Synchronization of estrus and ovulation in bovine females. Endocrine bases and treatments used
Keywords:
oestrous cycle, waves of follicular growth, synchronization of estrus and ovulation, beef cowsAbstract
In Mexico, reproductive performance in beef cows is low and the use of synchronization of estrus and ovulation may help to improve it, thus the objective of this review was to describe the endocrine regulation the oestrus cycle and follicular dynamics in cattle, highlighting how these processes can be manipulated by using exogenous hormones. Moreover, we also present some data of pregnancy per artificial insemination (P/AI) with the different protocols of synchronization of estrus and ovulation reported in the literature. Reviews and original articles on the estrus cycle and follicular dynamics in cattle were compiled and PRSE data were obtained from papers published from 2000 to 2023. The range of P/AI was from of 23 to 76%, however despite this wide range, in treatments based on estradiol and GnRH around of 50% of the data of P/AI are between 45 and 55%. In progestin-based protocols, 50% of the P/AI observations were between 55 and 65%. Currently, there are three main protocols for synchronizing oestrus and ovulation that can be used, agree with the revised literature herein, to obtain P/AI between 45 and 65% in most cases with these protocols.
http://dx.doi.org/10.21929/abavet2023.16
e2022-11
https://www.youtube.com/watch?v=k2kox38NV-k
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