Recria de novilhas mestiças aberdeen angus variedade red em campo nativo diferido ou pastagem de azevém

Abstract

The quest for higher reproductive efficiency in herds breeding and its economic viability are still the main challenges of the Brazilian beef cattle, characterized by a high slaughter age of males and higher age at calving of heifers. Based on these aspects, the objective of this work is to study the response of crossbred Red Aberdeen Angus beef heifers of different body conditions facing two alternative foods in the pre-mating. Seventy-five crossbred Red Aberdeen Angus heifers were used, with initial average weight of 288.9 kg, body condition score (BCS) initial average of 2.77 and an average age of 24 months, valued at two food systems: ryegrass (Lolium multiflorum) and grazing reserved natural pasture. The grazing method adopted was stocking continues, with increasing stocking, being separated into two diets and three BCS. The initial BCS ratings were grouped in major (BCS> 2.9 points), medium (between 2.7 and ECC 2.9 points) and lower (BCS <2.7 points). The initial stocking was 1.28 animal units (AU) for grazing ryegrass and 0.47 AU to natural pasture. The data were evaluated by analysis of variance. The crude protein (CP) from natural pasture was 9.72% to shallow cut and 12.22% grazing simulation. Heifers kept on natural pasture had higher final body weight, greater daily weight gain, total weight gain. The variables BCS, BCS gain, and weight gain according to the initial BCS did not differ among groups. Both natural pasture as ryegrass can be used for rearing of heifers in the two years mating systems.