牛,羊矿物质复合舔块的使用效果研究

通过动物饲养试验、消化代谢试验等对作者研制的牛、羊复合矿物质舔块进行了应用效果研究．饲养对比试验结果表明，补喂舔块能提高黄牛日增重８２％（Ｐ＜０．０５），提高山羊日增重３０％（Ｐ＜０．０５），促生产效果十分明显。消化代谢试验结果表明，补喂舔块使干草和稻草的干物质、有机物消化率分别提高１２．０％～１３．１％、１０．４％～１２．７％；稻草消化率提高到氨化稻草同样水平．用尼龙袋法测定结果表明，加喂舔块可提高干草、稻草和氨化稻草的干物质瘤胃降解度，加速稻草干物质的降解速率．舔块还能加快稻草、干草纤维的瘤胃消化速率，缩短干草纤维消化时间，增加内容物通过瘤胃速度．综合结果，使稻草和干草纤维的瘤胃内有效消化量得到改善。

Effects of Mineral-urea Lick Blocks on Nutrient Digestibility,Nitrogen Utilization of Low Quality Roughages and Liveweight of Local Ruminants

A minerals-urea lick block (MLB) was manufactured as feed supplement to improve nutrient digestibility, nitrogen (N) utilization of low quality roughages and growth rates of local ruminants. Two feeding trials (Trials 1 and 2), one with local yellow cattle and one with local goats, were conducted to compare the performance of animals grazed on natural unimproved hill pasture with or without MLB. Cattle with access to blocks had daily gain of 370g/d and were significantly better than the controls at 203 g/d. The liveweight gain of goatswith access to blocks was also significantly higher (P<0.05) than those without blocks (95vs 73 g/d. In trial 3, three yearling lambs equipped with rumen cannula were used to study effects of-supplementation with MLB on the kinetics of ruminal fibre digestion, nutrient digestibility and N utilization of rice straw (RS), ammonia bicarbonate-treated RS (ABRS) and hay prepared from natural pasture. The digestibility of dry matter and organic matter of RS was increased by 13. 1 and 12. 7% (P<0.05) and approached to that of ABRS. Nitrogen retention was highest in lambs on ABRS alone, followed by hay with MLB, and was lowest in animals on RS with MLB. Block did not greatly influence the rumen degradation of dry matter in any of the all three diets, The RS and hay had similar values for the potential extent and rate of fibrous materials digestion. Neither the potential extent or rate of fibre digestion for RS and ABRS was influenced by the MLB feeding, but the kd for hay was increased significantly. It is inferred that minerals and urea lick blocks can be used to improve the productive performance of local ruminants offered low quality roughages.