Effects of probiotic and yeast extract supplementation on oxidative stress, inflammatory response, and growth in weaning Saanen kids

This study aimed to investigate the effects of probiotic and yeast extract supplementation on the metabolic, immune, and oxidative status of Sannen goat kids during the weaning challenge. Forty goat kids were randomly assigned to four groups: a probiotic group (Pr) (basal diet + mixture of Bacillus subtilis, Bacillus lechiniformis, Streptococcus Thermophilis, and Enterococcus faecium), a yeast cell wall extract group (YC) (basal diet + Saccharomyces cerevisiae), a probiotic and yeast cell wall extract group (Pr + YC) (basal diet + mixture of probiotic and yeast cell wall extract), and a control group (basal diet). Treatments were administered 21 days prior to weaning (80 +/- 2 days of life) until 21 days post-weaning except for the control group. Blood samples were collected at four different time points, including 21 days before weaning, 2 days post-weaning (weaning time), 7 days post-weaning, and 21 days post-weaning. Average levels of triiodothyronine, thyroxine, total protein (TP), albumin, globulin, blood urea nitrogen (BUN), total antioxidant capacity (TAC), serum adenosine deaminase (ADA), nitric oxide ( NO), ferritin, glucose, cortisol, triglyceride, non-esterified fatty acid (NEFA), B-hydroxybutyric acid (BHBA), and body weight were measured. The average levels of cortisol tended to be higher in the Pr group in comparison to the control group (P = 0.07) and the Pr + YC group (P = 0.10). NEFA was found to be higher and tended to be higher in the control group compared to the Pr + YC group (P > 0.001) and Pr group (P = 0.10), respectively. Additionally, the BHBA concentration was higher in the control group compared to the Pr group (P > 0.001). No differences were observed in the concentration of other measured parameters among the treatments. The concentration of cortisol tended to be higher (P = 0.10) at the weaning time as compared to the third sampling time. Furthermore, the concentration of TAC was observed to be higher (P > 0.01) at the weaning time in comparison to the third and fourth sampling times. The concentration of NO was higher (P > 0.01) at the third sampling time when compared to the first sampling time. A reduction in NEFA and BHBA levels may suggest an improvement in the metabolic status of the supplemented animals during the weaning challenge. However, supplementation with probiotics and yeast cell wall extract did not appear to have an effect on the oxidative status of the animals. The increase in TAC and NO levels observed during the weaning time may indicate an increase in oxidative stress during this period.