Caracterização química, digestibilidade, fermentação ruminal e produção de leite em vacas alimentadas com resíduo de cervejaria nas rações

Abstract

The objective of the present study was to chemically and biologically characterize the fermented brewers grain (FBG) in ruminants feed. The carbohydrates and protein fractions according to CNCPS, the fatty acid and aminoacid profile, the dry matter (DM) and crude protein (CP) effective degradability (ED), the DM and CP ruminal digestibility in vitro (RDIV) and the intestinal digestibility in vitro (IDIV) of the rumen-undegradable protein (RUDP) of the WBG were realized. The total and partial digestibility of nutrients and ruminal variables were determined in four Holstein steers with ruminal and duodenal cannula fed with 0%; 8% 16% and 24% FBG inclusion leves. It was evaluated the FBG inclusion on production and quality milk of multiparous Holstein cows feed with FBG inclusion levels of 0%; 5%; 10% and 15% and with a milk´s production average of 28 kg/day. Data obtained from DM and CP degradability of WBG, FBG and SBM were submitted to variance analysis in randomized design block, with three animals (repetitions), using the UFV linear model (1997) and the averages were compared by the Tukey test. A latin square 4x4´s experimental design was used to determinate the nutrients total and partial DC. To determinate the production and quality milk values it was used an totally casualized design with seven animals (repetitions), the data were interpreted using variance analysis (P<0.05) and the differences obtained among FBG inclusion levels were submitted to regression analisys. The FBG presented 30% of CP from which 25.80% correspond to the fraction A + B of CP available to ruminal fermentation and 60.65% represent fraction B2 + B3, protein available in the intestine for animal metabolism. The CP ED of FBG varied from 51.6% to 33.8% with the increase in the solids passage rate of 2% to 8%/hour, what characterize it as protein source of slow ruminal degradability. The CP RDIV of FBG was 42.65%. The RUDP IDIV of FBG was 72.53% and RUDP degradable in the small intestine was 39.36%. The FBG protein presented 12.1% of lysine concentration and 4.2% of methionine total essential aminoacids. The value of the FBG total carbohydrate (TCH) was 60.85%, from which, 22.68% represented the carbohydrates of quick ruminal fermentation (sugars + starch) and 45.02% the carbohydrate of degradable cellular structure and 32.30% of undegradable carbohydrate. The FBG presented 23.79% of saturated fatty acids and 76.21% of unsaturated fatty acids with a unsaturated/saturated relation of 3.21:1. The Total digestibility coefficients (TDC), ruminal (RDC) and intestinal (IDC) of DM, CP, NDF and ADF were not influenced (P > 0.05) by the FBG inclusion levels in the rations of 0%; 8%; 16% and 24% in DM. However the IDC of MO and CHT increased (P < 0.05) linearly with FBG inclusion levels in rations. The poroduction and the milk quality were not influenced (P > 0.05), but TDC of DM, CP and EE increased (P < 0.05) linearly with 0%; 5%; 10% and 15% of FBG inclusion in the dairy cows ration.