Degradação in vitro e trânsito ruminal da fibra em dietas com suplementos lipídicos

• Autor(a) principal: Bettero, Vitor Pereira
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5739
• topic: Taxa de passagem; Fibra; Modelos matemáticos; Passage rate; Fiber; Mathematical models; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA

This study was carried out to evaluate the behavior of the fiber in the digestive tract through the kinetics of passage of particles from the forage and concentrate in cows fed diets with different lipid sources, the correlation of these parameters on the dry matter intake (DMI) and neutral detergent fiber (NDFI), percentage of fat in milk (G) and corrected milk yield for 3,5% fat (CMY), as well as evaluate the in vitro degradation dynamics of neutral detergent fiber (NDF) of the diets. Five Holstein lactating primiparous cows, which had 99 ± 22 days of lactation, 480.4 ± 2.8 kg body weight and daily milk production of 20.14 ± 2.23 kg. The treatments were constituted from the addition of different lipid sources in diets: 1- Control (without added fat source) 2- ground soybean, 3- cottonseed; 4- soybean oil and 5- calcium salts (Megalac-E ®). No significant differences (P> 0.05) between treatments regarding to the passage of solids in the rumen neither in the stover nor concentrated fraction. Global mean estimate for the parameters of passage rate (γ) was 0.038 and 0.055 h-1 for forage (chromium) and concentrate (lanthanum), respectively. Despite numerical differences, the residence times in the rumen-reticulum (TMRR) did not differ between diets, showing an average value of 52.84 and 38.15 hours to forage and concentrate, respectively. The only significant effect with respect to the passage rate was a high negative correlation between the rate of passage of concentrate (γLA) and DMI. There was no difference for all other correlations tested. There were no significant differences of the potentially degradable NDF (pdNDF). The effective degraded fraction (FEDT) was not significantly different between treatments. There was less undegradable NDF (I) in treatments without added lipid and calcium salts (38.47 and 36.61%, respectively) compared to other treatments. Dietary supplementation with lipid sources on their own, inert, or partially protected, at about 5% of dry matter, does not alter the kinetic parameters of passage of particles of roughage and concentrate and the in vitro NDF degradation.