Alleviation of cyclic heat stress in broilers by dietary supplementation of mannan-oligosaccharide and Lactobacillus-based probiotic: Dynamics of cortisol, thyroid hormones, cholesterol, C-reactive protein, and humoral immunity

Abstract

Heat stress (HS), one of the major problems of tropical and subtropical countries, adversely affects the production performance of poultry. Keeping this in view, the present study was designed to investigate some of the biological markers of HS in broilers as modulated by dietary supplementation of mannan-oligosaccharide (MOS) and a Lactobacillus-based probiotic (LBP), either alone or in combination. Two hundred fifty 1-d-old-chicks were randomly divided into 5 groups. From d 22, the birds were either kept at the thermoneutral zone (TN) or exposed to HS to the conclusion of study, d 42. Birds were fed either a corn-based basal diet (TN and HS groups) or the same diet supplemented with 0.5% MOS (HS-MOS group), 0.1% LBP (HS-LBP group), or their combination. Birds were immunized against Newcastle disease virus on d 4 (intraocular; live attenuated) and d 20 (drinking water; live attenuated) and infectious bursal disease virus on d 8 (intraocular; live intermediate strain) and d 24 (drinking water; live attenuated). Birds were killed on d 42 to collect serum for determination of cortisol, thyroid hormones, cholesterol, C-reactive protein, and postvaccinal antibody titers. Results revealed that dietary supplementations decreased (P < 0.05) the serum cortisol and cholesterol concentrations and increased (P < 0.05) thyroxine concentration compared with the HS group without affecting triiodothyronine concentration. The percentage of the C-reactive protein-positive birds was higher (P < 0.05) in the HS group compared with the TN group. Dietary supplementations improved humoral immunity against Newcastle disease virus and infectious bursal disease virus during HS. In conclusion, dietary supplementation of either MOS or LBP alone or in combination can reduce some of the detrimental effects of HS in broilers.

Dietary Mannan Oligosaccharides Modulate Gut Microbiota, Increase Fecal Bile Acid Excretion, and Decrease Plasma Cholesterol and Atherosclerosis Development

“…Additionally, in different studies using a variety of experimental animal models, it was shown that dietary supplementation with MOS lowered plasma cholesterol levels 14, 15, 16. However, the mechanism by which MOS exert their effect is not fully established.…”

Effect of Heat Stress on the Expression of GABA Receptor mRNA in the HPG Axis of Wenchang Chickens

“…Under high temperature, the bird's body resists to HS by inducing the release of hypothalamic-pituitary hormones, i.e., they regulate their physiological activities, such as metabolism, immunity, and reproduction, etc. via synthesis and release of hormones related to the adrenal axis, thyroid axis, and gonadal axis (Akazome et al, 2002;Elnagar et al, 2010;Sohail et al, 2010;Yin et al, 2011). HS induces the expression of numerous genes, such as heat shock protein 70, growth-and metabolism-related genes (EGFR, SFRP1, and PDK4), immune-related genes (HSF1, Bcl-2, and Bax-α), reproductive hormone receptor-associated genes (LHR, ESR, PRLR, and FSHR), rhythmic genes (Per2), etc.…”

Enzymatic Hydrolysis of Porang by Streptomyces violascens BF 3.10 Mannanase for the Production of Mannooligosaccharides

“…Broiler chicks fed with prebiotics were increased in weight gain, feed conversation efficiency, nutrient digestibility, while the jejunal content viscosity was decreased (Sundu et al, 2006). On the other hand, dietary supplementation with prebiotics reduced some negative effects of heat stress in broilers (Sohail et al, 2010).…”