productive and metabolic responses of holstein dairy calves to different milk dry matter concentrations and two free water provision schedules

This study was aimed to assess the effects of reducing free water access time and feeding milk at various dry matter (dm) concentrations on water consumption, growth performance, dm intake (dmi), and blood metabolites of holstein dairy calves. sixty holstein dairy calves [42 ± 3.0 kg of body weight (bw)] were used in a 3 × 2 factorial randomized block design with the main factors including milk dm (low, medium, and high dm; ldm, mdm, and hdm, 125, 140, and 155 g/kg, respectively) and water access time (short and long-time free water access, st and lt respectively). neither milk dm concentration nor water access time had any effect on the mean water intake (l/d). increasing the concentration of liquid feed in both water provision schedules, improved the final bw, average daily gain (adg), heart girth, and withers and hip heights. however, main blood metabolites were not affected by milk dm. the lt calves that consumed the highest milk dm (hdm) had the greatest adg compared to other treatments (p<0.05). a trend was found for the interaction between milk dm and water access time as in the st calves, the final bw was greater than lt at 125 and 140 g/kg milk concentrations (p=0.08) but at 155 g/kg milk dm, the highest final bw was found in lt calves. it was concluded that under the environmental condition similar to this study, water provision duration for neonatal calves could be reduced to once a day (just 2 h) however, we do not recommend increasing the dm content of milk by more than 140 g/kg when water is provided freely, 2 h once a day.