摘要
The purpose of this study was to evaluate intake, digestibility and efficiency of microbial protein synthesis of beef heifers fed with sugarcane silage with different calcium oxide (CaO) levels (0, 7.5; 15 g/kg), fresh sugarcane and corn silage. The same concentrate was offered at 5 g/kg bodyweight (BW) for every diet. Five ruminally and abomasally fistulated beef heifers (373.8 ± 33.12 kg BW) were used in a 5 × 5 Latin square design. Heifers fed sugarcane silage diets presented lower dry matter (DM) intake than those fed fresh sugarcane. Corn silage provides greatest DM intake compared with other roughages. CaO levels had a quadratic positive effect (P < 0.05) on DM and total digestible nutrients (TDN). For TDN intake (3.43 + 4.39 CaO – 2.56 CaO2) the maximum TDN intake of 5.31 kg/day was obtained at 8.6 g/kg CaO. The total apparent digestibility for neutral detergent fibre increased with CaO levels. An increase in nitrogen balance was observed with the inclusion of CaO in the sugarcane silage. Corn silages-based diets provide greater DM intake and digestibility and nitrogen balance compared with the diets based on sugarcane. Adding CaO to sugarcane as it is ensiled improves DM intake and TDN than diet sugarcane silage without CaO. However, the use of high levels of CaO (15 g/kg) in sugarcane at ensiling decreases the diet intake. Based on the maximum energy intake, the use of 8.6 g/kg CaO in sugarcane at ensiling is recommended.
摘要译文
本研究的目的是评估饲喂不同氧化钙（CaO）含量（0，7.5）的甘蔗青贮饲牛的小母牛的摄入，消化率和微生物蛋白质合成的效率。 15 g / kg），新鲜的甘蔗和玉米青贮饲料。每种饮食均以5 g / kg体重（BW）提供相同的浓缩物。在5×5拉丁方形设计中，使用了五个瘤胃和反胃瘘的牛小母牛（373.8±33.12千克体重）。饲喂甘蔗青贮饲料的小母牛的干物质摄入量低于饲喂新鲜甘蔗的母牛。与其他粗饲料相比，玉米青贮饲料可提供最大的干物质摄入。 CaO水平对DM和总可消化营养素（TDN）具有二次正效应（P <0.05）。对于TDN摄入量（3.43 + 4.39 CaO – 2.56 CaO2），当8.6 g / kg CaO时，最大TDN摄入量为5.31 kg /天。中性洗涤剂纤维的总表观消化率随CaO含量的增加而增加。在甘蔗青贮饲料中加入CaO可以观察到氮平衡的增加。与以甘蔗为基础的日粮相比，以玉米青贮为基础的日粮可提供更高的干物质摄入和消化率以及氮平衡。与未添加CaO的甘蔗青贮饲料相比，在青贮的甘蔗中添加CaO可以提高DM摄入量和TDN。然而，青贮时在甘蔗中使用高水平的CaO（15 g / kg）会减少饮食摄入。根据最大能量摄入，建议在青贮时在甘蔗中使用8.6 g / kg CaO。
K. A. K. de Moraes [A] [C];E. H. B. K. de Moraes [A];D. S. Pina [A];S. C. Valadares Filho [B]. Nutritional parameters of beef heifers fed diets with different roughages[J]. Animal Production Science, 2018,58(10): 1869-1875