Milk yield and composition, feed intake and stocking rate of crossbread cows in tropical grasses managed in a rotational grazing system

Abstract

The objective of this study was to evaluate milk yield and composition, dry matter intake, and stocking rate in pastures with tanzania grass (Panicum maximum cv. Tanzânia), star grass (Cynodon nlemfuensis cv. Estrela-Africana), and marandu grass (Brachiaria brizantha cv. Marandu). The grasses were managed in a rotational grazing system with Holstein x Zebu crossbreed cows, with a 30-day resting period and three days of paddock occupation. The pastures were fertilized with 1,000 kg/ha/year using the 20:05:20 (NPK) formula, split in three applications during the rainy season. It was used a complete random block experimental design with three factors being studied and two replications. In the experiment, four cows/paddock were used and, when it was necessary, regulator animals were added in order to obtain a supply of 7% body weight green forage dry matter. The animals were individually fed concentrate at 2 kg/day during the experimental period. Milk yield did not differ among the three grasses, with values of 9.1; 9.1; and 8.7 kg/cow/day for pastures with tanzania grass, star grass and marandu grass, respectively. Similarly, grass did not affect milk chemical composition. Stocking rate was similar among the three grasses, with values of 4.6; 4.5 and 5.0 UA/ha for tanzania grass, star grass and marandu grass, respectively. The highest dry matter intake was observed for tanzania grass with 2.6% of the body weight while stargrass (2.3%) and marandu grass (2.4%) did not differ among each other. The highest dry matter intake on tanzania grass pasture was not reflected on milk yield per animal. Milk yield and composition and stocking rate are similar among the evaluated grasses.