Effects Of Different Diet Concentrate:Forage Ratio On Growth Of Forestomach Epithelium In Goats

The study contains two main parts.1、The effects of different concentrate/forage ratio on the growth of rumen2、The effects of different concentrate/forage ratio on the morphology of omasum epithelium.1The effects of different diet concentrate/forage ratio on the growth of ruminal epithelium in goats9young goats were divided randomly into3groups (n=3), high concentrate/forage (60:40, H), middle concentrate/forage ratio(35:65, M), and low concentrate/forage (10:90, L). The goats were slaughtered for taking sample from rumen and omasum after21d. The VFA concentration were measured by GC. The cell cycle was analyzed by flow cytometry. The mRNA expression of cyclin D1and CDK4was measured by RT PCR. The forestomach epithelium morphology were observed by histological slices. The MDH enzyme activity was measured by biochemstry analylsis.1) The pH for H and M was significantly lower than the L, The total VFA and concentration of butyrate of rumen fluid in the H and M were significantly higher than those in L group (P<0.05). It was found the percentage of cell number in Go/Gi-phase for H was significantly lower than L(P<0.05), while the percentage of cell number of S-phase (the phase of DNA synthesis) and the G2/M-phase (the phase of cell mitosis) of the H was significantly higher than L. It demonstrated high concentarte/forage (60:40) diet accelerated progression of the cell cycle; high concentrate/forage group increased cyclin Dl mRNA expression which was significantly higher than that of L (P<0.05), it also provided evidence that high concentrate/forage diet accelerated cell cycle progression2) The sloughing of SC of rumen epithelium papilla for H was significantly higher than the L (P<0.05); and the thickness and cell layers were significantly less than the L (P<0.05); additionally the number of SB in H was significantly higher than L, it demontrated that high concentrate/forage diet (60:40) pomoted SB division and lead to cell number increase. All the above showed the high concentrate/forage (60:40) not only enhanced SB proliferation, but also accelerated cell death of SC. MDH enzyme activity showed the high concentrate/forage ratio diet enhance rumen epithelium energy metabolism.3)It was found that in M, the length and surface area of rumen epithelium papilla were significantly higher than that of H (P<0.05) from mesurement. It indicated that middle concentrate/forage ratio(35:65) increase the obsorption area for rumen epithelium2The effects of different diet concentrate/forage ratio on the growth of omasum epitheliumThe feeding method was the same to first Part Experiment One. Results showed that the amount of corneous layer in the L was significantly higher than that of the H group(P<0.05), and the amount of SG and SS layer, cell number in average unit were significantly higher than that of the H (P<0.05), that is opposite to the rumen results; however, the amounts of cells in SB in the H were higher than the L. The above results demonstrated low concentrate/forage ratio(10:90) diet was benefit to increase cell number of SG+SS.However, there existed no significance for G0/G1and S+G2/M percentage among three groups by flow cytometry(P>0.05).It need our further research for the effects of different diet concentrate/forage ratio on the growth of omasal epithelium.