Browsing by Author "Calik, Ali"

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    Dietary Non-Drug Feed Additive as an Alternative for Antibiotic Growth Promoters for Broilers During a Necrotic Enteritis Challenge
    Calik, Ali; Omara, Islam I.; White, Mallory B.; Evans, Nicholas P.; Karnezos, T. Peter; Dalloul, Rami A. (MDPI, 2019-08-13)
    Necrotic enteritis, caused by Clostridium perfringens, is an enteric disease that leads to poor performance and increased mortality, resulting in significant economic losses in poultry production. This study evaluated the effects of a proprietary prebiotic, probiotic, and plant extract blend on performance of broilers during coccidiosis challenge leading to necrotic enteritis (NE). In total, 744 Cobb500 male broilers were randomly allocated to 3 treatments (8 replicates, 31 birds/pen) including, the negative control (NC) fed a basal diet; the positive control (PC) fed a basal diet with Virginiamycin; and the additive group fed basal diet with a blend of prebiotic, probiotic, and plant extract (BSN). A unique, naturally occurring NE model developed to mimic field conditions was implemented to challenge the birds. This model consists of spraying a concentrated commercial coccidiosis vaccine on litter and feed upon bird placement, which, in conjunction with the presence of C. perfringens spores in the environment, leads to the development of a NE outbreak one week post vaccine application. At the onset of NE on d7, three birds/pen were selected for scoring NE lesions. Body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were recorded on days 7, 14, 28, and 42. Carcass composition was assessed by dual energy X-ray absorptiometry (DXA) analysis on day 42. Dietary supplementation of BSN significantly (p < 0.05) improved FCR during starter and grower periods. Dietary treatments had no effect on NE lesions in the small intestine. DXA analysis revealed slightly higher lean content in BSN birds compared to NC. These results showed that dietary supplementation of the BSN blend significantly improved broilers performance during the early NE challenge phase, as well as in the grower period.
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    Influence of dietary vitamin E and selenium supplementation on broilers subjected to heat stress, Part I: Growth performance, body composition and intestinal nutrient transporters
    Calik, Ali; Emami, Nima K.; White, Mallory B.; Walsh, Maria C.; Romero, Luis F.; Dalloul, Rami A. (Elsevier, 2022-06)
    High ambient temperature is one of the most common stressors in modern poultry production, resulting in reduced feed intake, weight gain, and increased mortality. This study evaluated the effects of vitamin E (Vit E) and organic selenium (Se) supplementation on performance, body composition, core body temperatures, and mRNA abundance of nutrient transporters in the jejunum of broilers exposed to daily 4-h elevated temperature during d 28 to 35. A total of 640 Cobb male birds were randomly allocated to 32 floor pens in a 2 x 2 factorial arrangement that included ambient temperature (thermoneutral, [TN]; or heat stress, [HS]) and dietary treatments (basal diet or Vit E + Se). Four rooms were used (2 TN and 2 HS) each housing half of the 8 replicate pens per group. Vit E and organic Se were added to the basal diet at the rate of 250 mg/kg and 1 mg/kg diet, respectively. Data were subjected to a 2-way ANOVA using the GLM procedure of JMP (SAS). During the HS period, birds fed the Vit E/Se diet had significantly lower mortality compared to nonsupplemented group (1.92% vs. 7.01%). Moreover, dietary Vit E/Se supplementation had a significant effect on performance by increasing BWG, FI, and European production efficiency factor (EPEF) during the entire experimental period (d 0-35). Dietary Vit E and Se supplementation significantly increased carcass, tissue, lean, and fat weights as well as bone mineral content (BMC) and bone mineral density (BMD) on d 35. Birds fed Vit E/Se supplemented diet had significantly lower (P = 0.010) core body temperature compared to birds fed the basal diet on d 30. Dietary treatment did not influence mRNA abundance of PepT1, SGLT1, or NaPi-IIb on d 28 or d 35. However, HS significantly upregulated levels of PepT1 and NaPi-IIb (P < 0.001) and downregulated that of SGLT1 (P = 0.017) on d 28. In conclusion, dietary Vit E and Se supplementation significantly improved broiler growth performance and carcass composition, and reduced heat-related mortality and core body temperature (on d 30) without influencing the mRNA abundance of intestinal nutrient transporters.
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    Influence of dietary vitamin E and selenium supplementation on broilers subjected to heat stress, Part II: oxidative stress, immune response, gut integrity, and intestinal microbiota
    Calik, Ali; Emami, Nima K.; Schyns, Ghislain; White, Mallory B.; Walsh, Maria C.; Romero, Luis F.; Dalloul, Rami A. (Elsevier, 2022-06)
    This study evaluated the effects of vitamin E (Vit E) and selenium (Se) supplementation on mRNA abundance of antioxidant, immune response, and tight junction genes, as well as taxonomic and functional profiles of ileal microbiota of broilers exposed to daily 4-h elevated temperature during d 28 to 35. A total of 640-day-old Cobb male broiler chicks were randomly allocated to 32 floor pens in a 2 x 2 factorial arrangement that included ambient temperature (thermoneutral [TN] or heat stress [HS]) and dietary treatments (basal diet or Vit E + Se). Vit E and organic Se were added to the basal diet at the rate of 250 mg/kg and 1 mg/kg, respectively. Liver and jejunum tissue samples were taken on d 27 (1 bird/pen), d 28 and d 35 (2 birds/pen) from birds for qPCR analysis. Data were subjected to a 2-way ANOVA using the GLM procedure of JMP. Ileal contents were taken on d 27 and d 35 for microbial profiling. Microbiota data were analyzed in QIIME 2 and significance between treatments identified linear discriminant analysis effect size (LEfSe, P < 0.05). Dietary Vit E/Se significantly downregulated the mRNA levels of HSPs in liver and jejunal tissues of the HS-challenged birds both on d 28 and d 35. Moreover, mRNA abundance of TLR2, INF alpha, IFN gamma, IL-1 beta, IL-10, and iNOS in the liver were significantly downregulated in birds fed the Vit E/Se diet on d 35. However, dietary treatment had no significant impact on oxidative stress, immunity, and gut integrity related genes analyzed in jejunal tissues on d 28 and d 35, except downregulation of IFN gamma on d 35 (P = 0.052). LEfSe analysis revealed that Lachnospiraceae FE2018 and Ruminococcaceae NK4A214 groups was enriched in the Vit E/Se birds on d 35. Moreover, PICRUSt analysis predicted significant functional differences among the treatment groups. In conclusion, dietary supplementation of Vit E/Se mitigated the negative effects of HS potentially via improving antioxidant status, regulating cytokine responses and modifying ileal microbiota and its function.
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    Necrotic Enteritis in Broiler Chickens: The Role of Tight Junctions and Mucosal Immune Responses in Alleviating the Effect of the Disease
    Emami, Nima K.; Calik, Ali; White, Mallory B.; Young, Mark; Dalloul, Rami A. (MDPI, 2019-07-31)
    Necrotic enteritis (NE) continues to present major challenges to the poultry industry, and the etiologic agent Clostridium perfringens is the fourth leading cause of bacterially-induced food- borne illnesses in the US. This study was designed to evaluate the effects of a probiotic during naturally occurring NE. On day of hatch, 1080 Cobb 500 male broilers were randomly allocated to three groups (12 replicate pens/treatment, 30 birds/pen) including (1) negative control (NC): corn-soybean meal diet; (2) positive control (PC): NC + 20 mg virginiamycin/kg diet (0.450 kg Stafac®20/ton); and (3) NC + PrimaLac (1.36 and 0.91 kg/ton from 1–21 and 22–42 days, respectively). One day (d) post placement, all birds were challenged by a commercial live oocyst coccidia vaccine as a predisposing factor to NE. Body weight and feed intake were measured at the onset of NE (d 8) and end of each feeding phase. On d 8, small intestines of two birds/pen were examined for NE lesions, and jejunum samples from one bird were collected for mRNA gene expression analysis of tight junction proteins, cytokines, and nutrient transporters. Data were analyzed using the JMP software and significance between treatments identified by LSD (p < 0.05). Compared to NC, supplementation of probiotic reduced d 1–42 mortality; however, PC was the only group with significantly lower mortality. Despite significantly improved feed conversion ratio (FCR) in PC and probiotic groups during d 1–42, average daily gain was only higher in PC (77.69 g/bird) compared with NC (74.99 g/bird). Furthermore, probiotic and PC groups had significantly reduced lesion scores in the duodenum and jejunum compared to NC. Expression of claudin-3 was higher, while expression of zonula occluden-2 tended (p = 0.06) to be higher in probiotic-supplemented birds compared to NC. Moreover, birds fed the probiotic diet had significantly higher expression of IL-10, IL-17, AMPK-α1, and SGLT1 mRNA compared to NC birds. The expression of PepT1 was higher for the probiotic-supplemented group compared to PC. IFN-γ expression was lower in PC compared to NC, while there was no difference between probiotic and NC. There were no differences in gene expression of sIgA, TNF-α, IL-1β, and IL-22 among treatments. Collectively, these data indicate that in a naturally occurring NE model, supplementation of a probiotic helps to improve FCR and reduce lesions, potentially due to the improvements in mRNA expression of tight junctions, cytokines, and nutrient transporters.