Fontes de gordura na dieta de vacas em lactação
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Data
2012-02-24
Autores
Freitas Júnior, José Esler [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi avaliar a biohidrogenação ruminal e o fluxo intestinal de ácidos graxos em vacas leiteiras suplementadas com diferentes fontes de gordura dietética. Foram utilizadas 8 vacas da raça Holandesa no terço médio de lactação (80 ± 20 dias em lactação; média ± DP) canuladas no rúmen e abomaso (580 ± 20 kg de peso corporal; media ± DP), agrupadas em dois quadrados latinos 4 x 4 balanceados, alimentadas com as seguintes dietas: 1) Controle (C), dieta a base de milho e farelo de soja; 2) Óleo de soja refinado (OS); 3) Grão de soja in natura (GS); e 4) sais de cálcio de ácidos graxos insaturados (SCAG). A produção de leite e o consumo de matéria seca foram mensurados diariamente durante todo o período experimental. As amostras utilizadas para análise da composição e o perfil de ácidos graxos do leite foram coletadas de dois dias alternados, sendo provenientes das duas ordenhas diárias. As amostras de sangue para análise dos metabólitos sanguíneos foram coletadas em tubos vacuolizados por punção da veia e/ou artéria coccígea e em tubos com EDTA para análise do perfil de acidos graxos. Para avaliação da fermentação ruminal as amostras de líquido ruminal foram coletadas nos tempos zero (antes da alimentação), e 2, 4, 6, 8, 10 e 12 horas após alimentação matinal. A digestibilidade foi determinada por meio da utilização do indicador externo óxido crômico. O indicador FDNi foi utilizado para estimativa do fluxo abomasal de matéria seca. Foram utilizados dois modelos para calcular a biohidrogenação ruminal: Modelo A) calculado pela taxa de desaparecimento entre o consumido e o fluxo abomasal; Modelo B): calculado por meio da dinâmica ruminal, taxa fracional de desaparecimento ruminal, e fluxo abomasal. Não houve efeito das fontes de gordura sobre o consumo e a digestibilidade aparente total da...(Resumo completo, clicar acesso eletrônico abai
The aim of this study was to evaluate the ruminal biohydrogenation and intestinal flow of fatty acids in dairy cows supplemented with different sources of dietary fat. Eight Holstein cows in the mid lactation (80 ± 20 day in milk; mean SD) cannulated in the rumen and abomasum (580 ± 20 kg of weight; mean ± SD) with milk yield of 25 kg/d were assigned randomly into two 4 x 4 Latin squares, fed the following diets: 1) control (C); 2) refined soybean oil (SO); 3) whole soybean raw (WS) and 4) calcium salts of unsaturated fatty acids (CSFA). Milk yield and dry matter intake were measured daily throughout the experimental period. The samples used for analysis of composition and fatty acid profile of the milk were collected from two alternate days, and from the two daily milkings. Blood samples for analysis of blood metabolites were collected in tubes vacuolated by vein puncture and/or coccygeal artery and were collected in tubes with EDTA to obtain the plasma. To evaluation of the rumen fermentation ruminal fluid samples were collected at time zero (before feeding), and 2, 4, 6, 8, 10 and 12 hours after morning feeding. The digestibility was determined by using the external marker chromic oxide. The marker NDFi was used to determine the abomase flow from the dry matter. Two models were used to calculate the rate biohydrogenation: Model A): calculated by disappearance rate using abomasal fatty acids flow, and fatty acids intake and; Model B): calculated by ruminal turnover, fractional passage rate and fractional biohydrogenation rate and ruminal pool for each fatty acid. There was no effect of fat sources on intake and total apparent digestibility of the dry matter and nutrients and on yield and milk composition, microbial protein synthesis, fatty acid profile of milk and blood. The balances of nitrogen and energy were also not... (Complete abstract click electronic access below)
The aim of this study was to evaluate the ruminal biohydrogenation and intestinal flow of fatty acids in dairy cows supplemented with different sources of dietary fat. Eight Holstein cows in the mid lactation (80 ± 20 day in milk; mean SD) cannulated in the rumen and abomasum (580 ± 20 kg of weight; mean ± SD) with milk yield of 25 kg/d were assigned randomly into two 4 x 4 Latin squares, fed the following diets: 1) control (C); 2) refined soybean oil (SO); 3) whole soybean raw (WS) and 4) calcium salts of unsaturated fatty acids (CSFA). Milk yield and dry matter intake were measured daily throughout the experimental period. The samples used for analysis of composition and fatty acid profile of the milk were collected from two alternate days, and from the two daily milkings. Blood samples for analysis of blood metabolites were collected in tubes vacuolated by vein puncture and/or coccygeal artery and were collected in tubes with EDTA to obtain the plasma. To evaluation of the rumen fermentation ruminal fluid samples were collected at time zero (before feeding), and 2, 4, 6, 8, 10 and 12 hours after morning feeding. The digestibility was determined by using the external marker chromic oxide. The marker NDFi was used to determine the abomase flow from the dry matter. Two models were used to calculate the rate biohydrogenation: Model A): calculated by disappearance rate using abomasal fatty acids flow, and fatty acids intake and; Model B): calculated by ruminal turnover, fractional passage rate and fractional biohydrogenation rate and ruminal pool for each fatty acid. There was no effect of fat sources on intake and total apparent digestibility of the dry matter and nutrients and on yield and milk composition, microbial protein synthesis, fatty acid profile of milk and blood. The balances of nitrogen and energy were also not... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Vacas em lactação - Dieta, Bovino de leite - Nutrição, Biohidrogenação ruminal, Ruminal biohydrogenation
Como citar
FREITAS JÚNIOR, José Esler. Fontes de gordura na dieta de vacas em lactação. 2012. xxi, 120 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2012.