Estratégias de alimentação para vacas leiteiras: uso de glicerina como fonte energética e quitosana como modulador de fermentação ruminal

• Autor(a) principal: Paiva, Pablo Gomes de [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/143031; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/14-07-2016/000865998.pdf
• topic: Bovino de leite; Glicerina; Nutrição animal; Digestão; Amido; Alimentos - Aditivos; Animal nutrition

Two experiments were conducted to evaluate the effects of different feeding strategies on dairy cows performance. Thus, the objective of this study was to evaluate the effects of increasing levels of crude glycerin (Experiment 1) and chitosan (Experiment 2) in the diet of dairy cows on dry matter intake, nutrient digestibility, ruminal fermentation, milk yield and composition. The experiment 1: twenty-four Holstein cows (eight rumen cannulated; 184±50 DIM; 594±39 kg BW) were assigned to six 4 x 4 Latin square design, with 21-day periods and the 7 last days for sampling. Cows were assigned within each square to receive one of the following diets: Control or 0 g of glycerin/kg DM; 70 g of glycerin/kg DM; 140 g of glycerin/kg DM; and, 210 g of glycerin/kg DM partially replacing ground corn of diet. Dry matter intake and milk production linearly decreased, specially when crude glycerin was added up to 210 g/kg of the diet. However, addition of glycerin did not affect milk composition. Total-tract digestibility of DM, CP and EE were linearly increased, and NDF linearly decreased, mainly in the 210 g/kg of glycerin inclusion in the diet. Feeding glycerin changed ruminal fermentation, with increased propionate and butyrate, and decreased acetate concentrations, resulting in lower acetate: propionate ratio, especially when glycerin was added up to 210 g/kg of the diet. High crude glycerin levels (210 g/kg DM) in the diets of mid-late lactation dairy cows increased dry matter digestibility and ruminal propionate; but, had negative effect on dry matter intake and milk production. Experiment 2: eight rumen cannulated Holstein cows (215.4 ± 60.9 DIM; 641.6 ± 41.06 kg of BW) were assigned into a replicated 4 x 4 Latin square design with 21 d periods. Cows were assigned to receive one of treatments, as following: CO) control (without chitosan), C75, C150 and C225 addition of 75, 150 and 225 mg/kg of BW chitosan placed through rumen cannula ...