Desempenho produtivo e parâmetros metabólicos de vacas leiteiras alimentadas com rações contendo silagem de milho e/ou sorgo

• Autor(a) principal: Caetano, Leandro Batista Urzêda
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/3920
• topic: Forragem; FDN; Leite; Forage; NDF; Milk; ZOOTECNIA::PRODUCAO ANIMAL

The objective of this study was to evaluate milk production, consumption of dry matter, ingestive behavior the digestibility and ruminal kinetics of crossbred lactating cows fed rations whose fiber neutral detergent (NDF) corn silage was replaced by NDF silage forage sorghum. It was 8 cows divided in two 4x4 Latin square balanced. Each experimental period lasted 21 days, with 14 days of adaptation and seven days of collection. The experimental isonitrogenous diets were formulated to contain 38 % total NDF and 33 % NDF of forage. Increasing levels of substitution of corn silage for NDF silage sorghum (0, 33 , 66 and 100 % replacement ) were used . The in vitro NDF degradability of corn silage at 30 and 48 hours was higher than sorghum silage. The cud and chewing time expressed in min/times of intake in min/d, min / kg DM and min/Kg of NDF was not affected by the replacement levels. Replacement levels propitiated linear effect for rumination min / kg DM and min / kg of NDF and chewing on min / kg of NDF and increased linearly to chew on min / kg of DM. Replacement levels propitiated linear increasing effect for dry matter and NDF (kg/d). The NDF and NDFi showed linear increase. Replacement levels provided linear effect for DM digestibility in the total tract. None of the related production and milk composition variables were influenced by the progressive replacement of NDF corn silage NDF for sorghum silage. The "pool size" of ruminal MN, MS and NDFi were not affected by the replacement levels of NDF. There was a trend of linear increase to the rate of DM disappearance and the passing rate of the NDFi. Replacement levels propitiated linear effect for the renewal fee. There was no effe ct of the substitution for "mat" and average ruminal pH of ruminal fluid. Under the conditions of this study corn silage can be replaced by sorghum silage feeding without loss in animal productivity.