Revista Brasileira de Zootecnia
On-line version ISSN 1806-9290
SAMPAIO, Alexandre Amstalden Moraes; BRITO, Rodolfo Marques de and CARVALHO, Ricardo de Moraes. Comparison of Diet Evaluation Systems for Cattle in an Intensive Beef Production Model: Feedlot of Young Bulls. Rev. Bras. Zootec. [online]. 2002, vol.31, n.1, pp. 157-163. ISSN 1806-9290. http://dx.doi.org/10.1590/S1516-35982002000100018.
Thirty ¾ Canchim + ¼ Nelore young bulls with 417 kg of body weight and 15 months of age, were confined during 84 days. The animals were fed with diets composed with corn silage, corn grain, cottonseed meal, soybean meal, whole soybean and mineral mix, adjusted in agreement with the recommendations of the Metabolizable Protein System (MP), Cornell Net Carbohydrate and Protein System (CNCPS) and Intestine Digestible Protein System (PDI), for predicted body weight gain of 1.3 kg/head/day. The daily body weight gain did not differ among treatments CNCPS, MP and PDI, with 1.51; 1.48; and 1.13 kg/head, respectively. The economic analysis revealed net profit of R$116.25; R$148.30; and R$108.51/head for CNCPS, MP and PDI systems, respectively. The diets adjusted by CNCPS and MP systems provided superior animal performance than that expected, while the diet adjusted by PDI system did not allow the predicted body weight gain.
Keywords : beef cattle; corn silage; cottonseed meal; requirements; soybean meal.