The Effects of Shortening Dry Period on Colostrum Quality and Holstein Calves Performance

There is limited information available about the relationship between dry period shortening and calves health and their performance. One-hundred twenty Holstein cows and their calves were used to evaluate dry period length on colostrum quality and calves health. Treatments were arranged in a 3×2×2 factorial design that included dry period (30-d, 42-d and 56-d), parity (primiparous or multiparous) and BCS (BCS<3.2, BCS≥3.2), and calves were blocked by sex. First milking after parturition was collected and its density was recorded. Calves were fed first colostrum meal in nipple-bottles within 1.2 h of birth. Maternal colostrum was fed in amounts of 1.5 L/meal for first two meals. Thereafter, pooled transitional milk was fed for the next four meals. Any calf which did not receive maternal colostrum from first milking were removed from the study. Calves were weighed at 0 h, 42, and 90 d. Fecal and health scores was estimated every day by method of Larson. No significant differences due to dry period length were detected for colostrum density (1.0636±0.0086, 1.0582±0.0161, 1.0673± 0.0128 gm/ml for 30, 42 and 56 d treatments, respectively), and calves ADG (0.474±0.094, 0.516±0.060 and 0.479± 0.152 kg/d, respectively), health, and incidence of diarrhea. Although, colostrum protein and SNF content were affected by dry period shortening (P<0.01). Data indicated that a short dry period can reduce colostrum quality but its effect on calf health and performance is not significant.