[Nutritional and metabolic evaluation of feeding lambs with growing levels Of protein amino acids]

ABSTRACT The objective was to evaluate the inclusion of protected lysine and methionine levels on the diet, over the nutritional parameters and energetic and hepatic metabolites of growing lambs. Five lambs ½ blood Dorper x Santa Inês, with approximately eight months of age and average weight of 50kg, were distributed in a 5x5 latin square scheme (five treatments and five replicates). The treatments consisted of the inclusion of different levels of lysine and methionine protected from ruminal degradation (MicroPEARLS LM®) in the diet, being: 0g, 8g, 16g, 24g and 32g. The diet was composed of corn silage and concentrated 30V:70C in the ratio. A digestibility assay was performed to determine dry matter intake and digestibility (DMI/DDMI), nitrogen balance and blood metabolites. The DMI (kg/day) in relation to the metabolic weight had a positive linear equation, being higher in treatment 32g, as well as the ingested nitrogen and nitrogen balance, being positive in all treatments. There was no difference (P>0.05) for the digestibility of DM, energetic and hepatic metabolism. Lysine and methionine protected from ruminal degradation can be included in the diet of growing lambs up to 32g without causing negative effects on DM digestibility and metabolism.

摘要 本研究旨在评估日粮中添加过瘤胃保护赖氨酸与蛋氨酸（lysine and methionine protected from ruminal degradation）水平对生长羔羊的营养参数、能量代谢及肝脏代谢产物的影响。试验选取5只1/2无角道塞特（Dorper）×圣塔因内斯（Santa Inês）混血羔羊，年龄约8月龄，平均体重50kg，采用5×5拉丁方试验设计（5个处理组，5个重复）。各处理组为在日粮中添加不同水平的过瘤胃保护赖氨酸与蛋氨酸（MicroPEARLS LM®），添加量分别为0g、8g、16g、24g和32g。试验日粮由玉米青贮与浓缩饲料按30V:70C的比例配制而成。本试验开展消化代谢试验，用以测定干物质采食量与消化率（DMI/DDMI）、氮平衡及血液代谢产物水平。以代谢体重计的干物质采食量（kg/d）呈正线性变化，32g添加组的采食量最高；摄入氮量与氮平衡亦呈现相同趋势，且所有处理组的氮平衡均为正值。干物质消化率、能量代谢与肝脏代谢相关指标均无组间显著差异（P>0.05）。过瘤胃保护赖氨酸与蛋氨酸可在生长羔羊日粮中添加至32g，且不会对干物质消化率及代谢产生负面影响。