The probiotic Bacillus licheniformis ameliorates heat stress-induced impairment of egg production, gut morphology, and intestinal mucosal immunity in laying hens

Abstract

We investigated the effect of a 12-d exposure to 34°C plus dietary inclusion of the probiotic Bacillus licheniformis on the egg production, gut morphology, and intestinal mucosal immunity of laying hens. Ninety-six commercial hens (Hy-Line Brown) at the age of 60 wk were randomly allocated to 4 groups. After a period of laying rate adjustment (14 d), all the hens were subjected to 2 temperature treatments (12 d). Birds in 1 group were raised at 21°C and fed a basal diet, and birds in the other 3 groups were raised at 34°C and fed a basal diet supplemented with 0, 10(6), or 10(7) cfu of B. licheniformis per gram of feed, respectively. Rearing at 34°C depressed egg production and feed intake (P < 0.05). Compared with birds kept at 21°C, birds kept at 34°C had elevated serum levels of tumor necrosis factor-α (d 6), IL-1 (d 6 and 12), and corticosterone (d 6); decreased villus height (ileum: d 6; cecum: d 6 and 12) and ratio of villus height to crypt depth (ileum: d 6; cecum: d 6 and 12); fewer intraepithelial lymphocytes (ileum: d 6; cecum: d 6) and IgA-secreting cells (ileum: d 6; cecum: d 6 and 12); and more mast cells (ileum: d 6; cecum: d 6 and 12; P < 0.05). The number of goblet cells in the cecum increased at d 6 in heat-treated birds, and then deceased at d 12 (P < 0.05). Moreover, morphological examination showed injury to the villi of birds kept at 34°C. In general, inclusion of 10(7) cfu/g of B. licheniformis in the diet of heat-stressed hens was effective in overcoming the observed decline in egg production and feed intake, restoring the impaired villus structure, and sustaining a balanced mucosal immune response. Therefore, the probiotic B. licheniformis may be useful for ameliorating the adverse influence of heat on the egg production and gut health of laying hens.

Influence of β-galacto-oligosaccharide on growth performance and components of intestinal barrier in broilers during heat stress

“…Exposure to heat stress resulted in a decline in the IEL count in all segments of the small intestine. Similar observations were made in broilers by Deng et al, (2012). However, these results are in contrast with those reported by Ashraf et al (2013) and QuinteiroFilho et al (2010).…”

Effects of Kluyveromyces marxianus Isolated from Tibetan Mushrooms on the Plasma Lipids, Egg Cholesterol Level, Egg Quality and Intestinal Health of Laying Hens

“…The addition of beneficial bacteria to a diet can recover the intestinal integrity, thereby increasing nutrient bioavailability and absorption (Burel & Valat, 2009;Deng et al, 2012). Probiotics also improved gut health, which directly improved the birds' health and performance (Burel & Valat, 2009).…”

Effects of Chromium Picolinate Supplementation on Growth Performance, Small Intestine Morphology and Antioxidant Status in Ducks Under Heat Stress Conditions

“…It was revealed that chickens exposed to acute heat stress (30 °C/24 h) presented a reduction of the ileum's crypt depths but no significant differences in the villus height and villus: crypt ratio (Burkholder et al), this showed that heat stress via changing the intestinal morphology and structure increased the organism risk of illness. Compared with birds kept at 21 °C, birds kept at 34°C had decreased villus height, ratio of villus height to crypt depth and fewer intraepithelial lymphocytes (Deng et al, 2012), suggested that thermal stress damaged the normal intestinal health. In our study, at day 35, ducks in HS group had deeper crypt depth than those in CrPic group in ileum.…”