Effects of dietary oil sources and fat extraction methods on apparent and standardized ileal digestibility of fat and fatty acids in growing pigs

Background:There is a lack of data for the standardized ileal digestibility(SID) of fat and fatty acids in national feed databases.In addition,it is important to specify the procedures used for fat analyses.Therefore,an experiment was conducted to 1) determine the apparent ileal digestibility(AID) and SID of fat and fatty acids in ten different oil sources for growing pigs and to develop prediction equations for SID of fat based on fatty acid composition;and 2) compare the effect of the fat extraction methods on the calculated values for endogenous loss and digestibility of fat.Methods:Twenty-two barrows(initial body weight:32.1 ± 2.3 kg) were surgically fitted with a T-cannula in the distal ileum,and allotted to 1 of 11 experimental diets in a 4-period Youden Square design.A fat-free diet was formulated using cornstarch,soy protein isolate and sucrose.Ten oil-added diets were formulated by adding 6% of dietary oil sources to the fat-free diet at the expense of cornstarch.All diets contained 26% sugar beet pulp and 0.40% chromic oxide.Results:The endogenous loss of ether extract(EE) was lower than that of acid-hydrolyzed fat(AEE;P < 0.01).There were significant differences in the AID and SID of fat and saturated fatty acids across the dietary oil sources(P < 0.05).The SID of AEE for palm oil was lower than that of sunflower oil,corn oil,canola oil,rice oil and flaxseed oil(P < 0.01).The AID and SID of fat ranged from 79.65% to 86.97% and from 91.14% to 99.18%.Although the AID of EE was greater than that of AEE(P < 0.01),there was no significant difference in SID of EE and AEE except for palm oil.The ratio of unsaturated to saturated fatty acids(U/S) had a positive correlation with SID of fat(P < 0.05),whereas C16:0 and long chain saturated fatty acids(LSFA) were significant negatively correlated with SID of fat(P < 0.01).The best-fit equation to predict SID of fat was SID AEE = 102.75-0.15 × LSFA-0.74 × C18:0-0.03 × C18:1(Adjusted coefficient of determination = 0.88,P < 0.01).Conclusions:When calculating the SID of fat,the EE content of the samples can be analyzed using the direct extraction method,whereas the acid hydrolysis procedure should be used to determine the AID of fat.Fat digestibility of dietary oils was affected by their fatty acid composition,especially by the contents of C16:0,LSFA and U/S.

Fermented mixed feed alters growth performance,carcass traits,meat quality and muscle fatty acid and amino acid profiles in finishing pigs

This study was conducted to investigate the effects of fermented mixed feed(FMF)on growth performance,carcass traits,meat quality,muscle amino acid and fatty acid composition and mRNA expression levels of genes related to lipid metabolism in finishing pigs.In the present study,144 finishing pigs(Duroc×Berkshire×Jiaxing Black)were randomly allocated to 3 dietary treatments with 4 replicate pens per group and 12 pigs per pen.The dietary treatments included a basal diet(CON),a basal diet+5%FMF and a basal diet+10%FMF.The experiment lasted 38 d after 4 d of acclimation.The results showed that 5%and 10%FMF significantly increased the average daily gain(ADG)of the females but not the males(P<0.05),but FMF supplementation showed no impact on carcass traits.Moreover,10%FMF supplementation increased the meat color45 min and meat color24 h values,while it decreased the shear force relative to CON(P<0.05).In addition,10%FMF significantly increased the contents of flavor amino acids(FAA),total essential AA(EAA),total non-EAA(NEAA)and total AA relative to CON(P<0.05).Furthermore,the diet supplemented with 10%FMF significantly increased the concentration of n-3 polyunsaturated fatty acids(PUFA),n-6 PUFA and total PUFA,and the PUFA to saturated fatty acids ratio(P<0.05),suggesting that FMF supplementation increased meat quality.Moreover,compared with the CON,10%FMF supplementation increased the mRNA expression of lipogenic genes,including CEBPα,PPARγ,SREBP1 and FABP4,and upregulated the expression of unsaturated fatty acid synthesis(ACAA1 and FADS2).Together,our results suggest that 10%FMF dietary supplementation improved the female pigs’growth performance,improved the meat quality and altered the profiles of muscle fatty acids and amino acids in finishing pigs.This study provides a reference for the production of high-quality pork.

Endogenous chitinase might lead to differences in growth performance and intestinal health of piglets fed different levels of black soldier fly larva meal

This study aimed to investigate the effects of different levels of black soldier fly(BSF)replacing soybean meal(SBM)in diets on the performance and health condition of piglets.A total of 180 weaned piglets were allocated into 5 treatments:BSF0(corn-soybean meal basal diet),BSF25(BSF replacing 25%SBM),BSF50(BSF replacing 50%SBM),BSF75(BSF replacing 75%SBM)and BSF100(BSF replacing 100%SBM).During the whole period,in comparison with BSF0,average daily gain(ADG)and average daily feed intake increased in the BSF25 and BSF50 groups,whereas ADG decreased in the BSF75 and BSF100groups(P<0.05).The result of quadratic fitting curve showed that piglets exhibited the highest ADG when BSF replaced around 20%SBM.Compared with BSF0,organic matter and dry matter digestibility improved in the BSF25 group,whereas ether extract digestibility decreased in the BSF100 group(P<0.05).In comparison with BSF0,piglets from the BSF25 group showed a higher duodenal ratio of villus height to crypt depth,increased jejunal sucrase activity,serum neuropeptide Y and ghrelin levels,elevated ileal immunoglobulin(Ig)A,Ig G and Ig M contents and a lower leptin level,and piglets from the BSF100 group exhibited an increased relative weight of kidney(P<0.05).However,no significant differences were observed in the expression level of tight junction proteins and chitin-degrading enzyme.Additionally,compared with BSF0,the abundance of short chain fatty acid producing bacteria such as Ruminococcaceae,Faecalibacterium and Butyricicoccus increased,and potential pathogenic bacteria decreased in piglets from the BSF25 group,whereas piglets from the BSF100 group had a greater abundance of harmful bacteria.In conclusion,BSF replacing 25%SBM in diets could improve digestive parameters,immune function and intestinal microbiota,and thus improved growth performance of piglets.However,BSF replacing 100%SBM showed an adverse effect on piglet performance,and the reason might be related to the limited amount of chitin-degrading enzyme.