Publications by authors named "Marcelo M Dias"
Article Synopsis
- The study aimed to extend the proestrus phase in Angus crossbreed beef cows by administering prostaglandin F2α (PGF) early in a timed artificial insemination (TAI) protocol.
- Cows were divided into two treatment groups based on the timing of PGF administration, with results showing that those treated with PGF on day 7 had a higher estrus expression (91.3% vs 79.1%) and increased pregnancy rates per TAI (63.9% vs 50.6%).
- Despite lower progesterone levels in PGF7 cows, the treatment did not significantly affect preovulatory follicle size, but it improved outcomes in cows with medium and large follicles.
Ovulation synchronization protocols are well established in beef and dairy cows. However, the protocol response rate is around 70-90%. In beef cows, factors such as inadequate nutrition and calf presence negatively impact the response of progesterone (P4)/estradiol-based ovulation synchronization protocols by interfering with GnRH release and consequently reducing LH pulsatility and final follicular development.
View Article and Find Full Text PDFThis study compared estradiol cypionate (ECP) or GnRH as ovulation inducers at the end of a timed AI (TAI) protocol in Angus heifers. On day 0, heifers (n = 415), between 22 and 24 months of age, were treated with an intravaginal 1 g progesterone (P4) insert and 2 mg of estradiol benzoate. On day 8, heifers had P4 removed, received 500 μg cloprostenol, and were randomized into two groups: ECP [n = 214; 0.
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