Abstract
This study was carried out to examine the effects of ginger liquid extract (GLE) on the growth, immune response, antioxidative defence mechanism, and general health of Holstein calves. Sixteen calves (4-d old) were included in the experiment and randomly assigned to groups, and they were fed whole milk containing GLE at a rate of 0, 0.50, 0.72, and 1% of the milk amount consumed. Calves consuming 1% GLE were weaned at an earlier age and gained better body weight (BW) compared to the other groups. The group fed with 0.50% GLE consumed less daily starter than the other groups. The administration of GLE resulted in a non-significant decrease in fecal score (FS), the number of days with diarrhea (DDN), and illness (IDN) among the calves. Notably, the 1% GLE exhibited a significant inhibitory effect on the growth of E. coli, while its effect on the growth of other pathogenic bacteria was not statistically significant. Despite the non-significant reduction in malondialdehyde (MDA), total oxidative status (TOS), and oxidative stress index (OSI) values, the 1% GLE demonstrated support for antioxidative defence mechanism and immune response. The results indicated that 1% GLE can be effective in promoting the health of calves by enhancing their immune response and antioxidant capacity. This suggests that incorporating 1% GLE into their overall well-being, potentially leading to improved health outcomes and performance in calf rearing operations.