Effect of maternal factors on immunity of pre-weaning calves

Aghakhani, M., Shahraki, A.D.F., Tabatabaei, S.N., Toghyani, M. and Rafiee, H. 2023. Effect of maternal factors on immunity of pre-weaning calves. Animal Nutrition and Feed Technology, 23:195–203.

The objective was to evaluate the effect of factors related to cow and calves on immunity of calves during pre-weaning period. The calves were grouped based on serum total protein (STP) concentration as: 4.30 to 6.00, 6.10 to 6.60, 6.70 to 7.20 and greater than 7.30. Effects of lactation, dry-off period and length of pregnancy of cows related to experimental calves were surveyed. STP concentrations 24 h after colostrum feeding had significant (P<0.0001) differences. Colostrum intake (P=0.09), colostrum quality (P<0.05), calf immunity (P<0.05), calve weight at birth time (P<0.01), as well as length of pregnancy (P<0.05) had significant effect on serum STP concentration. STP concentration at d 10, was greater (P<0.0001) for calves in groups 3 and 4 (6.26 and 6.35 g/dL) than those in the groups 1 and 2 (5.70 and 5.87 g/dL). However, at d 35, calves in the group 4 (6.16 g/dL) had the greatest (P<0.0001) STP concentration. Concentration at d 10 was significantly affected by lactation number (P<0.01), length of pregnancy (P<0.05), as well as length of dry period (P<0.05), whereas at d 35 of calves life only lactation number (P<0.05) was significant.