al 1998b; Sutherland et al, 2002a), LA combined with cautery of the amputation wounds (Sylvester et al 1998b; Sutherland et al, 2002b), LA combined with the non-steroidal anti-inflammatory drugs (NSAIDs) ketoprofen and phenylbutazone (McMeekan et al 1998a; Sutherland et al, 2002a), and ketoprofen alone (McMeekan et al 1998a). These data have been interpreted in terms of the operation of pain mechanisms and the practical usefulness of the different strategies in reducing the acute pain-induced distress caused by dehorning.

There are two areas that still require attention. The first is a reassessment of the beneficial effects of LA plus ketoprofen in reducing the acute cortisol distress response to dehorning. The second is to evaluate for the first time the effects of LA, the sedative/analgesic xylazine and the reversal agent tolazoline, used in different combinations, on the acute cortisol distress response to dehorning. Xylazine is being used increasingly with dehorning and its effects need to be evaluated.

  • Local anaesthesia plus ketoprofen

We have shown that the beneficial effects of LA plus ketoprofen in preventing or reducing the delayed cortisol distress response to dehorning which occurs when LA wears off appears to depend on the duration of action of the LA. Ketoprofen injected at the same time as lignocaine (giving nerve blockade for about 2 hours) virtually abolished the delayed cortisol response (McMeekan et al 1998a), whereas ketoprofen plus bupivacaine (4 hour action) resulted in a delayed cortisol response which was not significant (McMeekan et al 1998a) and ketoprofen plus lignocaine then bupivacaine (6 hour action) only marginally reduced the delayed cortisol response (Sutherland et al, 2002a). There is a need to reassess the effects of lignocaine plus ketoprofen to ensure that the benefit observed before (McMeekan et al 1998a) is a consistent effect. We did that in this study by the addition of two extra groups (see below).

  • Local anaesthesia, xyline and tolazoline combinations

Lignocaine plus the sedative/analgesic xylazine, with or without the reversing agent tolazoline, are being used increasingly when dehorning calves. However, the efficacy of these alleviation strategies has not been examined. In the present study, therefore, we defined the acute cortisol responses of calves to scoop dehorning using different combinations of these drugs.

Such was the cortisol elevation in the LaXD calves, that it differed significantly from that in the D calves between 5.5 and 8 hours after dehorning (p=0.001-0.019), never and did not return to Co or X values before 8 hours.

The mean cortisol concentrations in the LaXT calves and the LaXDT calves rose sharply to be significantly greater than that of control and dehorned calves at time 0(p=0.001). Note that this time is immediately before dehorning and injection of tolazoline, and thus is consistent with the significant rise in LaX and LaXD calves at the same point in time. Following tolazoline administration in the LaXT calves the mean cortisol continued to rise, peaking at 90 nmo/L above pretreatment values at 0.5 hours, and then declined to a plateau at one third of this peak level by 1.5 hours. The mean cortisol concentration remained significantly greater (p=0.001-0.037) than control calves for at least 4.5 hours, except at 1.5 hours. The mean rise in cortisol level in LaXDT calves also peaked at 0.5 hours (100 nmol/L), and was significantly greater than that values in Co and D calves at this time (p=0.0.035). The mean cortisol concentration then declined to approximately half this peak level by 1.5 hours after dehorning, and then progressed to a second longer lasting peak of 80-90 nmo/L between 2.5 and 5 hours. After 5 hours the mean level began to decline so that by 8 hours it was not significantly different from any other group, but it did remain significantly elevated above its own pre-treatment level throughout (p=0.001-0.002). Throughout the 8 hour trial, the mean cortisol levels in LaXDT calves was significantly greater than those in Co calves from 0 to 6.5 hours (p=0.001-0.003), in D calves from 0 to 0.5 and 3.5 to 7 hours (p=0.002-0.010) and in LaXDT calves from 2.5 to 6 hours; (p=0.001-0.017).

The mean cortisol concentrations in the LaXDT calves significantly (p=0.001-0.010) exceeded those in the LaXD calves from 0.5 to 5 hours after dehorning.

The integrated cortisol responses for each treatment group are shown in Table 1.

APPROACH & OUTCOMES

  1. The mean plasma cortisol response and by inference the stress response to scoop dehorning in 3 month old calves given no sedative nor analgesic drugs was typical of the pattern observed in many previous dehorning studies (Petrie et al, 1996; McMeekan et al, 1997, 1998a,b; Sylvester et al, 1998a,b, Sutherland et al, 2002a,b). Thus, there was an immediate rise in plasma cortisol concentration, which peaked 0.5 hours after dehorning. Values then declined to a plateau level by 1.5 hours and remained at that level for a further 2.5 hours after which they returned to levels seen before treatment and in Co, LaK, LaX and X calves.
  2. 2. Administration of local anaesthetic plus ketoprofen to calves 15 minutes prior to scoop dehorning (LaKD) resulted in a markedly reduced mean post-dehorning stress response throughout the 8 hour study period. In fact the mean cortisol level in these calves was found not to significantly differ from that observed in the Co and la control groups at any time during the trial. This result is consistent with that obtained in previous studies where the stress response was eliminated (McMeekan et al., 1998) or at least significantly reduced (Sutherland et al., 2002a) in dehorned calves administered given a similar combined local anaesthetic-ketoprofen treatment. This further highlights the benefit of such a dual analgesic approach in terms of minimising the pain apparently experienced by calves following amputation dehorning.
  3. The administration of xylazine 15 minutes prior to dehorning significantly reduced but did not eliminate the cortisol peak that immediately follows horn removal. In contrast, xylazine with additional administration of local anaesthetic (LaXD) reduced the immediate cortisol peak such that it was not significantly different from non-dehorned control calves (LaX) 30 minutes after horn removal. This is to be expected since xylazine has only mild/moderate(??) analgesic actions and so while sedated, the calves that received this drug only, would still be likely to perceive the pain of horn amputation, although probably less than those calves that received no drugs at all (D calves). Calf reactive behaviour to needle pricks around the horn base followed a similar trend with 4,22 and 38 positive responses recorded within the first two hours of the trial in LaXD, XD and Co plus X calves, respectively. A similar discrepancy between xylazine and xylazine plus local anaesthetic administration with regard to calf behavioural responses following cautery dehorning has been noted in a previous study (Grondahl-Nielsen et al, 1999). Thus it is suggested here that if xylazine is to be administered to calves prior to scoop dehorning, the additional administration of local anaesthetic is warranted if the initial pain of horn amputation is to be markedly reduced or eliminated.
  4. From 30 minutes after dehorning both the X and the LaX calves had mean cortisol levels similar to those of Co calves for a further 3-4 hours. During this time the cortisol response of D calves was significantly elevated above those of XD calves for 1 hour. Noting that xylazine was administered 20 minutes before dehorning, this then approximates to the stated 85 minute duration of xylazine’s moderate(??) analgesic action as indicated by a return of responsiveness to needle pricks around the neck area (Takase et al., 1986). Why xylazine appears to significantly alleviate, but not eliminate, the pain of scoop dehorning 30 minutes after amputation (significant effect) and subsequently for about 3 hours (non-significant), as indicated by the plasma cortisol levels, could be explained by its moderate analgesic action. Thus, xylazine may fail to counteract completely the higher magnitude pain associated with the horn amputation itself, but may alleviate the subsequent lower levels of pain more effectively (indicated by the cortisol response in D calves;) until its effects diminish from about 3 hours after dehorning.
  5. Three to four hours after dehorning the mean cortisol concentrations began to rise in the LaXD and XD calves to become significantly higher than those in Co, LaX and X calves, and eventually exceeded those in D calves. In fact the mean response in the LaXD calves was such that it never returned to control levels before the trial’s end at 8 hours. This apparently surprising phenomena of the cortisol concentrations in dehorned calves given local anaesthetics exceeding that of dehorned calves given none once the local anaesthetic wears off, has been described in previous dehorning studies (Petrie et al, 1996; McMeekan et al, 1998b; Sutherland et al, 2002a, b). Previously it was suggested that the act of giving local anaesthetic prior to dehorning calves may merely delay rather than reduce the overall pain-induced distress associated with horn amputation, due to subsequent inflammation-related pain once the nerve block effects wear off (McMeekan et al, 1998a). This inflammatory-related pain may be less at the same time after dehorning in calves given no local anaesthetic because of the beneficial anti-inflammatory effects of endogenous cortisol release immediately following horn amputation (e.g. D calves;) The fact that giving xylazine with local anaesthetic resulted in a similar delayed stress response after dehorning to that seen in other studies when local anaesthetic was used (Petrie et al, 1996; McMeekan et al 1998b) perhaps not surprising. Xylazine has virtually no anti-inflammatory actions and so the tissue reaction at the wound site would be likely to progress in a similar manner whether local anaesthetic is given with or without xylazine.
  6. It is of interest to note that the peak mean cortisol level in LaXD calves occurred 6 hours after horn removal, an identical time to an observed peak incidence of head shaking and ear flicking occurred in a previous disbudding study (Faulkner and Weary, 2000), thus suggesting supporting our earlier contention (Petrie et al, 1996a; McMeekan et al, 1998a,b; Sylvester et al, 1998b) that this delayed rise in plasma cortisol concentration reflects the appearance of pain-induced distress or of at least significant irritation in the calves at this time.
  7. Comparison of the integrated cortisol responses in D, LaXD and XD calves revealed no significant difference between any of these three groups with regard to the total cortisol response elicited over the 8 hour after dehorning. This is not to say however that the character of the pain-induced stress was similar. Local anaesthetic administration prior to dehorning would still be advised since is has consistently been shown in this and previous studies to significantly reduce the stress response which immediately follows horn amputation (Petrie et al, 1996; McMeekan et al, 1998a,b; Sylvester et al, 1998b; Graf and Senn, 1999, Grondahl-Nielsen et al., 1999; Sutherland et al, 2002a, b).
  8. Administration of the xylazine reversal agent, tolazoline, to LaXDT calves minutes after dehorning and to non-dehorned LaXT calves was associated with significantly elevated mean cortisol levels 25 minutes later in comparison to their dehorned (D) and control (Co) counterparts. This is despite the fact that these calves also received xylazine and local anaesthetic, of which the latter drug virtually abolished the plasma cortisol peak which immediately followed dehorning in those calves (LaXD) not receiving tolazoline. As both the LaXT and LaXDT calves had markedly elevated cortisol levels not significantly different from each other 30 minutes after dehorning offers the following suggestions: i.e. that is was not a failure of local anaesthetic to suppress the pain-induced distress of horn amputation in those calves that also received the xylazine-tolazoline combination, but the presence of another stressor eliciting HPA activation. Sedating an animal and then having that sedation reversed shortly after may indeed be a stressful experience for the animal. Another possibility is direct stimulation of the HPA axis by tolazoline or a reversal of xylazine inhibition of the HPA axis by this same drug, totally independently of adverse psychogenic effects on the calf.
  9. The cortisol response to psychological stressors is apparently reduced if xylazine is given to cattle (Brearley et al., 1990) and goats (Sanhouri et al., 1992) prior to the onset of the stressor, with this suppressant effect probably acting above the level of the pituitary gland (Sanhouri et al., 1992), However, in the present study, X, LaX and LaXT calves, all given xylazine, had cortisol levels no lower than those of Co calves given no xylazine. In fact at time 0 (the time of the second blood sample) the cortisol concentrations were significantly higher in all calves that received xylazine 20 minutes previously (X, XD, LaX, LaXD, LaXT and LaXDT), compared to those that had not (Co, LaK, LaKD). This suggests that xylazine did not inhibit HPA activity’ indeed, quite the reverse, that the onset of xylazine sedation caused mild/moderate distress to the calves.
  10. There was a marked difference between the cortisol levels in the LaX calves and LaXT calves at time 0.5 hours. The latter group had significantly higher levels, so much so that they were similar to the cortisol peak concentrations in the D calves, but then returned to near control levels by 1 hour after tolazoline administration. A similar time frame effect, as measured by changes in plasma cortisol concentrations, of tolazoline antagonism (relative to a saline control) of the oc2 agonist detomidine has been observed in ponies, with the highest cortisol concentration measured at 0.5 hours post-antagonism, returning to baseline by 1 hour (Carroll et al., 1997).
  11. Dehorned LaZDT calves exhibited a similar cortisol peak over the first 2 hours after dehorning as their non-dehorned counterparts (LaXT calves), and likewise a similar peak to dehorned calves given no analgesia (D calves). However, after 2 hours in the LaDXT calves, at the time equivalent to beginning of the plateau stress response in the D calves, a marked second cortisol peak occurred which was significantly elevated above the cortisol values in any other group. This raises the question of why tolazoline administration in dehorned calves given local anaesthetic and in calves that were not dehorned should have elicited such a marked cortisol response by 0.5 hours. Presumably in both groups little or no pain would have been experienced by the calves, which leads to the idea that either the cortisol elevation at this time is a reflection of psychological stress exacerbated by prior tolazoline administration (the combined stress effects of the onset of sedation, followed quickly by its reversal), or due to direct stimulation of the HPA axis by this tolazoline. The latter possibility, if true, would confound interpretation of the cortisol responses to tolazoline in terms of distress.
  12. While the results of this study raise doubts about the use tolazoline with xylazine in terms of the distress it might elicit following scoop dehorning [reference to the integrated cortisol response curves reveals that this group had the highest value of any group], one must temper this view with the benefits of providing early reversal of sedation. These include the reduction of bloat, regurgitation, pressure damage to nerves and muscles and other problems which may be associated with recumbent sedation in ruminants (Kitzman et al., 1982). Prevention of such sequelae may be as important in minimising welfare compromise to calves following dehorning as the prevention of the pain directly associated with the amputation procedure itself.
  13. In conclusion, in terms of minimising the overall stress response, which follows scoop dehorning this study, re-confirms that the dual analgesic approach of ketoprofen and local anaesthetic administration is most beneficial. Although prior administration of xylazine may offer greater ease of calf handling (a valuable asset in itself), the consequence of its use, particularly if given in the absence of local anaesthetic and in the presence of tolazoline, warrants further investigation in terms calf welfare compromise following scoop dehorning.

PUBLICATIONS

Brearley, J.C., Dobson, H., Jones R.S.. Investigations into the effect of two sedatives on the stress response in cattle. Journal of Veterinary Pharmacological Therapeutics 13, 367-377, 1990

Carroll, G.L., Mathews, N.S., Hartsfield, S.M., Slater, M.R., Champney, T.H., Erickson, S.W. The effect of detomidine and its antagonism with tolazoline on stress-related hormones, metabolites, physiologic responses and behaviour in awake ponies. Veterinary Surgery, 26, 69-77, 1997

Faulkner, P.M., Weary, D.M. Reducing pain after dehorning in dairy calves. Journal of Dairy Science 83, 2037-2041, 2000

Graf B, Senn M. Behavioural and physiological responses of calves to dehorning by heat cauterisation with or without local anaesthesia. Applied Animal Behavioural Science 62, 153-171, 1999

Grondahl-Nielsen, C., Simonsen, H.B., Damkjer, Lund. J., Hesselholt, H. Behavioural endocrine and cardiac responses in young calves undergoing dehorning without and with the use of sedation and analgesia. Veterinary Journal 158, 14-20, 1999

Link, R.P., Smith, J.C. Comparison of some local anaesthetics in cattle. Journal of the American Veterinary Medical Association 129, 306-309, 1956

McMeekan, C.M., Mellor, D.J., Stafford, K.J., Bruce, R.A., Ward, R.N., Gregory, N.G. Effects of shallow scoop and deep scoop dehorning on plasma cortisol concentrations in calves. New Zealand Veterinary Journal 45, 69-71, 1997

McMeekan, C.M., Stafford, K.J. Mellor, D.J., Bruce, R.A., Ward, R.N., Gregory, N.G. Effects of regional analgesia and/or a non-steroidal anti-inflammatory analgesic on the acute cortisol response to dehorning in calves. Research on Veterinary Science 64, 147-150, 1998a

1.14 FMA 169

Programme Title:

Develop generic HACCP models for food assurance programmes, based on scientific validation of the hazards

Programme Leader:

Sandra Walker

Institution:

AgriQuality New Zealand

Summary

The goal of the project was met; to utilise Codex HACCP methodology to develop a HACCP Plan for each sector group at the same time ensuring compatibility with existing industry programmes and providing MAF with robust HACCP models that can be incorporated into MAF Standards.

Continuous consultation with MAF Food staff was undertaken to ensure the application of HACCP principles was consistent with MAF Food’s application of HACCP and followed Codex Guidelines on HACCP application.

The Literature search, HACCP Model development and Implementation guide have been developed for MAF.

This project identified that it is more appropriate for the produce industry in New Zealand to apply HACCP principles and Good Agricultural Practices (GAP) as appropriate instead of all the HACCP principles, unless enough scientific evidence and food safety objectives for HACCP plans are available.

Further development of the work undertaken in this project would benefit from direct participation of relevant industry members in conjunction with MAF Food as/or when appropriate.

Goal:

Review and align existing Hazard Analysis Critical Control Point (HACCP) models for Fresh Produce to MAF requirements.

Utilise Codex HACCP methodology to develop a HACCP Plan for each sector group at the same time ensuring compatibility with existing industry programmes and providing MAF with robust HACCP models that can be incorporated into MAF Standards.

Background

The initial project reference FMA 101 was initiated by MAF Biosecurity Authority in response to industry feedback that existing quality assurance specification were causing difficulties. Project FMA 169 was undertaken to review FMA 101 and provide a scientific basis to HACCP models.

Approach & Outcomes

Project FMA 101 was reviewed

An international Literature search was undertaken to identify food safety issues, hazards, controls and desired outcomes over the range of crops listed below:.

  • Root crops – potatoes, carrots, onions,
  • Fruit crops – apples, kiwifruit, summerfruit, sub-tropicals,
  • Seeds/sprouts,
  • Leafy green – lettuce, brassicas,
  • Glasshouse – tomatoes, capsicums,
  • Berryfruit, and
  • Organic crops.

The results were analysed and used to develop the HACCP models. An Implementation Guide was developed. Final report was written.

Continuous consultation with MAF Food staff was undertaken to ensure the application of HACCP principles was consistent with MAF Food’s application of HACCP and followed Codex Guidelines on HACCP application.

The international Literature search validated scientifically (wherever possible) the potential biological, chemical and physical hazards that have been identified, both for conventional and organic production systems.

Obtaining information from NZ sources for microbial, chemical and physical hazards was difficult. In some instances research has not been undertaken or is currently operating under private funding regimes and the researchers were unable to access this information.

Generic HACCP Models have been developed for the range of fresh produce listed in the Approach above, using information obtained from the literature search in conjunction with analysis of some specific production systems operating in New Zealand.

The HACCP models developed can be incorporated into MAF Standards for a fresh produce safety assurance programme as such a programme is developed.

The implementation guide and Objective 1 & 2 report provides guidance to the different levels of the sector to ensure both effective uptake of and maximum benefits from, the models.

The recommendation from FMA 101 for a separate Code of Practice for HACCP application is no longer considered appropriate because the Fresh Produce Industry has since taken more ownership and responsibility for food safety and produce integrity.

PUBLICATIONS:

Objective 1. International Literature search

Objective 2. Generic HACCP model

Objective 3. Implementation Guide

Final Report

  • Objectives 1 & 2 have been combined into one document – “Generic HACCP Models for Food Assurance” Objective 1 – Stage 1 & 2 International Literature Search, Objective 2 HACCP Models Report, dated August 2001.
  • Objective 3 is a separate document Titled “Generic HACCP Models for Food Assurance – Implementation Guide”, dated September 2001.
  • Final report is a separate document Titled: Generic HACCP Models for Food Assurance – Final Report” dated December 2001.

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