Efeito da aplicação de Gonadorelina no momento da IATF e da manifestação de estro na taxa de concepção de fêmeas bovinas de corte

Abstract

Reproductive biotechnologies can be tools for optimizing productivity and reproductive productivity of the herd. Fixed-time artificial insemination (TAI) has played an important role in this process by shortening the interval between deliveries, as well as enabling the exact timing of insemination as vaccines without waiting for the natural manifestation of estrus, thus programmed The birth of calves, optimizing the use of the workforce of the property. However, not all the animals leave the TAI protocol, which results in the non processing or the low estrous expression, reducing the design rate. Therefore, it was aimed to have tried the purpose of the application of gonadorelin at the time of TAI in the rate of design of cattle with partial manifestation or not of manifestation of estrus. 593 cattle was submitted to ovulation synchronization protocol based on progesterone (P4) and estradiol benzoate (BE). On the day of removal of the intravaginal device from P4 the base of the tail of the animals were marked with marker stick. At the time of TAI the animals were evaluated and classified according to the assessment of the tail base in the manifestation of positive, partial or negative. Half of the animals with partial or negative manifestation were with an application of gonadorelin (GnRH), being formed 5 groups based on the manifestation of estrus and the applications of gonadorelin. The data was analyzed by regression logotype being included in the group model. In analyzing the data, assessing whether GnRH applied at the time of the TAI does not promote an increase in animal reproduction display rates in the age group does not show statistical differences between the analyzed groups