Effect Of Whole-Plant Corn Silage Diet On Nutrient Utilization,Hematology And Ghrelin Expression In Jejunum Of Growing-Fattening Pigs

Under the background of national policy of “grain changed into feed”,the aim of the present study was to investigate the effects of whole-plant corn silage diet on growth performance,nutrient utilization,hematology and ghrelin expression in jejunum of growing-fattening pigs.Through the feeding experiment,the growth performance,nutrient utilization,hematology and intestinal molecular index is analyzed.The most suitable addition ratio is obtained.These results provide the theoretical basis for the promotion and implementation of whole plant maize.A total of 32 growing-fattening pigs(Duroc × Landrace × Large White)with the similar age and average body weight(33.16±3.49 kg)were allocated into 4 treatments with 8 replicates randomly,and animals were fed individually in a metabolic cage for 98 days after 7 days adaptation.The control group(SC0)was fed basal diet.Dietary nutrition level was determined according to the reference of NY/T65-2004 lean pig feeding standard.In the three test treatments for 30~60 kg growing pigs,20%(GSC20),30%(GSC30)and 40%(GSC40)whole-plant corn silage diet at milk stage was used to replace the basal diet,respectively.The nutrient contents of the three test treatments diets were 98%,96% and 94% of the control,and the crude fiber(CF)levels of the four test treatments were 3.0%,3.5%,4.0% and 4.5%,respectively.In the three test treatments for 60~100 kg fattening pigs,40%(FSC40),50%(FSC50)and 60%(FSC60)whole-plant corn silage diet at milk stage was used to replace the basal diet,respectively.The nutrient contents of the three test treatments diets were 97%,94% and 91% of the control,and the crude fiber(CF)levels of the four test treatments were 3.0%,4.0%,5.0% and 5.5%,respectively.There was no significant difference in the content of nutrients under dry matter basis among treatments(P>0.05).Results showed that with the increasing of whole-plant corn silage diet in growing-fattening pigs,average daily gain(ADG),nutrient digestibility(DM,OM,CP,EE and GE),biological value(BV),net protein utilization(NPU),metabolizable energy/gross energy(ME/GE),hemoglobin,ceruloplasmin(CER),total protein(TP),albumin(ALB),blood urea nitrogen(BUN),triglyceride(TG),total cholesterol(TCHO),immunoreactive integrated poptic density(IOD)and mRNA of ghrelin in jejunum decreased(P<0.05)linearly,but the average daily feed intake(FB-ADFI),average daily crude fiber intake(ADCFI),average daily dry feed intake(ADDFI),feed gain ratio in fresh sample basis(FB-F/G),feed gain ratio in dry basis(DM-F/G)and alkaline phosphatase(ALP)increased(P<0.05)linearly.Compared with the control,no significant effect on the growth performance,apparent digestibility and utilization of nutrients,protein utilization rate(BV and NPU),hematology,serum oxidative stress index,serum enzyme,serum metabolite and ghrelin expression in jejunum of 20% to 30% whole-plant corn silage diet in growing pigs and 40% to 50% whole-plant corn silage diet in fattening pigs were observed(P>0.05).However,the ADG,apparent digestibility and utilization of nutrients,hematology,CER,TP,ALB,IOD and mRNA of ghrelin in jejunum of 40% whole-plant corn silage diet in growing pigs and 60% whole-plant corn silage diet in fattening pigs were significantly decreased(P<0.05).In conclusion,whole-plant corn silage diet at milk stage can be used as low nutrient level diet for growing-fattening pigs,and it can guarantee the production performance and improve the health status of pigs.The appropriate ratio of growing and fattening pigs was 20%~30% and 40%~50%,respectively.These results provide a theoretical basis for the implementation of national policy of “grain changing into feed” and the application of whole plant corn in the pig’ production.