Life Sciences Commons^™

Effects Of Bull Exposure On Postpartum Intervals And Reproductive Performance In Beef Cows: A Progress Report, C.D. Naasz, H.L. Miller, B.A. Petijean, R.H. Haigh

South Dakota Beef Report, 1986

The effects of bull exposure on time from calving until estrus, conception rates and calving interval were studied for mature beef cows. In the spring of I985 and 1986, cows were randomly allotted to one of two treatment groups. Cows were exposed to vasectomized bulls after calving until breeding or no bull exposure. Cows were heat detected twice daily and blood samples were collected weekly to determine progesterone levels. Heat detection data and progesterone levels indicated onset of estrous cycles occurred earlier in bull exposed cows than non-exposed cows. Conception rates to a timed insemination were not different between the …

Preliminary Results On Fertility, Prolificacy, Lamb Production, And Carcass Traits Of Romanov Sheep In Canada, Mohamed Hamed Fahmy

3rd World Congress on Genetics Applied to Livestock Production

Performance of 14 ewes imported from France and their progeny born in Canada over a period of five years are reported. Least-squares means for fertility were 100% for ewes mated in the fall and winter and 42% for those mated in the summer (May - June). Litter size at birth (2.86 ± .15) and at weaning (2.10 ± .15) were significantly affected by season of mating and parity. The most prolific matings were those of the fall (3.18) and of ewes in their 5th parity (3.54). On the average .52 (18.2%) lambs died at birth and a further .25 (8.7%) …

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 …

Feed For Autumn Lambing Ewes, B R. Beetson

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

Department of Agriculture feeding trials with grazing sheep have consistently shown that the level of supplementation should be set for survival and little more, because beyond that the additional costs of supplementary feeding usually outstrip the benefits from extra production.

Even sheep in the greatest need - autumn lambing ewes in late pregnancy and the early part of lactation before and during the break of season - can be fed less than was thought necessary to achieve acceptable production.