Suplementação lipídica para vacas em lactação: perfil de ácidos graxos e teor de ácido linoléico conjugado na gordura do leite

• Autor(a) principal: Machado, Henrique Valentim Nunes
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1835
• topic: Proteína microbiana; Eficiência alimentar; Consumo alimentar; Microbial protein; Feed efficiency; Feed consumption; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

The study was conducted to evaluate the effects of different lipid sources in diets of lactating cows on the following parameters: dry matter intake and nutrients apparent digestibility, milk production and composition, fat content of CLA in milk; general profile of fatty acids in milk fat, blood levels of urea, triglycerides, HDL, LDL, VLDL, total cholesterol and glucose, nitrogenous compounds balance, microbial protein synthesis, concentration of volatile fatty acids and ammonia concentration of rumen fluid. We used five primiparous Holstein, PO (pure source) and PC (pure by crosses), distributed in a 5 x 5 Latin square. The treatments were characterized by the following experimental diets: control (no added lipid) diet with raw ground soybean, cottonseed diet, diet with soybean oil diet with calcium salts of fatty acids (Megalac ® E). Most values for intake and digestibility of dry matter and food fractions showed no differences between diets, consumption of indigestible neutral detergent fiber (INDF) was higher for diet with cottonseed, as well as the digestibility protein seems to be higher in treatment with soybean oil. Productive performance, there was increased production in kg / day of milk, lactose in milk and nonfat dry milk, when the soap was used as calcium supplement. Within the profile of fatty acids contained in milk fat, treatment with calcium soap and raw ground soybean, led to higher concentrations of polyunsaturated fatty acids and C18: 2. Supplementation with calcium salts of fatty acids was responsible for the higher production of conjugated linoleic acid (CLA), with values nearly double the other treatments. The concentration of CLA in milk fat, although not shown statistically significant, was also higher for this supplement. Regarding the metabolism of nitrogenous compounds, nitrogen excretion via urine was higher in cows fed diets supplemented with soybean oil. The fat supplements, with the exception of calcium soap, increased the microbial protein synthesis. As for the ammonia concentration in rumen fluid was obtained upper value for the control treatment and lower value for the treatment of raw soy beans and ground coffee, while blood parameters remained unchanged. The fat supplement, calcium soap (Megalac ® E), positive influence on the profile of fatty acids contained in milk fat, especially with regard to the amount of CLA. Moreover, aspects of production and milk composition were not affected by this supplement.