Desempenho de bezerras de corte em azevém (Lolium multiflorum Lam.), sob dois métodos de pastoreio, com ou sem o fornecimento de suplemento energético

Abstract

The livestock system in Rio Grande do Sul has undergone several changes in its structure, mainly due to the increase in agricultural activities, reducing the areas destined for livestock. Even with the reduction of the grazing area, the size of the beef cattle herd in the state has remained constant over the years. This fact indicates that pasture management techniques that increase the stocking rate, without prejudice to individual performance, should be better studied. Among these techniques are the grazing method with rotational stocking and the provision of supplements for grazing animals. The experiment was carried out in an area belonging to the Animal Science Department of the Federal University of Santa Maria, with field evaluations from July to November 2017. The characteristics of ryegrass pasture, productive performance, forage intake and the ingestive behavior of beef heifers in ryegrass (Lolium multiflorum Lam.) pasture, under two grazing methods (continuous and rotating) and with or without the supply of whole corn grain (0 and 0.76% of body weight) (PC)) as a supplement. The animals evaluated were Angus heifers with a mean initial age of seven months and 150±4.6 kg BW. The experimental design used was complete randomized blocks, with repeated measurements in time, with four treatments and three area replications. Beef heifers in ryegrass, under the rotational or continuous grazing method and receiving 0.76% of the body weight of corn or not, change the way of searching in the pasture harvest process, maintain the same grazing, rumination and idle times and provides similar pasture intake, total intake of crude protein and neutral detergent fiber, resulting in equal individual weight gain of the animals. Rotational grazing for beef calves in the rearing phase provides an increase in stocking rate and consequently in weight gain per area (GPA). The use of 0.76% of body weight of corn grain in ryegrass pasture provides an increase in stocking rate, in GPA, greater gain in croup height and greater gain in body condition score.