本文旨在探讨饲粮赖氨酸水平对生长獭兔生长性能、氮代谢及血清免疫和生化指标的影响。选用平均体重为(665±123) g的断奶獭兔200只,随机分成5组(每组40个重复,每个重复1只),分别饲喂赖氨酸水平为0.55%、0.70%、0.85%、1.00%和1.15%的试验饲粮。预试期7 d,正试期53 d。结果表明:饲粮赖氨酸水平对平均日采食量、平均日增重和料重比无显著影响(P>0.05)。饲粮赖氨酸水平显著或极显著影响食入氮(P=0.006 5)、氮沉积(P=0.045 9)和氮生物学效价(P=0.022 6),而对粪氮排出量、尿氮排出量、可消化氮、氮表观消化率和氮利用率无显著影响(P>0.05)。饲粮赖氨酸水平为1.00%和1.15%的组的食入氮极显著高于饲粮赖氨酸水平为0.55%和0.70%的组(P<0.01)。饲粮赖氨酸水平为0.70%、0.85%、1.00%和1.15%的组的氮沉积和氮生物学效价显著高于饲粮赖氨酸水平为0.55%的组(P<0.05)。饲粮赖氨酸水平极显著影响血清免疫球蛋白A(P<0.000 1)、免疫球蛋白G(P<0.000 1)和免疫球蛋白M含量(P<0.000 1)。饲粮赖氨酸水平为0.70%、0.85%、1.00%和1.15%的组的免疫球蛋白A、免疫球蛋白G和免疫球蛋白M含量均极显著低于饲粮赖氨酸水平为0.55%的组(P<0.01)。饲粮赖氨酸水平除显著影响血清胆固醇浓度(P=0.016 7)外,对血清总蛋白、球蛋白、尿素氮含量以及谷丙转氨酶活性均无显著影响(P>0.05)。综合考虑本试验所测指标,生长獭兔的饲粮适宜赖氨酸水平为0.55%~0.70%。

This experiment was conducted to study the effects of dietary lysine level on growth performance, nitrogen metabolism, serum immune and biochemical indices of growing Rex rabbits. Two hundred weanling Rex rabbits with an average body weight of (665±123) g were randomly assigned to 5 groups with 40 replicates in each group and each replicate contained 1 rabbit. Rabbits in the 5 groups were fed experimental diets containing 0.55%, 0.70%, 0.85%, 1.00% and 1.15% lysine, respectively. There was a pretrial period of 7 days followed by an experimental period of 53 days. The results showed as follows: dietary lysine level did not significantly affect average daily intake (ADI), average daily gain (ADG) and feed/gain (F/G) (P>0.05). Dietary lysine level had significant influence on nitrogen intake (P=0.006 5), nitrogen retention (P=0.045 9) and biological value of nitrogen (P=0.022 6), but had no significant influence on fecal nitrogen output, urine nitrogen output, digestible nitrogen, nitrogen apparent digestibility and nitrogen utilization rate (P>0.05). The nitrogen intake in the groups with the diets containing 1.00% and 1.15% lysine was significantly higher than that in the groups with the diets containing 0.55% and 0.70% lysine (P<0.01). Compared with the group with the diet containing 0.55% lysine, the nitrogen retention and biological value of nitrogen in the groups with the diets containing 0.70%, 0.85%, 1.00% and 1.15% lysine were significantly increased (P<0.05). The contents of immunoglobulin A (P<0.000 1), immunoglobulin G (P<0.000 1) and immunoglobulin M (P<0.000 1) in serum were significantly affected by dietary lysine level. The contents of immunoglobulin A, immunoglobulin G and immunoglobulin M in serum in the groups with the diets containing 0.70%, 0.85%, 1.00% and 1.15% lysine were significantly lower than those in the group with the diet containing 0.55% lysine (P<0.01). The dietary lysine level had significant influence on serum cholesterol content (P=0.016 7), but had no significant influence on contents of total protein, globulin and urea nitrogen, and alanine aminotransferase activity in serum (P>0.05). Considering all indices of this experiment, the appropriate lysine levels in the diet of growing Rex rabbits are 0.55% to 0.70%.