Effects Of Sea Buckthorn Pomace On Growth Performance,Ruminal Fermentation And Digestive Metabolism Of Fattening Sheep

The objective of this study was to evaluate the effect of SBP on the growth performance,rumen fermentation,and digestion and metabolism of fattening sheep(0%,8%,16%,24%),in vitro gas production and nylon bag method were used to evaluate the nutritional value of diets with different levels of SBP.Then,40 Dupo × small tail Han sheep hybrid ram lambs were used to conduct feeding and digestion and metabolism experiments.The results showed as follows: 1)the addition of different levels of SBP can increase the gas production in vitro and decrease the pH of fermentation broth.The lowest pH in 24 SBP group(P<0.05).SBP increases the concentration of NH3-N and MCP.The content of acetic acid and total volatile fatty acid increased significantly(P<0.05),the highest values found in 16 SBP group.Additionally,the effective degradation part of DM(P<0.05)and NDF(P<0.01)increased significantly.2)The lambs fed 16 SBP and 24 SBP had higher average daily gain and dry matter intake than those fed control diet(P<0.05),the net meat weight of the 16 SBP and 24 SBP groups significantly higher than that of the control group(P<0.05).The final weight of 16 SBP group was significantly higher than that of control group(P<0.05).The GR value of 24 SBP group was significantly higher than that in the other three groups(P<0.05),the content of intramuscular fat in 16 SBP and 24 SBP group significantly higher than that in control group(P<0.05).The shear force in 8SBP and 16 SBP group was also significantly higher than that in control group(P<0.05).Additionally,the pH of abomasum juice and duodenum decreased with the addition of SBP(P<0.05),however,there was no significant difference in pH in other digestive tract stages among treatments.3)The contribution of nutrient oxidation to heat production was not affected by the treatments(P>0.05).The DM and CP intake increased significantly(P<0.05)with the increase of SBP,while the digestibility of NDF and ADF significantly decreased with the increase of SBP in diets.With the increase of SBP content in diet,the intake of GE increased significantly(P<0.001),and the amount of energy loss in feces also increased significantly(P<0.01).The loss of urine energy showed a declined trend(P<0.1),and the loss of methane in 8SBP and 16 SBP group was the lowest(P<0.05).No significant difference was observed in MEI among treatment groups,with average value of 1125.4 k J/kg BW0.75.The loss of fecal nitrogen significantly increased(P<0.001)with the increase of dietary SBP inclusion,and the deposition amount of 16 SBP group was largest.Therefore,the addition of 16% SBP in the diet can increase the energy deposition in fattening sheep.In conclusion,the addition of SBP to the diet can improve the fermentation in vitro and increase the degradation rate of nutrients.Feeding experiment showed SBP can improve the average daily weight gain,feed intake,and net meat yield of fattening sheep,and increase the content of intramuscular fat.Energy deposition of fattening sheep increased when lambs were fed a ration containing 16% SBP.Therefore,SBP can be used as a new feed resource for fattening lambs,and the optimal proportion was 16.0% under the condition of this study.