and Implications The ever high feed costs in swine production contribute to the largest variable expense for today’s producers. Due to this fact, research has focused on increasing feed efficiency. In this study, residual feed intake (RFI) was utilized as a measure of feed efficiency in lines of purebred Yorkshire pigs that were selected for increased and decreased feed efficiency on a standard corn-soybean diet that was high in energy and low in fiber (control diet). The low RFI (LRFI) line was selected for increased feed efficiency while the high RFI (HRFI) line was selected for reduced feed efficiency. In generations 8 and 9, the low and high RFI lines were challenged with a low energy, high fiber diet (LEHF). This diet reflects the addition of alternative feed stuffs to swine diets in commercial settings in order to decrease feed costs. Results indicate that the difference in feed efficiency between the two lines was substantially lower when fed the LEHF diet compared to the control diet. Thus, when pigs are fed diets with substantial byproducts, it is important that pigs are also selected for efficiency under such diets.

Excessive heat exposure reduces intestinal integrity and post-absorptive energetics that can inhibit wellbeing and be fatal. Therefore, our objectives were to examine how acute heat stress (HS) alters intestinal integrity and metabolism in growing pigs. Animals were exposed to either thermal neutral (TN, 21°C; 35-50% humidity; n=8) or HS conditions (35°C; 24-43% humidity; n=8) for 24 h. Compared to TN, rectal temperatures in HS pigs increased by 1.6°C and respiration rates by 2-fold (P<0.05). As expected, HS decreased feed intake by 53% (P<0.05) and body weight (P<0.05) compared to TN pigs. Ileum heat shock protein 70 expression increased (P<0.05), while intestinal integrity was compromised in the HS pigs (ileum and colon TER decreased; P<0.05). Furthermore, HS increased serum endotoxin concentrations (P=0.05). Intestinal permeability was accompanied by an increase in protein expression of myosin light chain kinase (P<0.05) and casein kinase II-α (P=0.06). Protein expression of tight junction (TJ) proteins in the ileum revealed claudin 3 and occludin expression to be increased overall due to HS (P<0.05), while there were no differences in claudin 1 expression. Intestinal glucose transport and blood glucose were elevated due to HS (P<0.05). This was supported by increased ileum Na(+)/K(+) ATPase activity in HS pigs. SGLT-1 protein expression was unaltered; however, HS increased ileal GLUT-2 protein expression (P=0.06). Altogether, these data indicate that HS reduce intestinal integrity and increase intestinal stress and glucose transport.

Immune system stimulation (ISS) can cause physiological changes in the intestine and impact nutrient utilization in pigs. Our previous work showed that ISS reduced the apparent ileal digestibility of dietary protein and amino acids, increased ex vivo active nutrient transport, but had no effect on transepithelial resistance. A gene expression study was conducted to further investigate the impact of ISS on small intestinal function and integrity. Sixteen of 28 gilts (BW 63 ±4 kg) were injected (i.m.) every 48 h, for 7 d, with increasing amounts of E.coli lipopolysaccharide. Remaining pigs were injected with saline. Pigs were euthanized to collect ileal tissue. Total RNA was extracted and reverse transcribed, and gene expression was determined by qPCR. Immune system stimulation increased expression of MUC2 and SGLT1 by 1.6 and 2.0 folds, respectively (P < 0.05), but had no effect on MUC5AC and GLUT2 (P >; 0.10). No effect of ISS was observed on the expression of genes that control tight junctions, i.e. claudin‐3 and 4, occludin, ZO‐1 and MLCK (P >; 0.10). Collectively, these results suggest that systemic ISS does not affect intestinal integrity and barrier function, but alters absorptive capacity of the small intestine. Reduced apparent ileal digestibility of protein and amino acids in ISS pigs may be associated with increased gut endogenous protein loss, since mucin is the main component of such loss. USDA 2011–68004‐30336

The growth and performance of 24 nursery pigs fed a fungal cultivation of Rhizopus oligosporus (RO) was evaluated in a 28-day feeding and digestibility study. Nursery pigs average start weight of 5.62 ± 0.35 kg were provided ad libitum access to a corn-soybean diets containing three levels of RO, 0, 10, or 20%. Diets were formulated to be isocaloric and isolysinic, and contained the digestibility marker titanium dioxide. There was no difference in pig performance based on dietary inclusion of RO fungus. However, total tract DE was improved when feeding RO. Altogether, these data indicate that Rhizopus oligosporus cultivated on distillers stillage and bioproducts can be used in nursery swine diets with no negative effects on performance.

Distillers dried grains with solubles (DDGS) from corn contain relatively large amounts of polyunsaturated fatty acids and some yeast components, which may increase oxidative stress and alter immune function, respectively, when fed to pigs. Therefore, indicators of oxidative stress and immune status were determined in pigs (n = 24; initial BW 103.8 +/- 5.9 kg) fed corn soybean meal-based diets or diets containing 35% DDGS for 38 days. On day 38, blood samples were collected for plasma and erythrocyte glutathione, 4-hydroxynonenal (4-HNE) protein adduct, nitrite, oxygen radical absorbance capacity, and thiobarbituric acid reactive substances (TBARS) analyses. Peripheral blood mononuclear cells were isolated, and lysates were analyzed for 4-HNE, superoxide dismutase-1 and glutathione-s-transferase-4. Fresh urine was collected and analyzed for F-2-isoprostane and TBARS. Plasma immunoglobulin A (IgA), IgG, and fecal IgA were determined, and on day 39, pigs fed each diet were injected intramuscularly with saline (n = 6 pigs per diet) or Escherichia coli lipopolysaccharide (LPS; n = 6 pigs per diet) and plasma cytokines and metabolites were determined at 4 h post LPS injection. There were no differences in basal circulating indicators of oxidative stress between dietary treatment groups, but urinary TBARS were increased (p<0.05) in pigs fed DOGS as compared to pigs fed the control diet. Plasma concentrations of IgA and IgG were increased (p<0.05) in DOGS-fed pigs versus pigs on the control diet. In pigs fed DDGS, body temperatures were greater (p<0.05) at 4 h post-LPS than pigs fed corn-soybean meal diets, but LPS-induced alterations of plasma cytokines or metabolites were not different between dietary treatment groups. In conclusion, feeding DDGS does not alter circulating oxidative stress indicators, but increases urinary TBARS. Furthermore, dietary DOGS enhance humoral immunity, but in general do not alter the systemic response to LPS. Published by Elsevier B.V.

Although butyrate modulates proliferation and cytokine production by PBMC in some species, the role of butyrate as a regulator of immunocyte function in the pig has not been studied. Therefore, the primary objective of this study was to determine whether butyrate influences peripheral blood mononuclear cell (PBMC) proliferation, cytokine secretion and mRNA expression in the pig in vitro. We also sought to determine whether alterations in cytokine production attributable to butyrate were associated with changes in the expression of suppressor of cytokine signaling-3 (SOCS3). Porcine PBMC were isolated from venous blood and stimulated with concanavalin A (ConA) in the presence or absence of sodium butyrate at 0.2 or 2.0 mM. Butyrate at 2.0 mM suppressed (P<0.05) ConA-induced PBMC proliferation and led to a paradoxical increase (P<0.05) in IL-2 mRNA expression. The secretion and mRNA expression of interferon-gamma (IFN-gamma) by ConA-activated PBMC was increased (P<0.05) by butyrate at 2.0 mM. Exposing activated PBMC to butyrate at 2.0 mM decreased (P<0.05) the secretion of interleukin-10 (IL-10). In contrast, butyrate at 0.2 mM increased (P<0.05) both IL-10 secretion and mRNA expression. Activation of porcine PBMC with ConA increased (P<0.05) the expression of SOCS3 mRNA, and butyrate treatment further augmented (P<0.05) SOCS3 mRNA expression in a dose-dependent manner. Mechanistically, pretreatment with the adenyl cyclase inhibitor 2,5-dideoxyadenosine abolished (P<0.05) the inhibitory effect of 2.0 mM butyrate on IL-10 secretion, and partially reversed (P<0.05) the increase in IFN-gamma secretion induced by 2.0mM butyrate. These data indicate that the effect of butyrate on cytokine production by porcine PBMC is dose-dependent, and that butyrate increases the expression of SOCS3 in activated PBMC. In addition, we provide evidence that the effects of butyrate on IFN-gamma and IL-10 production are mediated in part via a cAMP-dependent mechanism.

The paper describes the major river basins—the Saskatchewan, Nelson and Churchill—and Manitoba’s location in the lower reaches of these basins. The number of Canadian and United States jurisdictions meeting across these basins is identified.The need is stressed for interjurisdictional cooperation for effective planning and development of the water resources of Manitoba. The various international and interprovincial mechanisms are described with examples to illustrate how Manitoba must cooperate with upstream jurisdictions through the International Joint Commission and the Prairie Provinces Water Board.A summary is provided of programs since 1930, when water resources were transferred to the province, as well as an indication of the thrust for water planning in the early 1980s to support the value-added concept for the primary and secondary sectors of the agricultural economy in Manitoba.

Scientific abstract: Two experiments were conducted to determine the effects of dietary sodium butyrate on growth performance and response to E. coli. lipopolysaccharide (LPS) in weanling pigs. In the first 28 d experiment, 180 pigs (initial BW 6.3 kg) were fed 0, 0.05, 0.1, 0.2, and 0.4% sodium butyrate, or 110 mg/kg dietary tylosin. There was no effect of dietary sodium butyrate or tylosin on overall G:F, but there was a linear trend (P < 0.07) towards decreased ADFI and ADG as levels of sodium butyrate increased. In a second 28 d experiment, 108 pigs (initial BW 6.3 kg) were assigned to three dietary treatments: 1) no antibiotics; 2) 0.2% sodium butyrate; or 3) 55 mg/kg carbadox. On d 14, a subset of pigs from the no antibiotic and butyrate treatment groups were challenged with E. coli LPS or injected with sterile saline in a 2x2 factorial arrangement (± LPS challenge; ± dietary butyrate; n = 6 pigs/treatment group). Four hours after LPS challenge, blood samples were obtained, and samples of LM, liver, and ileum were collected for gene expression analysis. Serum samples were analyzed for IL-6, tumor necrosis factor alpha (TNFalpha), alpha1-acid glycoprotein, cortisol, IGF-I, insulin, and metabolites. Tissue cytokine and IGF-I gene expression were measured by real-time PCR. Feeding diets containing sodium butyrate or carbadox did not alter ADG or ADFI compared to pigs fed the