The Differences Of Digestion And Metabolism Of Ewes During Nonpregnancy,Pregnancy And Lactation

The objective of this study was to evaluate the difference of digestibility,rumen fermentation and blood parameter during non pregnancy,pregnancy and lactation of ewes,and investigate the effects of digestibility in different physiological stages of ewes.Experiment 1: six pregnancy(pregnant for 80 days)and six nonpregnancy ewes(Body weight50±1.28 kg,3-4 years old)were randomly selected,Experimental periods continue 21 d,including 15 d of adaptation and 7 d of sampling.The results showed that the concentrations of progesterone and estradiol,the digestibility of P,Ca and ADL in pregnant were significantly higher than that in nonpregnancy ewes(P<0.01).The digestibility of DM,Ca,P,ADF and ADL were correlated with the concentrations of progesterone and estradiol in serum(P<0.05).Experiment 2: This study evaluated the effects of different doses of progesterone(1,3,8,11,23 ng/m L),estradiol(150,222 pg/m L)and their combination on in vitro fermentation.The results showed that the degradation rate decreased(P<0.05),the content of NH3-N and MCP decreased(P<0.01),and the ratio of propionic acid to acetic acid decreased(P<0.05),the ratio of propionic acid,isobutyric acid and isovaleric acid increased(P<0.01).The degradation rate increased with estradiol addition(P<0.05).There were significant interaction between progesterone and estradiol on degradation rate,NH3-N and MCP(P<0.05)..Experiment 3: 12 ewes(body weghit 53.28±5.9 kg,3-4 years old)were randomly selected.Experiment include five stages: non pregnancy,40 days of pregnancy,80 days of pregnancy,120 days of pregnancy and lactation.The adaptation period was 14 days,and 7 days of the sampling period.The results showed that the digestibility of DM,OM,CP,NDF,ADF and Ca in lactation was higher than that pregnancy and empty(P<0.05),and DMI in 120 days of pregnancy was higher than that 40 and 80 days of pregnancy(P<0.01).The digestibility of DM,OM,CP,ADF and Ca was the lowest in five periods(P<0.01)at 120 days of pregnancy,and the digestibility of DM and OM at 40 and 80 days of pregnancy was higher than empty(P<0.01).CP digestibility in pregnancy was higher than nonpregnancy(P<0.05).The digestibility of NDF in 80 days of pregnancy and nonpregnancy was higher than that in 40 days and 120 days of pregnancy(P<0.01).The ADF digestibility was significantly higher in the 80 days of pregnancy than in the nonpregnancy(P<0.05).EE digestibility was higher in lactation and 40 days of pregnancy(P<0.05).Lactation and pregnancy were higher than that in nonpregnancy(P<0.01).NH3-N and TVFA were the lowest at 120 days of pregnancy(P<0.05).The activity of β-glucosidase,xylanase and endoglucanase was the highest at 120 days of pregnancy(P<0.05).The activity of β-glucosidase and pectinase in pregnancy higher than that in nonpregnancy(P<0.05).In conclusion,the changes of ewe physiological will cause the changes of digestibility,rumen fermentation and blood hormone.and progesterone and estradiol affect rumen fermentation,which is the factors affecting digestibility.