Effects of supplementing yeast fermentate in the feed or drinking water on stress susceptibility, plasma chemistry, cytokine levels, antioxidant status, and stress- and immune-related gene expression of broiler chickens

Abstract

This study aimed to elucidate the mechanism by which adding Saccharomyces cerevisiae –derived yeast fermentate to the feed ( XPC ) or drinking water reduces stress in poultry. Day-old male Cobb 500 broiler chicks were assigned to 1 of 3 treatments: stressed control ( CS ), stressed + XPC (1.25 kg/metric ton feed, day 0–43; XPC), or stressed + AviCare (160 mL/100 L drinking water, day 0–43; AVI). All birds were spray-vaccinated for coccidiosis (day 0), raised on reused litter, spray-vaccinated for Newcastle/Bronchitis (day 18), and exposed to heat stress (32°C–34°C) and feed/water withdrawal for 12 h (day 18). Blood samples were collected to assess plasma corticosterone ( CORT ) and heterophil/lymphocyte ( H/L ) ratio (60 birds/treatment; day 40); plasma biochemistry and growth hormone (12 birds/treatment; day 38); and serum serotonin and plasma prolactin, thyroid hormones, antioxidant capacity, and selected cytokines (12 birds/treatment; day 39). Composite asymmetry scores were obtained from 60 birds/treatment on day 41. Organs were collected from 20 birds/treatment on day 43 to measure gene expression of CYP1A2 and melanocortin 2 receptor ( MC2R ) in the adrenal glands and IL10 and AvBD1 in the spleen. Serotonin was lower in CS than XPC ( P = 0.049), whereas AVI was intermediate. Plasma interleukin (IL)-1β was higher in AVI than CS ( P = 0.009) and XPC ( P = 0.009). The CS treatment had higher CORT than AVI ( P = 0.013) and XPC ( P = 0.037) and higher H/L ratios than AVI ( P = 0.026) and XPC ( P = 0.034). Expression of CYP1A2, MC2R, and IL10 was lower ( P < 0.05) in XPC and AVI compared with CS. Furthermore, IL10 expression was lower in XPC than AVI ( P < 0.05). Adding yeast fermentate to the feed or drinking water reduced measures of stress and MC2R gene expression in birds exposed to acute and rearing stressors. However, differences in IL10 gene expression and circulating serotonin and IL-1β suggest that supplementing yeast fermentate in the feed is slightly more effective than supplementation via the drinking water in mitigating the physiological effects associated with the stress response in broilers.

Antioxidant Status, Blood Constituents and Immune Response of Broiler Chickens Fed Two Types of Diets with or without Different Concentrations of Active Yeast

“…This effect enhances the ability of poultry to handle stress and infectious agents. In another study [ 10 ], the authors investigated the mechanism by which SC enhances the oxidative status of broiler chickens. The authors included SC in either the feed or drinking water of stressed broilers and measured CYP1A2 and melanocortin-2 receptor (MC2R) gene expression in the adrenal glands and IL10 and AvBD1 in the spleen.…”

“…The authors concluded that using SC in broilers’ feed or drinking water for 40 days decreased stress and MC2R gene expression. They also showed that supplementation of SC fermentate in the feed was marginally more effective than adding it to drinking water in stimulating oxidative status and reducing stress in broiler chickens [ 10 ] and in detoxifying nitrate (21, 22) and aflatoxin (22, 23).…”

“…Saccharomyces cerevisiae (SC) has been used in poultry feed rations to enhance resistance to aflatoxicosis in poultry [ 9 ]. The antioxidant status and capacity of poultry have been shown to be significantly enhanced by supplementing poultry feed rations with SC, either alone or in combination with probiotics [ 10 , 11 ]. The weights of the primary and secondary immune organs in broilers have been shown to be increased after dietary supplementation with active yeast, potentially indicating immunocompetence in broilers [ 12 ].…”

Effects of organic chromium sources on growth performance, lipid metabolism, antioxidant status, breast amino acid and fatty acid profiles in broilers

“…This result could be related to the fact that the Cr‐yeast is produced by culturing yeast cells in a trivalent Cr‐containing medium. Yeast may have positive effects on the regulation of inflammatory processes 41 …”

Yeast Fermentate-Mediated Reduction of Salmonella Reading and Typhimurium in an in vitro Turkey Cecal Culture Model

“…A likely mechanism associated with XPC is rooted in the demonstrated changes to the microbiota in response to XPC supplementation, shifting the metabolites present, and ultimately reducing Salmonella fitness (Park et al, 2017;Rubinelli et al, 2016;Feye et al, 2019). The same mechanism likely drives the immune-modulating response that reduces peripheral inflammation while increasing the phagocytosis of Salmonella (Feye et al, 2016b(Feye et al, , 2019Nelson et al, 2020).…”