Comparative effects of dietary methionine and cysteine supplementation on redox status and intestinal integrity in immunologically challenged-weaned pigs.

Sulfur-containing amino acids such as methionine and cysteine play critical roles in immune system and redox status. A body of evidence shows that metabolic aspects of supplemented Met and Cys may differ in the body. Therefore, the study aimed to investigate the effects of dietary Met and Cys supplementation in immunologically challenged weaned pigs. Forty weaned piglets (6.5 ± 0.3 kg) were randomly allocated to five treatment groups. The treatment included: (1) sham-challenged control (SCC), (2) challenged control (CC), (3) MET (CC + 0.1% DL-Met), (4) CYS (CC + 0.1% L-Cys), and (5) MET + CYS (CC + 0.1% DL-Met + 0.1% L-Cys). On day 7, all pigs were intramuscularly injected with either Escherichia coli O55:B5 lipopolysaccharides (LPS) or phosphate-buffered saline. Blood, liver, and jejunum samples were analyzed for immune response and redox status. The CC group had lower (P < 0.05) villus surface area and higher (P < 0.05) flux of 4-kDa fluorescein isothiocyanate dextran (FD4) than the SCC group. A lower (P < 0.05) glutathione (GSH) concentration was observed in the jejunum of pigs in the CC group than those in the SCC group. Dietary Cys supplementation increased (P < 0.05) villus surface area, GSH levels, and reduced (P < 0.05) the flux of FD4 in the jejunum of LPS-challenged pigs. Dietary Met supplementation enhanced (P < 0.05) hepatic GSH content. Pigs challenged with LPS in the MET group had lower serum IL-8 concentration than those in the CC group. There was a Met × Cys interaction (P < 0.05) in serum IL-4 and IL-8 concentrations, and Trolox equivalent antioxidant capacity. Dietary L-Cys supplementation restored intestinal integrity and GSH levels that were damaged by lipopolysaccharides administration. Dietary DL-Met supplementation improved hepatic GSH and reduced systemic inflammatory response, but antagonistic interaction with dietary L-Cys supplementation was observed in the inflammatory response and redox status.

Effects of levan-type fructan on growth performance, nutrient digestibility, diarrhoea scores, faecal shedding of total lactic acid bacteria and coliform bacteria, and faecal gas emission in weaning pigs.

BACKGROUND: The use of antibiotics as growth promoters in feed has been fully or partially banned in several countries. The objective of this study was to evaluate effects of levan-type fructan on growth performance, nutrient digestibility, faecal shedding of lactic acid bacteria and coliform bacteria, diarrhoea scores, and faecal gas emission in weaning pigs. A total of 144 weaning pigs [(Yorkshire × Landrace) × Duroc] were randomly allocated to four diets: corn-soybean meal-based diets supplemented with 0, 0.1, 0.5, or 1.0 g kg-1 levan-type fructan during this 42-day experiment. RESULTS: During days 0 to 21 and 0 to 42, average daily gain and average daily feed intake were linearly increased (P < 0.01) with increasing dietary levan-type fructan inclusion. The apparent total tract digestibility of dry matter, crude protein, and gross energy were linearly increased (P < 0.001) with increasing dietary levan-type fructan content. With increasing levels of levan-type fructan, faecal lactic acid bacteria counts were linearly increased (P = 0.001). CONCLUSION: The results indicate that dietary supplementation with increasing levan-type fructan enhanced growth performance, improved nutrient digestibility, and increased faecal lactic acid bacteria counts in weaning pigs linearly. © 2017 Society of Chemical Industry.

Zearalenone exposure impairs ovarian primordial follicle formation via down-regulation of Lhx8 expression in vitro.

Zearalenone (ZEA) is an estrogenic mycotoxin mainly produced as a secondary metabolite by numerous species of Fusarium. Previous work showed that ZEA had a negative impact on domestic animals with regard to reproduction. The adverse effects and the mechanisms of ZEA on mammalian ovarian folliculogenesis remain largely unknown, particularly its effect on primordial follicle formation. Thus, we investigated the biological effects of ZEA exposure on murine ovarian germ cell cyst breakdown and primordial follicle assembly. Our results demonstrated that newborn mouse ovaries exposed to 10 or 30µM ZEA in vitro had significantly less germ cell numbers compared to the control group. Moreover, the presence of ZEA in vitro increased the numbers of TUNEL and γH2AX positive cells within mouse ovaries and the ratio of mRNA levels of the apoptotic genes Bax/Bcl-2. Furthermore, ZEA exposure reduced the mRNA of oocyte specific genes such as LIM homeobox 8 (Lhx8), newborn ovary homeobox (Nobox), spermatogenesis and oogenesis helix-loop-helix (Sohlh2), and factor in the germline alpha (Figlα) in a dose dependent manner. Exposure to ZEA led to remarkable changes in the Lhx8 3'-UTR DNA methylation dynamics in oocytes and severely impaired folliculogenesis in ovaries after transplantation under the kidney capsules of immunodeficient mice. In conclusion, ZEA exposure impairs mouse primordial follicle formation in vitro.

The influence of N-acetyl-l-cysteine on damage of porcine oocyte exposed to zearalenone in vitro.

Zearalenone (ZEA), one of the mycotoxins produced by Fusarium fungi, impacts porcine reproduction by interfering with the estrogen signaling pathway. Previous studies have shown that ZEA inhibits porcine oocyte maturation through the formation of aberrant spindle. To explore the effect of ZEA on porcine oocyte meiotic maturation, the extent of both nuclear and cytoplasmic maturation was examined in this study. Compared with control group, presence of ZEA (3 µM) during oocyte maturation, significantly inhibited the polar body extrusions from 71% to 51%, and significantly increased intracellular reactive oxygen species (ROS) level (12.01 vs. 5.89). Intracellular glutathione (GSH) content in ZEA treatment group was lower than in the control group (1.08 pmol/oocyte vs. 0.18 pmol/oocyte), and cortical granules of cortical area distributed oocytes were reduced (88% vs. 62%). ZEA decreases cumulus expansion in both morphology and mRNA level (HAS2, PTX3, TNFAIP6 and CX43). Addition of N-acetyl-l-cysteine (NAC) to the oocyte maturation media reversed the ZEA-induced inhibition of polar body extrusion (from 69% to 81%), up-regulated ROS (from 7.9 to 6.5), down-regulated GSH content (from 0.16 to 0.82 pmol/oocyte) and recovered cumulus cells expansion in morphology and mRNA level. It is concluded that ZEA affects both oocyte nucleus and cytoplasmic maturation during in vitro maturation, and NAC can reverse these damages to some extent.

Effects of dietary protein content and crystalline amino acid supplementation patterns in low protein diets on intestinal bacteria and their metabolites in weaned pigs raised under Different sanitary conditions.

The objective of this experiment was to investigate the effects of dietary crude protein (CP) content and crystalline amino acids (CAA) supplementation patterns in low CP (LCP) diets on intestinal bacteria and their metabolites in weaned pigs raised under clean (CSC) or unclean sanitary conditions (USC). One hundred forty-four piglets (6.35 ±â€…0.63 kg) were assigned to one of six treatments in a 3 × 2 factorial arrangement based on CP content and sanitary conditions in a randomized complete block design to give eight replicates with three pigs per pen over a 21-d period. Diets consisted of a high CP (HCP; 21%) and two LCP (18%) diets supplemented with 9 CAA (Lys, Met, Thr, Trp, Val, Ile, Leu, His, and Phe) or only six CAA (Lys, Met, Thr, Trp, Val, and Ile) to meet the requirements. The CSC room was washed weekly, whereas the USC room had sow manure spread in the pens from the beginning of the study and was not washed throughout the experiment. Jejunum and colon digesta were sampled on day 21. Both jejunum and colon digesta were analyzed for ammonia nitrogen, short-chain fatty acids, and biogenic amines but only colon digesta was analyzed for microbiome composition (16s rRNA sequencing on MiSeq). Data were analyzed using R software for 16S rRNA and the MIXED procedure of SAS for microbial metabolites. Sanitation, CP content, and CAA supplementation patterns did not affect the diversity of colonic bacterial composition in weaned pigs. Pigs raised under USC had greater (P < 0.05) jejunal ammonia nitrogen concentration than those raised under CSC. Pigs fed LCP diets had reduced (P < 0.05) jejunal ammonia nitrogen concentration compared to those fed the HCP diet. Interactions between sanitation and dietary CP content were observed (P < 0.05) for: (1) jejunal acetate and (2) colonic spermidine and spermine, whereby (1) acetate concentrations decreased from NCP to LCP in pigs raised under the CSC but those concentrations increased under the USC, and (2) spermidine and spermine concentrations increased in LCP diets compared to HCP diet under USC, unlike CSC which did not show any difference between HCP and LCP. In conclusion, reducing dietary CP lowered ammonia nitrogen content regardless of sanitation and increased microbial metabolites in weaned pigs raised under USC. However, LCP diets with different CAA supplementation patterns did not affect bacterial diversity in weaned pigs, regardless of the hygienic conditions where the animals were housed.

Lowering dietary crude protein concentration by 3% to 4% units has been used as one of the strategies to promote growth and improve the gut health of weaned pigs. Undigested and endogenous protein could be available for microbial fermentation, and protein fermentation is considered detrimental to the gut health of the host animal. The unclean sanitary condition model mimics commercial raising conditions and stimulates a low-grade inflammatory and immune response. Ammonia nitrogen is one of the harmful metabolites derived by protein fermentation and pigs fed low-protein diets had decreased ammonia nitrogen than those fed high-protein diets. Also, pigs raised under unclean sanitation had greater ammonia nitrogen than those raised under clean sanitation. However, sanitation, protein content, and crystalline amino acids supplementation patterns did not affect the diversity of colonic bacterial composition in weaned pigs. The results obtained from the present study showed that a low protein diet could be used to improve gut health in weaned pigs.

Coarse, but not finely ground, dietary fibre increases intestinal Firmicutes:Bacteroidetes ratio and reduces diarrhoea induced by experimental infection in piglets.

Using dietary fibre to control childhood diarrhoea has rarely been discussed. However, dietary fibre is being proposed to prevent diarrhoea in piglets. The present study aimed to study the effects of introducing fibre in the post-weaning piglet diet and its particle size on the intestinal ecosystem before and after an experimental infection with Escherichia coli. A total of thirty-six post-weaning piglets were assigned to four experimental diets: a negative control (NC) diet, the same diet with 4 % wheat bran coarse (WBc) particle size or finely milled (WBF) and a positive control (PC) diet with an antibiotic. On day 9, animals were challenged with E. coli. Faecal and digesta samples were obtained before and after the experimental infection and changes in the microbial ecosystem were measured. Animals fed the WBc and the PC diets showed a significant reduction in the faecal score compared with the NC diet. The inclusion of WBc in the diet increased total volatile fatty acid concentration, reduced Bacteroidetes in the faeces before and after the experimental infection compared with the NC diet and increased Firmicutes at the end of the experiment. Based on the results, diarrhoea scours and the composition of the pig gut microbial community are modified by the inclusion of a relatively small amount of wheat bran in the diet, being the physical presentation of the fibre a determinant of that difference.

Calcium-sensing receptor is not expressed in the absorptive enterocytes of weaned piglets.

The calcium-sensing receptor (CaSR) is a kokumi receptor that plays an essential role in nutrient sensing and animal physiology, growth, and development. Pig CaSR (pCaSR) was identified and characterized in the intestine. However, further research is still needed to confirm the expression of CaSR in the epithelial cells isolated from weaned piglets. In this study, primary enterocytes were isolated and characterized from the ileum of weaned piglets by the Weiser distended intestinal sac technique and fluorescence-activated cell sorting (FACS) based on sucrase-isomaltase (SI) as an enterocyte-specific marker. The expression of CaSR was investigated in both primary enterocytes and the intestinal porcine enterocyte cell line-j2 (IPEC-J2) by droplet digital polymerase chain reaction (ddPCR), immunofluorescence staining, and Western blotting. Results demonstrated that porcine enterocytes could be obtained using FACS with the SI as the enterocyte-specific marker and that pCaSR is not expressed in both porcine ileal enterocytes and IPEC-J2 cells, which specifically identified the expression of pCaSR in ileal enterocytes with sensitive and specific approaches.

The calcium-sensing receptor (CaSR) has been identified as a nutrient sensor along the gastrointestinal tract and plays a pivotal role in food digestion, nutrient absorption, and energy metabolism. Hence, elucidating the expression pattern of pig CaSR (pCaSR) in the intestinal segments, especially in the absorptive enterocytes, could reveal the significance of pCaSR in nutrient sensing in the gastrointestinal tract. In the present work, after isolating enterocytes from the ileum of weaned piglets, we investigated the expression of pCaSR in porcine enterocytes through a combination of biological tools at both gene and protein expression levels. Data observed in the current study revealed that porcine enterocytes could be obtained by using cell sorting with a digestive enzyme (sucrase-isomaltase) as the enterocyte-specific marker. Plus, the pCaSR is not expressed in either isolated porcine ileal enterocytes or the intestinal porcine enterocyte cell line-j2 (IPEC-J2).

Effects of dietary protein content and crystalline amino acid supplementation patterns on growth performance, intestinal histomorphology, and immune response in weaned pigs raised under different sanitary conditions.

The aim of this experiment was to investigate the effects of dietary crude protein (CP) contents and crystalline amino acids (CAA) supplementation patterns on growth performance, intestinal histomorphology, and immune response in weaned pigs under clean (CSC) or unclean sanitary conditions (USC). A total of 144 weaned pigs (6.35 ± 0.63 kg body weight) were assigned to 6 treatments in a 3 × 2 factorial arrangement based on CP content and sanitary conditions using a randomized complete block design, giving 8 replicates per treatment with 3 pigs per pen. Pigs were fed one of three diets for 21 d: one high CP (HCP; 22%) and two low CP (LCP; 19%) diets supplemented with 9 indispensable AA or only 6 AA (Lys, Met, Thr, Trp, Val, and Ile) as CAA. The CSC room was washed weekly, whereas the USC room had sow manure spread in the pens and was not washed throughout the experiment. Body weight and feed disappearance were recorded weekly. Blood was sampled from 1 pig per pen weekly, and the same pig was euthanized for jejunal tissues sampling on day 21. Pigs raised under USC had reduced (P < 0.05) average daily gain (ADG) and gain to feed ratio (G:F) in week 2, but contrary results that greater (P < 0.05) ADG and G:F were found in pigs under USC in week 3. Overall, there was an interaction where G:F did not differ between HCP and LCP under CSC, however, LCP decreased (P < 0.05) G:F compared to HCP under USC. Pigs fed the HCP diet had higher (P < 0.05) fecal scores than those fed the LCP diets throughout the experiment. Pigs fed the LCP had higher (P < 0.05) villus height to crypt depth ratio than those fed the HCP. An interaction was observed where goblet cell density in the jejunum was higher (P < 0.05) in pigs fed LCP than HCP under CSC, but no difference was found between HCP and LCP under USC. Different CAA supplementation patterns did not influence both growth performance and histomorphology. Pigs raised under USC had greater (P < 0.05) plasma interleukin (IL)-10 and IL-6 concentrations and reduced (P < 0.05) plasma tumor necrosis factor-alpha concentration. Also, the LCP diets resulted in a greater (P < 0.05) plasma IL-10 concentration. In conclusion, overall growth performance did not differ between HCP and LCP under CSC, but LCP diets reduced G:F under USC. Feeding LCP diets to weaned pigs improved gut morphology under USC and ameliorated systemic inflammation induced by USC, whereas CAA supplementation patterns did not affect growth performance and gut morphology.

Reducing dietary crude protein (CP) content reduces nitrogen excretion to the environment and undigested protein availability to enteric pathogens in the hind gut resulting in reduced postweaning diarrhea and improved gut health. To meet the amino acid requirements in low CP diets, supplementation of essential amino acids in nursery diets is necessary, and the availability of more feed-grade crystalline amino acids allows low CP diets to be practically formulated. The sanitation challenge model mimics commercial raising conditions and stimulates a low-grade inflammatory and immune response. Although low CP diets decreased the feed efficiency in pigs raised under unclean conditions in this study, improved gut histomorphology and ameliorated inflammatory response were obtained in pigs fed low CP diets. However, no effect was found in crystalline amino acids supplementation patterns. The outcomes of this study confirmed that low CP diets could be used to improve gut health and ameliorate immune response in weaned pigs.

Heat processing increased the digestibility of phosphorus in soybean expeller, canola meal, and canola expeller fed to growing pigs.

It is hypothesized that heat processing may increase P digestibility in different protein sources fed to growing pigs. A study was conducted to determine the apparent total tract digestibility (ATTD) and standardized total tract digestibility (STTD) of P in soybean expeller (SBE) produced from oil extraction using dry extrusion and expelling and to investigate the effects of heat treatment on the ATTD and STTD of P in SBE, canola meal (CM), and canola expeller (CE) fed to growing pigs. Thirty-six growing barrows with an initial body weight of 19.0 ± 1.0 kg (mean ± SD) were assigned to 1 of 6 experimental diets in a completely randomized design to give 6 replicates per diet. The experimental design was a 3 × 2 factorial arrangement including three oilseed meals with or without heat treatment. The diets were formulated to contain non-autoclaved or autoclaved (at 121 °C for 60 min) SBE, CM, and CE as the sole source of P. Limestone was included in diets to maintain a Ca:total P ratio of 1.3:1 across diets. Pigs were individually housed in metabolism crates for 12 d, including 7 d for adaptation and 5 d for total collection of feces. Pigs were offered their daily ration at 2.8 times their maintenance energy requirement. Data were analyzed using the PROC MIXED of SAS. Heat treatment increased (P < 0.05) the ATTD and STTD of P. Pigs fed the SBE diets had greater (P < 0.05) ATTD and STTD of P than pigs fed CM and CE diets. For the autoclaved ingredients, the values of STTD of P were 49.4%, 23.2%, and 25.8% for SBE, CM, and CE, respectively, whereas STTD of P in non-autoclaved SBE, CM, and CE were 48.5%, 20.2%, and 22.5%. Heat treatment increased (P < 0.05) the ATTD of Ca. In conclusion, heat treatment increased ATTD and STTD of P and ATTD of Ca in SBE, CM, and CE fed to growing pigs. The ATTD and STTD of P in SBE determined in the current study were 41.0% and 48.5%, respectively.

Effect of oat particle size on energy and nutrient utilization in growing pigs.

An experiment was conducted to determine the energy content of oats and to investigate the effects of oat particle size on nutrient and energy balance in growing pigs. Eighteen barrows (23.56 ± 0.94 kg initial body weight) were randomly assigned to one of the three dietary treatments with six replicates per treatment. Whole oats were ground with a hammermill fitted with 4.8- and 3.2-mm screens to make coarse and medium particle size oats, respectively. Medium oats were further ground with a rotary steel cutting grinder fitted with a 2.0-mm screen, and the further ground oats were mixed with medium oats in a 1:3 ratio to make fine oats. Three experimental diets consisted of 96.3% of the coarse, medium, or fine oats as a sole source of energy were used. Pigs were fed diets for 16 d, including 10 d for adaptation and 6 d for total fecal and urine collection. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. All data were analyzed using the MIXED procedure of SAS with the individual pig as the experimental unit. The geometric mean particle sizes for coarse, medium, and fine oats were 765, 619, and 569 µm, respectively. Pigs fed the medium oats diet tended to have (P < 0.10) greater apparent total tract digestibility (ATTD) of starch, neutral detergent fiber, and gross energy than those fed coarse oats diet. The medium oats diet contained greater (P < 0.05) digestible energy (DE), metabolizable energy (ME), and net energy (NE) than the coarse oats diet. Pigs fed the fine oats diet had lower (P < 0.05) ATTD of Ca and P than those fed the coarse oats diet. The DE, ME, and NE contents of fine oats were comparable with those of coarse oats. The determined NE contents for coarse, medium, and fine oats were 2,335, 2,615, and 2,521 kcal/kg on a dry matter basis, respectively. The NE content in medium oats was greater (P < 0.05) than the NE values predicted using published equations. In conclusion, it was suggested to grind whole oats for 619 µm concerning energy utilization. Further grinding to 569 µm reduces Ca and P digestibility.

Energy content of intact and heat-treated dry extruded-expelled soybean meal fed to growing pigs.

An experiment was performed to evaluate the energy content of extruded-expelled soybean meal (EESBM) and the effects of heat treatment on energy utilization in growing pigs. Eighteen growing barrows (18.03 ± 0.61 kg initial body weight) were individually housed in metabolism crates and randomly allotted to one of three dietary treatments (six replicates per treatment). The three experimental diets were the following: a corn-soybean meal-based basal diet and two test diets with simple substitution of a basal diet with intact EESBM or heat-treated EESBM (heat-EESBM) at a 7:3 ratio. Intact EESBM was autoclaved at 121 °C for 60 min to make heat-treated EESBM. Pigs were fed the experimental diets for 16 d, including 10 d for adaptation and 6 d for total collection of feces and urine. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. The energy content of EESBM was calculated using the difference method. Data were analyzed using the Mixed procedure of SAS with the individual pig as the experimental unit. Pigs fed heat-EESBM diets showed lower (P < 0.05) apparent total tract digestibility of dry matter (DM), gross energy, and nitrogen than those fed intact EESBM. A trend (P ≤ 0.10) was observed for greater heat increments in pigs fed intact EESBM than those fed heat-EESBM. This resulted in intact EESBM having greater (P < 0.05) digestible energy (DE) and metabolizable energy (ME) contents than heat-EESBM. However, no difference was observed in net energy (NE) contents between intact EESBM and heat-EESBM, showing a tendency (P ≤ 0.10) toward an increase in NE/ME efficiency in heat-EESBM, but comparable NE contents between intact and heat-EESBM. In conclusion, respective values of DE, ME, and NE are 4,591 kcal/kg, 4,099 kcal/kg, and 3,189 kcal/kg in intact EESBM on a DM basis. It is recommended to use NE values of feedstuffs that are exposed to heat for accurate diet formulation.

Diet complexity and l-threonine supplementation: effects on nutrient digestibility, nitrogen and energy balance, and body composition in nursery pigs.

This study was conducted to investigate the effects of dietary complexity and l-Thr supplementation on energy and nutrient utilization in nursery pigs. Thirty-two nursery pigs (7.23 ± 0.48 kg) were randomly assigned to a 2 × 2 factorial treatment arrangement based on diet complexity (complex vs. simple) with different levels of l-Thr supplementation. The complex diet contained animal protein sources (e.g., fish meal and plasma) and a dairy product (e.g., dried whey) to mimic a conventional nursery diet. The simple diet was formulated with corn, wheat, and soybean meal. Both diets were supplemented with l-Thr to contain either 100% or 115% (SUP Thr) of the estimated standardized ileal digestible Thr requirement for 9 kg body weight pigs (NRC, 2012). The pigs were individually housed in metabolism crates and fed an experimental diet ad libitum for a 7-d adaptation period and 5 d of total but separate urine and fecal collection. On day 14, all pigs were euthanized to determine body composition. The diet complexity, l-Thr supplementation, and their interactions were considered main effects. Pigs fed the complex diet tended to exhibit greater (P < 0.10) apparent total tract digestibility (ATTD) of ash and urinary energy output than those fed the simple diet. The complex diet had greater (P < 0.05) digestible energy and net energy contents than the simple diet. Furthermore, the complex diet-fed pigs had lower (P < 0.05) plasma urea nitrogen concentration on day 14 than simple diet-fed pigs. The SUP Thr decreased (P < 0.05) ATTD of acid detergent fiber but trended (P < 0.10) toward a decrease in urinary nitrogen (N) output and an increase in N retention and body N mass. In conclusion, the simple diet for nursery pigs had lower digestible and net energy contents than a complex diet. The SUP Thr can improve N utilization and body protein deposition, irrespective of diet complexity.

Net Energy Net Energy Net EnergyNet EnerNet Energy of high-protein sunflower meal fed to growing pigs and effect of dietary phosphorus on measured values of NE.

An experiment was carried out to determine energy values of high-protein sunflower meal (HP-SFM) and to compare the energy values of HP-SFM determined using either a phosphorus (P)-deficient basal diet or a P-adequate basal diet. Twenty-four growing barrows were randomly assigned to 1 of 4 dietary treatments with 6 replicates per treatment. Four experimental diets including 2 basal diets containing 2 levels of standardized total tract digestible P (i.e., P-deficient and P-adequate) and the other 2 diets containing 30% HP-SFM with each basal diet (i.e., HP-SFM 1 diet and HP-SFM 2 diet) were formulated to determine the energy values of HP-SFM and to compare energy values of HP-SFM determined by the difference method using 2 basal diets. Pigs were fed diets for 15 d including 10 d for adaptation and 5 d for total collections. Pigs were then moved to indirect calorimetry chambers to determine total heat production (THP) and fasting heat production (FHP). A reduced (P < 0.01) amount of nitrogen was retained in pigs fed the P-deficient basal diet compared with those fed the other diets. The THP of pigs fed the HP-SFM 1 and 2 diets was greater (P < 0.01) than those fed the P-deficient basal diet with the intermediate value for pigs fed the P-adequate basal diet. The retained energy (RE) as protein of pigs fed the P-deficient basal diet was less (P < 0.01) but RE as lipid was greater (P < 0.01) than those fed the P-adequate basal, or HP-SFM 1 and 2 diets. However, there was no difference in FHP of pigs among the dietary treatments. The NE of HP-SFM determined using the P-deficient basal diet was 2,062 kcal/kg, as-fed basis, whereas the value determined using the P-adequate basal diet was 2,151 kcal/kg. Although no differences were observed in energy values, the amount of P in basal diet might affect energy balance by modifying N utilization, thus, a diet containing adequate amount of P is a more suitable basal diet when the difference method is used for calculation of NE in a feed ingredient.

Effect of dietary supplementation of xylanase in a wheat-based diet containing canola meal on growth performance, nutrient digestibility, organ weight, and short-chain fatty acid concentration in digesta when fed to weaned pigs.

This study was designed to determine the effect of dietary supplementation of xylanase on growth performance, nutrient digestibility, organ weight, digesta pH, and concentration of short-chain fatty acids (SCFA) of weaned pigs fed wheat-canola meal (CM) diets over a 35-d period. A total of 144 piglets (72 barrows and 72 gilts) weaned at 18 ± 2 d of age, with initial body weight (BW) of 6.2 ± 0.7 kg, received one of eight dietary treatments based on randomized complete block design. BW and feed intake were recorded weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Treatments consisted of a control wheat-soybean meal-based diet and wheat-regular (RCM), dehulled (DCM), or coarse CM (CCM) without and with 16,000 BXU/kg xylanase (Econase XT). All diets contained 500 FTU/kg of phytase (Quantum Blue 5G) and titanium dioxide (0.3%). Apparent total tract digestibility (ATTD) of neutral detergent fiber (NDF), crude protein (CP), phosphorous (P), calcium (Ca), dry matter, and diet were determined. On day 35, one pig per pen was euthanized to evaluate the main factors of protein, xylanase supplementation, and sex on organ weight, ileal and colon digesta pH, and colon digesta concentrations of SCFA. The main factors did not affect growth performance. Xylanase supplementation improved nutrient digestibilities in all diets and increased ileal and colonic digesta pH without affecting the growth performance of weaned pigs fed wheat and CM-based diets. A protein-xylanase effect (P < 0.05) resulted in increasing the ATTD of NDF from 28% to 32% and from 29% to 37% for RCM and DCM, respectively. The ATTD of CP was greater (P < 0.05) with xylanase supplementation (75% vs. 70%). Xylanase supplementation increased ATTD of P and Ca. A three-way interaction (P < 0.05) for protein-xylanase-gender for colon pH, acetic, and propionic acid in the colon digesta of pigs indicated that, in addition to the protein source, piglet sex could have influenced how xylanase works. Xylanase supplementation increased (P < 0.05) the weight of the liver and spleen and tended (P < 0.10) to increase the size of the kidney. In conclusion, dietary supplementation of xylanase increased nutrient digestibility and digesta pH but did not influence the growth performance of weaned pigs fed wheat and CM-based diets over a 35-d period.

Diet complexity and l-threonine supplementation: effects on growth performance, immune response, intestinal barrier function, and microbial metabolites in nursery pigs.

The aim of this study was to investigate the effects of diet complexity and l-Thr supplementation level on the growth performance, immune response, intestinal barrier function, and microbial metabolites in nursery pigs. Thirty-two weaned pigs (body weight 7.23 ± 0.48 kg) were randomly assigned to dietary treatments in a 2 × 2 factorial arrangement based on diet complexity (complex or simple) and dietary Thr content. The complex diet contained fish meal, plasma protein, and dried whey to mimic a conventional nursery diet. The simple diet was formulated with corn, wheat, and soybean meal and did not contain any animal products. l-Thr was supplemented to each diet to supply either 100% (STD Thr) or 115% (SUP Thr) of the NRC (2012) requirement for standardized ileal digestible Thr. Pigs were individually housed and fed experimental diets ad libitum for 14 d. Diet complexity, dietary Thr content, and their interactions were considered the main effects. Pigs fed the simple diet had greater (P < 0.05) plasma interleukin (IL)-10 and IL-6 concentrations compared with those fed the complex diet on days 7 and 14, respectively. Simple diet-fed pigs tended to show greater (P < 0.10) expression of genes encoding for tumor necrosis factor-α, claudin-1, and zonula occludens-1 in the jejunum compared with complex diet-fed pigs. The simple diet-fed pigs had greater (P < 0.05) concentrations of NH3-N in the jejunum digesta than did complex diet-fed pigs. The SUP Thr increased (P < 0.05) villus height and goblet cell (GC) density in villi and crypts in the jejunum and deepened (P < 0.05) crypts in the proximal colon. The SUP Thr resulted in the upregulation (P < 0.05) of occludin gene expression and a tendency toward the downregulation (P = 0.10) of IL-6 gene expression in the jejunum. Interactions (P < 0.05) between diet complexity and l-Thr supplementation level were observed in GC density in the crypt, NH3-N concentration in the jejunum, and the contents of acetate, propionate, and total volatile fatty acids in the colon. In conclusion, feeding a simple diet to nursery pigs resulted in systemic and intestinal inflammation. The SUP Thr diet did not normalize the simple diet-induced inflammation but improved gut integrity. SUP Thr seems to have greater benefits with a simple diet than with a complex diet. Therefore, SUP Thr in a simple diet could be a beneficial nutritional strategy for enhancing gut health.

Effect of dietary crude protein level on jejunal brush border enzyme activities in weaned pigs.

Forty weaned pigs (7.0 ± 0.5 kg, mean ± SD) were used to determine the effects of feeding a low crude protein, amino acid-supplemented diet to piglets on the activities of jejunal brush border enzymes. Pigs were randomly allotted to two diets: a 222 g crude protein (HCP) per kg diet, or a 173 g crude protein per kg diet supplemented with amino acids (LCP). Pigs fed the HCP diet had higher small intestine weight compared with those fed the LCP diet on day 7 after weaning. Diet had no effect on the specific activities of jejunal sucrase, lactase, leucine aminopeptidase, aminopeptidase A, aminopeptidase N and dipeptidyl peptidase IV. The activities of sucrase and lactase decreased (p < 0.05) from day 3 after weaning to day 7, but the activities of leucine aminopeptidase and aminopeptidase N increased. The results showed that feeding a low protein diet supplemented with amino acids according to the ideal protein ratio to piglets had no negative effect on the development of jejunal brush border enzymes.

Effects of thermally oxidized canola oil and tannic acid supplementation on nutrient digestibility and microbial metabolites in finishing pigs1.

The present study investigated the effects of oxidized canola oil and tannic acid (TA) supplementation on nutrient digestibility and microbial metabolites in finishing pigs. Four experimental diets were formulated to include 5% of either fresh canola oil (0 mEq/kg of peroxide value) or oxidized canola oil (180 mEq/kg of peroxide value). An equal portion of each diet was supplemented with 0.1% TA. Eight pigs (initial body weight of 82.89 ± 2.26 kg) were surgically fitted with a T-cannula at the distal ileum. At the beginning of the experiments, all pigs were fed a nitrogen-free diet for 7 d. Then, they were assigned to 4 dietary treatments according to an incomplete replicated 4 × 3 Latin square design with 3 periods to give 6 replicates per treatment. Each experimental period lasted for 9 d, starting with a 5-d adaptation period followed by 2 consecutive 2-d periods for fecal (day 6 and day 7) and ileal digesta (day 8 and day 9) collection. The inclusion of oxidized oil reduced (P < 0.05) the standardized ileal digestibility (SID) of Pro and the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of NDF. Also, pigs fed the oxidized oil tended to have lower (P ≤ 0.10) lactate and ammonia-nitrogen concentrations in the ileum and lower (P ≤ 0.10) acetate and propionate concentrations in the feces than those fed the fresh oil. The supplementation of 0.1% TA reduced (P < 0.05) the AID of NDF and the ATTD of gross energy, crude protein, and NDF. Additionally, the TA-supplemented diet tended to have a lower (P ≤ 0.10) digestible energy content than the nonsupplemented diet. Pigs fed the TA-supplemented diet showed reduced (P < 0.05) AID and SID of His, Cys, and Pro compared with those fed the nonsupplemented diet. There were interactive effects (P < 0.05) of oxidized oil and TA supplementation on acetate, isovalerate, total short chain fatty acids, and pH level in the ileum. In conclusion, the results indicated that the effects of oxidized oil are greater on microbial activities rather than nutrient digestibility. Although negative effects of dietary TA supplementation were observed in relation to nutrient digestibility, TA supplementation was found to ameliorate these negative effects of oxidized oil on microbial metabolites. Therefore, further studies are required to investigate the interaction between dietary oxidized oil and TA in relation with the gut microbiota in pigs.

Energy content and nutrient digestibility of diets containing Lactobacillus-fermented barley or wheat fed to weaned pigs.

This study was conducted to determine the energy content and apparent total tract digestibility (ATTD) of nutrients of diets containing Lactobacillus-fermented barley or wheat fed to weaned pigs. Thirty-six weaned pigs (8.14 ± 0.65 kg of body weight) were randomly assigned to 1 of 6 diets in a completely randomized design to give 6 replicates per diet. Pigs were individually housed in metabolism crates to determine digestible energy and metabolizable energy contents. Net energy was also calculated from the average of 2 equations published by Noblet et al. (1994). Diets were fed at 2.5 times the maintenance energy requirement for 10 d of adaptation and 5 d of total but separate urine and fecal collection. Samples of barley or wheat were fermented for 90 d under anaerobic conditions with an inoculum of either homofermentative Lactobacillus plantarum (Homo) or heterofermentative L. buchneri (Hetero). Three diets were formulated based on either barley or wheat to consist of a control diet containing 42% unfermented grain and 2 diets containing either Homo-fermented or Hetero-fermented grain. Preplanned contrasts were used to evaluate the effects of the inclusion of fermented barley or wheat and to compare the effects of Homo-fermented with Hetero-fermented grains. Fermented wheat inclusion in a diet increased ATTD of gross energy and phosphorus, and retention of gross energy by 1.9%, 6.8%, and 6.3%, respectively. Also, fermented wheat diets had greater (P < 0.05) metabolizable energy content and tended to have greater (P ≤ 0.10) net energy content than unfermented wheat diets. However, inclusion of fermented barley did not increase nutrient and energy digestibility. Hetero-fermented diets contained greater (P < 0.05) digestible energy and net energy content (DM basis) than Homo-fermented diets. Pigs fed barley-based diets showed less (P < 0.05) ATTD of DM, nitrogen, and gross energy than those fed wheat-based diets. In conclusion, wheat fermented with Lactobacillus-inoculum can be beneficially substituted for unfermented wheat, improving the ATTD of nutrient and energy, nitrogen retention, and energy content. Also, Hetero-inoculum is preferable to Homo-inoculum for grain fermentation considering greater energy content in weaned pigs.

Dietary D-xylose effects on growth performance, portal nutrient fluxes, and energy expenditure in growing pigs.

Xylanase is commonly added to pig diets rich in arabinoxylans to promote nutrient utilization and growth. However, high doses of xylanase could release high amounts of xylose in the upper gut, which could have negative nutritional and metabolic implications. However, the amount of xylose to elicit such adverse effects is not clear. Thus, two experiments were conducted to investigate the effects of dietary xylose on the growth performance and portal-drained viscera (PDV) fluxes of glucose (GLU), urea-N (BUN), insulin production, and O2 consumption in growing pigs. In Exp. 1, 64 pigs (21.4 ± 0.1 kg BW), housed as either two barrows or gilts per pen (eight pens per diet) were used to determine the effects of increasing levels of D-xylose (0, 5, 15, and 25%) in a corn-soybean meal-cornstarch-based diet on pig growth performance in a 28-d trial. Cornstarch was substituted for D-xylose (wt/wt) in the control diet. BW and feed intake were monitored weekly. D-xylose linearly reduced (P < 0.05) final BW, ADG, and G:F but not ADFI. However, final BW, ADG, and G:F of pigs fed 15% D-xylose did not differ from pigs fed 0% D-xylose. Thus, the results suggested that pigs could tolerate up to 15% dietary D-xylose. In Exp. 2, six gilts (22.8 ± 1.6 kg BW), fitted with permanent catheters in the portal vein, ileal vein, and carotid artery, were fed the 0% and 15% D-xylose diets at 4% of their BW once daily at 0900 h for 7 d in a cross-over design (six pigs per diet). On d 7, pigs were placed in indirect calorimeters to measure whole-animal O2 consumption and sample blood simultaneously for 6 h from the portal vein and carotid artery after feeding to assay GLU, O2, BUN, and insulin concentrations. Net portal nutrients and insulin production were calculated as porto-arterial concentration differences × portal blood flow (PBF) rate, whereas PDV O2 consumption was calculated as arterial-portal O2 differences × PBF. Diet had no effect on postprandial PBF, insulin production, and portal BUN flux and O2 consumption. Pigs fed 0% D-xylose had greater (P < 0.05) postprandial portal and arterial BUN concentrations, and portal GLU concentration and flux than pigs fed 15% D-xylose diet. In conclusion, feeding growing pigs a diet containing 15% D-xylose did not reduce pig performance or affect PDV energetic demand but reduced GLU fluxes.

Phosphatidylcholine could protect the defect of zearalenone exposure on follicular development and oocyte maturation.

Zearalenone (ZEA) is a well-known exogenous endocrine disruptor and can lead to severe negative effects on the human and animal reproductive process. Using a follicle culture model, we have previously shown that ZEA exposure significantly affected the follicular development and antrum formation but the underlying mechanisms are not well known. Therefore, in this study, we explored the metabolomic changes of granulosa cell (GC) culture media with or without ZEA exposure. The results showed that ZEA significantly increased phosphatidylcholine or phosphatidyl ethanolamine adducts in culture medium. A comprehensive analysis with the metabolome data from follicular fluid of small and large antral follicles showed that lyso phosphatidylcholine (LPC) was accumulated during follicle growth, but was depleted by ZEA exposure. Exogenous supplement with LPC to the follicle growth media or oocyte maturation media can partly protect the defect of ZEA exposure on follicular antrum formation and oocyte maturation. Taken together, our results demonstrate that ZEA exposure hinders the follicular growth and exogenous LPC can practically protect the defect of ZEA on follicular development and oocyte maturation.