Anatomical development and microbial flora changes of cecum in confined lamb at the age of 0～56days

The experiment was conducted to study the development characteristics and changes of microbial flora of cecum in confined lambs at the age of 0~56 d.Forty-five male Gansu modern sheep were killed and sampled at 0,7,14,21,28,35,42,49,56 days of age,the relative weights of cecum(weight of alimentary tract,weight of intestinal tract,weight of large intestine),the relative cubage(the cubage of alimentary tract,the cubage of intestinal tract,the cubage of large intestine),the relative length(the length of intestinal tract,the length of large intestine),the pH in contents of caecum and cecal mucosa,the quantity of lactobacillus and Escherichia coli were determined.The results showed that the increasing trend of the relative weights of cecum(weight of alimentary tract,weight of intestinal tract,weight of large intestine) and the relative cubage of cecum(the cubage of intestinal tract,the cubage of large intestine) was in accord with the declined trend.With the age increasing,they showed the change of 'decline-increase-deline'.At the age of 0~56 d,the pH in the contents of caecum and the cecal mucosa showed weakly acidic respectively 5.77~7.06 and 6.03~7.22.The pH in the contents of caecum was higher than the pH in the cecal mucosa.With the pH increasing,the quantity of Escherichia coli was declined in the contents of unit mass,but the quantity of Lactobacillus was increased.The Escherichia coli and Lactobacillus was existed at 0 d of the lamb,and the quantity of them was the highest in the contents of unit mass.The pH in the contents of caecum stabilized after 21 d.With the age increasing,the quantity of Escherichia coli and lactobacillus was declined in the contents of unit mass.the quantity of Escherichia coli stabilized after 28,the Lactobacillus stabilized after 35 d.The quantity of Escherichia coli was higher than the quantity of Lactobacillus during the experiment.Under stall-feeding after supplementary-feeding 7 d,Weaning at 28 d or 35 d of the lamb have no serious effects on the development morphology andpH of cecums,the quantity of Escherichia coli and Lactobacillus in the contents of unit mass.