ABSTRACT:In this study, the antibacterial substances ZnO, organic acids and a bacteriophage cocktail were added to the diet of weanling pigs to evaluate the effects on gut health. Dietary treatments were basal diet without any supplementation (Control) and basal diet either supplemented with 0.34% (2500 ppm) ZnO, 0.20% organic acids or with 0.10% bacteriophage cocktail. Faecal score was decreased in ZnO and bacteriophage cocktail treatments. The total number of ileal anaerobic bacteria, Bifidobacterium spp. and Lactobacillus spp. were higher in ZnO, bacteriophage cocktail and organic acids, while ileal coliforms and caecal Clostridium spp. were decreased in comparison to Control. Faecal coliforms (Day 7 and Day 21) and Clostridium spp. (Day 21 and Day 35) were lower in bacteriophage cocktail. The gain to feed ratio was improved in all supplemented groups. The digestibility of dry matter was increased at the end of the experiment in all supplemented groups, while that of crude protein was increased only at Day 21 in bacteriophage cocktail. Duodenal villus height was increased in ZnO and bacteriophage cocktail. Bacteriophage cocktail also showed a greater villus height in the small intestine. Supplementation of bacteriophage cocktail in weaning pig diets resulted in better growth performance, digestibility and gut development compared to Control, and thus, it can be concluded that its effects are comparable to ZnO or organic acids supplementation.

Objective: This study was conducted to investigate the effects of hot-melt extruded ZnO nano-particles (HME-ZnO) as an alternative for P-ZnO on growth performance, nutrient digestibility, Zn bioavailability, intestinal microbiota, and intestinal morphology of weanling pigs. Methods: A total of 450 piglets (Landrace×Yorkshire×Duroc) were randomly allotted to five treatments based on initial body weight and sex. The experimental diets were fed in a meal form as phase 1 from d 0 to 14 and phase 2 from d 15 to 28. Treatments were the control diet without ZnO supplementation, the diet containing 2,500 ppm Zn as ZnO, and three diets containing 500, 1,000, or 2,500 ppm Zn as HME-ZnO. Results: The overall result showed a higher (p<0.01) average daily gain in weanling pigs fed ZnO-supplemented diets in comparison to the control diet. There was a decrease (p<0.01) in fecal score in the ZnO-supplemented diets. Dietary supplementation of ZnO improved (p<0.05) crude protein digestibility. The weanling pigs fed the P-ZnO diet had a lower (p< 0.01) Zn digestibility in the feces than HME-ZnO supplemented treatments. Weanling pigs fed diets supplemented with ZnO had greater (p<0.05) Lactobacillus spp. populations and lower Clostridium spp. (p<0.05) and Coliforms (p<0.01) populations in the ileum. Weanling pigs fed diets supplemented with increasing concentrations of HME-ZnO linearly decreased Clostridium spp. (p<0.05) and Coliforms (p<0.01) in the ileum. Lower (p<0.05) Clostridium spp. and Coliforms counts in the colon were observed in pigs fed with ZnO-supplemented diets. Weanling pigs fed diets supplemented with ZnO showed a greater (p<0.01) villus height in the duodenum. Conclusion: Dietary supplementation of HME-ZnO and P-ZnO showed a potential to improve the digestibility of protein, intestinal Coliform and Clostridium, villus height in duodenum and ileum. Moreover, HME-ZnO showed a higher Zn digestibility compared with P-ZnO.

This study investigated the effect of dietary astaxanthin (AST) on the meat quality, antioxidant status, and immune response of chickens exposed to heat stress. Four hundred and eighty male broilers were assigned to four treatments including AST0, AST20, AST40, and AST80 with 0, 20, 40, and 80 ppm astaxanthin supplementation levels, respectively. There was a linear decrease of malondialdehyde (MDA) in leg muscle. Catalase and superoxide dismutase levels in the plasma were linearly increased. There was a linear increase in the level of total antioxidant capacity in the leg muscle. The 3-ethylbenzothiazoline-6-sulfonate reducing activity of leg muscle was significantly increased in the AST80 treatment. The AST40 treatment showed an increase in 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity of leg muscles. Breast meat redness and yellowness were linearly increased. The astaxanthin-supplemented treatments exhibited lower drip loss and MDA concentration of leg muscle compared with the AST0 treatment at days 3 and 9 of storage. Supplementation of 40 or 80 mg/kg astaxanthin significantly decreased heat shock protein (HSP)27, HSP70, tumor necrosis factor alpha, and interleukin-6 expression in the livers. The feather corticosterone was significantly lower in the astaxanthin-supplemented treatments than in the AST0 treatment. In conclusion, astaxanthin decreased the hyperthermic stress level and improved meat quality, and antioxidant status of chickens exposed to heat stress.

The present study investigates the effect of zinc oxide (ZN), bacteriophage (BAC) or their combination on the growth performance and gut development in weaning pigs. A total of 200 weaned pigs were allotted to four treatments including two levels (0 and 0.34%) of ZN and two levels (0 and 0.10%) of BAC cocktail. Supplementation of both BAC and ZN in the diet improved average daily gain and gain to feed ratio in all three phases. The apparent total tract digestibility (ATTD) of dry matter was consistently increased in BAC. A higher digestibility of dry matter was observed in ZN group at phase-I and II. The ATTD of crude protein was increased in BAC group at phase-I and III. ZN increased ATTD of crude protein during phase III. In all phases, the population of total anaerobic bacteria, Bifidobacterium spp., Lactobacillus spp., Clostridium spp. and coliforms were higher in BAC and ZN groups with the exception for coliforms in ZN at the end of experiment. The duodenum (p < 0.05) and jejunum (p < 0.01) villus heights were considerably increased in BAC group but the ileal villus height was not affected by the addition of BAC in the diet. Similar increase (p < 0.05) in the duodenal (p ¼ 0.06) and jejunal (p < 0.01) villus heights were also observed in ZN supplemented groups. The overall faecal score was reduced (p < 0.01) by BAC and tended to decrease (p ¼ 0.07) by ZN. Thus both ZN and BAC are useful for improving the performance and gut health in weaning pigs without any interactive effects. ARTICLE HISTORY

Two experiments were conducted to investigate the effects of dietary supplementation of bacteriophage cocktail, probiotics and a combination of these two supplements on performance and gut health of weanling pigs. In Experiment 1, 150 weaned piglets were randomly allotted to three treatments on the basis of BW. The dietary treatments included a basal diet supplemented with 0 (control), 1.0 and 1.5 g/kg bacteriophage cocktail. Pigs fed 1.0 and 1.5 g/kg bacteriophage product had greater (P < 0.05) average daily gain (ADG), apparent total tract digestibility of dry matter from day 22 to 35, ileal Lactobacillus spp., villus height (duodenum and jejunum), and fewer coliforms (ileum) and Clostridium spp. (ileum). In Experiment 2, 200 weaned piglets were randomly allotted to four treatments. Dietary treatments included basal diet, basal diet supplemented with 3.0 g/kg fermented probiotic product (P), 1.0 g/kg bacteriophage cocktail (B) and combination of 1.0 g/kg bacteriophage cocktail and 3.0 g/kg fermented probiotic product. Pigs fed bacteriophage cocktail diets had greater (P < 0.05) overall ADG, gain to feed ratio (G : F), fecal score from day 8 to day 21, and pigs fed bacteriophage cocktail diets had fewer coliforms (ileum) Clostridium spp. (ileum and cecum). Probiotics significantly increased G : F, colonization of Lactobacillus spp. in ileum. At day 35, bacteriophage treatment group showed greater (P < 0.05) villus height of the duodenum, but a deeper crypt in duodenum. The present results indicate that the bacteriophage cocktail had a potential to enhance the performance and gut health of weanling pigs, however their combination with probiotics did not show an interaction.

The present study investigated the effects of back-fat thickness at d 107 of gestation and housing types during gestation on reproductive performance and behavior of sows. A total of 64 crossbred sows (Landrace×Yorkshire) in their 3 to 4 parities were allotted to one of four treatments (n = 16) over two consecutive parities. During each parity, sows were assigned to two gestational housing types (stall or group housing) and two level of back-fat thickness (<20 or ≥20) at d 107 of gestation. Gestating sows were transferred from gestational crates to stalls or pens (group housing) 5 weeks before farrowing. All sows were moved to farrowing crates on d 109 of gestation. At weaning, back-fat thickness changes were lesser (p<0.05) in sows having back-fat thickness <20 mm than that of sows with ≥20 mm back-fat thickness at 107 d of gestation. Group housed sows had greater (p<0.05) feed intake and shorter (p<0.05) weaning-to-estrus interval than that of sows in stalls. At weaning, back-fat thickness changes were lesser (p<0.05) in group housed sows than that of sows in stalls. The number of piglets at weaning, growth rate and average daily gain were greater (p<0.05) in group housed sows than that of sows in stalls. During gestation, walking duration was more (p<0.05) in group housed sows. Group housed sows had lesser (p<0.05) farrowing duration and greater (p<0.05) eating time than that of sows in stalls. Result obtained in present study indicated that sows with ≥20 mm back-fat thickness at 107 days had better reproductive performance. Additionally, group housing of sows during last five week of gestation improved the performance and behavior and reproductive efficiency of sows.

The exogenous enzymes are less consistent in their effects as their beneficial effects depend upon the types and level non-starch polysaccharides (NSP) present in the diets. Therefore, exogenous enzymes should be selected on the basis of types and amount of the NSP in the pig diets. The objectives of the present experiments were to investigate the effects of dietary level of mannan and β-mannanase supplementation on growth performance, apparent total tract digestibility (ATTD) of energy and nutrients, and blood metabolites of growing pigs. In Exp. 1, 96 barrows were randomly allotted to four treatments on the basis of BW. There were four replicates in each treatment with six pigs per replicate. The dietary treatments were a corn-soybean meal (SBM)-based control diet and three other diets consisted of the control diet supplemented with 400, 800 or 1600 U of β-mannanase/kg diet. The final BW, average daily gain (ADG) and blood glucose increased (linear, P < 0.05) with increasing concentrations of dietary β-mannanase. The ATTD of dry matter (DM), gross energy (GE) and β-mannan was higher (linear, P < 0.05) with increase in dietary β-mannanase concentrations. In Exp. 2, 288 barrows were allotted to six treatments in a 2 × 3 factorial arrangement of mannan level (high v. low) and addition of β-mannanase (0, 400 or 800 U/kg diet). There were four replicates in each treatment with 12 pigs/replicate. Pigs were fed corn-SBM-based low-mannan diet (6.1 g/kg) or high-mannan (25.2 g/kg) diet in which corn and SBM were partially replaced with 50 g/kg diet palm kernel meal. All diets were fed in meal form for 42 days. Pigs fed diets supplemented with β-mannanase had greater ( P < 0.05) final BW, ADG, feed to gain (F : G), the ATTD of DM, GE, and β-mannan and blood glucose concentration compared with pigs fed diets without β-mannanase. In addition, the final BW, ADG, F : G and the ATTD of GE and β-mannan were reduced ( P < 0.05) in low mannan level. The dietary level of mannan and the β-mannanase supplementation had no effects ( P > 0.05) on the concentrations of blood total cholesterol, triacylglycerides and blood urea nitrogen. These results indicate that supplementation of β-mannanase to low-or high-mannan diets have potential to improve the performance of growing pigs. In addition, palm kernel meal may partially replace corn and SBM without reducing pig performance if β-mannanase is added to diet.Keywords: blood metabolites, growing pigs, performance, mannan, β-mannanase ImplicationsThe β-mannan accounts for 15% to 35 % (soy-based to palm-based) of total non-starch polysaccharides content of the pig diets, β-galactomannan, is a polysaccharide with repeating units of mannose, with galactose or glucose, or both, often found attached to the β-mannan. Pig digestive tract lacks the enzymes targeting β-1, 4-mannosyl bond and α-1, 6-galactosyl bonds, which limits the nutrient utilization and growth performance. These results indicate that β-mannanase have potential to improve the performance of growing pigs, and palm kernel meal m...

This study was conducted to investigate the effects of bacteriophages in different environments on growth performance, digestibility, ileal and caecal microbiota, gut morphology and immunity of weanling pigs. Two hundred piglets were randomly assigned to four treatment groups with five replicate pens with 10 pigs per pen. A 2 × 2 factorial arrangement of treatments was used to investigate the response of weanling pigs to supplemental bacteriophages (0 and 1.0 g/kg of diet) in contaminated or hygienic environments. Bacteriophages supplementation did not affect average daily gain (ADG), average daily feed intake (ADFI) and gain:feed in phases I and III; however, there was a significant improvement in ADG and gain:feed in phase II. The supplementation of bacteriophages increased the overall gain:feed of pigs. The overall result showed a greater ADG and ADFI in hygienic room. There were reductions in population of both ileal (p < 0.05) and caecal (p < 0.01) Clostridium spp. and ileal coliforms (p < 0.01) with the inclusion of bacteriophages in the diet. Bacteriophages increased ileal Lactobacillus and caecal Bifidobacterium and tended to increase ileal Bifidobacterium (p = 0.08). Contaminated environment decreased ileal Lactobacillus and caecal Bifidobacterium and tended to increase ileal Clostridium (p = 0.08) and coliforms (p = 0.08). Total anaerobic bacteria was tended to decrease (p = 0.06) in contaminated environment. Jejunal villus height increased in pigs received bacteriophages, but they did not affect other morphological items. The interaction between bacteriophages and environment tended to be significant (p = 0.06) for ileal villus height and ileal villus height to crypt depth ratio. The overall faecal score was significantly greater in hygienic environment and bacteriophages groups. The present findings indicate that there is an interactive effect on feed efficiency between bacteriophages and contaminated environment. In addition, bacteriophages improve jejunum morphology, and intestinal microbiota of pigs.