Soybean meal and coast cross hay digestibilities with bos taurus fed with different ratios roughage/concentrate in their diets

The objective of this work was to evaluate the apparent digestibility of soybean meal and of “coast-cross” hay with different levels of roughage: A = 40%; B = 60%; C = 80% and D = 100% hay on the diets. Digestion trial was runned with 8 steers, 200 kg average live weight, in a complete randomized design. The period of faeces collection was seven days. Digestion coefficients were: DM 71,61%, 71,43%, 60,39% and 62,61%; CP = 73,32%, 78,12%, 73,55% and 74,34%; CF = 59,74%, 66,56%, 63,80% and 65,74%; ENN = 75,95%, 73,94% 58,02% and 60,93%; EE = 72,90%, 70,84%, 61,04% and 63,30%, for A, B, C and D treatments, respectively. TDN values were: A = 63,13%, B = 62,20%, C = 54,96% and D = 51,28%. Digestion coefficents of DM and NFE and TDN values increased, as more concentrates were employed on cattle's diets. O presente trabalho teve por objetivo avaliar a digestibilidade (aparente) do farelo de soja e do feno de “coast-cross" em diferentes proporções de volumoso: A = 40%: B = 60%; C = 80%; e D = 100%, de feno nas dietas. Os animais utilizados foram 8 bovinos, com peso médio de 200 kg, que permaneceram em gaiolas metabólicas. O período de coleta de fezes foi de 7 dias. Os coeficientes médios de digestibilidade foram: MS = 71,61%, 71,43%, 60,39% e 62,61%; PB = 73,32%, 78,12%, 73,55% e 74,34%; FB = 59,74%, 66,56%, 63,80 e 65,74%; ENN=75,95% 73,94%, 58,02% e 60,93%; EE = 72,90%, 70,84%, 61,04% e 63,30%, para os tratamentos A, B, C e D, respectivamente. Os valores de NDT foram: A = 63,13%; B = 62,20%; C = 54,96%; e D = 51,28%. As digestibilidades da MS, ENN e os valores de NDT aumentaram à medida que a proporção de concentrado era aumentada na ração (P < 0,01).