Suplementação nitrogenada ruminal e/ou abomasal em bovinos alimentados com forragem tropical de alta qualidade

• Autor(a) principal: Batista, Erick Darlisson
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5726
• topic: Compostos nitrogenados; Suplementos; Consumo; Fibra em detergente neutro; Nitrogenous compounds; Supplements; Intake; Neutral detergent fiber; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL

The objective of this work was to evaluate the effects of supplementation with nitrogenous compounds in the rumen and, or in the abomasum on intake, digestibility, rumen dynamics of fibrous compounds and on the parameters of nitrogenous compounds metabolism in cattle fed tropical forage quality. Four Nellore young bulls, averaging 280±10 kg body weight (BW) and fitted with rumen and abomasum cannulas, were used. The following treatments were evaluated: control (only forage), ruminal nitrogenous compounds supplementation (daily supply of 224 g of crude protein in the rumen), abomasal nitrogenous compounds supplementation (daily supply of 224 g of crude protein in the abomasum), and ruminal and abomasal nitrogenous compounds supplementation (daily supply of 224 g of protein, being 112 g in the rumen and 112 g in the abomasum). The basal diet consisted of Tifton 85 (Cynodon spp.) hay, which presented average crude protein (CP) content of 98.6 g/kg of dry matter (DM). The experiment was implemented and analyzed according to a 4 4 Latin square design, balanced for residual effects, with four treatments, four animals and four experimental periods lasting 29 days each. The experimental periods consisted of three phases or sub-periods. At first one, it was evaluated the animal response in terms of intake without supplementation. In the second sub-period it was assessed the evolution of intake according to supplementation. In the third sub-period, it was supposed that animals were under a steady state with regard intake, digestibility and metabolism according to the treatments. From this assumption, it was evaluated the digestibility, the rumen dynamics of fibrous compounds, and the characteristic of the rumen and metabolism of nitrogenous compounds. There was no effect of the treatments (P>0.10) on voluntary intake of neutral detergent fiber (NDF) during the first two experimental sub-periods. During the third sub-period, there was no effects of treatments (P>0.10) on total DM, forage and NDF intake. However, the CP intake was increased by supplementation (P<0.10). Supplementation increased (P<0.10) the digestibility coefficients of DM, CP and content total digestible nutrients (TDN). The ruminal digestibility of DM and CP, although not globally affected by supplementation were reduced linearly with the displacement of supplemental rumen to the abomasum. Additionally, a positive linear effect (P<0.10) on the change of local to supplement the rumen to the abomasum was found on the intestinal digestibility of DM and CP. The mass and rumen passage and degradation rates of NDF were not affected by treatments. As observed for CP intake, apparent nitrogen balance was also enhanced (P<0.10), being an average 43% higher for treatments involving supplementation compared to control. The efficiency of utilization of absorbed nitrogen was not affected globally by supplementation (P>0.10), however a positive linear effect (P<0.10) was observed on this variable with the displacement of supplementation to the abomasum. The concentrations of ruminal ammonia nitrogen and urea nitrogen in serum were increased by the supplementation (P<0.10), also showing a linear effect (P<0.10), with the displacement of local supplementation of rumen to the abomasum. The nitrogenous compounds in the rumen was not affected by supplementation (P>0.10), being, however, observed a linear effect (P<0.10) with the change of supplemental rumen to the abomasum. The fractional excretion of urea nitrogen was increased by the provision of nitrogen supplementation (P<0.10). There was no effect of the treatments (P>0.10) on the urinary excretion of 3-methylhistidine and degradation of muscle protein. The intestinal flow of microbial N synthesis was not affected by supplementation (P>0.10), however a linear effect (P<0.10) was observed with the change of place of supplementation in the rumen to the abomasum. Supplementation with nitrogenous compounds in the rumen and/or the abomasum in cattle fed tropical forage quality allows to increase nitrogen retention in the animal organism similarly. However, the efficiency of nitrogen utilization is enhanced with the deployment of supplemental rumen to the abomasum.