摘要
【目的】研究营养限饲及补偿对羔羊小肠黏膜结构生长发育的影响。【方法】选用80只平均体重为(14.72±1.10)kg的3月龄乌珠穆沁羔羊,按照体重相近原则分为4个试验组,即对照组(CG)、限制Ⅰ组(RG1)、限制Ⅱ组(RG2)和限制Ⅲ组(RG3)。营养限制期(0—60 d)4组对应日粮能氮水平分别为ME:10.61、10.49、8.36和8.10 MJ.kg-1;CP:150.8、92.4、150.1和62.7 g.kg-1。营养补偿期(60—150 d)各组饲喂同一能氮水平日粮(ME:9.77 MJ.kg-1;CP:124.8 g.kg-1)。试验期间每周称重并在限制期开始、限制期结束和补偿期结束,分别从各组选取4只与组内平均体重相近的羔羊,屠宰后迅速取其十二指肠、空肠和回肠中段,用多聚甲醛磷酸缓冲液固定。经H.E染色后,光镜下观察小肠黏膜的形态结构。【结果】营养限制结束,RG1、RG2组羔羊平均体重显著低于CG组(P<0.05),RG3组羔羊体重极显著低于CG组(P<0.01);在补偿期后60 d,RG3组平均日增重显著高于CG组(P<0.05),表现出较高的生长速率。不同能氮营养水平限制饲养后对小肠结构发育有影响,限制能量(RG2)比限制蛋白(RG1)表现出更高的补偿效应。【结论】乌珠穆沁羔羊受不同能氮营养水平限饲后,羔羊体重和小肠黏膜发育均表现出补偿生长效应,而且低能高氮限饲羔羊比高能低氮限饲羔羊表现出更强的补偿效应,限饲蛋白对小肠黏膜发育影响更大。当以ME(8.36 MJ.kg-1)和CP(150.1 g.kg-1)限饲60 d并经过90 d的营养恢复后,羔羊小肠黏膜发育实现了完全补偿,小肠吸收功能增强,生长速率加快。
[Objective] The effects of undernutrition （0-60 d） and compensation （60-150 d） on live weight （BW） and development of small intestinal mucosa in lambs were investigated. [ Method ] Eighty Wu Zhu Mu Qin lambs at average live weight （14.72 ± 1.10） kg, were divided into control group （CG）, restricted group 1 （RG1）, restricted group 2 （RG2） and restricted group 3 （RG3）. Dietary nutrition level were （ME： 10.61 MJ-kgq, CP： 150.8 g·kg-1）, （ME： 10.49 MJ.kgq, CP： 92.4 g·kg-1）, （ME： 8.36 MJ·kg-1, CP： 150.1 g·kg-1） and （ME： 8.10 MJ·kg-1, CP： 62.7 g·kg-1） during undernutrition period for CG, RG1, RG2 and RG3, respectively. However, in nutritional compensation phase all groups were offered the same levels diet （ME： 9.77 MJ·kg-1, CP： 124.8 g·kg-1）. Weight of lambs was measured every week. Four lambs of each group were slaughtered at 0 d （at the beginning of undernutrition period）, 60 d （at the end of undernutrition period） and 150 d （the end of nutrition compensation period）. The samples of duodenum, jejunum and mid-ileum were taken and fixed by using paxaformaldehyde phosphate buffer. ARer HE staining, morphological structure of intestinal mucosa were observed under light microscope. [Result] The results showed that at the end of nutrition restriction period, the average live weight of RG1, RG2 （P〈0.05） and RG3 （P〈0.01） was significantly lower than that of CG. However, during the nutrition compensation period, the growth rate of RG3 was significantly higher than that of CG （P〈0.05）. Development and growth of the small intestine mucosa were affected by nutrition level of diets. The energy restricted group （RG2） showed better compensatory potency than that of the protein restricted group （RG1）. [ Conclusion ] The results indicated that after restriction by different levels of energy and protein all lambs showed compensatory effect in live weight and small intestinal mucosa growth. The development of small intestine mucosa was more prone to be influenced by dietary protefn content other than energy concentration. After 60 d restriction by the nutrition level of ME： 8.36 MJ·kg-1, CP： 150.1 g·kg-1, the development of small intestinal mucosa of RG2 reached complete compensation at the end of nutrition compensation period, and nutrients absorption and growth rate also increased correspondingly.
出处
《中国农业科学》
CAS
CSCD
北大核心
2011年第17期3613-3621,共9页
Scientia Agricultura Sinica
基金
国家自然科学基金项目(30860194)
关键词
营养限制
营养补偿
羔羊
小肠
黏膜结构
体重
undernutrition
compensation
lamb
small intestine
mucosal structure
body weight
