营养限饲与补偿对蒙古羔羊结肠组织学结构的影响

Effect of Nutrient Restriction and Compensation on Colon Histological Structure of Mongolian Sheep Lambs

旨在研究限饲及不同方式补饲对蒙古羔羊公羔结肠组织学结构的影响。选用30只4月龄健康、体况中等的蒙古羔羊公羔,平均体重为(20.70±3.51)kg,随机平均分为对照组(CG)、限制组(RG),限制饲养60 d后补偿饲养60 d。试验动物均处于同一饲养环境下。限制期结束,从2组中随机选5只羔羊屠宰采样。补偿期将对照组(CG)、限制组(RG)剩余的试验动物分成羊草组(CH组和RH组)和秸秆组(CM组和RM组)2组,CH组、RH组饲喂精粗比为5∶5的青干草,CM组、RM组饲喂精粗比7∶3的秸秆,补偿饲养60 d后,全部屠宰,采集结肠3 cm左右,收集于甲醛磷酸缓冲液(40 g/L,pH值为7.4)固定,制作石蜡切片,进行H·E染色。在显微镜下测量结肠黏膜层、黏膜下层、内环肌层和外纵肌层的厚度(结肠浆膜层容易移位、脱落和损伤,会造成试验结果误差,该试验不对结肠浆膜层进行研究)。利用SPSS 21.0统计软件分析及处理数据。结果发现,该试验条件下,蒙古羔羊受到60 d营养限制后,结肠黏膜层厚度差异显著(P<0.05);黏膜下层、内环肌层、外纵肌层厚度差异不显著(P>0.05)。羊草组蒙古羔羊受到60 d营养补偿后,结肠黏膜层、黏膜下层、内环肌层、外纵肌层厚度差异不显著(P>0.05);秸秆组蒙古羔羊受到60 d营养补偿后,结肠黏膜下层厚度差异显著(P<0.05),结肠黏膜层、内环肌层、外纵肌层厚度差异不显著(P>0.05)。由以上结果可以得出:营养限制一段时间后,蒙古羔羊公羔结肠黏膜层厚度升高。

The aim of the present study was to investigate the effect of different restricted feeding and compensatory feeding programs on colon histological structure of ram lambs of Mongolian Sheep. A total of 30 4-month-old healthy ram lambs of Mongolian Sheep with moderate body condition and average weight of （20.70±3.51 ） kg were included and randomly and averagely divided to control group （CG） and feeding restriction group （RG）. The ram lambs received a compensatory feeding program for 60 days after they were restrictively fed for 60 days. All of the animals were reared in the same environment. At the end of the restricted feeding period, 5 ram lambs were selected from CG and RG and were slaughtered and sampled. During the compensatory feeding period, the remaining ram iambs from CG and RG were assigned to Leymus chinensis feeding group （CH and RH groups） and straw feeding group （CM and RM groups）. The CH and RH groups were fed green hay with concentrate to forage ratio of 5：5, and the CM and RM groups were fed straw with concentrate to forage ratio of 7：3. At the end of compensatory feeding period, all of the ram lambs were slaughtered. The colon tissue samples with a length of 3 cm were collected and were fixed in formaldehyde solution phosphate buffered （40 g/L, pH value=7.4）. The paraffin sections of the colon tissue samples were prepared and were stained routinely with hematoxylin and eosin. The thickness of mucosa layer, submucosa layer, internal circular muscle layer and outer longitudinal muscle layers of colon were measured by using microscopy. Due to the fact that the serous layer was prone to displace, exfoliate and injury, which produced errors in experiment, the thickness measurement of serous layer were not included in this study. The data were statistically analyzed by SPSS 21.0 software. The results showed that significant differences in thickness of colon mucosa layer between RG and CG were observed （P〈0.05）, no significant differences in thickness of submucosa layer, internal circular muscle layer and outer longitudinal muscle layers of colon between CG and RG were found （P〉0.05）. There were no significant differences in thickness of all layers of colon between RH and CH （P〉0.05）. Significant differences in thickness of colon submucosa layer between RM and CM were observed （P〈0.05）, no significant differences in thickness of mucosa layer, internal circular muscle layer and outer longitudinal muscle layers of colon between RM and CM were found （P〉0.05）. The combined data shows that the thickness of colon mucosa layer of ram lambs of Mongolian Sheep is increased after a period of nutrient restriction.