Effects Of Feeding Pattern On The Nutrition Digestibility,carcass Quality And Gut Microbiota Compositing Of Growing Pigs

This study mainly investigated the effects of feeding patterns on nutrient digestibility,carcass quality and intestinal microbial composition of growing pigs,including the following three parts:Experiment one: the objective of the present study was to study the effects of feeding schedule on growth performance,carcass quality and lipid metabolism of growing-finishing pigs.A total of 48 growing-finishing pigs(initial BW 61.4 ± 2.5 kg)were assigned to one of the 2 feeding schedule(had free access to diet and restricted meal frequency)in a randomized complete block design.The whole experiment lasted for 8 weeks and the slaughter weight was about 120 kg.Pigs had free access(FA)to diet were fed on an ad libitum basis and restricted meal frequency(RMF)group were fed twice daily during the 8-weeks experimental period.The results showed that the RMF fed pigs had lower average daily feed intake,average daily gain,carcass weight,dressing percentage and average backfat thickness than that for pigs had free access to feed(P <0.05).In addition,the RMF fed pigs had lower m RNA expression levels of fatty acid synthase and peroxisome proliferator-activated receptor γ than pigs had free access to diet(P <0.05).In summary,the RMF feeding regime decreases the growth performance,dressing percentage and lipid deposition,but has no effect on meat quality of growing-finishing pigs.The RMF feeding regime decreases lipid deposition by decreasing lipogenesis.Experiment two: The present study was conducted to investigate the effects of me al frequency on apparent ileal digestibility(AID)and apparent total tract digestibility(ATTD)of gross energy(GE)and nutrients.A total of 24 growing pigs(initial BW 40.7±1.3kg)were surgically fitted with simple T-cannulas at the distal ileum and assigned to 2 treatments with 12 replicates of one pig: M2(Pigs were fed twice per day)and M12(Pigs were fed 12 times per day).The experimental period comprised of 9 d.The results showed that the average daily feed intake(ADFI),average daily gain(ADG)and feed efficiency of growing pigs were not affected by meal frequency(P >0.1).The hindgut disappearance of EE,ADF(P <0.05),NDF(P <0.01)were lower for M2 pigs compared with M12 pigs.There was a tendency for M2 pigs to have a lower the hindgut disappearance and the ATTD of ADF and CP than M12 pigs(P <0.1).In summary,the hindgut disappearance and ATTD of GE and nutrients increase with increasing meal frequency.Experiment three: The present study was conducted to investigate the effects of feeding pattern(pigs were fed either ad libitum or 3 meals per day)on the growth performance,nutrient digestibility and gut microbiota composition in growing pigs.A total of 120 growing pigs(initial BW 26.0 ± 0.4 kg)were assigned into two groups in which pigs were fed ad libitum(FA)or three meals per day(M3)according to the BW and gender of pigs.This experiment lasted 28 days.The results showed that no significant difference was observed for apparent total tract digestibility(ATTD)of nutrient between treatments(P >0.05).At the phylum level,relative abundance of bacteroidetes of pigs in M3 groups was lower than that in FA groups(P <0.05).However,the relative abundance of tenericutes and verrucomicrobia in FA groups were greater than that in M3 groups(P <0.05).In summary,feeding frequency had no effect on nutrient digestibility,but less frequent feeding altered gut microbiota composition and improved feed efficiency in growing pigs.Overall conclusion: reducing feeding frequency can reduce lipid deposition and change intestinal microbial composition,but it has some negative effects on nutrient digestibility.