Effectiveness of Short-Term Cooling and Vitamin E for Alleviation of Infertility Induced by Heat Stress in Dairy Cows
| Autor: | Alan D. Ealy, Carlos F. Aréchiga, D.R. Bray, Carlos A. Risco, Peter J. Hansen |
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| Rok vydání: | 1994 |
| Předmět: |
Infertility
medicine.medical_specialty Hot Temperature medicine.medical_treatment Cattle Diseases Dinoprost Placebo Animal science Estrus Pregnancy Internal medicine Genetics medicine Animals Vitamin E Dairy cattle Estrous cycle business.industry food and beverages medicine.disease Cold Temperature Parity Pregnancy rate Endocrinology Gestation Cattle Female Animal Science and Zoology business Infertility Female Food Science |
| Zdroj: | Journal of Dairy Science. 77:3601-3607 |
| ISSN: | 0022-0302 |
| Popis: | Four experiments were performed to determine whether cooling cows during final maturation of oocytes and early embryonic development or injection of vitamin E at AI prevented adverse effects of heat stress on pregnancy rates in lactating Holstein dairy cows. In Experiment 1, cows were placed in a cooling facility containing sprinklers and forced ventilation or received shade only from 2 to 3 d before until 5 to 6 d after breeding. Although cooling had no effect on detection of estrus, pregnancy rates were increased slightly for cooled cows (8 of 50 cows; 16.0%) compared with those for cows exposed to shade only (2 of 32 cows; 6.2%). In Experiments 2 through 4, cows were administered 3000 IU of vitamin E or placebo i.m. at AI during two consecutive summers and one winter in Florida. Administration of vitamin E had no consistent beneficial effect on pregnancy rates during summer or winter. Short-term cooling improved pregnancy rates slightly in heat-stressed cows, but administration of vitamin E had no beneficial effects on pregnancy rates during heat stress. Further improvements in cooling schemes during early pregnancy and delineation of antioxidant effects are necessary before such systems become practical for improvement of fertility in heat-stressed dairy cows. |
| Databáze: | OpenAIRE |
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