IATF is a biotechnology of choice in reproduction that has been widely used in order to reduce
reproductive and health problems, enabling healthier calves to be obtained, in addition to
reducing the breeding season and the number of bulls on the property. As important productive
indices, the Body Weight (BW) and the Body Condition Score (BCS) reflect the nutritional
status of the animals and are determining factors for the success of the IATF. The present study
aimed to evaluate body weight, body condition score, follicular diameter and conception rate
in Nelore (Bos indicus) cows submitted to estrus resynchronization in IATF. The experiment
was carried out at the Eldorado farm, owned by Grupo Bopil King Ranch, municipality of
Piçarras, State of Pará, from December 2020 to august 2021. On the day of collection for
experimental data, 8 batches were analyzed, accounting for 471 females first-calf Nellore breed.
The evaluation procedures of the cyclic activity of the cows were performed by means of
ultrasound, evaluating the presence or absence of the corpus luteum (CL) and follicular size.
During this procedure, the animals were weighed with the aid of an electronic scale, installed
in the containment chute, and then the Body Condition Score (BCS) was measured, classifying
the females as thin, adequate or obese. Statistical analyzes were performed by evaluating the
data of the variables, submitted to the Normality (Cramer Von Mises) and Homoscedasticity
(Levene) tests. Once these assumptions were satisfied, the variables were submitted to
association between the response variables using the Chi-square and Fisher tests, analyzed in
the Bioestat statistical software, with a significance of p<0.05. There was no influence of the
variables eCG doses, follicular diameter, presence of corpus luteum and body condition score
on the conception rate. There was an influence of body weight on conception rates, as females
with body weight less than or equal to 400 kg had a better pregnancy rate at the end of the estrus
resynchronization protocol. The evaluation of these variables made it possible to decide on the
best protocol to be used by the property, enabling the technical follow-up adequate to the
productive needs of the animals.
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