摘要
This study was carried out aiming to evaluate the effects of yeast or monensin supplementation on dry matter intake, nutrients digestibility, ruminal volatile fatty acids profile, ruminal pH and ammonia concentration, microbial protein synthesis, and the balance of nitrogen compounds of cattle fed high concentrate diet (80 % dry matter (DM) basis) with two different levels of starch. Eight crossbred beef steers fitted with rumen cannula were assigned to two simultaneous 4 × 4 Latin squares arranged in a 4 × 2 factorial design. Two different starch levels (23 and 38 % of DM) were assigned to each Latin square, independently. Within each Latin square, four treatments were randomly assigned to the experimental animals (control; monensin; 1-g yeast [1 g/100 kg body weight (BW)/day] treatment; and 2.5-g yeast [2.5 g/100 kg BW/day] treatment). Feed additives did not influence ruminal pH (P > 0.05). Total ruminal volatile fatty acids (VFA) concentration was greater (P < 0.05) in the diet with the lowest starch level. Similarly, monensin and 1-g yeast treatments resulted in greater (P < 0.05) VFA concentration in the rumen. Monensin inclusion in the diet with the highest starch level led to a decrease (P < 0.05) in lactate concentration in the rumen. However, acetate levels were increased (P < 0.05) by the inclusion of 1 g of yeast in the diet with lowest starch level. Ruminal concentrations of propionate and butyrate, and ammonia-N were not influenced (P > 0.05) by none of the additives evaluated. However, propionate concentration was greater (P < 0.05) in the low-starch diets. Low-starch diets resulted in lower ruminal ammonia-N concentration and greater neutral detergent fiber digestibility (P < 0.05). The excretion of urinary nitrogenous compounds, purine derivatives, synthesis of microbial protein, microbial efficiency, and balance of nitrogenous compounds were not affected by treatments evaluated (P > 0.05). Monensin or yeast inclusion in high concentrate beef cattle diets in tropical regions as in Brazil is not justified by do not alter nutrient digestibility, nitrogen balance, and main ruminal parameters.
摘要译文
本研究进行了旨在评估酵母或莫能菌素补充的干物质摄取，营养素消化率，瘤胃挥发性脂肪酸概况的作用，瘤胃pH值和氨氮浓度，微生物蛋白的合成，和牛饲喂高浓缩物日粮（80％的干物质（DM）的基础上）的两个不同水平的淀粉的氮化合物的平衡。装有瘤胃套管八杂交肉牛的牛肉被分配到两个同步4两种不同的淀粉含量（DM的23和38％）被分配给每个拉丁方，独立。在每个拉丁方，四种处理被随机分配到实验动物（对照;莫能菌素; 1-克酵母[1克/ 100 kg体重（BW）/日]处理;和2.5克酵母[2.5克/ 100千克体重/天]治疗）。饲料添加剂不影响瘤胃pH值（P05）在饮食与最低的淀粉水平。同样，莫能菌素和1-克酵母治疗导致更高（P莫能菌素列入饮食导致减少的最高水平淀粉（P05）在没有评估的添加剂。然而，丙酸浓度高于（P低淀粉饮食导致更低的瘤胃氨氮浓度和更大的中性洗涤纤维的消化率（P嘌呤衍生物，合成微生物蛋白，微生物效率和含氮化合物的平衡并没有受到评估治疗（P莫能菌素或酵母列入高精肉牛日粮在热带地区如巴西没有被合理不改变养分消化率，氮平衡，及主要参数瘤胃。
João Paulo Ismério dos Santos Monnerat [1] [1] Pedro Veiga Rodrigues Paulino [1] Edenio Detmann [1] Sebastião Campos Valadares Filho [1] Rilene Diniz Ferreira Valadares [1] Márcio Souza Duarte [1]. Effects of Saccharomyces cerevisiae and monensin on digestion, ruminal parameters, and balance of nitrogenous compounds of beef cattle fed diets with different starch concentrations[J]. Tropical Animal Health and Production, 2013,45(5): 1251-1257