FACTORS ASSOCIATED WITH THE ONSET OF OVARIAN ACTIVITY OF CATTLE COMMONLY REARED IN THE HUASTECA VERACRUZANA

Abstract

Objective: This research aimed to identify the factors that affect the onset of ovarian activity in prepuberal heifers in the Huasteca Veracruzana of Mexico.

Design/methodology/approach: Samplings were taken from animal production units of the municipality of Tantoyuca, Veracruz. The onset of ovarian activity was determined by the presence of ovarian follicles and corpus luteum by ultrasonography technique. Zoometric indices and body condition were calculated at the same time, and it was registered the zootechnical practices that were given to the animals in the last six months before the sampling day. A poll was applied to characterize the management of animal production units, the main topics in the poll were: health, reproduction, nutrition, and nursing. All animals available within selection criteria in the production units were sampled. A multiple linear regression (Statistical Analysis Software Version 9.4) and cluster analysis (R Studio Version 1.1.419) were used to identify the main categorical variables that affected the model.

Results: The onset of ovarian activity mainly depends on the anatomic development of the heifers. The biostimulation (male effect) on the heifers, has an important effect on reducing the age at puberty.

Limitations on study/implications: The investigation was developed during a long drought period in the region.

Findings/conclusions: The genetic mosaic of the evaluated animals in the production units did not affect the onset of ovarian activity of the heifers, however, those crossbred (Bos taurus x Bos indicus) begin the ovarian activity younger.