Efficacy of lactobacilli to normalize production of corticosterone induced by unpleasant handling of broilers

Abstract

A study was conducted to investigate the effect of two Lactobacillus strains on hypothalamus pituitary adrenal (HPA) axis activity induced by supposedly unpleasant handling (UH) of broiler chickens. The three treatments were: (1) non-handled chicks fed basal diet (control); (2) unpleasantly handled-chicks fed basal diet (UH-BD) and (3) unpleasantly handled-chicks fed basal diet supplemented with the probiotic, lactobacilli (UH-BDL). Chicks were exposed to UH from days 1 to 21. Treatment UH-BDL received probiotics in their diet for the whole experimental period. Blood corticosterone (CS) concentrations were monitored at 14, 28, 35 and 42 days of age and selected caecal bacterial groups were enumerated in 14-day old birds. Unpleasant handling significantly increased blood CS concentrations at 14 and 28 days of age. Blood CS concentration decreased with age over the course of the experimental period. Lactobacillus supplementation did not reduce blood CS concentration in broilers in the UH-BDL treatment. Moreover, the UH treatment did not alter caecal bacterial numbers in the 14-day old broilers while the probiotic numerically increased total anaerobes and lactobacilli. Overall, it seems as if the efficacy of lactobacilli to modulate stress-related high HPA-axis activity depends on gastrointestinal tract microbial alteration. However, Lactobacillus salivarius subsp. salicinius JCM 1230 and L. agilis JCM 1048 were able to reestablish a proper microbial balance in the caecum of the chickens. ________________________________________________________________________________

Gut microbiota and transportation stress response affected by tryptophan supplementation in broiler chickens

“…Physiologically, these changes may lead to depletion of muscle glycogen reserves and therefore affecting the rate and extent of pH decrease, which could affect meat quality (Debut et al 2003). On the other hand, stressful experience may disturb the balance of intestinal microbiota and lead to excessive growth of pathogens while decreasing the proportion of beneficial bacteria such as Lactobacilli and Bifidobacteria (Meimandipour et al 2010;Zhang et al 2016). Proliferation of Bifidobacteria and Lactobacilli in the gut can increase non-anxious behaviour in mouse through vagus nerve, maybe through bacteria-derived neuroactive elements (Saulnier et al 2013).…”

Gut microbiota and feather pecking : Integrating microbiota, behaviour, stress, serotonin and the immune system

“…With regard to the stress system, most studies to date identified effects of gut microbiota on basal CORT level in chickens. Manipulating microbiota via probiotic treatment did not alter basal CORT level in unpleasantly handled broilers 1 (Meimandipour et al, 2011), broilers (Cengiz et al, 2015;Yan et al, 2018) or laying hens, but it reduced basal ACTH level in laying hens (Lei et al, 2013). Similarly, prebiotic treatment did not alter basal CORT level in broilers (Houshmand et al, 2012).…”