LAUSR

Abstract The aim of this study was to investigate interactions between milk feeding quantity (FL) and feeding frequency (FF) on intake, growth performance, rumen development and blood metabolites in dairy calves. A total of 48 Holstein calves (n = 12 calves per treatment: 6 males and 6 females) were randomly assigned to one of four treatments, including (1) two low plane of milk feeding (2 meals/d, LPM-2×; 3 meals/d, LPM-3×; total milk intake = 210 L) and two high plane of milk feeding (2 meals/d, HPM-2×; 3 meals/d, HPM-3×; total milk intake = 371 L). Calves fed HPM had higher BW, ADG, blood glucose and triglycerides concentration during the preweaning. Calves fed HPM received more ME, total DMI and ate less starter than LPM calves during preweaning. Regardless of the milk feeding quantity, with increasing FF, starter intake, total DMI and ME were reduced without a negative effect on ADG. Calves fed 3 times/d compared with 2 times/d had a lower final hip width. Calves fed HPM had higher ruminal pH and molar proportion of acetate and acetate to propionate ratio, but less molar proportion of propionate and butyrate and total VFA compared with calves fed LPM on d 35 of the study. Interaction between milk feeding level and feeding frequency was observed for plasma glucose concentration with HPM-3× calves having the greatest value at d 35 of study. In conclusion, at both levels of milk feeding, calves did not benefit from the increased feeding frequency, but calves benefitted from HPM. Highlights Calves did not benefit from increased milk feeding frequency at either low or high plane of milk feeding. The performance of calves on low plane of milk feeding was constrained by the low nutrient intake and not the feeding frequency. Regardless of plane of milk feeding, feeding 3 meals/d reduced total DM and starter intake with no detrimental effects on overall average daily gain.