Fixed-Time Artificial Insemination Versus Artificial Insemination at Stalk Detected in Cows And Heifers

Objective: The objective of the present study was to evaluate the pregnancy rate of IACD and IATF in cows and heifers. Theoretical framework: Artificial insemination at a fixed time (IATF) and artificial insemination at detected heat (IACD) are essential tools in livestock farms, improving the production and reproduction of the herd in a short time, considering that differences sometimes occur between the pregnancy rate of cows and heifers with different treatments influencing the production of the herds. Methodology: 194 heifers and 200 Bos taurus x Bos indicus crossbred cows were used. The animals that entered IATF on a random day of the estrous cycle were synchronized with an intravaginal device of Progesterone and Estradiol. The animals that entered IACD were monitored. visual of the characteristic signs of heat twice a day for a period of two hours each, to carry out artificial insemination (AI), the statistical analysis was carried out with the help of the SAS software. Results and discussion: The pregnancy rate among the 215 heifers and cows in the IACD group was 64.00% and 44.00%, respectively, unlike the IATF group with a total of 179 animals, a pregnancy rate of 91.14% for heifers and 78.00% in cows, showing statistically significant differences in follicular size for cows and heifers under treatment with IACD and similar for IATF. Implications of the research: The cyclicity of heifers was efficiently induced in the hormonal protocols with IATF, this group of animals had a higher pregnancy rate and greater follicular diameter unlike the IACD group. Originality/Value: This study contributes to the understanding and effectiveness of using reproductive biotechnologies in livestock herds to increase production and profitability, thus being more sustainable.