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Tan J.,China Agricultural University | Tan J.,Purdue University | Applegate T.J.,Purdue University | Liu S.,China Agricultural University | And 2 more authors.
British Journal of Nutrition | Year: 2014

The present study investigated the effects of dietary arginine (Arg) supplementation on intestinal structure and functionality in broiler chickens subjected to coccidial challenge. The present study was a randomised complete block design employing a 3 × 2 factorial arrangement (n 8) with three dietary concentrations of Arg (11.1, 13.3 and 20.2 g/kg) with or without coccidial vaccine challenge (unchallenged and coccidial challenge). On day 14, birds were orally administered with coccidial vaccine or saline. On day 21, birds were killed to obtain jejunal tissue and mucosal samples for histological, gene expression and mucosal immunity measurements. Within 7 d of the challenge, there was a decrease in body-weight gain and feed intake, and an increase in the feed:gain ratio (P<0.05). Jejunal inflammation was evidenced by villus damage, crypt dilation and goblet cell depletion. Coccidial challenge increased mucosal secretory IgA concentration and inflammatory gene (iNOS, IL-1β, IL-8 and MyD88) mRNA expression levels (P< 0.05), as well as reduced jejunal Mucin-2, IgA and IL-1RI mRNA expression levels (P< 0.05). Increasing Arg concentration (1) increased jejunal villus height (P< 0.05) and linearly increased jejunal crypt depth (P< 0.05); (2) quadratically increased mucosal maltase activity (P< 0.05) and linearly decreased mucosal secretory IgG concentration (P< 0.05) within the coccidiosis-challenged groups; and (3) linearly decreased jejunal Toll-like receptor 4 (TLR4) mRNA expression level (P< 0.05) within the coccidiosis-challenged groups. The mRNA expression of mechanistic target of rapamycin (mTOR) complex 1 pathway genes (mTOR and RPS6KB1) and the anti-apoptosis gene Bcl-2 quadratically responded to increasing dietary Arg supplementation (P<0.05). These results indicate that dietary Arg supplementation attenuates intestinal mucosal disruption in coccidiosis-challenged chickens probably through suppressing TLR4 and activating mTOR complex 1 pathways. © The Authors 2014. Source

Muir W.M.,Purdue University | Cheng H.-W.,Livestock Behavior Research Unit | Croney C.,Purdue University
Frontiers in Genetics | Year: 2014

As consumers and society in general become more aware of ethical and moral dilemmas associated with intensive rearing systems, pressure is put on the animal and poultry industries to adopt alternative forms of housing. This presents challenges especially regarding managing competitive social interactions between animals. However, selective breeding programs are rapidly advancing, enhanced by both genomics and new quantitative genetic theory that offer potential solutions by improving adaptation of the bird to existing and proposed production environments. The outcomes of adaptation could lead to improvement of animal welfare by increasing fitness of the animal for the given environments, which might lead to increased contentment and decreased distress of birds in those systems. Genomic selection, based on dense genetic markers, will allow for more rapid improvement of traits that are expensive or difficult to measure, or have a low heritability, such as pecking, cannibalism, robustness, mortality, leg score, bone strength, disease resistance, and thus has the potential to address many poultry welfare concerns. Recently selection programs to include social effects, known as associative or indirect genetic effects (IGEs), have received much attention. Group, kin, multi-level, and multi-trait selection including IGEs have all been shown to be highly effective in reducing mortality while increasing productivity of poultry layers and reduce or eliminate the need for beak trimming. Multi-level selection was shown to increases robustness as indicated by the greater ability of birds to cope with stressors. Kin selection has been shown to be easy to implement and improve both productivity and animal well-being. Management practices and rearing conditions employed for domestic animal production will continue to change based on ethical and scientific results. However, the animal breeding tools necessary to provide an animal that is best adapted to these changing conditions are readily available and should be used, which will ultimately lead to the best possible outcomes for all impacted. © 2014 Muir, Cheng and Croney. Source

Troche C.,Purdue University | Troche C.,University of Florida | Eicher S.D.,Livestock Behavior Research Unit | Applegate T.J.,Purdue University
British Journal of Nutrition | Year: 2015

Coccidia are protozoal parasites which compromise mucosal integrity of the intestine, potentiating poultry morbidity. The host's Zn status influences the course of infection. Therefore, two experiments were designed to determine how supplemental Zn regimens impacted jejunal and caecal immune status and Zn transporter expression. Coccivac®-B was administered weekly at ten times the recommended dose as a mild coccidial challenge (10CV). Zn was provided through a basal diet, supplemental zinc sulfate (ZnSO4), or a supplemental 1:1 blend of ZnSO4 and Availa®-Zn (Blend). Mucosal jejunum (Expt 1) and caecal tonsils (Expt 2) were evaluated for intracellular Zn concentrations and phagocytic capacity. Messenger expression of Zn transporters ZnT5, ZnT7, Zip9 and Zip13 were investigated to determine Zn trafficking. With 10CV, phagocytic capacity was decreased in jejunal cells by 2 %. In the caecal tonsils, however, phagocytic capacity increased with challenge, with the magnitude of increase being more pronounced with higher dietary Zn (10CV × Zn interaction; P= 0·04). Intracellular Zn within caecal tonsils was found significantly reduced with 10CV (27 %, P= 0·0001). 10CV also resulted in an overall increase in the ratio of Zip:ZnT transporters. With the exception of Zip13 transporter expression, dietary Zn source had little impact on any of the measured cellular parameters. Thus, intestinal mucosal tissues had reductions in intracellular free Zn during coccidial challenge, which was coupled with an upregulation of measured Zip transporters. This suggests that under coccidial challenge, intestinal cells attempt to compensate for the drop in intracellular Zn. © The Authors 2015. Source

Hu J.,Purdue University | Dennis R.L.,Livestock Behavior Research Unit | Zhao J.,Novus International Inc. | Cheng H.-W.,Livestock Behavior Research Unit
International Journal of Poultry Science | Year: 2016

In egg industry, transportations and mixing are common stressors for hens. The objective of this study was to determine if the dietary antioxidant supplement improves hen performance, egg quality and behavior following transportation and housing environment changes. At 28 week of age, floor pen housed Bovans Brown hens (n = 48) were transferred to 2-hen wire cages and randomly assigned to one of the four dietary treatments: standard layer ration (control) and antioxidant supplemented diets at 200, 400 and 600 ppm of Agrado for 2 weeks. Egg production was recorded daily. Egg quality and feed consumption were measured weekly on two consecutive days. Individual body weight and weight of internal organs were measured at the end of the study. Behaviors were recorded twice per week using scan sampling. All three treated groups had higher egg production and fewer broken eggs compared to the control group. Body weight loss was observed in all hens regardless of treatments. However, hens fed 400 ppm antioxidant tended to lose the least body weight. In addition, hens fed 400 ppm antioxidant displayed the lowest incidence of stereotypic pecking behaviors. There were no treatment effects on feed intake, liver and spleen weight, Haugh units and yolk color, heterophil to lymphocyte ratio and corticosterone concentrations. Adrenal weight tended to be lower in all treated hens compared to the controls but without dose effects. In conclusion, dietary supplementation of the antioxidant could be used as a practice strategy to improve hen productivity performance under management stress. © Asian Network for Scientific Information, 2016. Source

Felver-Gant J.N.,Purdue University | Dennis R.L.,Livestock Behavior Research Unit | Zhao J.,Novus International Inc. | Cheng H.-W.,Livestock Behavior Research Unit
International Journal of Poultry Science | Year: 2014

Heat stress (HS) causes oxidative damage, increasing mortality and reducing productivity in chickens. The objective of this study was to determine the benefits of antioxidant supplementation in laying hens during HS. Eighty 32-week-old W-36 White Leghorn hens were used in this study. Hens were randomly pair-housed in two adjacent rooms and fed a control diet (CF) or control diet mixed with Agrado Plus Ultra®, an antioxidant, at 160 mg/kg (AF) for two weeks. One room was then subjected to a hot climate (H) (33°C) for 8 days. Physical and physiological data were collected at day 1 and 8 during the treatment. Core body temperature was increased (p<0.0001) and BW (p<0.05) and liver weight (p<0.0001) were reduced in laying hens regardless of treatment. However, compared to its respective controls, the concentrations of heat shock protein 70 (HSP70) were increased in H-AF hens (p< 0.01) but not in H-CF hens (p>0.05) at 8 days during the process of HS. Similarly, HSP70 mRNA expression tended to increase in H-AF hens only (p = 0.09). Heat stress reduced the concentrations of total CO2and bicarbonate (p<0.05), indicating respiratory alkalosis and decreased vitamin A (p<0.01), vitamin E (p<0.0001) and glutathione peroxidase (p<0.05) concentrations but increased protein carbonyl concentrations (p<0.05), indicating protein oxidative damage. A temperature by feed interaction was observed in the concentrations of partial pressure CO2(pCO2, p<0.05), superoxide dismutase (SOD, p = 0.06) and protein carbonyl (p = 0.1). Heat stress-caused decreases in pCO2and SOD and increases in protein carbonyl concentrations were found in control hens but not in AF hens. These results suggest antioxidant supplementation attenuates oxidative stress response in laying hens. These data support the hypothesis that supplemental antioxidants improve hen well-being by reducing HS associated physical and physiological damage. © Asian Network for Scientific Information, 2014. Source

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