Changes in feed intake, nutrient digestion, plasma metabolites, and oxidative stress parameters in dairy cows with subacute ruminal acidosis and its regulation with pelleted beet pulp

The objectives of this study were to 1） determine the variation of nutrient digestion, plasma metabolites and oxidative stress parameters triggered by induced subacute ruminal acidosis （SARA）; and 2） evaluate the ability of pelleted beet pulp （BP） as a replacement for ground corn to alleviate SARA. Eight Holstein-Friesian cows were fed four diets during four successive17 day periods： 1） total mixed ration （TMR） containing 0% finely ground wheat （FGW） （WO）; 2） TMR containing 10% FGW （W10）; 3） TMR containing 20% FGW （W20）; and 4） TMR containing 10% BP as a replacement for 10% ground corn （BP10）. The SARA induction protocol reduced the mean ruminal pH from 6.37 to 5.94, and the minimum ruminal pH decreased from 5.99 to 5.41 from baseline to challenge period. Mean ruminal pH increased from 5.94 to 6.05, and minimum daily ruminal pH increased from 5.41 to 5.63, when BP was substituted for corn. The apparent digestibility of nutrients was not affected by the dietary treatments, except that the digestibility of neutral detergent fibre （NDF） and acid detergent fibre （ADF） was reduced in cows fed the W20 diet compared with cows fed the W0 and W10 diets, and cows fed the BP10 diet had higher NDF and ADF digestibility than the cows fed the W20 diet. Cows fed the W20 diet had a lower plasma concentration of 13-hydroxybutyrate （BHBA）, non-esterified fatty acids （NEFA）, cholesterol, triglyceride, and total antioxidative capacity （TAC）, and a higher plasma concentration of glucose, insulin, malonaldehyde （MDA）, super oxygen dehydrogenises （SOD）, and glutathione peroxidase （GSH-Px） than cows fed the W0 diet. Substitution of BP for corn increased concentrations of plasma BHBA and TAC, but decreased concentrations of plasma MDA. Our results indicate that reduction of fibre digestion; the concomitant increase of plasma glucose and insulin; the decrease of plasma BHBA, NEFA, cholesterol, and triglyceride; and changes of plasma oxidative stress parameters are highly related to SARA induced by W20 diets. These variables may be alternative candidates for SARA diagnosis. We also suggest that the substitution of BP for corn could reduce the risk of SARA, increase fibre digestion, and improve the antioxidant status in dairy cows.

Dietary supplementation of sodium butyrate enhances lactation performance by promoting nutrient digestion and mammary gland development in dairy cows

This experiment was to evaluate the influence of sodium butyrate(SB)addition on milk production,ruminal fermentation,nutrient digestion,and the development and metabolism regulation of the mammary gland in dairy cows.Forty Holstein dairy cows averaging 710±18.5 kg body weight,72.8±3.66 d in milk(DIM),and 41.4±1.42 kg/d milk production were divided into four treatments blocked by DIM and milk production.Treatments were control group,low SB,medium SB,and high SB with 0,100,200 and 300 g/d of SB addition per cow,respectively.The study lasted for 105 d.Production of milk,milk protein and lactose quadratically increased(P<0.05),while fat-corrected milk,energycorrected milk and milk fat yields linearly increased(P<0.05)with increasing SB addition.The digestibility of dietary dry matter,organic matter,and crude protein linearly increased(P<0.05),whereas the digestibility of ether extract,neutral detergent fibre,and acid detergent fibre quadratically increased(P<0.05).Ruminal pH quadratically decreased(P=0.04),while total volatile fatty acids(VFA)quadratically increased(P=0.03)with increasing SB addition.The acetic acid to propionic acid ratio increased(P=0.03)linearly due to the unaltered acetic acid molar percentage and a linear decrease in propionic acid molar percentage.Ruminal enzymatic activity of carboxymethyl-cellulase and a-amylase,populations of total bacteria,total anaerobic fungi,total protozoa,Ruminococcus albus,R.flavefaciens,Butyrivibrio fibrisolvens,Fibrobacter succinogenes,and Ruminobacter amylophilus linearly increased(P<0.05).Blood glucose,urea nitrogen,and non-esterified fatty acids linearly decreased(P<0.05),while total protein concentration linearly increased(P=0.04).Moreover,the addition of SB at 200 g/d promoted(P<0.05)mRNA and protein expression of PPARγ,SREBF1,ACACA,FASN,SCD,CCNA2,CCND1,PCNA,Bcl-2,GPR41,and the ratios of p-Akt/Akt and p-mTOR/mTOR,but decreased(P<0.05)mRNA and protein expressions of Bax,caspase-3,and caspase-9.The results suggest that milk production and milk fat synthesis increased with SB addition by stimulating rumen fermentation,nutrient digestion,gene and protein expressions concerned with milk fat synthesis and mammary gland development.

Dietary fibers with low hydration properties exacerbate diarrhea and impair intestinal health and nutrient digestibility in weaned piglets

Background:This study aimed to investigate the hydration properties of different-source fibrous materials by com-paring their water-binding capacity(WBC),water swelling capacity(WSC),viscosity,and in vivo effects of selected samples on growth performance,nutrient digestibility,diarrhea,and intestinal health in weaned piglets.Methods:A total of 13 commercially available fibrous materials were first compared in chemical composition and in vitro hydration property.Subsequently,40 weaned piglets were randomized to five experimental dietary groups(8 piglets per group):control diet(a basal diet without dietary fiber,CON),basal diet supplemented with 5%microcrys-talline cellulose(MCC),5%wheat bran(WB),5%Moringa oleifera leaf powder(MOLP),or 5%sugar beet pulp(SBP),fol-lowed by analyzing their growth performance and diarrhea rate in a 28-d experiment.After the feeding experiment,anaesthetized piglets were killed,and their intestinal and colon content or plasma samples were analyzed in nutrient digestibility,intestinal morphology,intestinal barrier,short-chain fatty acids(SCFAs),and bacterial population.Results:In vitro studies showed low hydration properties for WB and MCC,while medium hydration properties for MOLP and SBP.In vivo studies indicated that compared with medium hydration property groups,low hydration prop-erty groups showed(1)exacerbated diarrhea,impaired intestinal health,and reduced apparent fecal digestibility of dry matter,gross energy,acid detergent fiber,and neutral detergent fiber;(2)decreased SCFAs concentration and rela-tive levels of Lactobacillus and Bifidobacterium,but increased levels of Escherichia coli and Brachyspira hyodysenteriae in colon contents.Additionally,SBP showed optimal performance in reducing diarrhea and increasing SCFAs produc-tion.Correlation analysis revealed a positive correlation of fiber hydration properties with in vitro SCFAs production,and diarrhea index and nutrient digestibility were negatively and positively correlated with SCFAs levels in the colon contents of weaned piglets,respectively.Conclusions:Different-source dietary fibers varied in their hydration properties and impacts on diarrhea,microbial composition and SCFAs production in weaned piglets.WB and MCC could exacerbate diarrhea and impair nutrient digestibility,probably because their low hydration properties were detrimental to gut microbial homeostasis and fermentation.Our findings provide new ideas for rational use of fiber resources in weaned piglets.

Effects of formic acid and corn flour supplementation of banana pseudostem silages on nutritional quality of silage,growth,digestion,rumen fermentation and cellulolytic bacterial community of Nubian black goats

The objective of this study was to evaluate the effects of adding formic acid and corn flour supplementation to banana pseudostem silages on the nutritional quality of these silages,growth,digestion,rumen fermentation and cellulolytic bacterial community of Nubian black goats fed these silages.Banana pseudostem silage was prepared either conventionally without any additives(CON)or mixed with 0.6% formic acid(F),10% corn flour(C),or both(F+C).Four experimental diets containing 40% of the corresponding silages were designed with roughage to concentrate ratio of 50:50(dry matter(DM)basis).A total of 48 Nubian black castrated goats(body weight(BW),(22.64±1.82)kg;4-mon-old)were randomized into one of the four treatment groups with 12 replicates of one castrated goat per replicate for each treatment in a completely randomized design.Each group was fed on one of the four experimental diets for 40 days.A factorial arrangement of treatments of 2(formic acid levels:0 and 0.6%)×2(corn flour:0 and 10%)was adopted.Formic acid supplementation increased(P<0.05)average daily gain,as well as lactic acid,propionate and butyric acid and water-soluble carbohydrate concentrations,but decreased(P<0.05)the feed conversion rate,pH value,acetate/propionate ratio,and butyric acid concentration relative to the CON group.Corn flour supplementation increased(P<0.05)the apparent digestibility of crude protein,neutral detergent fiber,and non-fibrous carbohydrate and Fibrobacter succinogenes,Ruminococcus albus,and Butyrivibrio fibrisolvens populations,but decreased(P<0.05)the Ruminococcus flavefaciens population relative to the CON group.There were no F×C treatment interactions(P>0.05)for any of the other indices except for the apparent digestibility of non-fibrous carbohydrate(NFC)(P<0.05).The results demonstrated that adding 0.6% formic acid and 10% corn flour supplementation to banana pseudostem silages improved the nutritional quality of these silages and enhanced the growth performance of Nubian black castrated goats by improving apparent nutrient digestibility,and regulating ruminal fermentation and bacteria populations.

Amino acid and mineral digestibility,bone ash,and plasma inositol is increased by including microbial phytase in diets for growing pigs

Background The effect of microbial phytase on amino acid and energy digestibility is not consistent in pigs,which may be related to the phytase dosage or the adaptation length to the diet.Therefore,an experiment was conducted to test the hypotheses that increasing dietary phytase after an 18-day adaptation period:1)increases nutrient and energy digestibility;2)increases plasma P,plasma inositol,and bone ash of young pigs;and 3)demonstrates that maximum phytate degradation requires more phytase than maximum P digestibility.Results Data indicated that increasing inclusion of phytase[0,250,500,1,000,2,000,and 4,000 phytase units(FTU)/kg feed]in corn-soybean meal-based diets increased apparent ileal digestibility(AID)of Trp(quadratic;P<0.05),and of Lys and Thr(linear;P<0.05),and tended to increase AID of Met(linear;P<0.10).Increasing dietary phytase also increased AID and apparent total tract digestibility(ATTD)of Ca and P(quadratic;P<0.05)and increased ATTD of K and Na(linear;P<0.05),but phytase did not influence the ATTD of Mg or gross energy.Concentrations of plasma P and bone ash increased(quadratic;P<0.05),and plasma inositol also increased(linear;P<0.05)with increasing inclusion of phytase.Reduced concentrations of inositol phosphate(IP)6 and IP5(quadratic;P<0.05),reduced IP4 and IP3(linear;P<0.05),but increased inositol concentrations(linear;P<0.05)were observed in ileal digesta as dietary phytase increased.The ATTD of P was maximized if at least 1,200 FTU/kg were used,whereas more than 4,000 FTU/kg were needed to maximize inositol release.Conclusions Increasing dietary levels of phytase after an 18-day adaptation period increased phytate and IP ester degradation and inositol release in the small intestine.Consequently,increasing dietary phytase resulted in improved digestibility of Ca,P,K,Na,and the first 4 limiting amino acids,and in increased concentrations of bone ash and plasma P and inositol.In a corn-soybean meal diet,maximum inositol release requires approximately 3,200 FTU/kg more phytase than that required for maximum P digestibility.

The effects of dietary fiber level on nutrient digestibility in growing pigs

The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.

Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake, digestibility, plasma metabolites, ruminal fermentation and fecal microflora of male Chinese Holstein calves

Twenty-eight male, weaned Chinese Holstein calves（（156.8±33.4） kg） were used to investigate the effects of dietary forage to concentrate ratio（F：C） and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement： whole-length forage（WL） with low F：C（50：50）; WL with high F：C（65：35）; short-length forage（SL） with high F：C（65：35）; and SL with low F：C（50：50）. Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size（-50% particles 〉19 mm）. Dry matter intake（DMI） and organic matter（OM） intake was increased by increasing both F：C（P〈0.01） and forage length（FL）（P〈0.05）, while acid detergent fiber（ADF） and neutral detergent fiber（NDF） intakes were only increased by increasing the F：C（P〈0.01）. The digestibility of NDF was increased as the FL increased（P〈0.01）, and it was also affected by interaction between F：C and FL（P〈0.05）. Cholesterol（CHO）（P〈0.01）, leptin（LP）（P〈0.05）, and growth hormone（GH）（P〈0.01） concentrations in plasma were increased as dietary F：C increased. A significant increase in plasma triglyceride（TG）（P〈0.01）, insulin（INS）（P〈0.05）, and GH（P〈0.01） levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F：C diets were significantly lower than those in high F：C treatment（P〈0.05）. Increasing the F：C enhanced ruminal acetic acid（P〈0.05） and acetic acid/propionic acid（P〈0.01）. Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F：C groups（P〈0.05）. Lower fecal scores（higher diarrhea rate） were observed in calves fed with SL hay compared to WL hay（P〈0.05）. Denatured gradient gel electrophoresis（DGGE） bands and richness index（S） were significantly affected by the interaction between F：C and FL（P〈0.05）, under high F：C, band numbers and richness index from WL group were higher than that from SL group（P〈0.05）, whereas there were no differences between WL andSL groups under low F：C（P〉0.05）. Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F：C（65：35） diet is suitable for weaned calves.

Effects of Guar (<i>Cyamopsis tetragonoloba</i>) Residues on the Performance and Nutrients Digestibility in Finishing Awassi Lambs

The nutritive quality of guar (Cyamopsis tetragonoloba) residues (GR) was investigated and the effects of partial replacement of wheat straw by GR on nutrients intake, digestibility, and growth performance. Twenty four male lambs, with average body weight (BW) of 40.3 ± 2.5 kg were divided into three groups. Lambs were fed individually for 104 days with concentrate mixture (18% crude protein) and wheat straw as a total mixed ration. Wheat straw was replaced with 0, 100 and 145 g/kg dry matter guar residues. All rations were isonitrogenous and isocaloric. The fattening trial lasted 104 days. At the end of week 10 of the trail, a digestion trial was performed using six lambs from each group. The composition of nutrients in the GR was 87%, 8.5%, 56.4% and 40.1% for DM, CP, NDF and ADF, respectively. DM and crude protein (CP) intake were not affected by the inclusion of GR. However, neutral detergent fibre (NDF) and acid detergent fibre (ADF) intake were lower in lambs fed GR compared to control lambs. At the end of the experiment, lambs fed 100 and 145 g GR/kg DM diets gained more weight (P < 0.05) than those fed the control diet. The same trend was found for feed conversion (CR). Results from this work suggested that GR had advantages compared to regular roughage (wheat straw) in regard to parameters investigated as well as the significant reduction in fattening diets cost.

Effects of the Standardized Ileal Digestible Lysine to Metabolizable Energy Ratio on Performance,Nutrient Digestibility,and Plasma Parameters of 10 to 28 kg Pigs

A total of 480 nursery pigs （Duroc x Landrace x Large White） were utilized in two experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine （SID- Lys） to metabolizable energy （ME） ratio on the performance, nutrient digestibility, plasma urea nitrogen （PUN） ,and plasma free amino acids of 10 to 28 kg pigs. In Exp. 1, 192 pigs （ 10.58 kg） were assigned to one of four treatments. The treatments consisted of diets with a ME content of 3.2, 3.25, 3.3, or 3.35 Mcal/kg with a constant SID-Lys：ME ratio of 3.7 g/Mcal. The experiment lasted 28 days. Pigs which were fed the diets containing 3.3 and 3.35 Mcal/kg ME had lower feed intakes （ P 〈 0.05）than those fed 3.2 Mcal/kg. Feed efficiency was linearly improved with increasing dietary ME （ P 〈0.05）. Increasing the dietary ME level also increased （P 〈0.05 ） dry matter and energy digestibility. Therefore,3.3 Mcal/kg ME was selected for Exp. 2 in which 288 pigs （ 10.60 kg） were assigned to one of six treatments. Treatments consisted of SID-Lys： ME ratios of 3.1,3.3,3.5,3.7,3.9, or 4.1 g/Mcal with all diets providing 3.3 Mcal of ME/kg. Weight gain and feed efficiency were increased （P 〈0.05 ） as the SID-Lys：ME ratio in diet increased. Based on a straight broken-line model ,the estimated SID-Lys：ME ratio to maximize weight gain was 3.74.

Effects of Xylanase and Protease Supplementation on Nutrient Digestibility in Diets Based on Peas and Wheat Fed to Weaned Pigs

This experiment was conducted to determine the effects of a commercial enzyme mixture providing xylanase and protease activities on the digestibility of dietary nutrients when added to diets based on peas and wheat and fed to 9. 5 to 15 kg pigs. Pigs were weaned at 18 to 21 days of age and fitted with a simple T-cannula at the distal ileum,6 to 7 days after weaning. After 5 to 7 days for adaptation to their diets, ileal digesta, and feces were collected. Enzyme supplementation had no effect on the apparent ileal or fecal digestibility of any dietary nutrient. There was a numerical improvement （ P 〉 0.05 ） in the ileal digestibility of fiber. In conclusion, xylanase and protease appeared to be ineffective in improving nutrient digestibility when supplemented in diets based on peas and wheat fed to weaned pigs.

Effects of Low Protein Diets on Nutrient Digestibility and Excretion in Finishing Pigs

The experiment was conducted to study the effects of low protein diets on nutrient digestibility and excretion of finishing pigs. For the 30-d trial,fortytwo duroc × landrace × yorkshire( DLY) finishing pigs with the initial weight of( 91. 13 ± 1. 64) kg were randomly divided into two groups,with three replicates in each group. The pigs in the two groups were fed with different crude protein( CP) levels( control groups: 15. 49% and low protein groups: 12. 59%). The results showed that:( 1) The digestibility of dry matter and crude fat( CF) in low protein groups were increased significantly( P < 0. 01),but there were no significant differences in digestibility among CP,calcium( Ca) and phosphorus( P);( 2) The digestibility of arginine( Arg) in low protein groups were 2. 02%( P <0. 05) lower than that in control groups. However,the digestibility of other amino acid were no difference between two groups;( 3) The nitrogen( N) excretion in low protein groups was 23. 96%( P < 0. 05) lower than that in control groups,but there were no significant differences in excretion among organic matter,P and Ca( P > 0. 05). The results showed that 2. 9% reduction of the CP in diets could improve nutrient digestibility and reduce the excretion of N,but reduced the digestibility of Arg.

The age at first consumption of forage in calves and its effect on growth and rumination in the short‑and long‑term

Background Previous investigations into the effect of dietary forage on calf performance have been inconsistent,and there is a paucity of information exploring the effect of age on the growth performance and rumination of calves.Eighty-four female Holstein calves(41.5±4.2 kg)were enrolled at birth,a subset of the calves were fed calf starter only(CON,n=21)while the rest(n=63)were classified into three treatment groups:the early(EHAY,n=26,5.1±0.8 d),the middle(MHAY,n=21,7.9±0.8 d)and the late(LHAY,n=16,12.1±1.4 d)hay consumers.The short-term effect of the age at first forage consump-tion(AFF)on calves’feed intake was monitored until d 84.In addition,the long-term effects of AFF on body weight,structural growth and rumination behavior were recorded until d 196.Rumen samples were collected on d 1,7,35,84 and 196 to ana-lyze the rumen fermentation,while fecal samples were collected from d 78 to 84 to estimate digestibility parameters.Results Treatment had no effect on feed intake.While,the EHAY calves tended to have lower BW and ADG compared to LHAY and CON calves.Several total-tract apparent digestibility parameters and digestible nutrients intake were significantly lower in EHAY calves compared with CON and LHAY calves.Calves in the EHAY group tended to begin ruminating ealier,while CON calves were the latest(12.3 vs.15.5 days of age).A treatment and time interaction was present for rumination time due to greater rumination in calves consuming hay compared to CON calves in week 10 to 12,the differences in rumination disappeared afterwards,no long-lasting significant differences in the rumina-tion and rumen fermentation parameters were found between treatments.Conclusions In conclusion,this study showed that hay consumption earlier in life(in the first week,around 5 days of life)could negatively affect the growth of the calf in the short and long term.Compared to consuming hay from the second week(around 12 days of life)or feeding concentrate only without hay,starting to consume hay from the first week could compromise nutrient digestibility and digestible nutrient intake independent of developing rumination behaviour and rumen fermentation.

The Effect of Dietary Supplementation with Phytase Transgenic Corn on Growth Performance,Phosphorus Utilization and Excretion in Growing Pigs (Sus scrofa)

Two experiments were conducted to investigate the effect of dietary supplementation with phytase transgenic corn （PTC） on growth performance,phosphorus （P） utilization and excretion in growing pigs.In Exp.1,180 pigs （Large White × Landrace,BW=37.7 kg） were randomly allotted to 4 treatments with 5 replicates of 9 pigs each in order to evaluate the effect of PTC supplementation in low-P diets on growth performance.Four corn soybean meal-based diets consisted of a positive control （PC） diet,a diet containing 500 units （U） of exogenous phytase kg-1 （EP） on the basis of low-P （inorganic P reduced by 0.05% from PC diet） and the low-P＋500 （PTC1） or 750 （PTC2） phytase U of PTC kg-1.In Exp.2,20 barrows （Large White×Landrace,BW=31 kg,4 treatments with 5 replicates of 1 pig each） were randomly selected to evaluate the effect of PTC in low-P diets on serum parameters and nutrient utilization.Diets in Exp.2 were similar to those in Exp.1 except that the EP group was replaced by a low-P diet without exogenous phytase supplementation as a negative control （NC） group.The results from Exp.1 showed that the average daily gain （ADG） in the PTC2 group was significantly higher （P〈0.05） than that in the EP group over all periods.On the other hand,the feed：gain （F：G） ratio of the EP group was significantly higher （P〈0.05） than that of the PTC2 group during 1-21 and 1-42 d,respectively.There were no differences in average daily feed intake （ADFI） among all treatments （P〉0.05）.The results from Exp.2 showed that the concentration of serum Ca in the NC group was the highest （P〈0.05）,while the concentration of serum P in the PTC2 group was the highest （P〈0.05） among all treatments.There was a significant decrease （P〈0.05） in the P apparent digestibility of the NC group compared with the other groups,and that of PTC2 group was the best.Furthermore,fecal P excretion was reduced （P〈0.05） from 1.80 g d-1 in the PC group to 1.28 g d-1 in the PTC2 group.In conclusion,dietary supplementation with PTC could reduce the application of inorganic P,decrease fecal P excretion,and improve the growth performance of growing pigs.

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.

Lignocellulose as an insoluble fiber source in poultry nutrition:a review

Extensive research in recent years into the use of various fiber sources in poultry nutrition has led to the perception that dietary fiber is more than a simple diet diluent.Several studies showed that the feeding of insoluble fiber sources such as oat hulls,sunflower hulls or wood shavings may affect digestive physiology and function improving chickens health and growth performance.In this context,the effect of lignocellulose as an insoluble dietary fiber source is increasingly being investigated.Lignocellulose is a component of plant cell walls and consists mainly of the insoluble carbohydrate polymers cellulose and hemicelluloses as well as the phenolic polymer lignin.Lignocellulose is chemically and physicochemically different from other insoluble fiber sources and thus possibly has different effects on poultry compared to traditional fiber sources.Several studies investigated the effect of dietary lignocellulose on growth performance,nutrient digestibility,gastrointestinal tract development and intestinal microbiota in broilers and laying hens.Studies differed in terms of feed formulation and lignocellulose inclusion level as well as products of different suppliers were used.The results obtained are inconsistent;beneficial,indifferent or detrimental effects of feeding lignocellulose were observed,so that a final assessment of lignocellulose as a“novel”insoluble fiber source is difficult.This review article summarizes the results of studies in connection with the feeding of lignocellulose to poultry,compares them with those that have used other insoluble fiber sources and illuminates the possible mechanisms of action.

Effects of benzoic acid(Vevo Vitall) on the performance and jejunal digestive physiology in young pigs

Background： As a organic acid, benzoic acid has become one of the most important alternatives for antibiotics,and its beneficial effect on performance in animals has been proven for a decade. However, knowledge of the effects of benzoic acid on jejunal digestive physiology, especially the antioxidant capacity and mucosal glucagon-like peptide2（GLP-2） concentrations is lacking.Methods： A total of 20 barrows [Duroc ×（Yorkshire × Landrace）] with an average body weight（BW） of 18.75 ± 0.2 kg were used in a 14-d trial to determine the potential mechanisms of benzoic acid supplementation on the performance,nutrient digestibility and jejunal digestive physiology in young pigs. All pigs were randomly allotted to 1 of 2 diets supplemented with 0 or 5000 mg/kg benzoic acid.Results： Relative to the control, benzoic acid supplementation increased the average daily feed intake（ADFI）, and average daily gain（ADG） in young pigs（P 〈 0.05）, improved the apparent total tract digestibility of dry matter（DM）,crude protein（CP）, ether extract（EE）, gross energy（GE） and crude ash（P 〈 0.05）, and enhanced the activities of trypsin,lipase and amylase in the jejunum（P 〈 0.05）. Similarly, relative to the control, supplementing benzoic acid in the diet resulted in a trend to reduce the p H values of the digesta（P = 0.06）, decreased crypt depth and increased the villus height to crypt depth ratio（P 〈 0.05） in the jejunum of pigs. Finally, benzoic acid supplementation increased the mR NA expression and concentration of glucagon-like peptide 2 and the activities of glutathione peroxidase and superoxide dismutase in the jejunal mucosa of young pigs（P 〈 0.05）.Conclusions： In conclusion, supplementation with 5000 mg/kg benzoic acid improved the performance of young pigs through promoting nutrient digestion, improving jejunal antioxidant capacity, and maintaining the jejunal morphology in young pigs.

Total Tract Apparent Digestibility, Serum Fatty Acid Profile, and Productive Performances of Mid-lactating Dairy Cows Fed with Dietary Betaine

It is hypothesized that betaine supplementation improves production performance in mid-lactation dairy cows.Twenty-one mid-lactation dairy cows were assigned to a 3×3 Latin square design with three periods of 28 d each and fed three treatments of betaine(0,100,and 200 g/d).Milk samples were collected on day 21 and day 28 of each period.During days 21 to 28,cows were fed with chromic oxide(15 g/d per cow).On days 26 to 28,fecal samples were collected to determine apparent total tract nutrient digestion.Blood samples were obtained on days 26 to 28 of each period for fatty acid(FA)analysis.Data were analyzed using the Proc Mixed in SAS.Apparent total tract dry matter(DM)digestibility tended to be greater for cows supplemented with 100 g betaine as compared to no dietary betaine(61 vs.58±1%;p=0.1).In contrast,DM intake(DMI),milk fat percent,milk yield,energy-corrected milk(ECM)yield,and milk FA composition did not differ among treatments.Supplementation of betaine can decrease the serum saturated FA C11,C12,C15 and C17,total monounsaturated FA,and C18:2 all trans-9,12.In addition,total serum n-3 polyunsaturated FA was significantly increased.This result can decrease total serum n-6 to n-3 ratio(6.80,7.07,and 6.50±0.16%,for 0,100,and 200 g betaine,respectively;p=0.04).Overall,even betaine supplementation did not change DMI or production,betaine could affect the DM digestibility and serum FA biosynthesis.

Wheat silage partially replacing oaten hay exhibited greater feed efficiency and fibre digestion despite low feed intake by feedlot lambs

This study aimed to investigate the feeding effect of wheat silage on growth performance,nutrient digestibility,rumen fermentation,and microbiota composition in feedlot lambs.Sixty-four male crossbred Chinese Han lambs(BW=27.8±0.67 kg,3 months of age)were randomly assigned to four ration groups with wheat silage replacing 0%(WS0),36%(WS36),64%(WS64),and 100%(WS100)of oaten hay on forage dry matter basis.The concentrate-to-forage ratio was 80:20 and the feeding trial lasted 52 d.Increasing wheat silage inclusion linearly decreased dry matter intake by 4%to 27%(P<0.01).However,increasing the wheat silage replacement of oaten hay by no more than 64%improved the feed efficiency by 14%as noted by the feed-to-gain ratio(P=0.04).Apparent digestibility of organic matter(P<0.01),neutral detergent fibre(P=0.04)and acid detergent fibre(P<0.01)quadratically increased.Ammonia nitrogen(P=0.01)decreased while microbial protein production(P<0.01)increased with the increase of wheat silage inclusion.Total volatile fatty acids concentration increased quadratically with the increase of wheat silage inclusion(P<0.01),and the highest occurred in WS64.The molar proportion of acetate(P<0.01)and acetate-to-propionate ratio(P=0.04)decreased while butyrate(P<0.01)and isovalerate(P=0.04)increased.Increasing wheat silage inclusion increased the Firmicutes-toBacteroidota ratio by 226%to 357%,resulting in Firmicutes instead of Bacteroidota being the most abundant phylum.The relative abundance of cellulolytic Ruminococcus numerically increased but that of amylolytic Prevotella(P<0.01)decreased as increasing wheat silage inclusion.Taken together,increasing wheat silage replacement of oaten hay by no more than 64%exhibited greater feed efficiency and fibre digestion despite low feed intake by feedlot lambs due to the change of Firmicutes-to-Bacteroidota ratio in the rumen.

Effect of fermented rapeseed meal on growth performance,nutrient digestibility,and intestinal health in growing pigs

To explore the effects of fermented rapeseed meal(FRSM)on growth performance and intestinal health,a total of 30 growing pigs were randomly allotted to three treatments consisting of corn-soybean meal diet(CSD),rapeseed meal diet(RSD),and fermented rapeseed meal diet(FRSD).Results showed that compared with RSD,FRSD feeding increased the average daily gain and final body weight in pigs(P<0.01).Compared with RSD feeding,FRSD feeding elevated the apparent digestibility of crude protein,acid detergent fiber,and ether extract in pigs(P<0.01).Moreover,the FRSD group exhibited greater apparent ileal digestibility of His,Thr,Lys,and Ser than the RSD group(P<0.01).The digestible energy,metabolic energy,and nitrogen utilization were higher in the FRSD and CSD groups than in the RSD group(P<0.01).As compared to the RSD,FRSD feeding decreased the serum concentration of leptin but significantly increased the concentrations of immunoglobulin(Ig)A,IgG,ghrelin,and enzyme activities of amylase,lipase,and trypsin in the pancreas(P<0.05).Interestingly,the villus height,the ratio of villus height to crypt depth,and the activities of brush border enzymes(e.g.,maltase and sucrase)in the small intestine were higher in the CSD and FRSD groups than in the RSD group(P<0.05).As compared to the RSD,the FRSD feeding not only increased the expression level of the occludin in the small intestinal epithelium(P<0.05)but also elevated the expression levels of claudin-1,MUC1,and PepT1 genes in the duodenum,and elevated the expression levels of SGLT1 and CAT1 genes in the jejunum(P<0.05).Importantly,FRSD feeding significantly decreased the abundance of Escherichia coli,but increased the abundance of Lactobacillus and the content of butyrate in the cecum and colon(P<0.05).These results indicated that compared with rapeseed meal,fermented rapeseed meal exhibited a positive effect on improving the growth performance and intestinal health in growing pigs,and the results may also help develop novel protein sources for animal nutrition and the feed industry.

Fermented soybean meal improves the growth performance, nutrient digestibility, and microbial flora in piglets

In order to increase nutritive values of soybean meal(SBM), 3 species of microbes were used to ferment SBM. Through a 3 x 3 orthogonal design and parameter measurements of soybean peptide and antinutritional factor contents in the fermented soybean meal(FSBM), it was estimated that the best microbial proportion of Bacillus subtilis, Hansenula anomala and Lactobacillus casei was 2:1:2 for SBM fermentation(P < 0.05). The further piglet feeding experiment showed that 10% FSBM substitute for SBM had no significant effect on growth performance of suckling piglets(d 7-28)(P> 0.05). However, newlyweaned piglets(d 28-38) fed 10% FSBM and different levels of plasma protein obtained higher average daily gain(ADG) and feed conversion ratio(FCR), compared with those without FSBM but with 6% plasma protein(P < 0.05). Piglets(d 38-68) fed diets supplemented with FSBM and soybean protein concentrate(SBPC) at 3.75% and 7.5% respectively increased nutrient digestibility,fecal enzyme activity and lactic acid bacteria counts, and decreased fecal Escherichia coli counts(P < 0.05), compared with the control. These data indicated that FSBM had positive effects on nutrient digestibility and fecal microflora for piglets.