Browsing by Author "White, Mallory B."

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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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    Inclusion of Quillaja Saponin Clarity Q Manages Growth Performance, Immune Response, and Nutrient Transport of Broilers during Subclinical Necrotic Enteritis
    Blue, Candice E. C.; Emami, Nima K.; White, Mallory B.; Cantley, Staci; Dalloul, Rami A. (MDPI, 2023-07-27)
    Necrotic enteritis (NE) is an intestinal disease that results in poor performance, inefficient nutrient absorption, and has a devastating economic impact on poultry production. This study evaluated the effects of a saponin-based product (Clarity Q, CQ) during an NE challenge. A total of 1200 male chicks were randomly assigned to four dietary treatments (10 pens/treatment; 30 birds/pen): treatment 1 (NC), a non-medicated corn–soybean basal diet; treatment 2 (PC), NC + 50 g/metric ton (MT) of bacitracin methylene disalicylate (BMD); and treatments 3 (CQ15) and 4 (CQ30), NC + 15 and 30 g/MT, respectively. On the day (d) of placement, birds were challenged by a coccidia vaccine to induce NE. On d 8, 14, 28, and 42, performance parameters were measured. On d 8, three birds/pen were necropsied for NE lesions. On d 8 and d 14, jejunum samples from one bird/pen were collected for mRNA abundance of tight junction proteins and nutrient transporter genes. Data were analyzed in JMP (JMP Pro, 16), and significance (p ≤ 0.05) between treatments was identified by Fisher’s least significant difference (LSD) test. Compared to PC and NC, CQ15 had higher average daily gain (ADG), while CQ30 had lower average daily feed intake (ADFI) and feed conversion ratio (FCR). NE lesions in the duodenum were lower in CQ15 compared to all other treatments. On d 8, mRNA abundance of CLDN1, CLDN5, AMPK, PepT2, GLUT2, and EAAT3 were significantly greater in CQ30 (p < 0.05) compared to both PC and NC. On d 14, mRNA abundance of ZO2 and PepT2 was significantly lower in PC when compared to all treatments, while that of ANXA1, JAM3, and GLUT5 was comparable to CQ15. In summary, adding Clarity Q to broiler diets has the potential to alleviate adverse effects caused by this enteric disease by improving performance, reducing intestinal lesions, and positively modulating the mRNA abundance of various tight junction proteins and key nutrient transporters during peak NE infection.
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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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    The Modulating Effect of Dietary Beta-Glucan Supplementation on Expression of Immune Response Genes of Broilers during a Coccidiosis Challenge
    Omara, Islam I.; Pender, Chasity M.; White, Mallory B.; Dalloul, Rami A. (2021-01)
    Simple Summary Avian coccidiosis is the leading parasitic disease in the poultry industry and means to control its damages continue to be explored. This study evaluated the feeding effects of a yeast-derived beta-glucan on expression of immune response genes in the spleen, thymus, and bursa of commercial broiler chickens during an Eimeria challenge. The study consisted of two dietary treatments (0% or 0.1% beta-glucan) each with or without a coccidiosis challenge. There were significant effects from dietary beta-glucan, Eimeria challenge, and their interaction for several gene targets in the spleen, thymus, and bursa on days 10 and 14 of age. Based on the current results, supplementation of dietary beta-glucan in Eimeria-challenged birds enhanced and modulated the expression of immune response genes during coccidiosis. This study investigated the effects of a yeast-derived beta-glucan (Auxoferm YGT) supplementation on mRNA expression of immune response genes in the spleen, thymus, and bursa of broiler chickens during a mixed Eimeria infection. Day (d)-old chicks (n = 1440) were fed diets containing 0% or 0.1% YGT. On d 8 post-hatch, half the replicate pens (n = 8) were challenged with a mixed inoculum of E. acervulina, E. maxima, and E. tenella. On d 10 and d 14 post-hatch, the spleen, thymus, and bursa were collected to evaluate mRNA abundance by quantitative real-time PCR. Data were analyzed using PROC GLIMMIX model (2-way interaction) and differences were established by LS-MEANS with significance reported at p <= 0.05. In spleen tissues at d 10, expression of interleukin (IL)-10 and inducible nitric oxide synthase (iNOS) were elevated in both 0.1% YGT-fed challenged and non-challenged birds. In thymus tissues at d 14, expression of IL-10, IL-17F, interferon (IFN)-gamma, iNOS, and macrophage migration inhibitory factor (MIF) were elevated in challenged birds fed 0.1% YGT. In bursal tissues at d 10 and d 14, expression of IL-10, IFN-gamma, iNOS (d 10 only), and MIF were elevated in 0.1% YGT-fed challenged and non-challenged birds. Dietary beta-glucan supplementation to chicken diets modulated their immune response to the Eimeria challenge.
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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.
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    Performance and Microbial Profiles of Broiler Chickens fed Phytogenic Feed Additives or Probiotics during Coccidiosis
    White, Mallory B. (Virginia Tech, 2018-02-06)
    The prophylactic use of antibiotics is rapidly being phased out of poultry operations. Diseases such as coccidiosis are extremely costly, and typically prevented with coccidiostats and antibiotics. New regulation banning antibiotics is mandating a search for new alternatives, such as probiotics and phytogenic feed additives (PFAs). Two separate studies were performed to evaluate the performance and microbial profiles of commercial broilers fed either PFAs or Eimeria challenged broilers fed probiotics. During the probiotics study, 1056 day-old male Ross broiler chicks were assigned to one of 6 treatments, 8 replicates per treatment, with 22 birds per floor pen in a 2x3 factorial arrangement, with DFM mix and coccidiosis challenge being the main factors. Treatments included a non-infected control (NC), a non-infected low level DFM-fed group (DL), a non-infected high level DFM-fed group (DH), an infected control (PC), an infected low level DFM-fed group (DL+), and an infected high level DFM-fed group (DH+). Performance measurements were taken on d0, d7, d14, d21, and d28. Mucosal scrapings from the ileum were obtained on d7, d14, d21, and d28 to determine microbial profiles. On d15, birds in the three infected groups were challenged with a mixed inoculum containing Eimeria maxima, E. tenella, and E. acervulina. Lesion scores were assessed on d21. Body composition was analyzed via Dual Energy X-Ray Absorptiometry (DXA) on d28. Results indicated a trend (P < 0.1) toward improved D28 body composition, lower Clostridium in DFM-fed challenged broilers compared to PC, and higher Bacillus in DH compared to DH+. Results were not significant for BW, BWG, FI, or lesion scores. The second study evaluated the effects of PFA provided as a dietary supplement over a 6-week period on performance and immune responses in broilers. In total, 1056 day-old male chicks were randomly assigned to 8 replicate pens (22 birds/pen) with 6 treatments including a standard corn/wheat basal diet, a basal with antibiotics, and 4 various combinations of PFA (PHY 1, 2, 3, and 4). Performance was assessed on day 7 (D7), 14, 28, and 42. Starter diet was fed D0-14, grower D14-28, and finisher D28-42. Microbial profiling was assessed on D7, 14, and 42, and body composition measured on D42 using Dual Energy X-Ray Absorptiometry (DXA). Results varied by week, but cumulatively, body weight gain (BWG) per bird was higher in PHY1 and 4, statistically similar to AGP and CTRL. With feed conversion ratio (FCR), PHY2 was higher than any other treatment between D0-42, while all other treatments were similar. PCR results were not statistically significant; however, DXA results indicated a higher lean to fat ratio in birds from PHY1-4 when compared to AGP, indicating an overall leaner bird in PHY treatments. The results of these studies suggest that diets supplemented with DFMs or PFAs result in improved broiler performance.