2. Materials & Methods
2.1 Project site
The study was carried out on No.4 Dairy Unit at Massey University (Fig. 1). This is a commercial scale, 500 cows, 200 ha, seasonal supply, research dairy farm. It was established to study the problems inherent to large-scale dairying and to provide a teaching resource for undergraduate and postgraduate programs. The present study extends two previous studies on the epidemiological aspects of Campylobacter jejuni on this farm.
Figure 1. Study site at No. 4 dairy farm, Massey University
2.2 Specimen collection
Cattle
Samples of rectal contents from 52 random selected dairy cows were collected during milking time (Fig 2). Approximately 1 g of each faecal sample collected was inoculated into Bolton’s broth on the farm and brought to the laboratory further processing within 2 hours of collection for. Sterile disposable gloves were used for the collection of each sample.
Figure 2. Rotary type milking shed at No. 4 dairy unit, Massey University
Sparrows
During several site visits prior to the start of sample collection, information as gathered regarding the sparrow’s congregation areas, trees and particular branches used for roosting, and the ideal times for collection of bird droppings.
Fifty-three faecal samples were collected from sparrows in and around Massey No. 4 dairy farm. An 8 X 10 feet tarpaulin was placed on the ground under a roosting tree to catch the bird droppings. Bird feed placed in electric trunking secured on wooden supports above the tarpaulin, served as bird attractant (Fig. 3). Sterile cotton wool swabs were used to collect fresh individual droppings from the tarpaulins for immediate inoculation into Bolton’s broth. Similarly, 53 faecal samples from sparrow droppings were collected from "The Square" in Palmerston North’s central business district.
Figure 3. Equipment used for the collection of sparrow droppings. Bird feed is placed into electric trunkings (arrows) over a clean tarpaulin. Birds feed on the seed and pass droppings onto the tarpaulin for collection.
Rodents
Rodents were caught in the feed storage area for the dairy shed using standard spring loaded, baited traps (Fig. 4). The animals were dissected in the laboratory and rectal contents collected from 65 rodents. Samples were placed in Bolton’s broth for microbiological examination.
Figure 4. Rodents trapped in rat trap
Flies
Fifty-six flies were captured on the dairy farm using flytraps. Collected flies were brought to the laboratory and dissected vertically and horizontally into four pieces and then inoculated into Bolton’s broth.
Other animals
No other animals such as farm dogs and feral animals were available for sampling during the study period.
Other samples
Other samples were collected from around the dairy farm including five silage, two aprons, two worker boots and two water samples from troughs in the grazing area (Fig. 5 and 6). Treated drinking water in the cattle grazing area is provided by the Massey University water supply system. Sterile cotton swabs were used to sample an area of about five cm2 of workers aprons and boots and were immediately placed into Bolton’s broth. Five silage samples of approximately 1 g each were collected using sterile forceps and also placed immediately into the Bolton’s broth.
The water samples were collected in sterile containers and brought to the laboratory for further processing within two hours of collection.
Figure 5. Silage is used as a supplementary feed
Figure 6. Water trough in the grazing area
Contact for Enquiries
Manager, Strategic Science Team
MAF Biosecurity New Zealand
PO Box 2526
Wellington
NEW ZEALAND
Phone: +64 4 894 0115
Fax: +64 4 894 0731
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