Effects Of Different Concentrate To Forage Ratio, Adding Different Levels Of Nicotinamide To Forage-type Diet On Rumen Microbial Metabolism Of Sheep

In vivo, coenzyme I (Nicotinamide adenine dinucleotide, NAD(H)) and coenzyme II (Nicotinamide adenine dinucleotide phosphate, NAD(P)H) are the coenzyme of many enzymes and they participate in all intracellular respiratory mechanism, Involves many metabolic pathway, closely related to the substance metabolism and energy metabolism of living organisms. research reports about the dynamic variation of NAD(P)H/NAD(P) of sheep rumen microorganisms ratio before and after the feeding, relationship sheep between NAD(P)H/NAD(P) ratio of sheep rumen and main intermediate metabolite content of microorganisms, microbial synthesis and rumen fermentation parameters are very rare. This papers selected Chinese Merino (Xinjiang type) as experimental animals, sheep rumen microbial system as object of study, effects of different concentrate to forage ratio, adding different levels of nicotinamide to forage-type diet on rumen microbial metabolism of sheep were studied. The main research results are as follows:Experiment I Six healthy Chinese merino sheep (Xinjiang Type, ram),1.5-years old, with the average body weight of35±1.48kg, were selected and were divided into4periods according to self-control experimental design. The scale of feeding concentrate (the forage was fed ad libitum) was400,520,640and760g.d-1.sheep-1in four test periods, respectively. The results showed that, the amount of rumen fluid Microbial Crude Protein(MCP)synthetic inclined to increase with the increase of the concentrate proportion of forage ratio on the diet of sheep. sheep "non-structural carbohydrate intake" and reducing sugar concentration of each time point exponential fitting curve equation is(correlation coefficient r=0.9965): y=0.142e0.4927x, it present linear relationship between reducing sugar concentration and the amount of rumen fluid MCP synthetic, exponential fitting curve equation is(correlation coefficient r=0.9959):y=1.0416x+1.7207. there was strong correlativity between ratio of reducing sugar concentration of NH3-N concentration and the amount of rumen fluid MCP synthetic, linear fitting curve equation is(correlation coefficient r=0.9985):y=0.9922x+1.5575. the content of the NAD(P) and NAD(P)H of rumen microorganism decreased with the increasing concentrate proportion of the forage ratio on the sheep feed.Experiment II This experiment divided into4period, control period was added0mg.d-1.sheep-1nicotinamide and the test period was added100mg,150mg,200mg nicotinamide/kg.DM.d.sheep respectively. The results showed logarithmic function relationship between the amount of rumen microbial NAD(P) and intake of nicotinamide, fitting curve equation is(correlation coefficient r=0.9894):y=2.0422Ln(x)+3.6274. The NADH/NAD ratio of ruminal microorganisms decreased with adding of nicotinamide in diet. When fed was the forage-diet, the adequate requirement for nicotinamide of growing sheep was100-150mg nicotinamide/kg.DM.In this study two mathematic models are established between concentration of NAD(P) in rumen microorganisms and reducing sugar in rumen fluid, concentration of reducing sugar in rumen fluid and intake of non-structure carbohydrate. rumen protozoa with a high ratio of NAD(P)H/NAD(P), Bacteria is shown as a high ratio of NAD(P)/NAD(P)H, adding different levels of nicotinamide to forage-type diet to improve the amount of in the rumen bacteria, rumen protozoa cells NAD(P), to improve rumen microbial metabolic activity.