Performance of weaned Nelore and crossbred calves grazing Cynodon dactylon cv. Coastcross fertilized pastures supplemented with concentrate

Revista Brasileira de Zootecnia

Cruz, Geraldo Maria da¹  Alencar, Maurício Mello de²  Tullio, Rymer Ramiz¹  Alleoni, Guilherme Fernando⁴  Rodrigues, Armando de Andrade¹  Oliveira, Gilson Pereira de³ 

[1] Embrapa Pecuária Sudeste, São Carlos;Embrapa Pecuária Sudeste;UNESP, Jaboticabal;Instituto de Zootecnia, Nova Odessa

关键词: Angus;    Canchim;    forage availability;    Simmental;    stocking rate;    weight gain   Introdução Em sistemas extensivos de criação;    a escassez periódica de forragem;    tanto em qualidade quanto em quantidade;    compromete o desenvolvimento dos bovinos;   

DOI  :  10.1590/S1516-35982009000100018

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

In three years of research, 223 purebred Nelore and crossbred Canchim × Nelore, Angus × Nelore and Simmental × Nelore calves received either mineral mixture or 3 kg/animal/day of a concentrate, containing 18.8% crude protein and 81.5% total digestible nutrients, on a dry basis, while in a rotational grazing of Cynodon dactylon cv. Coastcross, fertilized pastures. Available forage (kg dry matter/ha) was different for paddocks of cattle receiving mineral mixture (2,961 kg) from those receiving concentrate (3,383 kg). However, forage dry matter allowance was higher (9.9 kg/animal/day or 3.9% of BW) for cattle receiving mineral mixture than for cattle receiving concentrate in the diet (9.0 kg/animal/day or 3.3% of BW). Available forage had, on a dry basis, 13.6% crude protein, 79.8% neutral detergent fiber, 62.3% in vitro dry matter digestibility, 3.9 g/kg Calcium, 2.0 g/kg magnesium, 2.5 g/kg phosphorus, 22.7 g/kg potassium, 2.8 g/kg sulfur, 9.9 mg/kg copper, 22.5 mg/kg zinc, 98 mg/kg manganese and 188 mg/kg iron. Statistical interactions of genetic group × supplementation and year × supplementation were observed for average daily gain and for stocking rates while a grazing cycle × supplementation interaction was observed for stocking rates. The average daily gain of Nelore, Canchim × Nelore, Angus × Nelore and Simmental × Nelore, receiving mineral mixture in the diet, were 0.48, 0.63, 0.68 and 0.50 kg, respectively, while those animals receiving concentrate in the diet, were 0.87, 0.95, 0.99 and 0.95 kg, in the same order of genetic groups. Average stocking rates of pastures grazed by all genetic groups receiving mineral mixture in the diet was 6.1 animal units/ha, while the pastures grazed by Nelore, Canchim × Nelore, Angus × Nelore and Simmental × Nelore showed values of 7.5, 7.6, 8.8 and 9.0 animal units/ha, respectively, for animals receiving concentrate in the diet. The genetic group affects performance of cattle grazing coastcross and shows interaction with supplementation of diet with concentrate.

【 授权许可】

CC BY-NC