Low crude protein formulation with supplemental amino acids for its impacts on intestinal health and growth performance of growing-finishing pigs

Background Low crude protein(CP)formulations with supplemental amino acids(AA)are used to enhance intestinal health,reduce costs,minimize environmental impact,and maintain growth performance of pigs.However,extensive reduction of dietary CP can compromise growth performance due to limited synthesis of non-essential AA and limited availability of bioactive compounds from protein supplements even when AA requirements are met.Moreover,implementing a low CP formulation can increase the net energy(NE)content in feeds causing excessive fat deposition.Additional supplementation of functional AA,coupled with low CP formulation could further enhance intestinal health and glucose metabolism,improving nitrogen utilization,and growth performance.Three experiments were conducted to evaluate the effects of low CP formulations with supplemental AA on the intestinal health and growth performance of growing-finishing pigs.Methods In Exp.1,90 pigs(19.7±1.1 kg,45 barrows and 45 gilts)were assigned to 3 treatments:CON(18.0%CP,supplementing Lys,Met,and Thr),LCP(16.0%CP,supplementing Lys,Met,Thr,Trp,and Val),and LCPT(16.1%CP,LCP+0.05%SID Trp).In Exp.2,72 pigs(34.2±4.2 kg BW)were assigned to 3 treatments:CON(17.7%CP,meeting the requirements of Lys,Met,Thr,and Trp);LCP(15.0%CP,meeting Lys,Thr,Trp,Met,Val,Ile,and Phe);and VLCP(12.8%CP,meeting Lys,Thr,Trp,Met,Val,Ile,Phe,His,and Leu).In Exp.3,72 pigs(54.1±5.9 kg BW)were assigned to 3 treatments and fed experimental diets for 3 phases(grower 2,finishing 1,and finishing 2).Treatments were CON(18.0%,13.8%,12.7%CP for 3 phases;meeting Lys,Met,Thr,and Trp);LCP(13.5%,11.4%,10.4%CP for 3 phases;meeting Lys,Thr,Trp,Met,Val,Ile,and Phe);and LCPG(14.1%,12.8%,11.1%CP for 3 phases;LCP+Glu to match SID Glu with CON).All diets had 2.6 Mcal/kg NE.Results In Exp.1,overall,the growth performance did not differ among treatments.The LCPT increased(P<0.05)Claudin-1 expression in the duodenum and jejunum.The LCP and LCPT increased(P<0.05)CAT-1,4F2hc,and B0AT expressions in the jejunum.In Exp.2,overall,the VLCP reduced(P<0.05)G:F and BUN.The LCP and VLCP increased(P<0.05)the backfat thickness(BFT).In Exp.3,overall,growth performance and BFT did not differ among treatments.The LCPG reduced(P<0.05)BUN,whereas increased the insulin in plasma.The LCP and LCPG reduced(P<0.05)the abundance of Streptococcaceae,whereas the LCP reduced(P<0.05)Erysipelotrichaceae,and the alpha diversity.Conclusions When implementing low CP formulation,CP can be reduced by supplementation of Lys,Thr,Met,Trp,Val,and Ile without affecting the growth performance of growing-finishing pigs when NE is adjusted to avoid increased fat deposition.Supplementation of Trp above the requirement or supplementation of Glu in low CP formulation seems to benefit intestinal health as well as improved nitrogen utilization and glucose metabolism.

Effect of different dietary protein levels and amino acids supplementation patterns on growth performance, carcass characteristics and nitrogen excretion in growing-finishing pigs

Background:This study was conducted to determine the effects of different dietary protein levels and amino acids supplementation patterns in low protein diets on the growth performance,carcass characteristics and nitrogen excretion in growing-finishing pigs.Forty-two barrows(25.00±0.39 kg)were randomly assigned to 7 diets.Diet 1:the high crude protein diet with balanced for 10 essential amino acids(EAAs).Diet 2:the medium crude protein diet with 2%(approx)decreased protein level of Diet 1 and balanced 10 EAAs.Diet 3:the low crude protein diet with 4%decreased protein level of Diet 1 and balanced 10 EAAs.The protein levels of Diet 4,5,6 and 7 were the same as that of Diet 3.Diet 4 was only balanced for lysine(Lys),methionine(Met),threonine(Thr)and tryptophan(Trp);Diet 5 and 6 were further supplemented with extra isoleucine(Ile)or valine(Val),respectively;Diet 7 was further supplemented with extra Ile+Val.Results:Over the 112 days trial,the reduction of dietary protein by 2%or 4%with balanced10 EAAs significantly decreased nitrogen excretion(P<0.05),but had no effects on growth performance and carcass characteristics(P>0.05).In low protein diet,Val supplementation significantly increased body weight gain at 25–50 kg phase(P<0.05),while Ile supplementation at 75–100 kg phase and 100–125 kg phase significantly reduced the ratio of feed to gain(P<0.05).No effect of different dietary protein levels and amino acids supplementation patterns in low protein diets on carcass characteristics was observed(P>0.05).The total N excretion of pigs supplemented with only Lys,Met,Thr and Trp was numerically higher than that of pigs fed with extra Ile,or Val,or Ile+Val diets.Conclusion:In low protein diet,Val is more required than Ile in the early growing phage(25–50 kg),while Ile becomes more required in the late growing and finishing phage(75–125 kg).

Effects of Probiotics on Growth, Pork Quality and Serum Metabolites in Growing-finishing Pigs

A total of 72 growing-finishing pigs（56 days old） were used to investigate the effects of dietary probiotics on growing performance, pork quality and serum metabolites. Using single factorial experiment design, pigs were allotted to three groups（four pens/group and six pigs/pen）. Diet treatments were a corn-soybean meal（control group） and a corn-soybean meal with 1% probiotics（probiotics group） or 80 mg kg-1colistin sulfate（antibiotics group）. Pigs were slaughtered when pigs of the lightest averaged 90 kg（157 days of age）. There was no difference（p＆gt;0.05） in average daily gain or feed/gain, and the average daily feed intake of the antibiotics group was higher than that of the probiotics and the control groups（p＆lt;0.05）. Diet supplemented with probiotics reduced the drip loss and cooking loss of pork（p＆lt;0.05）. Dietary supplementation with probiotics significantly decreased the content of triglycerides, lowdensity lipoprotein and urea nitrogen in serum（p＆lt;0.05）, and increased the content of high-density lipoprotein in serum（p＆lt;0.05）. These results suggested improving effects of dietary probiotics on pork quality and serum metabolism in growing-finishing pigs.

Determination of the available energy values and amino acid digestibility of Flammulina velutipes stem waste and its effects on carcass trait and meat quality fed to growing-finishing pigs

Background:Flammulina velutipes stem waste(FVS)is the by-product of mushroom industry.The objectives of this study were to determine the available energy and amino acid digestibility of FVS fed to pigs,and to evaluate the effects of dietary FVS inclusion on growth performance,biochemical profile of serum,fecal short chain fatty acid(SCFA)concentration,carcass traits,meat quality,intestinal morphology and microflora of pigs.In Exp.1,twelve crossbred barrows with initial body weight(IBW)of 37.48±4.31 kg were randomly allotted to 2 dietary treatments,including a corn basal diet and an experimental diet containing 24.35%FVS.In Exp.2,twelve barrows fitted with an ileal T-cannula(IBW:32.56±1.67 kg)were randomly allotted to 2 dietary treatments,which included a N-free diet and an experimental diet containing 40.0%FVS.In Exp.3,ninety growing pigs(IBW:63.98±6.89 kg)were allotted to 1 of 3 treatment diets for 63 d,including a basal diet and 2 experimental diets with 2.5%and 5%FVS,respectively.Results:The digestible energy(DE)and metabolizable energy(ME)of FVS were 4.58 and 4.06 MJ/kg on dry matter basis,respectively,and the standardized ileal digestibility(SID)of indispensable AAs ranged from 17.50%to 59.47%.Pigs fed diets with 2.5%FVS showed no difference on average daily gain(ADG)and gain to feed ratio(G/F).Although dietary 5%FVS inclusion impaired apparent total tract digestibility(ATTD)of organic matter and gross energy,it elevated the SCFA concentration(P≤0.04)in gut and antioxidant capacity in serum.In addition,dietary FVS inclusion depressed the backfat thickness(P=0.03)in pigs.The longissimus dorsi muscle of pigs fed FVS revealed higher n-3 polyunsaturated fatty acid concentration and optimized fatty acid composition.Dietary 2.5%FVS inclusion also improved the intestinal development and health by increasing the villius height to crypt depth ratio(V/C)in jejunum(P<0.01),and promoting microbial diversity and beneficial microbiota proliferation.Conclusions:It is feasible to include moderate content of FVS as an unconventional fiber ingredient in diet of growingfinishing pigs.

Intrauterine growth restriction alters growth performance, plasma hormones,and small intestinal microbial communities in growing-finishing pigs

Background: The interaction of the gut microbiota with key metabolic and physiological processes may be associated with poor growth outcomes in animals born with intrauterine growth restriction(IUGR).Results: Growth performance, plasma hormone concentrations, and intestinal microbiota composition were analyzed in IUGR pigs and in normal birth weight(NBW) pigs when the NBW pigs reached 25, 50, and 100 kg of body weight(BW). Compared to NBW pigs, IUGR pigs had lower initial, weaned, and final BW, and lower average daily gain and average daily feed intake in all the considered time points. In the 25 kg BW group, IUGR pigs had higher concentrations of plasma ghrelin and pancreatic polypeptide(PP), but lower insulin concentration than NBW pigs, while the situation was reversed in the 50 kg BW group. As compared to NBW pigs, IUGR pigs had higher microbial alpha diversity in the jejunum and ileum;in the 50 and 100 kg BW groups, IUGR pigs had higher Firmicutes abundance but lower Proteobacteria abundance in the jejunum, and lower Lactobacillus abundance in the jejunum and ileum;in the 25 kg BW group, IUGR pigs showed higher unclassified Ruminococcaceae abundance in the ileum;and in 25 and 50 kg BW groups, IUGR pigs showed lower Ochrobactrum abundance in the jejunum.Spearman's correlation revealed that Lactobacillus was negatively correlated with growth performance, while unclassified Ruminococcaceae was positively correlated. Predictive metagenomic analysis detected significantly different expression of genes in the intestinal microbiota between IUGR and NBW pigs, suggesting different metabolic capabilities between the two groups.Conclusions: Growing-finishing IUGR pigs showed lower growth performance, higher microbial alpha diversity, and differences in plasma hormone concentrations compared to NBW pigs. Alterations in the abundance of Firmicutes,Proteobacteria, Ruminococcaceae, Lactobacillus, and Ochrobactrum in the small intestine may be associated with IUGR, and may therefore serve as a future target for gut microbiota intervention in growing-finishing IUGR pigs.

Alterations in intestinal microbiota composition coincide with impaired intestinal morphology and dysfunctional ileal immune response in growing-finishing pigs under constant chronic heat stress

Background:Previous studies had shown that short-term acute heat stress(HS)affected the host’s metabolism and intestinal microbiota independent of feed intake(FI)reduction,and long-term calorie restriction caused intestinal morphological injuries and gut microbial alterations.However,research on the effects of constant chronic HS on intestinal microbial composition and the roles of FI reduction played in is limited.This study aimed to investigate the effects of 7-day constant chronic HS on the composition of intestinal microbes in growing-finishing pigs,and its relationship with pigs’performance,intestinal morphology,and ileal immune response.Twenty-four growingfinishing pigs(Duroc×Large White×Landrace,30±1 kg body weight)were randomly assigned to three treatments(n=8),1)thermal neutral(TN)conditions(25±1℃)with ad libitum FI,2)HS conditions(35±1℃)with ad libitum FI,3)pair-fed(PF)with HS under TN conditions to discriminate the confounding effects of dissimilar FI,and the FI was the previous day’s average FI of HS.The small intestinal segments(duodenum,jejunum,and ileum)and feces were collected on d 8.Results:Results indicated that HS drastically declined(P<0.05)average daily gain(ADG)and average daily feed intake(ADFI)(about 61%)in comparison with TN,and caused hyperpyrexia,meanwhile PF caused hypothermia.Morphological observation by light and electron microscopes showed that both HS and PF treatment decreased(P<0.05)the villus and microvillus height compared with TN.Additionally,HS increased(P<0.05)protein expression of heat shock protein 70 in the duodenum,jejunum,and ileum.Furthermore,the expression of tight junction protein zonula occluden-1(ZO-1)in the duodenum and ileum,and Occludin in the ileum were enhanced(P<0.05)compared with TN and PF.Moreover,HS significantly enhanced(P<0.05)the mRNA relative expression of inflammatory cytokines(TLR-2,TLR-4,and tumor necrosis factor-α(TNF-α),IL-6,IL-8,PG1–5,β-defensin 2(pBD-2)),mucins(mucin-1 and mucin-2)and P65 protein level in the ileal mucosa tissue.Intestinal microbiota analysis by 16S rRNA sequencing showed lower(P<0.10)αdiversity in both HS and PF,and a separated cluster ofβdiversity among groups.Compared with TN,HS but not PF mainly reduced(FDR<0.05)Bacteroidetes(phylum),Bacteroidia(class)and elevated the proportions of Proteobacteria(phylum,FDR<0.05),Bacillales(order,FDR<0.05),Planococcaceae(family,FDR<0.05),Kurthia(genus,FDR<0.05),Streptococcaceae(family,FDR<0.10)and Streptococcus(genus,FDR<0.10).Notably,Lactobacillales(order)was decreased(FDR<0.05)by PF alone.Furthermore,the Spearman correlation analysis indicated that the microbes prevalent in HS were positively(P<0.05)associated with intestinal morphological injuries indicators and ileal immune response parameters,and the microbes reduced in HS were negatively(P<0.05)with the performance data.Conclusions:Intestinal morphological injuries and ileal immune response caused by constant chronic HS independent of FI showed close connections with alterations in intestinal microbiota in growing-finishing pigs.

Effects of dietary protein restriction on muscle fiber characteristics and m TORC1 pathway in the skeletal muscle of growing-finishing pigs

Background： To investigate the effects of dietary crude protein（CP） restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs（62.30 ± 0.88 kg）were allotted to 3 groups and fed with the recommended adequate protein（AP, 16 % CP） diet, moderately restricted protein（MP, 13 % CP） diet and low protein（LP, 10 % CP） diet, respectively. The skeletal muscle of different locations in pigs, including longissimus dorsi muscle（LDM）, psoas major muscle（PMM） and biceps femoris muscle（BFM） were collected and analyzed.Results： Results showed that growing-finishing pigs fed the MP or AP diet improved（P 〈 0.01） the average daily gain and feed： gain ratio compared with those fed the LP diet, and the MP diet tended to increase（P = 0.09） the weight of LDM. Moreover, the ATP content and energy charge value were varied among muscle samples from different locations of pigs fed the reduced protein diets. We also observed that pigs fed the MP diet up-regulated（P 〈 0.05） muscular m RNA expression of all the selected key genes, except that myosin heavy chain（My HC） IIb,My HC IIx, while m RNA expression of ubiquitin ligases genes was not affected by dietary CP level. Additionally, the activation of mammalian target of rapamycin complex 1（m TORC1） pathway was stimulated（P 〈 0.05） in skeletal muscle of the pigs fed the MP or AP diet compared with those fed the LP diet.Conclusion： The results suggest that the pigs fed the MP diet could catch up to the growth performance and the LDM weight of the pigs fed the AP diet, and the underlying mechanism may be partly due to the alteration in energy status, modulation of muscle fiber characteristics and m TORC1 activation as well as its downstream effectors in skeletal muscle of different locations in growing-finishing pigs.

Effects of the standardized ileal digestible lysine to metabolizable energy ratio on performance and carcass characteristics of growing-finishing pigs

A total of 2,121 growing-finishing pigs （Duroc × Landrace ×Large White） were utilized in six experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine （SID-Lys） to metabolizable energy （ME） on the performance and carcass characteristics of growing-finishing pigs. Exps. 1 （30 to 50 kg）, 2 （52 to 70 kg） and 3 （81 to 104 kg） were conducted to find an optimum ME level and then this level was used in Exps. 4 （29 to 47 kg）, 5 （54 to 76 kg） and 6 （84 to 109 kg） to test the response of pigs to different ratios of SID-Lys：ME. In Exps.1 to 3, four treatments were used consisting of diets with a formulated ME content of 3.1, 3.2, 3.3 or 3.4 in Exps. I and 2 while Exp. 3 used 3.05, 3.1 S, 3.25 or 3.35 Mcal/kg. A constant SID-Lys：ME ratio of 2.6, 2.3 or 2.0 g/Mcal was used in Exps. 1, 2 and 3, respectively. Weight gain was significantly increased with increasing energy level in Exp.1 while weight gain was unaltered in Exps. 2 and 3. For all three experiments, feed intake was decreased （P 〈 0.05） and feed efficiency was improved （P 〈 0.05） with increasing energy level. Tenth rib back fat thickness linearly increased （P 〈 0.05） with increasing energy level, in Exps. 4 to 6, five treatments were used consisting of diets with a SID-Lys：ME ratio of 2.4, 2.6, 2.8, 3.0 or 3.2 in Exp. 1, 2.1, 2.3, 2.5, 2.7, 2.9 or 3.2 in Exp. 2 and 1.8, 2.0, 2.2, 2.4, or 2.6 in Exp. 3. A constant ME level 3.2, 3.2 and 3.05 Mcal/kg was used in Exps. 1, 2 and 3, respectively （selected based on the results of weight gain）. For all three experiments, weight gain increased （P 〈 0.05） and feed efficiency improved linearly （P 〈 0.05） as the SID-Lys：ME ratio increased. Tenth rib back fat thickness linearly decreased （P 〈 0.0,5） as the SID-Lys：ME ratio increased. Based on a straight broken-line model, the estimated SID-Lys：ME ratio to maximize weight gain was 3.0, 2.43 and 2.2 for 29 to 47, 54 to76 and 84 to 109 kg of pigs, respectively.

Effects of Fermentation Bed Padding on Intestinal Flora,Serum Biochemical Indexes and Immune Function of Growing-finishing Pigs

[Objective]The paper was to study the effects of fermentation bed padding on intestinal flora,serum biochemical indexes and immune function of growing-finishing pigs.[Method]A total of 90 growing-finishing pigs(Duroc × Landrace × Yorkshire)with the body weight of(30.5±0.8)kg were randomly divided into five groups,three replicates each group,six pigs each replicate.The padding of five groups were:50%rice husk+50%sawdust(control group),100%spent mushroom substrate of Pleurotus eryngii(100%spent mushroom substrate group),15%rice husk+15%sawdust+70%spent mushroom substrate(70%spent mushroom substrate group),25%rice husk+25%sawdust+50%spent mushroom substrate(50%spent mushroom substrate group),35%rice husk+35%sawdust+30%spent mushroom substrate(30%spent mushroom substrate group).The pre-trial lasted 7 d,and the formal trial lasted 90 d.[Result]Compared with the control group,the number of Escherichia col in 100%,70%and 50%spent mushroom substrate groups decreased by 35.4%,24.0%and 20.8%,respectively(P<0.05);the number of salmonella successively decreased by 29.4%,19.3%and 15.2%,respectively(P<0.05);the number of lactobacillus successively increased by 21.7%,15.9%and 12.2%,respectively(P<0.05);and the number of bifidobacteria successively increased by 20.2%,16.7%and 11.8%,respectively(P<0.05).Compared with the control group,the total serum protein content in 100%,70%,50%and 30%spent mushroom substrate groups increased by 30.6%,33.0%,28.0%and 18.4%,respectively(P<0.05);and the serum urea nitrogen content decreased by 32.4%,34.5%,33.9%and 22.0%,respectively(P<0.05).There was no significant difference in serum albumin,aspartate aminotransferase(AST)and alanine aminotransferase(ALT)between treatment groups and control group.The IgA,IgG,IgM and IL-6 levels in serum of each treatment group were significantly different from those of the control group(P<0.05).There was no significant difference in IgA,IgG,IgM and IL-6 levels among 100%,70%and 50%spent mushroom substrate groups.[Conclusion]It improves the balance of intestinal microecological flora of growing-finishing pigs and enhances the immune performance of pigs by using spent mushroom substrate of P.eryngii as the fermentation bed padding.15%rice husk+15%sawdust+70%spent mushroom substrate is the optimal proportion of spent mushroom substrate for growing-finishing pigs.

Feeding Effect of Growing-Finishing Pigs under Fine Division of Feeding Stages

In order to study the feeding effect of fine division of feeding stages on the growing-finishing pigs,96 healthy Duroc × Landrace ×Yorkshire hybrid commercial pigs with similar age in days,size,and body weight about 15 kg,half boars and half sows,randomly divided into3 treatments( each treatment repeated 4 times,and each repetition 8 pigs). According to the body weight division standard,three stages,four stages,and five stages of feeding were adopted separately. The daily ration of with different nutrition levels was used,body weight and feed consumption were measured,and effects of different feeding methods on body weight increase,feed utilization,and economic benefits of growing-finishing pigs. The results showed that compared with the three-stage feeding,the body weight of five-stage and four-stage feeding increased by 4. 18%( P < 0. 01) and 2. 41%( P < 0. 05),respectively,and the body weight of five-stage feeding increased by 1. 74%( P < 0. 05) compared with that of four-stage feeding; the daily feed consumption of five-stage and four-stage feeding increased 3. 10%( P < 0. 01) and 1. 70%(P <0. 01),respectively,and the daily feed consumption of five-stage feeding was 1. 37% higher than that of four-stage feeding. The feed cost of five-stage feeding and four-stage feeding increased 3. 32%( P < 0. 01) and 1. 61%( P < 0. 05) separately,and the feed cost of five-stage feeding was 1. 69% higher than that of four-stage feeding( P < 0. 01). The income from average body weight increase of five-stage and fourstage feeding increased by 5. 47%( P < 0. 01) and 3. 59%( P < 0. 01) respectively,and the benefit of average body weight increase of fivestage feeding was 1. 81% higher than that of four-stage feeding( P > 0. 05). The crude protein consumption from average body weight increase of five-stage and four-stage feeding decreased by 2. 28%( P < 0. 01) and 1. 68%( P < 0. 01),respectively; the crude protein consumption from average body weight increase of five-stage feeding was 0. 67% lower than that of four-stage feeding; the feed conversion ratio of five-stage feeding,four-stage feeding,and three-stage feeding was 2. 92,2. 93,and 2. 95 respectively. The results showed that compared with the threestage feeding,the four-stage and five-stage feeding could significantly increase the body weight of the growing-finishing pigs,improve the feed utilization level and improve the economic benefits,and the effect of five-stage feeding was better than the four-stage feeding.

Effects of Fermented Nano Chinese Herbal Medicines Replacing Antibiotics on Production Performance and Carcass Quality of Growing-Finishing Pigs

[Objectives]To study the effects of fermented nano Chinese herbal medicines replacing antibiotics on the production performance and carcass quality of growing-finishing pigs.[Methods]200 healthy and disease-free Duroc-Landrace-Yorkshire(DLY)growing-finishing pigs with similar birth time(45±2 d)and body weight of about 31.5 kg were randomly divided into group A(fed with non-antibiotic basal diet),group B(fed with antibiotic basal diet),group C(fed with non-antibiotic basal diet+0.1%fermented nano Chinese herbal medicine preparation),group D(fed with non-antibiotic basal diet+0.3%fermented nano Chinese herbal medicine preparation)and group E(fed with non-antibiotic basal diet+0.5%fermented nano Chinese herbal medicine preparation).The experiment lasted for 90 d.At the end of the experiment,the production performance and carcass indicators were measured.[Results]Compared with group A,the final weight,average daily gain(ADG)and average daily feed intake(ADFI)of groups B,C,D and E were extremely significantly increased(P<0.01),while the feed-to-gain ratio(F/G)was extremely significantly decreased(P<0.01).Compared with group B,the ADG of group E was significantly increased(P<0.05),while the F/G was significantly decreased(P<0.05).Compared with group A,the slaughter rate and carcass length of pigs in groups B,C,D and E were extremely significantly increased(P<0.01);compared with group B,the slaughter rate of groups D and E was extremely significantly increased(P<0.01).[Conclusions]The fermented nano Chinese herbal medicine preparation has better effects in promoting growth than that of antibiotic additives,and it can significantly improve the carcass quality of growing-finishing pigs.

Dietary supplementation of Lonicera macranthoides leaf powder improves amino acid profiles in serum and longissimus thoracis muscle of growing-finishing pigs

A 60-days feeding trial was conducted to determine the effect of dietary supplementation of Lonicera macranthoides leaf(LML) on growth performance, meat quality, and free amino acid profiles in growingfinishing pigs. L. macranthoides leaves were harvested, air-dried and milled to powder. A total of 288 crossbred barrows(Large White x Landrace) with an average initial BW of 54.0 ± 3.4 kg were randomly allocated to 3 treatment groups and fed either a basal diet or a diet supplemented with 0.5% or 1.0% LML powder. Results showed that diet supplemented with LML powder did not affect average daily feed intake(ADFI) and feed: gain ratio(P> 0.05) in growing-finishing pigs. Moreover, diet supplemented with LML powder showed no significant effects on carcass traits(P > 0.05) including dressing percentage,backfat thickness and loin muscle area, and meat quality traits(P > 0.05) including meat color, intramuscular fat and cooking loss. However, diet supplemented with LML powder significantly improved free amino acid profiles in serum and longissimus thoracis muscle in growing-finishing pigs. Most importantly, dietary LML powder increased total free amino acids content(P < 0.001) and essential free amino acid content(P < 0.001) in longissimus thoracis muscle. These results indicate that LML has the potential to improve the nutritional value of meat through improving free amino acid profiles.

Gama-aminobutyric acid(GABA)alleviates hepatic inflammation via GABA receptors/TLR4/NF-kB pathways in growing-finishing pigs generated by super-multiparous sows

The offspring of super-multiparous sows face problems such as decreased growth performance,poor meat quality and even diseases in animal husbandry.Gama-aminobutyric acid(GABA)has long been known to promote growth and suppress inflammation,but little is known about the mechanisms.A total of 72 growing-finishing pigs from the 8th generation were randomly allotted to 2 groups with 6 replicates per treatment to receive a cornesoybean basal diet or the basal diet supplemented 20 mg/kg GABA for 60 d.After the animal-trial period,samples of serum and liver were collected for further analysis.Additionally,a lipopolysaccharide(LPS)-induced inflammatory model using HepG2 cells was established to explore the role of GABA on regulating hepatic inflammation.The results indicated that inflammatory cell infiltration occurs in the liver of progeny of super-multiparous sows,and dietary supplementation with GABA influenced liver morphology,increased activities of antioxidant enzymes and decreased the expression abundance of pro-inflammatory cytokines,including tumor necrosis factor-α(TNFα)and interleukin(IL)-1β,in the liver of growing-finishing pigs(P<0.05).In addition,GABA supplementation increased mRNA expressions of peroxisome proliferator-activated receptor g(PPARg)and GABA receptors(GABARs),and reduced the expression of toll-like receptor 4(TLR4)/nuclear factor-kB(NF-kB)signaling(P<0.05).Additionally,an in vitro experiment demonstrated that GABA decreased the expressions of hepatic TLR4/NF-kB signaling via activating GABARs under LPS-stress(P<0.05).In summary,liver injury may affect the growth performance of growing-finishing pigs by changing hepatic mitochondrial metabolism,the expression of pro-inflammatory cytokines and TLR4/NF-kB pathway and that GABA supplementation has a restorative effect by acting on GABARs.

Strategies to improve fiber utilization in swine

Application of feed processing methods and use of exogenous feed additives in an effort to improve nutrient digestibility of plant-based feed ingredients for swine has been studied for decades. The following review will discuss several of these topics, including： fiber characterization, impact of dietary fiber on gastrointestinal physiology, energy, and nutrient digestibility, mechanical processing of feed on fiber and energy digestibility, and the use of exogenous enzymes in diets fed to growing pigs. Taken together, the diversity and concentration of chemical characteristics that exists among plant-based feed ingredients, as well as interactions among constituents within feed ingredients and diets, suggests that improvements in nutrient digestibility and pig performance from mechanical processing or adding exogenous enzymes to diets fed to swine depends on a better understanding of these characteristics, but also relating enzyme activity to targeted substrates. It may be that an enzyme must not only match a target substrate（s）, but there may also need to be a ＇cocktail＇ of enzymes to effectively breakdown the complex matrixes of fibrous carbohydrates, such that the negative impact of these compounds on nutrient digestibility or voluntary feed intake are alleviated. With the inverse relationship between fiber content and energy digestibility being well described for several feed ingredients, it is only logical that development of processing techniques or enzymes that degrade fiber, and thereby improve energy digestibility or voluntary feed intake, will be both metabolically and economically beneficial to pork production.

Modelling Manure Production in Beef Calves: Development, Evaluation, and Application of a Complete vs. Simplified Prediction Model

There has been increased interest in quantifying the manure production of livestock, primarily driven by public authorities, who aim to evaluate the environmental impact of livestock production, but also at the farm level, to manage manure storage and availability of fertilizer for crop production. Moreover, current manure production estimates from intensively reared beef calves are higher than actual production due to changes in farming systems, advances in animal genetics and feed efficiency. This study aims to redefine and update manure production estimates in intensively reared beef calves to predict manure production as a policy and planning tool, as there are no current models available. A trial was conducted to collect data on manure production during the growing-finishing period (243 d) of 54 Limousine calves (from 346.7 to 674.0 kg live weight, LW). Such data were used to develop two models to predict manure excretion: (1) a complex mechanistic model (CompM), and (2) a simplified empirical model (SimpM). Both models were evaluated against an independent dataset including a total of 4,692 animals on 31 farms and 5 breeds. Results from CompM require interpretation because the model does not output a single value but a range of manure production (minimum, medium and maximum), and would therefore be more suitable for professional use. The SimpM could be considered simple, reliable, and versatile for predicting manure excretion at farm level. SimpM could be refined and improved by including data from other studies on beef cattle with distinct characteristics and management.