摘要
本试验旨在研究日粮粗蛋白质水平对生长期(断奶至3月龄)实验兔生长和免疫功能的影响。选用平均初始体重为(950±90)g的40日龄断奶实验兔60只,随机分为5组(每组12个重复,每个重复1只),分别饲喂粗蛋白质水平为12%(Ⅰ组)、14%(Ⅱ组)、16%(Ⅲ组)、18%(Ⅳ组)和20%(Ⅴ组)的等消化能(10.0 MJ/kg)等粗纤维(12%)日粮,进行6周饲养试验,并测定动物生长性能、免疫学指标和相关血液指标。结果表明:幼兔日增重(y)与粗蛋白质水平(x)间存在二次回归关系(y=-0.233x2+7.637x-40.335,r=0.79,P<0.01),日粮粗蛋白质水平为16.4%时,动物日增重最大。血清胰岛素样生长因子-Ⅰ含量以Ⅲ组和Ⅳ组较高,与Ⅰ组差异显著(P<0.05)。各组实验兔的自然杀伤细胞活力、脾脏指数和胸腺指数均以Ⅴ组最高,且Ⅴ组在以上3项指标上分别相应地与Ⅰ组、Ⅰ组和Ⅱ组差异显著(P<0.05)。脂多糖刺激指数以Ⅳ组较高,且与Ⅰ组差异显著(P<0.05)。Ⅲ组刀豆素蛋白刺激指数显著或极显著高于Ⅰ组和Ⅱ组(P<0.05或P<0.01)。日粮粗蛋白质水平对免疫球蛋白含量无显著影响(P>0.05),而Ⅳ组的白介素-1β的浓度显著高于Ⅰ组(P<0.05)。血清一氧化氮含量和超氧化物歧化酶活性以Ⅲ组和Ⅳ组为高,与Ⅰ组差异显著或极显著(P<0.05或P<0.01);而丙二醛含量则与超氧化物歧化酶活性的变化规律相反。由此可知,日粮粗蛋白质水平在16.4%时可满足生长期实验兔最大生长需要,该水平略低于实验兔维持最佳免疫状态对日粮粗蛋白质的需要。
The experiment was conducted to study the effects of dietary crude protein levels on growth performance and immune function in growing （weanling to 3 months old） laboratory rabbits. Sixty weanling （40-day-old） laboratory rabbits with an average initial body weight of （950 ± 90） g were randomly divided into 5 groups （with 12 replicates each and 1 rabbit in each replicate） and fed the diets with crude protein levels at 12% （group Ⅰ ）, 14% （group Ⅱ ）, 16% （group Ⅲ ）, 18% （group Ⅳ） and 20% （group Ⅴ ）, respectively. Five diets had similar content of digestible energy （10.0 MJ/kg） and crude fibre （12%）. The feeding trial lasted for 42 days, and the growth performance was measured during feeding trial and the blood indices and immunological parameters were determined when the trial was finished. The results showed as follows： the relationship between average dairy gain （y） and crude protein levels （x） may be expressed as y =- 0. 233x^2 ＋ 7. 637x - 40. 335 （r = 0.79, P〈0.01）, from which the optimal average diary gain could be estimated to be at 16.4% crude protein level The serum IGF- Ⅰconcentration in groups Ⅲ and Ⅳ was higher than that in group Ⅰ （P〈0.05）. The natural killer （NK） cell activity, spleen index and thymus index in group Ⅴ were the highest, and the above 3 indices （NK cell activity, spleen and thymus indices） in group Ⅴ were significantly higher than those in groups Ⅰ , Ⅰ and Ⅱ（P〈0.05）, correspondingly. The stimulation index （SI） by lipopolysaccharide （LPS） in group V was higher than that in group Ⅰ （P〈0.05）, and the SI by concanavalin A （ConA） in group m was higher than that in groups Ⅰ and Ⅱ （P〈0.05 or P〈0.01）. Dietary crude protein levels had no significant influence on the content of immune globulin, but the concentration of IL-1β in group IV was significantly higher than that in group Ⅰ （P〈0.05）. The activity of superoxide dismutase （SOD） and concentration of nitric oxide （NO） in groups Ⅲ and Ⅳ were significantly higher than those in group Ⅰ（P〈0.05 or P〈0.01）. However, the change of maleic dialdehyde （MDA） concentration was contrary to that of SOD activity. The results indicated that 16.4% of dietary crude protein level was optimal to maintain the highest growth performance of growing laboratory rabbit, and slightly higher protein level was required to satisfy the need of immune response.
出处
《动物营养学报》
CAS
CSCD
北大核心
2010年第1期75-81,共7页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
浙江省卫生厅资助项目(2006A094)
浙江省科技厅资助项目(2008F80003)
关键词
实验兔
粗蛋白质
生长性能
免疫功能
Laboratory rabbits
Crude protein
Growth performance
Immune function
