环境温度和饲粮营养浓度对生长期母兔代谢能利用率的影响

THE EFFECT OF AMBIENT TEMPERATURE AND DIET TYPE OF METABOLIZABLE ENERGY UTILIZATION IN GROWING FEMALE RABBITS

选用6只9周龄新西兰母兔,评定环境温度和饲粮营养浓度对生长期母兔代谢能利用率的影响。试验在密闭式的小动物呼吸测热柜中进行。分别对处于环境温度为20±2℃和30±2℃,采食两种不同营养浓度的试兔进行测试。饲粮营养水平实测值,分别为12.22kJ ME/g和13.49kJ ME/g;粗蛋白质(CP)分别为17.3％和21.6％;中性洗涤纤维(NDF)分别为23.7％和16.5％。结果表明:环境温度影响试兔的能量平衡,它与采食量间存在着显著的相关。20±2℃时,相关系数r=0.798;30±2℃时,相关系数r=0.875。在本试验设计范围内,饲粮营养浓度并不影响代谢能食入量(ME_I),热增耗(HP)和能量平衡(EB)。当环境温度为20±2℃和30±2℃时,表观代谢能转化率(NE/ME)分别为51％和71％;每天每兔每千克代谢体重代谢能维持需要分别为396 kJ和361 kJ。试验结果认为:环境温度影响营养物质消化率(P<O.05)。饲粮营养浓度影响代谢能利用率(P<O.05)和有机物质消化率(P<0.05)。于物质消化率(P<0.01)、有机物质消化率(P<0.05)和中性洗涤纤维消化率(P<0.05),均显著地影响代谢能利用率。

Six New Zealand White growing female rabbits of nine week age were used to evaluate the effect of ambient temperature and diet type on metabolizable energy utilization. Calorimetric measurements were made on either high or low nutrient density diets at either 20±2℃ or 30± 2℃, The two experimental diets were formulated to contain either 12.22 KJ or 13.49KJ of metabolizable energy/g,17.3% or 21.6% crude protein, and 23.7% or 16.5% neutral detergent fiber. Energy balance was influ- enced by ambient temperature and related to energy intake(r=0.987, for 20±2℃; r=0.875, for 30+2℃), Metabolizable energy intake (MEI) , heat production (HP) and energy balance (EB) were not influenced by the diet nutrient density (P>0.05) .At 20±2℃ and 30±2℃, effeciency (NE /ME) of utilization of metabolizable energy was 0.51 and 0.71 respep ctively. Metabolizable energy for maintenance were 396 KJ/W^(0.75)/d an- 361 KJ/W^(0.75)/d, at 20±2℃ and 30±2℃,respectively. Energy utilizatiou was influenced by dry matter digestibility (P<0.01) , organic matter digestibility (P<0.05) and neutral detergent fiber digestibility(P<0.05) Ambitnt temperature influenced digestibility of nutrient matter(P<0.05). Diet type exerts influence over energy utilization and organic ma- tter digestibility (P<0.05).