Supplementation of vitamin E or a botanical extract as antioxidants to improve growth performance and health of growing pigs housed under thermoneutral or heat-stressed conditions

Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic losses.The objective of this study was to investigate the effects of supplemental vitamin E and a botanical extract in feed or drinking water on growth performance,intestinal health,and oxidative and immune status in grow-ing pigs housed under heat stress conditions.Methods Duplicate experiments were conducted,each using 64 crossbred pigs with an initial body weight of 50.7±3.8 and 43.9±3.6 kg and age of 13-week and 12-week,respectively.Pigs(n=128)were housed individually and assigned within weight blocks and sex to a 2×4 factorial arrangement consisting of 2 environments(thermo-neutral(21.2℃)or heat-stressed(30.9℃))and 4 supplementation treatments(control diet;control+100 IU/L of D-α-tocopherol in water;control+200 IU/kg of DL-α-tocopheryl-acetate in feed;or control+400 mg/kg of a botanical extract in feed).Results Heat stress for 28 d reduced(P≤0.001)final body weight,average daily gain,and average daily feed intake(-7.4 kg,-26.7%,and-25.4%,respectively)but no effects of supplementation were detected(P>0.05).Serum vitamin E increased(P<0.001)with vitamin E supplementation in water and in feed(1.64 vs.3.59 and 1.64 vs.3.24),but not for the botanical extract(1.64 vs.1.67 mg/kg)and was greater when supplemented in water vs.feed(P=0.002).Liver vitamin E increased(P<0.001)with vitamin E supplementations in water(3.9 vs.31.8)and feed(3.9 vs.18.0),but not with the botanical extract(3.9 vs.4.9 mg/kg).Serum malondialdehyde was reduced with heat stress on d 2,but increased on d 28(interaction,P<0.001),and was greater(P<0.05)for antioxidant supplementation compared to control.Cellular proliferation was reduced(P=0.037)in the jejunum under heat stress,but increased in the ileum when vitamin E was supplemented in feed and water under heat stress(interaction,P=0.04).Tumor necrosis factor-αin jejunum and ileum mucosa decreased by heat stress(P<0.05)and was reduced by vitamin E sup-plementations under heat stress(interaction,P<0.001).Conclusions The addition of the antioxidants in feed or in drinking water did not alleviate the negative impact of heat stress on feed intake and growth rate of growing pigs.

Oils with different degree of saturation:effects on ileal digestibility of fat and corresponding additivity and bacterial community in growing pigs

Background Oils are important sources of energy in pig diets.The combination of oils with different degree of saturation contributes to improve the utilization efficiency of the mixed oils and may reduce the cost of oil supplemented.An experiment was conducted to evaluate the effects of oils with different degree of saturation on the fat digestibility and corresponding additivity and bacterial community in growing pigs.Methods Eighteen crossbred(Duroc×Landrace×Yorkshire)barrows(initial body weight:29.3±2.8 kg)were surgically fitted with a T-cannula in the distal ileum.The experimental diets included a fat-free basal diet and 5 oil-added diets.The 5 oil-added diets were formulated by adding 6%oil with different ratio of unsaturated to saturated fatty acids(U:S)to the basal diet.The 5 oils were palm oil(U:S=1.2),canola oil(U:S=12.0),and palm oil and canola oil were mixed in different proportions to prepare a combination of U:S of 2.5,3.5 and 4.5,respectively.Results The apparent and standardized ileal digestibility(AID and SID)of fat and fatty acids increased linearly(P<0.05)as the U:S of dietary oils increased except for SID of fat and C18:2.The AID and SID of fat and fatty acids differed among the dietary treatments(P<0.05)except for SID of unsaturated fatty acids(UFA)and C18:2.Fitted one-slope broken-line analyses for the SID of fat,saturated fatty acids(SFA)and UFA indicated that the breakpoint for U:S of oil was 4.14(R^(2)=0.89,P<0.01),2.91(R^(2)=0.98,P<0.01)and 3.84(R^(2)=0.85,P<0.01),respectively.The determined SID of fat,C18:1,C18:2 and UFA in the mixtures was not different from the calculated SID of fat,C18:1,C18:2 and UFA.However,the determined SID of C16:0,C18:0 and SFA in the mixtures were greater than the calculated SID values(P<0.05).The abundance of Romboutsia and Turicibacter in pigs fed diet containing palm oil was greater than that in rapeseed oil treatment group,and the two bacteria were negatively correlated with SID of C16:0,C18:0 and SFA(P<0.05).Conclusions The optimal U:S for improving the utilization efficiency of mixed oil was 4.14.The SID of fat and UFA for palm oil and canola oil were additive in growing pigs,whereas the SID of SFA in the mixture of two oils was greater than the sum of the values of pure oils.Differences in fat digestibility caused by oils differing in degree of saturation has a significant impact on bacterial community in the foregut.

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.

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.

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.

Chemical composition,energy and amino acid digestibility in double-low rapeseed meal fed to growing pigs

Background： The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understandin9 of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs. This study was conducted to determine the chemical composition, dicjestible energy （DE） and metabolizable enercjy （ME） content, and apparent ileal digestibility （AID） and standardized ileal dicjestibility （SID） of amino acids （AA） for growincj pigs. Thirteen solvent-extracted double-low rapeseed meal （DLIRSM） samples were obtained from the main double-low rapeseed producing areas in China. Methods： The DE and ME contents of the 13 DLRSM samples were measured in cjrowin9 pigs （six pigs per DLRSM sample, average initial body weicjht （BW） =48.3 kg）. The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows （average initial BW = 35.3 kcj） by using two 6 x 6 Latin square designs. Each Latin square comprised one N-flee diet and 5 DLRSM test diets. Results： The chemical composition of DLRSM varied among samples, and the coefficient of variation was greater than ]0 % for ether extract （EE）, neutral detergent fiber （NDF）, acid detergent fiber （ADF）, calcium （Ca）, and total 91ucosinolates. The AA content of DLRSM varied among samples especially for lysine （Lys） and methionine （Met）. On a dry matter （DM） basis, the apparent total tract digestibility （ATFD） of gross energy （GE）, the DE and ME and the ME：DE ratio of DLRSM averaged 62.39 %, 2862 kcal/k9 and 2723 kcal/kcj, and 94.95 %, respectively. The mean value of S1D of Lys was 70.52 % which varied from 66.54-76.54 %. The SID of crude protein （CP）, Met, and threonine （Thr） averaged 72.81%, 82.41%, and 69.76 %, respectively. Conclusions： There was great variability in chemical composition especially in the concentration of EE, NDF and ADF, but no significant differences in energy content of the DLIRSM samples were observed. In addition, the AID and SID of all AA were relatively similar amoncj DLRSM samples except for that of Lys.

Ileum terminal antibiotic infusion affects jejunal and colonic specific microbial population and immune status in growing pigs

Background: Compared with oral antibiotics(primarily disrupt foregut microbiota), the present study used antibiotics with ileum terminal infusion to disrupt the hindgut microbiota, and investigated the changes in specific bacterial composition and immune indexes in the jejunum and colon, and serum of growing pigs. Twelve barrows(45 d of age, 12.08 ± 0.28 kg) fitted with a T-cannula at the terminal ileum, were randomly assigned to two groups and infused either saline without antibiotics(Control) or with antibiotics(Antibiotic) at the terminal ileum. After 25 d experiment, all pigs were euthanized for analyzing bacterial composition and immune status.Results: Ileum terminal antibiotic infusion(ITAI) altered dominant bacteria counts, with a decrease in Bifidobacterium, Clostridium cluster IV and Clostridium cluster IV in the colon(P < 0.05), and an increase in Escherichia coli in the jejunum(P < 0.05). ITAI decreased(P < 0.05) short-chain fatty acids concentrations in the colon. ITAI decreased interleukin-8(IL-8), IL-10 and secretory immunoglobulin A(sIgA) concentrations, and down-regulated IL-10, Mucin-1(MUC1), Mucin-2(MUC2) and zonula occludens-1(ZO-1) mRNA expression in the colonic mucosa(P < 0.05). In the jejunal mucosa, ITAI decreased interferon-γ(IFN-γ), tumor necrosis factor-α(TNF-α), s IgA and IgG levels together with down-regulation of IFN-γ, TNF-α, MUC2 and ZO-1 mRNA expression(P < 0.05). Furthermore, ITAI decreased IL-10, INF-γ, TNF-α, IgA and IgG concentrations in serum(P < 0.05). Correlation analysis revealed that the change in intestinal microbiota was correlated with alterations of Ig and cytokines.Conclusions: ITAI affected jejunal and colonic specific bacteria counts, and altered some immune markers levels in the jejunal and colonic mucosa and serum. These findings implicate the potential contribution of hindgut bacteria to immune response in the intestinal mucosa and serum of growing pigs.

Effect of Bacillus subtilis and Bacillus licheniformis supplementation in diets with low-and high-protein content on ileal crude protein and amino acid digestibility and intestinal microbiota composition of growing pigs

Background： Bacillus spp. seem to be an alternative to antimicrobial growth promoters for improving animals＇ health and performance. However, there is little information on the effect of Bacillus spp. in combination with different dietary crude protein（CP） levels on the ileal digestibility and microbiota composition. Therefore, the objective of this study was to determine the effect of Bacillus spp. supplementation to low-（LP） and high-protein diets（HP） on ileal CP and amino acid（AA） digestibility and intestinal microbiota composition.Methods： Eight ileally cannulated pigs with an initial body weight of 28.5 kg were randomly allocated to a rowcolumn design with 8 pigs and 3 periods of 16 d each. The assay diets were based on wheat-barley-soybean meal with two protein levels： LP（14% CP, as-fed） and HP diet（18% CP, as-fed）. The LP and HP diets were supplemented with or without Bacil us spp. at a level of 0.04%（as-fed）. The apparent ileal digestibility（AID） and standardized ileal digestibility（SID） of CP and AA was determined. Bacterial community composition from ileal digesta was analyzed by Illumina amplicon sequencing and quantitative real-time PCR. Data were analyzed as a 2 × 2 factorial design using the GLIMMIX procedures of SAS.Results： The supplementation with Bacillus spp. did not affect both AID and SID of CP and AA in growing pigs.Moreover, there was no difference in AID of CP and AA between HP and LP diets, but SID of cystine, glutamic acid,glycine, and proline was lower（P 〈 0.05） in pigs fed the HP diets. The HP diets increased abundance of Bifidobacterium spp. and Lactobacillus spp.,（P 〈 0.05） and by amplicon sequencing the latter was identified as predominant genus in microbiota from HP with Bacillus spp., whereas dietary supplementation of Bacillus spp. increased（P 〈 0.05） abundance of Roseburia spp.Conclusions： The HP diet increased abundance of Lactobacillus spp. and Bifidobacterium spp.. The supplementation of Bacil us spp. resulted in a higher abundance of healthy gut associated bacteria without affecting ileal CP and AA digestibility, whereas LP diet may reduce the flow of undigested protein to the large intestine of pigs.

Use of near-infrared reflectance spectroscopy for the rapid determination of the digestible energy and metabolizable energy content of corn fed to growing pigs

Background： The ability of near-infrared reflectance spectroscopy（NIRS） to determine the digestible energy（DE）and metabolizable energy（ME） content of corn fed to growing pigs was tested. One hundred and seventeen corn samples, comprising different planting regions and varieties were collected from all over China in a three-year period. The samples were randomly split into a calibration set（n = 88） and a validation set（n = 29）. The actual and calculated DE and ME content of the corn samples was determined by digestion-metabolism experiments and the prediction equations of Noblet and Perez（J Anim Sci. 71：3389–98,1993）. The samples were then subjected to NIRS scanning and calibrations were performed by the modified partial least square（MPLS） regression method based on77 different spectral pre-treatments. The NIRS equations based on the actually determined and calculated DE and ME were built separately and then validated using validation samples.Results： The NIRS equations obtained from actually determined DE, the coefficient of determination for calibration（RSQcal）, cross-validation（R^2CV）, and validation（RSQv） were 0.89, 0.87 and 0.86, and these values for determined ME were 0.87, 0.86 and 0.86. For the NIRS equations built from calculated DE, the RSQcal, R^2CV, and RSQvvalues were 0.88, 0.85 and 0.84, and these values for calculated ME were 0.86, 0.84 and 0.82. Except for the equation based on calculated ME（RPD_v= 2.38, 〈 2.50）, the other three equations built from actually determined energy and calculated DE produced good prediction performance（RPD_vranging from 2.53 to 2.69, 〉 2.50） when applied to validation samples.Conclusion： These results indicate that NIRS can be used as a quantitative method for the rapid determination of the available energy in corn fed to growing pigs, and the NIRS equations based on the actually determined energy produced better predictive performance than those built from calculated energy values.

The Effect of Soybean Meal Fermented by Aspergillus usami on Phosphor Metabolism in Growing Pigs

[Objective] The experiment aimed to check the pigs＇ digestive utilization of phosphor and other nutrient components in fermented soy- bean meal. [ Method] 15 8-week old two-way cross growing pigs （average weight was 23.6 kg） were selected and divided randomly into 3 groups, 5 pigs per group. The method of total feces collection was adopted to compare the digestibility of phosphor and other nutrient components in growing pigs fed respectively by fermented soybean meal by Aspergillus usami and normal soybean meal. The experimental design were normal soybean group （NS group, P： 0.087%）, fermented soybean meal group （FS group, P： 0.089%）, normal soybean ＋ fermented soybean meal mixing group （ MS group, P： 0.089% ）. [ Result] The results indicated that the digestibility of growing pigs in FS group was significantly higher than that of NS group. Meanwhile, the digestibility of crude protein was significantly improved. [ Conclusion] The above results indicated that Feeding with soybean meal fermented by Aspergillus usami not only could increase the digestibility of phosphor and protein, but also decrease the excretion of phosphor and nitrogen.

Determination of basal ileal endogenous losses and standardized ileal digestibility of amino acids in barley fed to growing pigs

Background： Basal ileal endogenous amino acid（AA） losses（IAAend） and standardized ileal digestibility（SID） values of cereal grains, such as barley, are apparently underestimated when determined according to the nitrogen（N）-free method. Regression analysis between the dietary apparent ileal digestible content（c AID） and total crude protein（CP） and AA can be considered as alternative approach to obtain more accurate values for IAAendand SID of AA in cereal grains.Methods： Eight hulled barley genotypes were used, with barley being the only source of CP and AA in the assay diets. The diets contained 95 % as-fed of these eight barley genotypes each, ranging in CP content between 109.1 and 123.8 g/kg dry matter（DM）. Nine ileally T-cannulated barrows, average body weight（BW） 30 ± 2 kg, were allotted to a row-column design comprising eight periods with 6 d each and nine pigs. On d 5 and the night of d 6 of every period, ileal digesta were collected for a total of 12 h. The IAAend and the SID were determined by linear regression analysis between c AID and total dietary CP and AA.Results： There exist linear relationships between cA ID and total CP and AA（P 〈 0.001）. The IAAend of CP, Lys, Met, Thr and Trp amounted to 35.34, 1.08, 0.25, 1.02 and 0.38 g/kg DM intake（DMI）, respectively, which are greater compared to average IAAend determined previously under N-free feeding conditions. The SID of CP, Lys, Met, Thr and Trp was 90,79, 85, 79 and 86 %, respectively, and was greater when compared to tabulated values. Moreover, these SID values were greater than those reported in literature, based on correction of apparent ileal digestibility（AID） of CP and AA for their IAAendvalues. Summarized, the results of the present regression analysis indicate greater IAAendin barley-based diets compared to those obtained by N-free feeding.Conclusions： For low-protein feed ingredients like barley the regression method may be preferred over correction of AID values for their IAAenddetermined under N-free feeding conditions, as intercepts and slopes of the linear regression equations between cA ID and total dietary CP and AA provide direct estimates of IAAendand SID of CP and AA in the presence of the assay feed ingredient.

Methodological impact of starch determination on starch content and ileal digestibility of starch in grain legumes for growing pigs

Background： Grain legumes represent a valuable energy source in pig diets due to their high starch content. The present study was conducted to determine the content and apparent ileal digestibility（AID） of starch in different grain legume cultivars for pigs by means of both a polarimetric and enzymatic method for starch determination.Methods： Three experiments were conducted with six barrows each which were fitted with ileal T-cannulas. In total, 18 diets including six different cultivars of faba beans（Vicia faba L.） and peas（Pisum sativum L.）, five different cultivars of lupins（Lupinus luteus L., Lupinus angustifolius L.）, and one diet with a soybean meal（SBM） were fed.Results： The starch content of faba beans and peas was greater（P ＆lt; 0.05） when determined polarimetrically than enzymatically（438 vs. 345 g/kg dry matter（DM） in faba beans and 509 vs. 390 g/kg DM in peas, respectively）.Considerable lower starch contents were obtained in lupins and SBM, with 82 and 48 g/kg DM（analyzed polarimetrically） and ＆lt;1.1 and 3 g/kg DM（analyzed enzymatically）, respectively. Mean values for contents of neutral detergent fiber（NDF） and acid detergent fiber（ADF） in grain legumes ranged from 111 and 79 g/kg DM in peas to248 and 207 g/kg DM in lupins, respectively. Contents of condensed tannins in the colored flowered faba bean cultivars ranged from 2.1 to 7.4 g/kg DM. The AID of starch was greater（P ＆lt; 0.05） in pea than in faba bean cultivars,and using the polarimetric starch determination method resulted in greater（P ＆lt; 0.05） digestibility values than using enzymatic starch analysis（84 vs. 80% in faba beans and 86 vs. 83% in peas）. Moreover, AID of starch differed（P ＆lt; 0.05）within pea cultivars and starch digestibility in faba beans decreased linearly（P ＆lt; 0.05） as the content of condensed tannins increased. However, there was no relationship between contents of NDF and ADF and AID of starch in pea and faba bean cultivars.Conclusion： Both contents and AID of starch in grain legumes can vary as influenced by the analytical method used for starch determination. Generally, starch digestibility is greater when measured by polarimetric rather than enzymatic methods.

Effects of Dietary Starch Source on Nutrient and Energy Absorption via the Portal Vein of Growing Pigs

Four crossbred （Duroc x Landrace x Yorkshire） boars, weighing an average of 22.40 ± 1.08 kg and fitted with permanent catheters in their portal and mesenteric veins as well as their carotid artery,were utilized in a 4 × 4 latin square design experiment in order to investigate the effects of different starch sources （maize ,brown rice, sticky rice, and resistant starch） on the absorption of energy sources through the portal vein. Portal blood flow averaged 30.68, 28.40, 29.99, and 30. 12 mL/min per kg BW for pigs fed the maize, brown rice, sticky rice, and resistant starch diets, respectively, and did not dif- fer （P 〉 0.05） between treatments. The absorptions of glucose, plasma ammonia, and total amino acids were significantly lower （P 〈 0.05 ） in pigs fed the resistant starch diet than pigs fed the other starch sources. In contrast, significantly （ P 〈 0.05 ） higher amounts of propionate and total volatile fatty acids were absorbed from the portal vein of pigs fed resistant starch than pigs fed diets based on maize, brown rice, or sticky rice. In addition, significantly （P 〈 0.05） more lactic acid was absorbed from the portal vein by pigs fed the sticky rice diet than pigs fed the other three diets. The energy absorbed from the portal vein in the form of glucose and amino-N as well as the total energy absorbed was significantly （P 〈 0.05） lower in pigs fed the resistant starch diet than pigs fed the other three starch sources. In contrast, the amount of energy absorbed in the form of volatile fatty acids was significantly （P 〈 0.05 ） higher in pigs fed resistance starch than pigs fed the other three starch sources. The total energy absorbed through the portal vein as a percentage of the gross energy and digestible energy consumed in pigs fed maize were 50.8% and 54.6%, respectively, which were significantly （P 〈 0.05 ） higher than the values in pigs fed resistant starch （41.5% and 46.6% respectively）. The results indicate that energy is absorbed in different forms and with different utilization efficiencies in the digestive tract of pigs as a result of feeding different starch sources. Starch sources supplying most of their energy in the form of glucose had higher energy utilization efficiencies, while starch sources supplying most of their energy in the form of volatile fatty acids or lactic acid had lower energy utilization efficiencies.

Supplemental Effects of Zinc Oxide on the Utilization of Cassava Plant Meal by Growing Pigs in the Humid Tropics

The objective of this study was to evaluate the effects of zinc oxide （ZnO） as an additive on cassava plant meal through the growth, serum metabolites and heamatological indices of growing pigs for eight weeks. Four experimental diets were formulated in this study. All the four diets contained 60% cassava plant meal. Diet 1 contained 0 ppm of ZnO, while diets 2, 3 and 4 contained 125, 250 and 300 ppm of ZnO, respectively. The cassava plant meal contained unpeeled tuber plus leaves and tender stems. The unpeeled cassava tuber was mixed with leaves and tender stem at ratio 2.5：1, while the ratio of the leaves and tender stem was 5：1. A total of 16 growing pigs （Large White x Hampshire） with initial mean weight of 24.92 - 0.37 kg were used in this study. They were randomly distributed into the four experimental diets formulated. There were four animals per diet and each animal served as a replicate. The diets were formulated to contain about 19% crude protein and 2.5 kcal/g metabolizable energy. This experiment was completely randomized designed. The results of this study showed that weight gain, feed intake and feed conversion ratio were not significantly （P 〉 0.05） affected by the inclusion of ZnO, although numerically 250 ppm gave the better values. The serum metabolites, such as the total protein, albumin, urea and cholesterol, were not significantly （P 〉 0.05） affected by the inclusion of ZnO. However, the serum creatinine and glucose were significantly （P 〈 0.05） affected. Moreover, haematological indices, such as the packed cell volume （PCV）, haemoglobin （FIB） and red blood cell （RBC）, were not significantly （P 〉 0.05） affected by the inclusion of ZnO; while the white blood cell （WBC） was significantly （P 〈 0.05） affected. It can be concluded from this study that ZnO could be used as an additive to improve the utilization of cassava plant meal by growing pigs.

Influence of dietary Lys levels and dietary net energy levels on growth performance and nitrogen balance of growing pigs

Two experiments were conducted to determine the effects of L y s ine（Lys） and Net Energy （NE） levels on growth performance （Exp. I） and N balance （Exp. 2） in growing pig. In Exp. 1, 36 castrated pigs [21.35 -4- 0.55 kg of body weight （BW）] were allotted to six treatments with six replicates per treatment. Pigs were fed two levels of Lys （low and high） and three levels of NE （low, med, or high） in a 2×3 factorial arrangement. The experiment lasted for 35 d. There were no effects of dietary Lys and NE on pig performance （P〉0.05, but a Lys×NE interaction in ADG was observed （P〈0.05）. In Exp. 2, 24 pigs were used to determine the effects of diet in Exp. 1 on pig N balance. Neither Lys nor NE level affected N retention （g/d） （P〉0.0）. Lys×NE interaction in N retention （g/d） （P〈0.01） and in N apparent biological value （ABV） （P〈0.05） was observed. Pigs fed the low Lys diet had lower serum urea nitrogen （SUN） concentrations compared with the high Lys treatment （P〈0.01）. Pigs fed the med-NE diet had lower SUN concentrations compared with the pigs fed the low-NE diet （P〈0.1）. These results suggest that pigs from 21 kg to 50 kg BW fed diets containing 0.83% standardized ileal digestible Lysine and 2351 Kcal of NE/kg had maximum ADG and N retention.

Effects of Exogenous NSP Enzymes(Xylanase, β-glucanase and Cellulase) on Morphology and Functions of Digestive Tract in Growing Pigs Fed with Paddy-Based Diets

Ninety Landrace×Jia 35±0. 40 kg weight growing pigs were randomly allotted to three treatments , each of which was replicated three times with ten pigs per replicate. The pigs were reared on either a conventional corn-based diet (control I ) or a paddy-based diet (control I ) or a paddy diet supplemented with 0.2% NSP enzymes (test group). All pigs were given ad libitum access to both feed and water. The results of feeding trial showed that supplementation of NSP enzymes significantly increased ADG by 8.78% (P< 0.05) and decreased F/G by 9. 42% (P<0. 05) over the control group Ⅱ. No significant differences were found in ADG and F/G between control group I and the test group. The digestive trial showed that adding NSP enzymes significantly improved apparent digestibility of CP, EE and CF by 18. 76 (P<0. 01), 16.04 (P <0.05) and 108. 57%(P<0. 05), respectively, compared to control Ⅱ. The activities of proteolytic enzyme and α-amylase in duodenal contents were increased by 99. 07 (P<0. 01) and 18. 41% (P<0. 05) with the addition of NSP enzymes. No significant differences between test and control Ⅱ group were found in activities of the pepsin in the gastric content, the trypsin and lipase in duodenal contents. the disaccharidase and y-glutany transferase (γ-GT) in intestinal mucosa, but there was a tendency towards higher activities associated with the NSP enzymes diet(P>0. 05). The lengths of the villi within the duodenal, jejunal and ileal sections of the small intestine of pigs receiving the NSP enzymes diet were increased by 23. 68 (P<0. 05), 56. 00 (P<0. 01) and 76. 90%(P<0. 01) respectively, relative to the pigs in controlⅡ.

Effects of Multi-enzyme Preparations on Growth Performance, Apparent Total Tract Digestibility and In Vitro Digestibility for Growing Pigs

The aim of this study was to investigate the effects of enzyme supplementations on performance of growing pigs, apparent total tract digestibility （ATTD） and in vitro digestibility （IVD） of nutrients. 224 growing pigs weighing 30-4-1.2 kg were allocated to fed basal diets supplemented with 0, 0.1, 0.15 or 0.2 g/kg enzyme preparations in growth trail. Those four diets were used for in vio＇o digestibility study. Pigs fed enzyme-supplemented diets improved average daily gain and decreased ratio of feed/gain （P〈0.05）. Enzyme supplementations increased ATTD of dry matter, energy, crude protein, neutral detergent fiber, acid detergent fibre and hemicellulose （P〈0.05）. Supplementation with enzymes improved reducing sugar production and the IVD of dry matter, crude protein, neutral detergent fiber, acid detergent fibre, total arabinoxylans, galacturonic acid, hemicellulose and cellulose. 0.015% enzyme supplementation in diets seemed to be sufficient to achieve maximum growth performance, nutrients digestibilities and reducing sugar production. Collectively, these results suggested that the supplementation of enzymes in diet increased the digestibilities of nutrients through the promotion of NSP degradation, thereby enhancing growth performance of growing pigs.

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.

Time-course effects of different fiber-rich ingredients on energy values,microbiota composition and SCFA profile in growing pigs

This study was to investigate time-course effects of different types of dietary fiber on the energy values,fecal microbiota and short-chain fatty acid(SCFA)concentration in growing pigs.A total of 24 barrows(initial body weight,19.8±0.5 kg)were assigned to 4 dietary treatments based on body weight(BW)in a completely randomized design,including a basal diet(CON)and 3 fiber-rich diets replacing corn,soybean meal and soybean oil in the CON diet with 20%sugar beet pulp(SBP),defatted rice bran(DFRB)or soybean hull(SBH),respectively.Fresh feces were sampled on d 7,14 and 21,followed by 5 d total feces and urine collections.The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7,14 or 21.However,fiber inclusion decreased the DE and ME of the diet(P<0.05)regardless of the time effect.Principal coordinate analysis(PCoA)revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times(P<0.05)and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point(P<0.05).With adaptation time increased from 7 to 21 d,cellulose-degrading bacteria and SCFA-producing bacteria(e.g.,Ruminococcaceae_UCG-014,Rikenellaceae_RC9_gut_group and Bifidobacterium)increased in the fiber inclusion diets,and pathogenic genera(e.g.,Streptococcus and Selenomonas)were increased in the basal diet(P<0.05).Furthermore,the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet,as reflected by the concentration of propionate,butyrate,isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet(P<0.05).Collectively,our results indicated at least 7 d adaptation was required to evaluate the energy values of fiber-rich ingredients,as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet,especially for insoluble dietary fiber.

iTRAQ-based quantitative proteomic analysis of longissimus muscle from growing pigs with dietary supplementation of non-starch polysaccharide enzymes

Non-starch polysaccharide enzymes（NSPEs） have long been used in the feed production of monogastric animals to degrade non-starch polysaccharide to oligosaccharides and promote growth performance. However, few studies have been conducted on the effect of such enzymes on skeletal muscle in monogastric animals. To elucidate the mechanism of the effect of NSPEs on skeletal muscle, an isobaric tag for relative and absolute quantification（i TRAQ） for differential proteomic quantitation was applied to investigate alterations in the proteome in the longissimus muscle（LM） of growing pigs after a 50-d period of supplementation with 0.6% NSPEs in the diet. A total of 51 proteins were found to be differentially expressed in the LM between a control group and the NSPE group. Functional analysis of the differentially expressed protein species showed an increased abundance of proteins related to energy production, protein synthesis, muscular differentiation, immunity, oxidation resistance and detoxification, and a decreased abundance of proteins related to inflammation in the LM of the pigs fed NSPEs. These findings have important implications for understanding the mechanisms whereby dietary supplementation with NSPEs enzymes can promote growth performance and improve muscular metabolism in growing pigs.