Influence of single-sire and multiple-sire natural mating on pregnancy rate of beef heifers
| Autor: | D.D. Lunstra, D.B. Laster |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Gynecology
Estrous cycle medicine.medical_specialty animal structures Equine animal diseases Sire food and beverages Biology Semen quality Pregnancy rate Animal science Food Animals behavior and behavior mechanisms medicine Animal Science and Zoology Mating Small Animals reproductive and urinary physiology |
| Zdroj: | Theriogenology. 18:373-382 |
| ISSN: | 0093-691X |
| DOI: | 10.1016/0093-691x(82)90159-5 |
| Popis: | Twelve mature Angus bulls possessing similar semen quality were used to study the effects of single and multiple services and single-sire and multiple-sire mating on pregnancy rate of beef heifers. Heifers were observed for natural estrus twice daily and mated within 6 hr of onset of estrus. Pregnancy rate was determined by rectal palpation at 60 days post-mating. Pregnancy rate of heifers receiving one service per estrus averaged 62.1% (n=124) and pregnancy rate of heifers receiving multiple services (single-sire) per estrus averaged 62.9% (n=105). Pregnancy rate per estrus of heifers mated to three sires (multiple-sire, one service per sire; 74.0%, n=123) was significantly higher than that of heifers mated to a single sire (62.9%). The range in pregnancy rate per bull for single-sire matings was large (0 to 95%), but this range was reduced among the same bulls used for multiple-sire matings (68 to 84%). These results indicate that pregnancy rate to one service did not differ (P>.10) from pregnancy rate to multiple services among single-sire matings, but multiple-sire matings increased (P |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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