In situ degradability of dry matter, organic matter and crude protein of some feeds in crossbred steers

Abstract

The objective of this work was to evaluate the in situ degradability of DM, OM and CP in coast-cross hay (CH), soybean hulls (SH), grounded com grain (CG), soybean meal (SBM), poultry by-product meal (PBM) and starea 72 (ST), estimated by nailon bags in the rumen. It was used six crossbred steers (Holstein x Zebu), fed with a total mixed ration (60:40 rougage/concentrate). A 6 X 6 Latin square design was used to study a 2 X 3 factorial arrangement: three protein sources and two SH levels as a replacement for CH. To estimate DM, OM and CP effective degrabability (ED), a passage rate of5%/h was considered. Higher DM, OM and CP solubility for ST were found. DM, OM and CP disappearance for CG and SH were similar. Values of potential degrabability for DM were 54.5; 88.7; 93.4; 97.5; 61.4 and 86.4%; for OM were: 51.8; 88.4; 93.4; 96.6; 66.9 and 87.3%; for CP were: 65.2; 92.1; 95.6; 99.2; 60.5 and 88.1 %; for ED were: 36.1; 53.3; 66.7. 77.4; 54.0 and 76.6%; for DM were: 32.4; 51.1; 65.6; 76.5; 59.1 and 77.2% and for OM were: 51.1; 68.4; 67.8; 79.6; 53.0 and 84.1 %, for CP, CH, SH, CG, SBM, PBM and ST, respectively.