日粮蛋白质水平对梅花鹿瘤胃内pH值、NH_3-N和VFA浓度的影响

THE EFFECT OF DIETARY PROTEIN LEVELS ON THE pH VALUES,NH_3-N AND VFA CONCENTRATIONS IN THE SIKA DEER'S RUMEN

选用4头装置永久性瘤胃瘘管的成年梅花鹿,用4种含有不同蛋白质水平的日粮,按4×4拉丁方试验设计,对瘤胃内pH值、氨态氮(NH_3—N)和总挥发性脂肪酸(TVFA)浓度进行了测定,并研究了它们的动态变化规律以及VFA组分百分率。试验结果表明,在饲根精粗比为30:70条件下,日粮蛋白质水平对瘤胃内pH值影响较小(P>0.05);对NH_3—N浓度影响较大(P<0.05),随着日粮蛋白质水平的提高,瘤胃内NH_3—N浓度也随之升高;对TVFA浓度也有一定的影响,但各日粮间差异不显著(P>0.05)。通过VFA的组分分析发现,各日粮组间C_2/C_3比值基本接近,即它们的发酵类型基本相同。

According to 4×4 latin square experiment design, four ahult sika deer installed rumen fistula were fed with four supplement feed of different protein levels which were 10.02%, 14. 07% , 18.13% and 22.18% , respectively . VFA concenuations , pH values and NH3-N concentrations in the rumen were determined. The dynamic variations of the three metabolic parameters were measured. The main experimental results were as follows:①pH values of rumen were not significantly influenced by dietary protein levels (P> 0.05). pH values of rumen of the deers fed the four diets varied within the normal physiological range of 6.45~6.48. ②The dietary protein levels had a marked effect on NH3-N concentrations of rumen fluids (P < 0. 05), which increased with dietary protein levels rosely. NH3-N concentrations of rumen fluids of the deers in different experimental groups were 6. 65,10. 26,12. 51 and 15.04mg / 100ml, respectively. The crude protein intake(CPI) of the deer had a posi-tive linear correlation with NH3-N concentration of rumen fluids:NH3-N(mg / 100ml) = 0.059CPI(g) -4.41(r = 0.86,n = 16).③TVFA concentrations of rumen fluids of the deers in different experimental groups were 64. 59, 81. 89, 86. 48 and 95. 78mM / L, respectively. However, there were no significant differences in TVFA concentrations of the rumen fluids between different experimental groups(P>0.05).④The dynamic NH3-N variation of individual deers indicated that NH3-N was higher at 1 hour after eating than before eating (at 8:00 a.m.), then gradually decceased.⑤The results of VFA analyses indicated that the proportions of VFA in the rumen varied regularly in all experimental groups. The ratio of C2 to C3 were above 4.18 in different experimental groups. The patterns of fermentation were similar.