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At least 721 records · Page 40Linked to original sources
PubMed1984

Effect of health status on culling and reproductive performance of Holstein cows.

Data were from 492 cows that calved between October 1976 and May 1977 in eight Holstein herds in Michigan. Cows were classified as those without any health-related problems during lactation; those with minor reproductive health problems not serious enough to require veterinary treatment; and those with health problems severe enough to require veterinary treatment. Among primiparous cows 4.4, 16.2, and 19.1% were culled from healthy, minor, and problem groups, whereas among multiparous cows, these percentages were 11.2, 19.1, and 31.7. Among healthy cows 33.3, 38.9, and 27.8% of total culls were classified as production, reproduction, and other. Among minor and problem cows, these percentages were 31.6, 42.1, and 26.3 and 22.6, 58.5, and 18.9. The odds of being culled were 4.3 and 5.2 times as great as for first lactation cows in minor and problem groups and 1.9 and 3.7 times as great as for older cows in the two health-problem groups. Primiparous cows in healthy group averaged 50 days to first detected estrus, 68 days to first service, and 95 days open. Least squares means for performance of primiparous cows in minor and problem groups and of multiparous cows in healthy, minor, and problem groups, as deviations from healthy cows, was days to first service, 9.1, 24.0, 2.0, 12.1, and 9.1; and days open, -7.0, 15.2, -9.1, 1.8, and 12.6. Primiparous cows with health problems were at a higher risk of being culled than multiparous cows with health problems.

Age Factors↗
PubMed2002

Reproductive performance of a transgenic boar carrying the bovine growth hormone gene (bGH).

The aim of this study was to obtain information on the possible influence of the bovine growth hormone gene (bGH) on gametogenesis and reproductive parameters of a 2-year-old Polish Landrace transgenic boar. The bGH gene construct had been introduced into the zygote of the boar with the use of the microinjection technique. On the basis of the available documentation we established that the fertility of the investigated transgenic (bGH) boar was low in comparison with other animals of the Polish Landrace breed, with a poor libido, ineffective matings and, on average, 3 live piglets less per litter. Samples of testis tissue from the boar were obtained after castration. In total, we observed 100 spermatocytes and all of them had normally paired bivalents. It is possible that the boar's lower fertility was caused by some, as yet unknown factor.

Animals↗
PubMed2006

An estimation of reproductive performance of farmed elk (Cervus elaphus) in North America.

North American farmed elk (Cervus elaphus) producers were surveyed to determine period specific rates of calving, abortion, and dystocia, and to examine the effect of reproduction-related mortality on the productivity of farmed elk. The overall calving rate was 86.3% and the calving rate for adult cows was found to be significantly higher than that for heifers. Abortions were seen on 7.6% of farms and the overall abortion rate was approximately 0.6%. Dystocia was experienced in 5.9% of births. Neonatal mortality, summer mortality, weaning mortality, and postweaning mortality rates were calculated and compared. Failure to produce a live neonate was responsible for 64% of the total reproductive loss and calf mortalities from birth to 1 year of age accounted for 36%. Failure to produce a live neonate had a more significant effect on productivity than did mortalities from birth to 1 year of age, suggesting that reproduction has a greater economic effect on elk farms than neonatal mortality.

Abortion, Veterinary↗
PubMed2003

The effects of the periodical use of in-feed chlortetracycline on the reproductive performance of gilts and sows of a commercial pig farm with a history of clinical and subclinical viral and bacterial infections.

The objective of this study was to assess the effects of in-feed chlortetracycline (CTC) as a measure of preventing or minimizing infectious problems of reproductive failure in gilts and sows. In a farm of 400 Large White x Landrace gilts and sows with a clinical history of porcine respiratory and reproductive syndrome (PRRS) virus, the animals were treated with CTC. Treatment consisted of 10 g CTC sow/day for 15 days every 3 months. It improved the health status of sows by decreasing post-farrowing clinical mastitis and vaginal discharges, abortions, return-to-oestrus and irregular return-to-oestrus rates. These beneficial effects had a positive impact on the performance of the litter. More piglets were born live and weaned. These positive effects improved with repeated use of CTC. The serological evidence of PRRS virus, Leptospira spp. and Chlamydia spp. and the subsequent beneficial use of the antimicrobial agent indicate that reproductive failure, possibly resulting from the bacterial agents can be controlled with in-feed use of broad spectrum antimicrobials.

Abortion, Veterinary↗