Effects of dietary Bacillus subtilis supplementation and calcium levels on performance and eggshell quality of laying hens in the late phase of production.

ABSTRACT: The objective of this study was to evaluate the effects of dietary Bacillus subtilis supplementation and calcium (Ca) levels on performance, eggshell quality, intestinal morphology, and relative calbindin-D28k (CALB1) mRNA level of laying hens in the late phase of production. An experiment employing a 2 × 3 factorial arrangement of 3 levels of Ca (3.5, 4.0, and 4.5%) and the absence or presence of B. subtilis was carried out with a total of 576 Hy-Line Brown laying hens aged 72 to 79 wk. Every group had 8 replicates of 12 birds each. The results showed that 4.0 and 4.5% Ca levels improved (P < 0.05) apparent retention and serum Ca content of aged laying hens. Compared with the 3.5% Ca level, the 4.0% Ca level in diets increased (P < 0.05) thickness, eggshell weight, shell ratio, and eggshe

SUBMITTER: Wang J 

PROVIDER: S-EPMC7936213 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature