Influência do processamento do grão de milho na digestibilidade de rações e no desempenho de bezerros Effects of corn grain processing on digestibility of diets and performance of calves

Objetivou-se avaliar a influência do processamento grão de milho (inteiro, tratado com uréia ou moído na forma de quirera) sobre a digestibilidade de rações e no desempenho de bezerros desmamados precocemente e mantidos em regime de confinamento. A dieta foi formulada com silagem de sorgo como volumoso, em uma relação volumoso:concentrado de 40:60, na matéria seca. A digestibilidade in vivo da matéria seca (MS), matéria orgânica, proteína bruta, extrato etéreo, fibra em detergente neutro, fibra em detergente ácido, celulose, energia bruta e amido, o pH das fezes e o consumo de MS foram efetuados em um ensaio com seis bezerros, castrados, com sete meses de idade. A influência das dietas no desempenho dos animais foi avaliada em ensaio com 15 bezerros não-castrados e idades semelhantes aos do ensaio de digestibilidade, com peso vivo inicial médio de 159 kg. O processamento do grão de milho não influenciou as variáveis analisadas, exceto o pH das fezes, que apresentou valor mais baixo nos animais que receberam dieta contendo grão de milho moído.<br>The effect of corn grain processing (whole, treated with urea, or crushed forms) on the digestibility of diets and performance in early weaned calves kept in feedlot was evaluated. The diet was formulated with silage sorghum as forage in 40:60 forage to concentrate ratio (%DM). Digestibility of dry matter (DM), organic matter, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, cellulose, gross energy and starch, fecal pH and DM intake were evaluated in an assay using six 7-mo castrated calves. Treatment effect on animal performance was evaluated in an assay using 15 non-castrated calves with ages similar to those of the digestibility assay, with initial 159 kg BW. The corn grain processing did not affect the evaluated characteristics, except for fecal pH, that was lower in the animals fed diet with crushed corn grain

Chemical composition and ruminal degradation kinetics of crude protein and amino acids, and intestinal digestibility of amino acids from tropical forages

The objective of this research was to determine the chemical composition and ruminal degradation of the crude protein (CP), total and individual amino acids of leaves from tropical forages: perennial soybean (Neonotonia wightii), cassava (Manihot esculenta), leucaena (Leucaena leucocephala) and ramie (Boehmeria nivea), and to estimate the intestinal digestibility of the rumen undegradable protein (RUDP) and individual amino acids of leaves from the tropical forages above cited, but including pigeon pea (Cajanus cajan). Three nonlactating Holstein cows were used to determine the in situ ruminal degradability of protein and amino acids from leaves (6, 18 and 48 hours of ruminal incubation). For determination of the intestinal digestibility of RUDP, the residue from ruminal incubation of the materials was used for 18 hours. A larger concentration of total amino acids for ramie and smaller for perennial soybean were observed; however, they were very similar in leucaena and cassava. Leucine was the essential amino acid of greater concentration, with the exception of cassava, which exhibited a leucine concentration 40.45% smaller. Ramie showed 14.35 and 22.31% more lysine and methionine, respectively. The intestinal digestibility of RUDP varied from 23.56; 47.87; 23.48; 25.69 and 10.86% for leucaena, perennial soybean, cassava, ramie and pigeon pea, respectively. The individual amino acids of tropical forage disappeared in different extensions in the rumen. For the correct evaluation of those forages, one should consider their composition of amino acids, degradations and intestinal digestibility, once the amino acid composition of the forage does not reflect the amino acid profiles that arrived in the small intestine. Differences between the degradation curves of CP and amino acids indicate that degradation of amino acids cannot be estimated through the degradation curve of CP, and that amino acids are not degraded in a similar degradation profile

Degradabilidade in situ da silagem de quatro genótipos de sorgo com e sem tanino: I - Matéria seca e proteína bruta In situ degradability of four sorgum silages with or without tannin: I - Dry mater and crude protein

Avaliaram-se a degradabilidade in situ da matéria seca (MS) e da proteína bruta (PB) da silagem de quatro genótipos de sorgo, dois com tanino (CMS XS 210 e BR 701) e dois sem tanino (CMS XS 214 e BR007) em um delineamento de blocos inteiramente ao acaso, com três repetições (animais), em arranjo de parcelas subdivididas. Os genótipos constituíram as parcelas e os tempos de digestão as subparcelas. O genótipo CMS XS 210 apresentou menor degradabilidade da MS em relação aos demais e os genótipos que continham tanino (CMS XS 210 e BR 701) apresentaram menores degradabilidades da PB em relação aos que não o continham.<br>The in situ procedure was used to evaluate the disappearance of dry matter (DM) and crude protein (CP) of four sorghum genotypes with (CMS XS 210 and BR 701) or without (CMS XS 214 and BR 007) tannin in a completely randomized block design experiment with three replicates (animals), in a split plot arrangement. The four genotypes were allotted to the plots and the time of disappearance to the split plot. The DM of CMS XS210 was less degraded when compared to the others and sorghums with tannin showed lower CP degradability when compared to the sorghums without tannin