Dietary yeast β-glucan supplementation improves eggshell color and fertile eggs hatchability as well as enhances immune functions in breeder laying hens

The study was conducted to evaluate the effects of dietary yeast beta-glucan (YG) on performance and immune functions in breeder hens in a non-challenged setting. A total of 512 43-week-old Hy-Line Brown breeder hens were assigned into four treatments, and fed a basal diet with YG at 0, 50,100 and 200 mg /kg for 8 weeks, respectively. Results showed that supplementation of YG did not affect production performance, but linearly increased hatchability (P < 0.05). Compared with the control, hens fed with 200 mg/kg YG had improved eggshell color and reduced mortality. Moreover, feeding 200 mg/kg YG significantly (P < 0.05) enhanced lymphocyte proliferation response to LPS, increased the percentage of peripheral blood CD3(+) T cells and phytohemagglutinin (PHA) skin response; remarkably down-regulated splenic TLR4, IL-6 and TGF-beta mRNA levels while upregulated TLR6 and IFN-gamma mRNA levels (P < 0.05). In addition, inclusion of YG at 200 mg/kg considerably promoted the production of serum cytokines, total IgA, and specific antibody titers against BSA, AIV and NDV vaccine (P < 0.05). These results suggested that dietary inclusion of 200 mg/kg YG could improve eggshell color and fertile eggs hatchability and enhance cellular and humoral immune function of breeder hens in a nonchallenged setting without disturbing immune homeostasis. (C) 2020 Elsevier B.V. All rights reserved.