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Published on: August 30, 2021
Reproductive cycles in Bos indicus cattle.
1Department of Animal Science, ESALQ, University of São Paulo, Piracicaba, São Paulo, Brazil. sartori@pq.cnpq.br
Bos indicus cattle exhibit distinct ovarian characteristics, including more follicles and follicular waves, compared to Bos taurus. These differences in reproductive cycles influence follicle deviation and may explain the success of in vitro embryo production in Zebu cattle.
Area of Science:
- Reproductive biology
- Comparative physiology
- Veterinary science
Background:
- Transrectal ovarian ultrasonography has been used to study reproductive cycles in Bos taurus and Bos indicus cattle.
- Bos indicus cattle generally show more follicles and follicular waves per estrous cycle than Bos taurus.
- Ovulation from smaller follicles in Bos indicus leads to smaller corpora lutea and potentially lower hormone levels.
Purpose of the Study:
- To compare ovarian function and reproductive cycles between Bos taurus and Bos indicus cattle.
- To explore the reasons behind the success of in vitro embryo production in Zebu cattle.
Main Methods:
- Utilized transrectal ovarian ultrasonic scanning.
- Evaluated reproductive cycles in heifers and cows under various management conditions.
Main Results:
- Bos indicus cattle possess larger antral follicle populations than Bos taurus.
- Significant differences exist in dominant follicle deviation size between the two breeds.
- Bos indicus ovulate from smaller follicles compared to Bos taurus.
Conclusions:
- Differences in ovarian function, particularly follicle population, are key to the success of in vitro embryo production in Bos indicus (Zebu) cattle.
- Nutritional status and management regimens can influence these reproductive findings.
- Breed-specific ovarian dynamics are crucial for reproductive efficiency in cattle.
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