Efficacy of phytase and/or chromium tripicolinate supplementation on dry matter and nitrogen digestibility and blood metabolites in grower pigs.

Phytase supplementation is widely used throughout the world for enhancing nutrient use efficiencies in pigs, while added chromium has been shown to help stabilize glucose metabolism by enhancing insulin sensitivity. Therefore, the objectives of this metabolism study were to examine the potential synergies of these additives to see if nutrient digestibilities and/or blood metabolites could be improved in grower pigs. A total of 12 Genesus terminal genetics grower pigs (20.7 kilograms (kg)) were allotted randomly in a crossover experiment with four periods and four dietary treatments based on a 2 x 2 factorial design via two groups. This provided 12 replicates per dietary treatment. Treatment (Trt) 1 consisted of a control diet without phytase while Trt 2 had decreased levels of soybean meal, calcium (Ca) and phosphorus (P) with added phytase (1,500 phytase units (FYT)/kg, HiPhorius®; dsm-firmenich, Plainsboro, NJ). The nutrient release values for amino acids, calcium and phosphorus were via standard recommendations from dsm-firmenich for the phytase. Treatment 3 consisted of the control diet without phytase with 200 parts per billion (ppb) of added chromium from chromium tripicolinate (Chromax®, Kent Nutrition Group, Inc., Muscatine, IA) while Trt 4 consisted of the diets with decreased levels of soybean meal, Ca and P with added HiPhorius (1,500 FYT/kg) and Chromax (200 ppb). With six metabolism crates available, four, one-week-long periods were utilized to evaluate each of the four treatments with each pig with two groups evaluated and pooled for data analysis. The pigs were allowed a 4-d acclimation period followed by a 3-d collection period with the experimental diets fed at 4% body weight each day. Water was administered to each pig at 2.5 times the amount of feed fed each day. On the last day of the collection period, blood samples were collected before the meal (fasting) and then two h after the meal (postprandial). There were no significant differences among treatments for both fasting and postprandial glucose and insulin levels. Added phytase resulted in a reduction (P < 0.05) in fasting blood urea nitrogen (N). Nitrogen digestibility and retention and dry matter (DM) digestibility were all improved (P < 0.01) with pigs fed supplemental phytase. Supplemental chromium was without effect on any of the N and DM digestibility measurements. These data suggest that supplemental phytase has positive effects for improving N and DM digestibilities.

Efficacy of water application of a humic substance, butyric acid, vitamins C, D, and E and/or electrolytes on performance and mortality in health-challenged nursery pigs¹.

Health challenges continue to be rampant in nursery pigs which has led to increased industry-wide mortality trends. Therefore, the objective of these three studies was to evaluate a water supplement (HV; HydraVantage, Kent Nutrition Group, Muscatine, IA) which is a proprietary blend of a humic substance, butyric acid, and vitamins C, D, and E, as well as an electrolyte blend on nursery pig performance and mortality. Experiment 1 consisted of 196 crossbred weanling pigs (7 pigs per pen with 14 pens per treatment) which were randomly allotted by BW to two treatments consisting of control (water for 33 d) or HV at 15 g/L of stock solution and proportioned through a medicator (1:128) for 11 d followed by water for 22 d. There were no performance differences. However, mortality was reduced (P < 0.01) from 6.12% for the control to 0.00% for HV. In experiment 2, there were 488 weanling pigs (6 to 10 pigs/pen with 14 pens per treatment) which were randomly allotted by BW to four treatments in a 34-d trial. Treatment 1 was control (water), and treatments 2 and 4 were HV at 15 g/L of stock solution for 11 and 34 d, respectively. Treatment 3 utilized HV at 15 g/L stock solution during days 0 to 11 with 7.5 g HV/L stock solution utilized during days 11 to 21 followed by water. No performance differences were observed among the four treatments. Mortality was 10.89%, 4.82%, 5.54%, and 7.26% for treatments 1 to 4, respectively, with treatment 1 having a higher mortality (P < 0.05) compared to treatments 2 to 4. In experiment 3, a 2 × 2 factorial study was conducted (7 pigs per pen with 14 pens per treatment) in which the treatments were: 1) water; 2) HV at 15 g/L stock solution for 34 d; 3) electrolytes at 241 g/L stock solution for 34 d; and 4) HV at 15 g/L of stock solution and electrolytes at 226 g/L of stock for 34 d. Overall pen gain tended to be improved (P = 0.09) with supplemental HV. Moreover, mortality was reduced (P = 0.06) by 36% (16.86% mortality for treatments 1 and 3 vs. 10.73% mortality for treatments 2 and 4). Supplemental electrolytes had no effect on mortality. These data suggest that HV has a positive effect by reducing mortality in nursery pigs undergoing health challenges.

Influence of high cyclic ambient temperature and water drinker design on growth performance and water disappearance of growing-finishing pigs.

The objective of this study was to determine effects of room temperature and drinker design on growth and water disappearance of growing-finishing pigs (26.9 ±â€…3.67 to 130.9 ±â€…5.10 kg live body weight). A split-plot design was used with a 2 × 2 factorial arrangement of treatments: Room Temperature (RT) [Thermoneutral (TN) vs. High (HI); main plot], Drinker Design (DD; Nipple vs. Cup; sub-plot). A total of 316 pigs were used, housed in 32 pens in 4 rooms (8 pens/room; 7 pens of 10 pigs and 1 pen of 9 pigs). Two rooms were on each RT treatment. Room temperature for the TN treatment was constant throughout each day but decreased from 24°C at the start to 20°C and 18°C on d 14 and 45 of the study period, respectively. For the HI treatment, a single, cyclic RT protocol was used throughout the study (30°C from 08:00 to 19:00 h and 20°C from 20:00 to 07:00 h, with 1-h transition periods). Pens had fully-slatted concrete floors and 1 feeder and drinker (either nipple or cup); floor space was 0.67 m2/pig. Pigs had ad libitum access to standard corn-soybean diets, formulated to meet or exceed NRC (2012) nutrient requirements. Water disappearance was measured using a meter fitted to the water line supplying each drinker. There were no interactions (P > 0.05) between RT and DD treatments. Drinker Design did not affect (P > 0.05) growth performance; water disappearance was 7.3% greater (P ≤ 0.05) for Nipple than Cup drinkers. Compared to the TN treatment, the HI treatment had no effect (P > 0.05) on gain:feed ratio, but resulted in lower (P ≤ 0.05) average daily gain (6.5%) and average daily feed intake (5.5%) and greater (P ≤ 0.05) average daily water disappearance (16.8%). These results suggest that both drinker design and RT can affect water disappearance, and that the high, cyclic RT regime used reduced growth performance of growing-finishing pigs. Further research is needed to determine the contribution of water intake and wastage to treatment differences in water disappearance.

Effect of drinker type on water disappearance of nursery pigs.

This study was conducted to evaluate the water disappearance of nursery pigs (from weaning to 6 wk post-weaning; 6.4 ±â€…1.07 to 22.0 ±â€…3.39 kg live body weight) using a randomized complete block design to compare two Drinker Type treatments: Nipple vs. Cup. A total of 336 pigs housed in 16 pens with 21 pigs per pen in 2 rooms (8 pens per room) were used. Pens had fully-slatted concrete floors; floor space was 0.32 m2/pig and there was one feeder and one drinker per pen. Pigs were fed corn-soybean-based diets formulated to meet or exceed nutrient requirements. Pigs and feeders were weighed at the start and end of the study. Water disappearance was measured using a water-flow meter fitted to the water pipeline supplying the drinker in each pen. For the overall study period, Drinker Type did not affect (P > 0.05) growth performance; however, average daily water disappearance was greater (P < 0.05) for Nipple than Cup drinkers (2.74 and 2.25 liters/d, respectively; SEM = 0.139). Water to feed disappearance ratio was greater (P < 0.05) for the Nipple than the Cup treatment (5.23 vs. 4.22 liters:kg, respectively; SEM = 0.263). These results suggest that water disappearance from nipple drinkers was greater than for cup drinkers. The lack of an effect of Drinker Type treatment on pig growth performance suggests that the treatment difference for water disappearance was most likely due to greater water wastage for the nipple drinkers rather than any effect on water intake per se.

Comprehensive Optical Strain Sensing Through the Use of Colloidal Quantum Dots.

The adaptation of colloidal quantum dots loaded within a polymer for use in nondestructive testing can be used as an optical strain gauge due to the nanomaterial's strain sensing properties. In this paper, we utilized InP/ZnS colloidal quantum dots loaded within a polymer matrix applied onto the surface of a dog-bone foil precoated with an epoxy. By employing an empirical formula and a calibration factor, there is a propinquity between both the calculated optical strain and mechanical stress-strain reference data. Fluctuations are observed, which may be due to both additional strain responses not seen by the mechanical data and quantum dot blinking. These results and methods show the applied use of this novel optical nondestructive testing technique for a variety of structures, especially for structures that operate in harsh environments.

Heat stress reduces intestinal barrier integrity and favors intestinal glucose transport in growing pigs.

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.

Butyrate differentially regulates cytokines and proliferation in porcine peripheral blood mononuclear cells.

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.

Lipopolysaccharide regulates myostatin and MyoD independently of an increase in plasma cortisol in channel catfish (Ictalurus punctatus).

The effects of lipopolysaccharide (LPS) on plasma cortisol and the expression of MyoD and myostatin (MSTN) mRNAs were evaluated in channel catfish. In addition, the effect of dexamethasone (Dex) on MyoD and MSTN mRNAs was examined. For the LPS injection experiments, juvenile channel catfish were injected intraperitoneally with 1.5 mg/kg LPS or sterile PBS. Blood was collected at 1, 3, 12, and 24 h post-injection for cortisol determination, and muscle samples were collected at 3, 12, and 24 h for mRNA analysis. For the Dex injection experiment, fish were injected with 1.0 mg/kg Dex or saline and muscle samples were collected at 12 and 24 h. There was no effect of LPS on plasma cortisol at any of the time points measured. Injection with LPS increased the abundance of MyoD mRNA at 3 and 12 h, and decreased the abundance of MSTN mRNA at 24 h. There was no effect of Dex injection on the abundance of MyoD mRNA. However, Dex injection decreased the abundance of MSTN mRNA at 12 h post-injection. These results suggest that LPS regulates the expression of MyoD and MSTN independently of an increase in plasma cortisol, and that the regulation of MyoD in the channel catfish differs from mammals in response to inflammatory stimuli. These results also confirm that exogenous glucocorticoids decrease the expression of MSTN as shown in other fish species.