Serum immunoglobulin concentrations in young dairy calves and their relationships with weight gain, onset of puberty and pelvic area at 15 months of age

Abstract

Serum immunoglobulin (Ig) concentrations in 100 young dairy calves from five herds were determined to establish whether they were related to subsequent weight gain, age at puberty and pelvic area at 15 months of age. Blood samples were collected from each calf at 6-48 h after birth and at 2 weeks of age for Ig concentrations, and monthly from 210 days of age onward for progesterone assay to indicate age at puberty. Pelvic area measurements were carried out at 15 months of age. Weight gains were expressed as percentage weight gain from birth to the age being considered. Mean serum Ig concentrations at 6-48 h of age varied between herds and decreased (P < 0.01) by 2 weeks in all herds, with one exception. The mean Ig concentrations in pooled data from the two Jersey herds were different (P < 0.001) at 6-48 h and 2 weeks of age from those in the two Friesian herds, but not between herds within these breeds. The Jersey breed had the highest serum Ig concentrations, while the Friesian breed had the lowest. Significant positive correlations were found between Ig concentrations at 6-48 h after birth and at 2 weeks of age in the Jersey breed (P < 0.05) and in the Illawarra herd (P < 0.01). Although there were positive correlations (P < 0.05) between serum Ig concentrations at 6-48 h and pelvic area at 15 months of age in one Jersey herd and between Ig concentrations (at 2 weeks of age) and pelvic area at 15 months in the Illawarra herd, there were no other correlations found between serum Ig concentrations at these ages and subsequent weight gain, age at puberty and pelvic area at 15 months. In conclusion, serum Ig concentrations during the first 2 weeks of calves' lives were generally not related to parameters of calf growth and reproduction.