The Growth Rate, Immune Status, Duodenal Development, and Cecal Microbial Diversity of 24-Day-Old Offspring of SD Rats Received Bacillus subtilis -Cu or CuSO 4 During Pregnancy and Lactation Periods

A total of 108 pregnant and lactation SD rats were divided into six groups, daily and orally dosed with Bacillus subtilis -copper (CuBs) and CuSO 4 (CuS) both at three doses equivalent to 1.5 mg (Cu deficiency), 3 mg, and 6 mg Cu per kg diet, and the effects of the Cu source and dosage on the growth rate, immune status, duodenal development, and cecal microbial diversity were examined on 24-day-old offspring rats. The six offspring rats from each group were randomly selected for measuring the body weight gain and taking blood samples, and three rats were sacrificed for taking duodenum and cecum content samples. We found CuBs increased the body weight gain, development of duodenal villi, and survival rate of the offspring; increased the IgM content and lysozyme activity in serum; reduced the intestinal permeability; and increased the abundances of Lachnospiraceae , Ruminococcaceae , and Intestinibacter in the cecal content, when compared with CuS. We also found that Cu deficiency showed detrimental effects on the body weight gain and length, the survival rate of the offspring, and the immune indices in serum, as well as the increased intestinal permeability. We concluded that CuBs is better Cu source than CuSO 4 for reproductive rats.