Abstract #444

# 444
Offering drinking water at birth could improve growth performance and fiber digestibility in Holstein heifer calves.
H. K. J. P. Wickramasinghe*1, A. J. Kramer1, J. A. D. R. N. Appuhamy1, 1Iowa State University, Ames, IA.

Although offering drinking water from birth is recommended, the average age of dairy calves when first offered drinking water is 17 d in the US The objective of this study was to examine the impact of the 17 d delay on water and starter intake, nutrient digestibility, health, and growth performance in dairy calves during the first 70 d of age. Thirty newborn Holstein heifer calves, balanced for parity of the dam (PD), birth weight, and month of birth (MB), were randomly assigned (n = 15) to receive water at birth (W0) or at 17 d of age (W17). Calves were bottle-fed with pasteurized whole milk 3 × daily (2 to 3 L per feeding) and weaned on d 49. Body weight (BW), hip height (HH), and body length (BL) were measured weekly. Blood (jugular) was drawn on d 14 and 21 and analyzed for hematocrit and haptoglobin concentration. On d 70, total feces weight (kg/d) were measured and analyzed for nutrient composition to calculate the total-tract digestibility of nutrients. Treatment effects were analyzed using linear mixed-effect models including fixed effects of treatment, PD, MB and random effect of the calf. W0 calves drank a significant amount of free water (0.704 ± 0.123 kg/d) during the first 17 d. W17 calves consumed more grain during the first 17 d (P = 0.015) and drank more water (P = 0.009) from d 18 to 42 than W0 calves. The starter intake was similar between W0 and W17 calves from d 18 to 70. The scours prevalence was significant in both groups between d 7 and 21 but the scours severity, hematocrit, and plasma haptoglobin concentrations were similar between the groups. The weekly BW and average daily gains were similar between W0 and W17 calves throughout the 70 d. BL and HH were similar between groups before weaning but W0 calves had greater BL (P = 0.087), and HH (P = 0.068) than W17 calves after weaning (d 50 to 70). Despite the similar grain intake, the NDF digestibility of W0 calves was greater than W17 calves on d 70 (P = 0.075). Offering drinking water at birth could have a positive impact on rumen development and growth performance after weaning.

Key Words: body length, hip height, NDF digestibility