Population Biology Commons^™

Reproductive Wastage In Sheep, R W. Kelly

Journal of the Department of Agriculture, Western Australia, Series 4

The average lambing performance of Western Australia's ewe flock fluctuates between 60 and 70 per cent. Although this level of performance and variation between years is important for the sheep industry, individual farmers are more concerned about performance of their own flocks.

Figure shows the range in lambing performances that exist between farms in this State in 1983-84. The seriously poor performance of many flocks is apparentm - 28 percent of farms had less than 60 per cent lambing. By contrast, 24 farms had performances better than 100 per cent. The reasons for the large differences between farms ( and …

A Survey Of Drench Resistance In Sheep Worms, J R. Edwards, R. Wroth, G. C. De Chaneet, R. B. Besier, J. Karlsson, P. W. Morcombe, D. Roberts, G. Dalton-Morgan

Journal of the Department of Agriculture, Western Australia, Series 4

Sheep worms which are resistant to chemical drenches have been detected with increasing freuency is Western Australia's south-western farming areas between 977 and 1980. These worms have anthelmintic resistance and such genetis resistance puts essential internal parasite control practices at risk.

This prompted veterinarians in the Esperance, Albany, Bunbury, Geraldton and Northam areas to survey farms to determine the prevalence of resistance to drenches and to define those sheep management practices which encourage its development.

This article describes the survey which was conducted to assess the extent of drench resistance, what causes its build-up and how it can be controlled …

The Place For Annual Brome Grass, G W. Anderson

Journal of the Department of Agriculture, Western Australia, Series 4

Grasses in the anual pastures of southern Australia are particularly important early in the growing season.

The main grass sown, has been annual rygrass, but concerns are emerging with 'annual ryegrass toxicity' and and 'in crop' competition.

This work looks at the role of annual brome grass in pastures.

Mating Weaners Does Not Affect Future Ewe Performance, R J. Suiter, K. P. Croker

Journal of the Department of Agriculture, Western Australia, Series 4

Maiden ewes in Western Australia are usually mated in their second year because of supposed ill-effects of earlier mating on the ewe's future production. Mating at a younger age however, providing there was no reduction in future performance, would provide for an extra lamb drop and thus increase the lifetime output of ewes.

Information from various sources indicated that weaners could be successfully mated providing their bodyweights were satisfactory. This trial was carried out to test the results of mating weaners under Western Australian conditions.

Special Field Days For Merino Breeders, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

More than 200 Merino stud breeders attended special stud breeding and fertility field days arranged for them by the Department of Agriculture recently.

Breeders attending represented some 40 per cent of the State's Merino studs.