饲粮苏氨酸水平对北京雏鸭生长性能、胴体品质、免疫机能和血清激素的影响

本试验旨在研究饲粮苏氨酸水平对北京雏鸭生长性能、胴体品质、免疫机能和血清激素的影响。选取320只1日龄健康的北京鸭公鸭,随机分为5组,每组8个重复,每个重复8只。各组饲粮中苏氨酸水平实测值分别为0.65%(对照)、0.69%、0.81%、0.88%和0.98%,试验期为21 d。结果表明:1)饲粮苏氨酸水平对雏鸭平均日增重和平均日采食量有极显著影响(P0.01),对照组雏鸭平均日增重和平均日采食量显著低于其他各组(P0.05)。2)饲粮苏氨酸水平对雏鸭胸肌率有显著影响(P0.05),对照组雏鸭胸肌率显著低于0.69%、0.81%、0.88%水平组(P0.05)。3)饲粮苏氨酸水平对雏鸭法氏囊指数、脾脏指数、胸腺指数影响不显著(P0.05)。饲粮苏氨酸水平对雏鸭法氏囊重和胸腺重有极显著影响(P0.01),对照组雏鸭法氏囊重显著低于其他各组(P0.05),对照组雏鸭胸腺重显著低于0.81%、0.88%水平组(P0.05)。4)饲粮苏氨酸水平对雏鸭血清三碘甲腺原氨酸(T3)含量有显著影响(P0.05),0.81%水平组的血清T3含量最高,显著高于对照组和0.98%水平组(P0.05)。5)苏氨酸需要量分别与平均日采食量、平均日增重和胸肌率呈二次曲线关系,并当三者达到最高值时北京雏鸭的苏氨酸需要量分别为0.860%、0.852%和0.837%。由此可见,饲粮中添加适宜水平的苏氨酸可提高雏鸭生长性能、胴体品质和免疫机能。

Effects of Dietary Threonine Level on Growth Performance,Carcass Traits,Immune Function and Serum Hormone of Peking Ducklings

This experiment was conducted to investigate the effects of dietary threonine (Thr) level on growth performance, carcass traits, immune function and serum hormone of Peking ducklings.Three hundred and twenty 1-day-old healthy Peking ducks were randomly allocated to 5 groups with 8 replicates per group and 8 ducklings per replicate.The measured values of dietary Thr level in 5 groups were 0.65% (control), 0.69%, 0.81%, 0.88% and 0.98%, respectively.The experiment lasted for 21 days.The results showed as follows: 1) dietary Thr level had significant effects on average daily gain (ADG) and average daily feed intake (ADFI) of ducklings (P<0.01), the ADG and ADFI of ducklings in control group were significantly lower than those in other groups (P<0.05).2) Dietary Thr level had significant effect on breast meat rate of ducklings (P<0.05), the breast meat rate of ducklings in control group was significantly lower than that in 0.69%, 0.81% and 0.88% groups (P<0.05).3) Dietary Thr level had no significant effect on Bursa of Fabricius index, spleen index and thymus index of ducklings (P>0.05).Dietary Thr level had significant effects on Bursa of Fabricius weight and thymus weight of ducklings (P<0.01), the Bursa of Fabricius weight of ducklings in control group was significantly lower than that in other groups (P<0.05), and the thymus weight of ducklings in control group was significantly lower than that in 0.81% and 0.88% groups (P<0.05).4) Dietary Thr level had significant effect on serum triiodothyronine (T3) content of ducklings (P<0.05), the serum T3 content in 0.81% group was the highest and significantly higher than that in control group and 0.98% group (P<0.05).5) The Thr requirements showed the quadratic relationships with ADG, ADFI and breast meat rate, the Thr requirements of ducklings were 0.860%, 0.852% and 0.837%, respectively, when the ADG, ADFI and breast meat rate got the max values.The results suggest that dietary supplemented with suitable Thr level can improve the growth performance, carcass traits and immune function of Peking ducklings.