Effects of particle size and phytase supplementation on apparent and standardized total tract digestibility of phosphorus in hybrid rye fed to growing pigs.

An experiment was conducted to investigate the effects of particle size (PS) and levels of phytase supplementation on the apparent (ATTD) and standardized (STTD) total tract digestibility of P in hybrid rye fed to growing pigs. Thirty-six growing barrows (23.6 ± 1.5 kg initial BW) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six dietary treatments were arranged in a 2 × 3 factorial with main effects of PS and phytase supplementation levels (0, 500, or 2,500 FTU/kg). Hybrid rye was ground using a hammermill mounted with 4.0- and 3.2-mm screens to obtain material with coarse and fine PS, respectively. Pigs were fed experimental diets for 11 d, including 5 d for adaptation and 6 d for total collection of feces. All data were analyzed using the MIXED procedure of SAS with PS, phytase, and their interaction as fixed effects. Orthogonal polynomial contrasts were used to test linear and quadratic effects of phytase level in both coarse and fine hybrid rye diets. The ATTD and STTD of P were greater (P < 0.05) in diets with fine than in those with coarse hybrid rye. Increasing levels of phytase supplementation linearly (P < 0.01) and quadratically (P < 0.01) improved the ATTD and STTD of P in hybrid rye diets. There were no interaction effects between PS and phytase supplementation on the ATTD and STTD of P in hybrid rye diets. In conclusion, PS reduction improved the digestibility of P in hybrid rye, and supplementing increasing levels of phytase improved P digestibility in linear and quadratic manner in growing pigs fed hybrid rye diets.

Cereal grains such as corn, wheat, and barley are widely used as an energy source in swine diets. However, due to their recent soaring prices, it is necessary to use alternative feedstuffs for swine. New commercial hybrid rye with improved ergot resistance and higher yield has been developed. This hybrid rye contains similar energy content as barley and sorghum, making it a promising ingredient for pigs. Phosphorus is an essential nutrient in swine diets for bone growth and cellular functions. However, most phosphorus in hybrid rye is bound to phytic acid, which is not digested well by pigs. The excessive phosphorus in swine manure may runoff and cause environmental problems such as eutrophication. Increasing phosphorus digestibility can decrease its excretion in pigs. Therefore, in the current study, we formulated six diets including fine or coarse hybrid rye particle size supplemented with three levels of phytase to determine the effects of particle size and phytase supplementation on phosphorus digestibility in hybrid rye. Our results showed that fine particle size and supplementing increasing levels of phytase could improve the phosphorus digestibility in growing pigs fed hybrid rye diets.

Flaxseed meal and oat hulls supplementation: impact on predicted production and absorption of volatile fatty acids and energy from hindgut fermentation in growing pigs.

A combination of in vivo (ileal cannulated pigs) and in vitro (fecal inoculum-based incubation) methodologies were used to predict the effects of dietary supplementation with soluble or insoluble dietary fiber on hindgut VFA production and absorption. Energy contribution from hindgut VFA and apparent ileal (AID) and total tract (ATTD) digestibility of energy and DM was also investigated. Twelve ileal cannulated Genesus barrows (initial BW: 35.1 ± 0.44 kg) were allocated to 1 of the 3 corn-soybean meal-based diets without (control), or with flaxseed meal (FM) or oat hulls (OH) in a 2-period cross-over design. Flaxseed meal and oat hulls were used as sources of soluble and insoluble fiber, respectively. In each period, 4 pigs were offered 1 of the 3 diets, for 12 d followed by fecal (day 13 and 14) and ileal digesta collection (day 15 and 16) (n = 8). Ileal digesta were collected, freeze-dried, and subjected to in vitro fermentation using fecal inoculum, to predict production and absorption of VFA and energy production, and digestibility of DM and energy. The quantity of acetic, propionic, butyric, and valeric acids produced by in vitro fermentation was higher (P < 0.05) for the diet containing flaxseed meal compared with the control and OH diets. The predicted quantity of VFA produced and absorbed in the hindgut was greater (P < 0.05) in pigs that consumed the FM diet than those fed the control or OH diet. Pigs fed the control diet had greater (P < 0.05) AID and ATTD of DM than pigs offered the OH or FM diet. The determined disappearance of DM was lower (P < 0.05) in pigs fed the control and OH diets than in pigs that consumed the FM diet. The quantity of digested energy in the upper gut was reduced (P < 0.05) more in pigs fed the OH diet than in pigs fed the FM diet. The consumption of the FM diet increased (P < 0.05) the quantity of digested energy, energy produced and absorbed from VFA in the hindgut, and the percentage contribution of VFA from fermentation to total tract digestible energy, compared with the control and OH diets. In conclusion, dietary supplementation with insoluble fiber from oat hulls reduced ileal digested energy more than soluble fiber from flaxseed meal. Addition of soluble fiber to pig diets increased the energy contribution from VFA produced by hindgut fermentation to the total tract digestible energy, compared with dietary addition of insoluble fiber.

Interactive effects of dietary fibre and lipid types modulate gastrointestinal flows and apparent digestibility of fatty acids in growing pigs.

A total of eight ileal and caecal cannulated Yorkshire barrows were used to determine the interactions of dietary fibre (DF) and lipid types on apparent digestibility of DM and fatty acids (FA) and FA flows in gastrointestinal segments. Pigs were offered four diets that contained either pectin or cellulose with or without beef tallow or maize oil in two Youden square designs (n 6). Each period lasted 15 d. Faeces, ileal and caecal contents were collected to determine apparent ileal digestibility (AID), apparent caecal digestibility and apparent total tract digestibility (ATTD) of dietary components. The interactions between DF and lipid types influenced (P <0·05) the digestibility of DM and FA flows. The addition of maize oil decreased (P <0·05) AID of DM in pectin diets, and the addition of beef tallow depressed (P <0·001) ATTD of DM in cellulose diets. Dietary supplementation with beef tallow decreased (P <0·05) the AID of FA in pectin-containing diets but had no effects in cellulose-containing diets. Dietary supplementation with beef tallow increased (P <0·05) AID of SFA and PUFA and the flow of ileal oleic, vaccenic, linolenic and eicosadienoic acids and reduced the flow of faecal lauric, docosatetraenoic and docosapentaenoic acids in pectin- and cellulose-containing diets. In conclusion, the interaction between DF type and lipid saturation modulates digestibility of DM and lipids and FA flows but differs for soluble and insoluble fibre sources, SFA and unsaturated fatty acids and varies in different gastrointestinal segments.

Ammonia-Nitrogen Added to Low-Crude-Protein Diets Deficient in Dispensable Amino Acid-Nitrogen Increases the Net Release of Alanine, Citrulline, and Glutamate Post-Splanchnic Organ Metabolism in Growing Pigs.

Background: Dietary ammonia is rapidly absorbed but poorly used for urea synthesis in pigs fed low-crude-protein (low-CP) diets deficient in dispensable amino acid (DAA)-nitrogen. Objective: We explored the effect of dietary ammonia on net amino acid (AA) balances in portal-drained viscera (PDV) and livers of pigs fed a diet deficient in DAA-nitrogen. Methods: Eight barrows with an initial body weight (BW) of 26.5 ± 1.4 kg (mean + SD) were surgically fitted with 4 catheters each (portal, hepatic, and mesenteric veins and carotid artery). The pigs were restricted-fed (2.8 × 191 kcal/kg BW0.60) for 7 d, and every 8 h a diet deficient in DAA-nitrogen supplemented with increasing amounts of ammonia-nitrogen (CP = 7.76%, 9.27%, and 10.77% for the control and low- and high-ammonia diets, respectively). The treatment sequence was based on a 3 × 3 Latin-square design with 3 consecutive periods. On the last day of each period, blood flows in portal and hepatic veins were determined with a continuous infusion of ρ-amino hippuric acid into the mesenteric vein. Consecutive blood samples were taken for AA concentration in blood plasma, and AA balances were calculated for PDV and the liver. Results: Cumulative release of citrulline (Cit) and proline (Pro) increased with ammonia supplementation in PDV but decreased for glutamine (Gln) and glycine (Gly) (Gln: -19.32 ± 3.56, -32.50 ± 3.73, and -42.11 ± 3.55 mmol/meal for the control and low- and high-ammonia groups, respectively; P ≤ 0.05). Cumulative release of alanine (Ala), glutamic acid (Glu), and Gln increased with ammonia supplementation across the liver (P ≤ 0.05). When combined, PDV+liver, the cumulative release of Ala, Cit, and Glu increased with ammonia-nitrogen supplementation (P ≤ 0.05). Conclusion: Dietary ammonia could be used as a nitrogen supplement to increase the synthesis of Ala, Cit, and Glu across splanchnic organs in pigs fed a diet deficient in DAA-nitrogen.

Ammonia Nitrogen Added to Diets Deficient in Dispensable Amino Acid Nitrogen Is Poorly Utilized for Urea Production in Growing Pigs.

Background: Including ammonia in low-crude protein (CP) diets deficient in dispensable amino acid (DAAs) increases nitrogen retention in growing pigs.Objective: We investigated the absorption and metabolism of dietary ammonia nitrogen in the portal-drained viscera (PDV) and liver of pigs fed a diet deficient in DAA nitrogen.Methods: Eight pigs with an initial mean ± SD body weight (BW) of 26.5 ± 1.4 kg were surgically fitted with 4 catheters each (portal, hepatic and mesenteric veins, and carotid artery). The pigs were fed (2.8 × 191 kcal/kg BW0.60), for 7 d and every 8 h, a diet deficient in DAA nitrogen supplemented with increasing amounts of ammonia nitrogen (CP: 7.76%, 9.27%, and 10.77%; indispensable amino acid nitrogen:total nitrogen ratio: 0.71, 0.59, and 0.50 for control and low- and high-ammonia diets, respectively). The treatment sequence was based on a Latin square design with 3 consecutive periods. On the last day of each period, blood flows in the portal and hepatic veins were determined with a continuous infusion of ρ-amino hippuric acid into the mesenteric vein. Serial blood samples were taken to determine ammonia and urea nitrogen concentration. Net balances of ammonia and urea nitrogen were calculated for the PDV and liver.Results: Cumulative (8 h) ammonia nitrogen appearance in the portal vein increased (P ≤ 0.05) with ammonia intake (433, 958, and 1629 ± 60 mg ammonia nitrogen/meal for control and low- and high-ammonia diets, respectively). The cumulative hepatic uptake of ammonia nitrogen increased (P ≤ 0.05) with ammonia nitrogen supply. The cumulative urea nitrogen appearance in the hepatic vein tended to increase (P ≤ 0.10) only in high-ammonia treatment (-92.5, -59.4, and 209.7 ± 92 mg urea nitrogen/meal for control and low- and high-ammonia diets, respectively) and, relative to the control diet, represented -6.0% and 11% of ammonia nitrogen intake.Conclusion: Dietary ammonia nitrogen is poorly utilized for urea production across splanchnic organs when pigs are fed diets deficient in DAA nitrogen.

Effect of low levels of dietary available phosphorus on phosphorus utilization, bone mineralization, phosphorus transporter mRNA expression and performance in growing pigs.

A study was conducted to examine the effects of different dietary levels of available phosphorus (aP) on P excretion, bone mineralization, performance and the mRNA expression of sodium-dependent P transporters in growing pigs. Sixty-day old growing pigs (n = 54) with an average initial BW of 19.50 ± 1.11 kg were randomly allocated to a control diet (C) containing 0.23% available phosphorus (aP), T1 containing 0.17% aP and T2 containing 0.11% aP. There were 6 pens per treatment with 3 pigs per pen. Body weight and feed intake were measured weekly. At the end of each week, one pig from each pen was housed in a metabolic crate for 24 h to collect fecal and urine samples and then sacrificed to obtain third metacarpal (MC3) bones and jejunal and kidney samples. Bones were scanned by Dual Energy X-ray Absorptiometry (DEXA). Fecal and urine samples were sub-sampled and analyzed for P content. The expression of P transporter mRNA in jejunum and kidney samples was measured using quantitative real-time polymerase chain reaction (qRT-PCR). Data were analyzed using GLM procedure of the Statistical Analysis System (SAS Institute version 9.2). Pigs fed the T2 diet had reduced (P < 0.05) average daily gain (ADG) and gain to feed (G:F) compared to those fed the C diet during week 2. Overall, ADG and G:F were also reduced (P < 0.05) in pigs fed the T2 diet compared to those fed the C and T1 diets. Bone mineral density (BMD) and bone mineral content (BMC) were reduced (P < 0.05) in pigs fed the T2 diet compared to those fed the C diet throughout the experiment. At week 1, jejunal mRNA expression of Na (+)-dependent phosphate transporter 2 (SLC34A2) was increased (P < 0.01) in pigs fed the T2 diet compared to C diet. Renal mRNA expression of Na(+)-dependent phosphate transporter 1 (SLC34A1) and SLC34A3 were increased (P < 0.05) in pigs fed the T2 diet compared to those fed the C diet at week 2 and was accompanied by lower (P < 0.05) urinary P in pigs fed the T2 diet during week 2 and week 3. In conclusion, growing pigs are highly sensitive to low dietary P as shown by reduced ADG, bone mineralization and urinary P level, but moderate reduction in dietary P up to 0.17% aP in the diet has the potential to reduce environmental pollution by reducing P concentration in swine manure and without compromising performance.

Performance and nutrient digestibility in growing pigs fed wheat dried distillers' grain with solubles-containing diets supplemented with phytase and multi-carbohydrase.

Effect of supplementing wheat dried distillers' grain with solubles (DDGS)-containing diet with enzymes on nutrient utilization by growing pigs was evaluated in two experiments. In Experiment 1, 60 pigs weighing ~30 kg were fed five diets that included a corn-based diet (Control), Control with 10% wheat DDGS (DDGS-PC), DDGS-PC without inorganic P source (DDGS-NC), and DDGS-NC plus phytase alone or with multi-carbohydrase for 4 weeks to determine average daily gain (ADG), average daily feed intake (ADFI) and gain-to-feed ratio (G:F). In Experiment 2, 30 barrows weighing 22 kg were fed five diets fed in Experiment 1 to determine nutrient digestibility and retention. Pigs fed DDGS-PC and Control diets had similar ADG and G:F. The ADG and G:F for DDGS-PC diet were higher (P < 0.05) than those for DDGS-NC diet. Phytase improved (P < 0.05) ADG, G:F, total tract P digestibility and P retention by 6.6, 8.7, 86.0 and 85.5%, respectively. Addition of multi-carbohydrase to phytase-supplemented diet did not affected growth performance, but reduced (P < 0.05) P retention. In conclusion, inclusion of 10% wheat DDGS in growing pig diet may not affect growth performance of growing pigs. Phytase supplementation to wheat DDGS-containing diet can eliminate the need for inorganic P supplement in pig diets.

Effects of 25-(OH)D3 on fecal Ca and P excretion, bone mineralization, Ca and P transporter mRNA expression and performance in growing female pigs.

A study was conducted to examine the effects of 25-hydroxyvitamin D3 (25-(OH)D3) on fecal Ca and P excretion, bone mineralization, performance and the mRNA expression of intestinal transporter genes in growing female pigs. Sixty-day old gilts (n = 24) with an average initial BW of 23.13 ± 1.49 kg were randomly allocated to a control diet (diet 1) containing wheat/corn/soybean meal and 150 IU kg(-1) of Vitamin D3, diet 1 + 50 µg of 25-(OH)D3 kg(-1) (diet 2) and diet 1 + 100 µg of 25-(OH)D3 kg(-1) (diet 3). The pigs were housed in an individual pen and had ad libitum access to feed and water for 42 days, and BWG and feed intake were measured weekly. Measures of bone mineralization and expression of Ca and P transporters mRNA were analyzed using Dual Energy X-Ray Absortiometry (DEXA) and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Data were analyzed using GLM procedure of the Statistical Analysis System (SAS Institute version 9.2). Fecal Ca and P concentration were significantly reduced (P ≤ 0.05) in pigs fed diets 2 and 3 compared with the control diet. Supplementation of 25-(OH)D3 did not significantly improve bone mineralization, animal performance and intestinal transporters mRNA expression except for SLC34A1, a sodium-dependent phosphate transporter 1. In conclusion, supplementation of 25-(OH)D3 in swine nutrition may not improve animal performance but has the potential to reduce environmental pollution by increasing dietary Ca and P retention while reducing their excretion.

Dietary glutamate supplementation ameliorates mycotoxin-induced abnormalities in the intestinal structure and expression of amino acid transporters in young pigs.

The purpose of this study was to investigate the hypothesis that dietary supplementation with glutamic acid has beneficial effects on growth performance, antioxidant system, intestinal morphology, serum amino acid profile and the gene expression of intestinal amino acid transporters in growing swine fed mold-contaminated feed. Fifteen pigs (Landrace×Large White) with a mean body weight (BW) of 55 kg were randomly divided into control group (basal feed), mycotoxin group (contaminated feed) and glutamate group (2% glutamate+contaminated feed). Compared with control group, mold-contaminated feed decreased average daily gain (ADG) and increased feed conversion rate (FCR). Meanwhile, fed mold-contaminated feed impaired anti-oxidative system and intestinal morphology, as well as modified the serum amino acid profile in growing pigs. However, supplementation with glutamate exhibited potential positive effects on growth performance of pigs fed mold-contaminated feed, ameliorated the imbalance antioxidant system and abnormalities of intestinal structure caused by mycotoxins. In addition, dietary glutamate supplementation to some extent restored changed serum amino acid profile caused by mold-contaminated feed. In conclusion, glutamic acid may be act as a nutritional regulating factor to ameliorate the adverse effects induced by mycotoxins.

Effects of chitosan on intestinal inflammation in weaned pigs challenged by enterotoxigenic Escherichia coli.

The aim of this study was to investigate whether supplementation with chitosan (COS) could reduce diarrhea and to explore how COS alleviates intestinal inflammation in weaned pigs. Thirty pigs (Duroc×Landrace×Yorkshire, initial BW of 5.65±0.27) weaned at age 21 d were challenged with enterotoxigenic Escherichia coli during a preliminary trial period, and then divided into three treatment groups. Pigs in individual pens were fed a corn-soybean meal diet, that contained either 0 (control), 50 mg/kg chlortetracycline, or 300 mg/kg COS for 21 days. The post-weaning diarrhea frequency, calprotectin levels and TLR4 protein expression were decreased (P<0.05) in both the COS and chlortetracycline groups compared with control. Simultaneously, supplemental COS and chlortetracycline had no effect on the mRNA expression of TNF-α in the jejunal mucosa, or on the concentrations of IL-1ß, IL-6 and TNF-α in serum. However, COS supplementation improved (P<0.05) the mRNA expression of IL-1ß and IL-6 in the jejunal mucosa. The results indicate that supplementation with COS at 300 mg/kg was effective for alleviating intestinal inflammation and enhancing the cell-mediated immune response. As feed additives, chitosan and chlortetracycline may influence different mechanisms for alleviating inflammation in piglets.

Low-fiber canola. Part 1. Chemical and nutritive composition of the meal.

The objective of the current study was to evaluate the chemical and nutritive composition of meals derived from a newly developed yellow-seeded Brassica napus canola and the canola-quality Brassica juncea . In comparison with its conventional black-seeded counterpart, meal derived from yellow-seeded B. napus canola contained more protein (49.8 vs 43.8% DM), more sucrose (10.2 vs 8.8% DM), and less total dietary fiber (24.1 vs 30.1% DM). B. juncea canola showed intermediate levels of protein, sucrose, and dietary fiber (47.4, 9.2, and 25.8%, respectively). The reduction in fiber content of yellow-seeded B. napus canola was a consequence of a bigger seed size, a lower contribution of the hull fraction to the total seed mass, and a lower content of lignin with associated polyphenols of the hull fraction. The meal derived from yellow-seeded B. napus canola would appear to have quality characteristics superior to those from black-seeded B. napus or yellow-seeded B. juncea.

Nutrient digestibility in finishing pigs fed phytase-supplemented barley-based diets containing soybean meal or canola meal as a protein source.

The effect of phytase on nutrient digestibility in finishing pigs fed barley-based diet with soybean meal or canola meal as protein source was investigated. Six ileal-cannulated barrows (70 kg initial BW) were fed five diets in a 5 x 5 Latin square design with one added column. The five diets were based on barley-soybean meal (BSBM) or barley-canola meal (BCM) without or with phytase at 500 FTU/kg, and a casein-cornstarch-based diet, which was used to estimate standardised ileal AA digestibilities. No interactions were detected between phytase and diet on any of the response criteria measured except for apparent total tract N digestibility, which was reduced in BSBM diet but not BCM diet by phytase. Phytase increased (p < 0.01) apparent ileal and total tract P digestibility in both BSBM and BCM diets by at least 17 percentage units, and tended (p < 0.10) to increase the apparent ileal digestibilities of histidine, isoleucine, threonine, valine, cysteine, glycine and tyrosine. In conclusion, the effect of phytase in barley-based diets for finishing pigs on all response criteria measured in this study, except apparent total tract N digestibility, was not influenced by protein source.

Ileal digestibility and endogenous flow of minerals and amino acids: responses to dietary phytic acid in piglets.

Effects of phytic acid (PA) on ileal mineral and amino acid (AA) digestibilities and ileal endogenous AA flow in piglets were investigated. Seven ileal-cannulated weanling pigs were fed a casein-maize starch-based diet with PA (as sodium phytate) at 0, 5, 10 or 20 g/kg in 4 x 4 Latin square design with three added columns to give seven observations per treatment. The basal diet was formulated to meet National Research Council energy and AA requirements for piglets. The respective digestibility and endogenous lysine loss were determined by indicator and homoarginine methods. The apparent ileal digestibility (AID) of Na, K and P was linearly and quadratically reduced (P < 0.05) by increased dietary PA concentration, whereas that of Ca and Mg was only linearly reduced (P < 0.05) by the dietary PA. The AID values for Mg and Na were negative ( - 0.03 and - 0.18, respectively) when PA was supplemented at 20 g/kg. The AID of isoleucine, leucine and valine responded quadratically to dietary PA concentration, though the differences between the AID values of the AA due to change in dietary PA concentration were marginal (at most by 1.8 percentage units). Furthermore, dietary PA did not affect (P>0.05) endogenous AA losses. The results suggest that PA has limited effect on the digestibility and endogenous losses of AA in piglets, but can reduce AID of Mg and Na partly by increasing endogenous losses of these minerals as evidenced by their negative AID values.

Effect of dietary supplementation of chitosan and galacto-mannan-oligosaccharide on serum parameters and the insulin-like growth factor-I mRNA expression in early-weaned piglets.

The study was to determine effects of dietary supplementation of chitosan (COS) and galacto-mannan-oligosaccharides (GMOS) on some serum biochemical indices, serum growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels, and hepatic and long gissimus muscle IGF-I mRNA expression in early-weaned piglets. Twenty six Duroc x Landrace x Yorkshire piglets at the age of 15 days were used. The piglets had access to creep feed during the suckling. Six piglets were sacrificed for sampling at the beginning of the study. The other 20 piglets were individually housed in metabolic cages and randomly allotted to four corn and soybean meal-based diets including the control group, the antibiotic group with 110 mg lincomycin/kg diet, the COS group containing 0.025% COS, and the GMOS group with 0.20% GMOS, respectively, in a 2-week feeding experiment. Blood urea nitrogen (BUN) level was reduced whereas serum total protein concentration was increased (P<0.05) in responses to the COS and GMOS supplementation. Dietary supplementation of COS and GMOS also increased (P<0.05) the serum GH and IGF-I levels along with enhanced hepatic and the muscle IGF-I mRNA abundance. Dietary supplementation of oligosaccharides such as COS and GMOS may improve growth and feed conversion efficiency by increasing plasma GH and IGF-I levels, in the early-weaned piglets.