Growth Performance, Health, and Immunocompetence of Preweaning Dairy Calves Fed with Stevioside
The objective of this study was to study the effect of stevioside (medical herbs) supplementation on growth and health of preweaning calves. The preweaning calves were more senitive to sickness because of lower immunoglobulin and more stress after birtrh. Thirty-six dairy calves fed with 0, 150, and 300 mg/kg of stevioside supplemented in calf starter. All calves were assigned with randomized complete block design. The calves were placed into individual pen after birth randomly. Calves were fed colostrum after birth until 3 d of age. Calves were fed calf starter and milk from d 4 to d 42 of age. Calves were fed 5 kg/h/d milk, 2 times a day, All calves were fed with calf starter and water in different bucket set in the front of pen. Growth, health, and stress indices were evaluated for 42 d. Average daily gain (367.8, 348.5, and 315.5 g/d for group 1, 2, and 3, respectively), feed intake, fecal score, and body cleanliness score of calves did not differ (P > 0.05) among treatments but feed intake was affected by week (P < 0.05). Calf health was also affected by week (P < 0.05). Immunoglobulin G was greater (P < 0.05) when calf was older. The ratio of Neutrophils and lymphocytes (stress indices), serum glucose and butyrate concentration decreased (P < 0.05) while immunoglobulin G increased (P < 0.05) when calf was older. The concentration of alpha-1 acid glycoprotein (AGP) and TNF-alpha did not differ (P > 0.05) among treatments. Growth and health performance of calves fed with three levels of stevioside did not differ (P > 0.05). At 3 wk of ages, immunoglobulin G of calves increased (P< 0.05) as 150 mg/kg stevioside was supplemented in calf starter.
Keywords: Stevioside, dairy calf, health