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.

An experiment was conducted to determine the digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents of canola meal (CM) and to investigate the effects of basal diet [corn diet vs. corn-soybean meal (SBM) diet] and methodology (difference method vs. regression method) on energy values of CM. Thirty-six growing barrows (20.8 ± 1.0 kg initial body weight [BW]) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six experimental diets included a corn diet, a corn-SBM diet, a corn diet with 15 or 30% of CM, and a corn-SBM diet with 15 or 30% of CM. The DE, ME, and NE of CM were determined using the corn diet or the corn-SBM diet as a basal diet. In each basal diet, two additional diets containing 15 or 30% of CM were formulated to compare the determined energy values by the difference method and estimated energy values from the regression method. Feeding level was set at 550 kcal ME/kg BW0.6 per day. Pigs were fed 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 (HP) and 12 h fasting HP. The DE, ME, and NE of CM determined by the difference method were within the 95% confidence intervals estimated for the DE, ME, and NE of CM by the regression method regardless of the basal diets used, which indicates that the difference and regression methods give equivalent DE, ME, and NE of CM. However, when the goodness of fit for the linear model was compared, the r2 of the regression analysis from the corn-SBM diet (0.78) was relatively greater than that from corn diet (0.40). The estimated NE of CM by the prediction equations generated by either the corn diet or corn-SBM diets were 2,096 kcal/kg and 1,960 kcal/kg (as-fed basis), respectively, whereas those values determined by the difference method were 2,233 kcal/kg and 2,106 kcal/kg (as-fed basis), respectively. In conclusion, the NE of CM determined in the current study was, on average, 2,099 kcal/kg (as-fed basis). The difference and regression methods do not give different NE value of CM fed to growing pigs. Although the NE values of CM determined using either the corn diet or the corn-SBM diet were not different, the greater r2 of the regression analysis from the corn-SBM diet than that from the corn diet suggests that the corn-SBM diet is a more appropriate basal diet for NE determination of ingredients.

No abstract

-This study was conducted to examine the effect of alpha-lipoic acid with vitamin C and E on growth performance, intestinal morphology, and meat quality in broiler chickens under tropical conditions. A total of 288 one-day-old male ROSS 308 chicks (40±0.1 g) were used in a completely randomized design and allotted to one of six dietary treatments to form sixe replicates per treatment (eight birds per cage). The six dietary treatments were: a corn-soybean meal-based diet (NC; no antimicrobial compounds added) with 8 ppm alpha-lipoic acid (ALA); 150 ppm vitamin C and 75 ppm vitamin E (E-75); E-75 plus ALA (E-75-ALA); 150 ppm vitamin C and 50 ppm vitamin E (E-50) plus ALA (E-50-ALA); and 150 ppm vitamin C and 25 ppm vitamin E (E-25) plus ALA (E-25-ALA). All dietary treatments were continuously provided in liquid form, dissolved in water. Birds were housed in a battery cage (n = 36), and were offered dietary treatments on an ad libitum basis. The ambient temperature was maintained at 32±1 ºC for the first three weeks and reduced gradually to 28 ºC by the end of the experiment (day 35) to induce moderate tropical condition. One bird per pen (n = 6), and another bird per pen (n = 6) were euthanized via cervical dislocation to obtain terminal ileum to measure villus height and crypt depth at day 21, and to harvest breast meat and drumsticks to evaluate meat quality traits at day 35, respectively. Dietary treatment E-75-ALA improved body weight and average daily gain compared with birds fed other dietary treatments from day 1 to day 35. Birds fed dietary treatment E-75-ALA and E-50-ALA had higher villus height than those fed the other dietary treatments at day 21. Dietary treatments E-75-ALA and E-50-ALA reduced thiobarbituric acid reactive substance (TBARS) in drumsticks compared with other dietary treatments, but only treatment E-75-ALA decreased TBARS in breast meat at day 35. Liquid form of antioxidant compounds such as E-75-ALA can improve growth performance, histology of terminal ileum, and meat quality traits in broiler chickens under moderate tropical condition for 35 days.

Twenty-eight piglets weaned at 21 days of age (6.94 ± 0.28 kg of body weight) were assigned to one of four dietary treatments for 14 days: 1) negative control (NC; a corn-wheat-soybean meal-based diet), 2) positive control (PC; NC + 0.025% antimicrobial growth promoter [AGP]), 3) ROD2 (2% red-osier dogwood [ROD]), and 4) ROD4 (4% ROD). All pigs were orally inoculated with Escherichia coli K88+ on day 8. The pre-planned orthogonal test was performed to compare 1) NC vs. PC and 2) NC vs. ROD. The inclusion of ROD in a nursery diet increased (P < 0.05) superoxide dismutase (SOD) activities and decreased (P < 0.05) malondialdehyde (MDA) concentrations in the serum. Moreover, pigs fed with ROD diets had shallower (P < 0.05) crypt depth and higher (P < 0.05) villus height to crypt depth ratio than those fed the NC diet. Dietary AGP supplementation reduced (P < 0.05) the MDA concentration in the ileum and serum at 24 h after challenge and improved (P < 0.01) the SOD activities in the serum. In conclusion, the inclusion of ROD in a nursery diet enhanced the antioxidative defense system and intestinal morphology, showing comparable effects with AGP supplementation.

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)

To study the effects of diet complexity and multicarbohydrase (MC) supplementation, 144 piglets (6.70 ± 0.81 kg of BW) weaned at 21 ± 2 d of age (1:1 male to female ratio) were assigned to 1 of 6 dietary treatments in a 3 × 2 factorial arrangement based on diet complexity (complex1, complex2, and simple) and MC addition (0 vs. 0.1% of MC). Diets were provided in a 2-phase feeding program with phase I (d 1 to 14) and phase II diets (d 15 to 28). Complex1 was formulated to mimic a conventional weaner diet with blood plasma, fish meal, dried whey, and skim milk powder, whereas complex2 partially or totally replaced these ingredients with various plant-based ingredients. The simple diet primarily comprised corn, wheat, and soybean meal. No interactions were found between diet complexity and MC supplementation ( > 0.10), except for apparent total tract digestibility (ATTD) of ash and globulin concentration on d 28 ( < 0.05). Pigs fed the complex1 diet had greater ( < 0.01) ADG, ADFI, and G:F than those fed the other diets during the first week after weaning. However, no differences in ADG or ADFI were observed for pigs fed the complex1 and simple diets throughout the 28-d experimental period ( > 0.10), whereas the complex2 diet led to lower ADG and ADFI compared with the complex1 diet ( < 0.05). Overall, G:F was greater for pigs fed the simple diet compared with those fed the complex1 diet ( < 0.01). Pigs fed the simple diet showed ATTD of DM, OM, GE, and ash comparable to those fed the complex1 diet on d 14 ( > 0.10). In contrast, greater ATTD of DM, OM, NDF, GE, and ash was observed ( < 0.05) in pigs fed the complex1 diet than in those fed the complex2 diet or the simple diet on d 28. The simple diet increased the lymphocyte proportion in serum compared with the complex1 diet ( < 0.01) on d 14. Pigs fed the complex1 diet had a greater ( < 0.05) ratio of villus height (VH) to crypt depth (CD) in the ileum compared with the other diets. The complex2 diet decreased ( < 0.05) the fecal score during 3 wk of the postweaning period compared with the complex1 diet. Dietary MC supplementation increased ( < 0.05) G:F during the overall experimental period, VH in the ileum, VH:CD ratio in the duodenum, and ATTD of DM and GE but it reduced fecal score ( < 0.05). In conclusion, feeding a simple diet resulted in BW comparable to feeding the complex1 diet, but it led to inferior intestinal morphology and ATTD of nutrients on d 28. Also, MC supplementation could be beneficial regardless of diet complexity.

Our understanding of nutrition has been evolving to support both performance and immune status of pigs, particularly in disease-challenged animals which experience repartitioning of nutrients from growth towards the immune response. In this sense, it is critical to understand how stress may impact nutrient metabolism and the effects of nutritional interventions able to modulate organ (e.g., gastrointestinal tract) functionality and health. This will be pivotal in the development of effective diet formulation strategies in the context of improved animal performance and health. Therefore, this review will address qualitative and quantitative effects of immune system stimulation on voluntary feed intake and growth performance measurements in pigs. Due to the known repartitioning of nutrients, the effects of stimulating the immune system on nutrient requirements, stratified according to different challenge models, will be explored. Finally, different nutritional strategies (i.e., low protein, amino acid-supplemented diets; functional amino acid supplementation; dietary fiber level and source; diet complexity; organic acids; plant secondary metabolites) will be presented and discussed in the context of their possible role in enhancing the immune response and animal performance.