本试验旨在研究断奶日龄对肉兔肠道发育的影响。试验选择初生肉兔120窝,随机分成4组,每组30窝,分别在出生后21、25、28和35日龄断奶,试验期56 d。结果表明:1)断奶日龄对肉兔28和35日龄胃、小肠和盲肠重有显著或极显著影响(P<0.05或P<0.01),随着断奶日龄延后呈增加趋势,断奶日龄对49和56日龄各消化器官重和各日龄小肠长度无显著影响(P>0.05);2)断奶日龄对十二指肠(28、35和49日龄)、空肠(28、35、42和49日龄)和回肠绒毛高度(28、35、42和49日龄)有显著或极显著影响(P<0.05或P<0.01),随着断奶日龄延后呈先增加后降低趋势,而对56日龄各肠段绒毛高度无显著影响(P>0.05),肉兔断奶后绒毛高度需要2~3周才能恢复,21日龄断奶组恢复最慢,35日龄断奶组恢复最快;3)断奶日龄对十二指肠(28和35日龄)、空肠(28、35和42日龄)和回肠隐窝深度(35日龄)有显著影响(P<0.05),随着断奶日龄延后呈降低趋势,而对49和56日龄各肠段隐窝深度无显著影响(P>0.05);4)断奶日龄对28和35日龄十二指肠、空肠和回肠绒毛高度/隐窝深度有极显著影响(P<0.01),随着断奶日龄延后呈增加趋势,而对56日龄各肠段空肠绒毛高度/隐窝深度无显著影响(P>0.05)。由此可见,断奶日龄对肉兔肠道49日龄前发育影响较大,对49日龄后影响变小;早期断奶降低了小肠黏膜绒毛高度,增加了隐窝深度;随断奶日龄延后,断奶造成的肉兔小肠黏膜受损程度减轻,断奶后一般需要2~3周才能恢复小肠黏膜结构。

This experiment was conducted to evaluate the effects of weaner days of age on intestinal development of meat rabbits. A total of 120 nests of new born meat rabbits borned were selected and randomly divided into four groups with 30 nests per group. The meat rabbits of four groups were weaned by the age of 21, 25, 28 and 35 days, respectively. The experiment lasted 56 days. The results showed as follows: 1) weaner days of age had significant effects on the weight of stomach, small intestine and caecum of rabbits by the age of 28 and 35 days (P<0.05), which tended to be increased by delayed weaner days of age, however, the weight of digestive organs and the length of small intestine of rabbits by the age of 49 and 56 days were not significantly affected (P>0.05). 2) Weaner days of age had significant effect on the height of villus of duodenum (28, 35 and 49 days of age), jejunum (28, 35, 42 and 49 days of age) and ileum (28, 35, 42 and 49 days of age) (P<0.05 or P<0.01), which tended to be firstly increased and then decreased by delayed weaner days of age, however, weaner days of age had no significant effect on the height of villus of duodenum, jejunum and ileum by the age of 56 days (P>0.05); the height of villus took 2 to 3 weeks to recover after weaned, the group weaned by the age of 21 days recovered slowest, and the group weaned by the age of 35 days recovered fastest. 3) Weaner days of age had significant effect on the depth of crypt of duodenum (28 and 35 days of age), jejunum (28, 35 and 42 days of age) and ileum (35 days of age) (P<0.05), which tended to be decreased by delayed weaner days of age, however, weaner days of age had no significant effect on the the depth of crypt of small inrestine of rabbits by the age of 49 and 56 days (P>0.05). 4) Weaner days of age had significant effect on villus height/crypt depth (V/C) of duodenum, jejunum and ileum of rabbits by the age of 28, 35 days (P<0.01), which tended to be increased by delayed weaner days of age, however, weaner days of age had no significant effect on V/C of small intestine of rabbits by the age of 56 days (P>0.05). It is concluded that weaner days of age can affect the intestinal development of rabbits before 49 days of age, but has little influence on that of rabbits after 49 days of age; early weaning can reduce the height of intestinal mucosal villus, but increase the depth of crypt; of earlier-weaned group; the damage on mucosa of small intestinal of rabbits can be alleviated by the delayed weaner days of age, and it generally require 2 to 3 weeks for rabbit to restore the structure of mucosa of small intestine.