The effect of bovine interferon-alpha I1 on pregnancy rate in heifers.
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Data
1992-05-01
Autores
Barros, C. M.
Newton, G. R.
Thatcher, W. W.
Drost, M.
Plante, C.
Hansen, P. J.
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Resumo
Bovine interferon-alpha I1 (bIFN-alpha) may be useful for enhancing fertility in sheep and cattle because it has extensive sequence homology with ovine and bovine trophoblast protein-1 and, like those proteins, extends corpus luteum lifespan. To test the effectiveness of bIFN-alpha to enhance fertility, several experiments were performed in which inseminated heifers were given i.m. injections of bIFN-alpha approximately at the time of embryo-mediated signals that result in maintenance of the corpus luteum. In Exp. 1, heifers given 20 mg of bIFN-alpha daily from d 14 to 17 tended (P less than .07) to have lower pregnancy rates at d 110 to 112 of gestation (36/75; 48% vs 43/72; 60%). Similar results were obtained in Exp. 2 when heifers received a single injection of 40 mg of bIFN-alpha or placebo at d 13 after estrus; pregnancy rates at d 42 were 39/104 (38%) for bIFN-alpha and 47/98 (48%) for placebo. In Exp. 3, heifers were given gradually increasing doses of bIFN-alpha or placebo from d 11 to 19, because such a regimen had been shown to reduce the number of heifers experiencing hyperthermia after bIFN-alpha injection. Pregnancy rates were 42/95 (44%) for bIFN-alpha and 62/111 (56%) for placebo. Across all three experiments, pregnancy rates were lower (P less than .01) for heifers treated with bIFN-alpha (117/274; 43%) than for heifers treated with placebo (152/281; 54%). In conclusion, these results demonstrate that, under the administration systems used, bIFN-alpha does not increase pregnancy rate, but rather tends to reduce it.
Descrição
Palavras-chave
recombinant interferon, animal, body temperature, cattle, double blind procedure, drug effect, estrus, female, fertility, fertilization, physiology, pregnancy, randomization, Animal, Body Temperature, Cattle, Double-Blind Method, Estrus, Female, Fertility, Fertilization, Interferon Type I, Recombinant, Pregnancy, Random Allocation, Support, Non-U.S. Gov't, Support, U.S. Gov't, Non-P.H.S.
Como citar
Journal of animal science, v. 70, n. 5, p. 1471-1477, 1992.