Replacing concentrates with a high-quality hay in the starter feed in dairy calves: Effects on nutrient intake, growth performance, and blood metabolic profile

Feeding concentrate-rich starter feeds to dairy calves increases the risk of ruminal acidosis due to a low concentration of structural fiber. In this study, we hypothesized that feeding high quality hay can be a strategy to overcome this risk while maintainig adequate supply with energy and protein. Therefore we examined nutrient intake, daily gain and concentration of metabolites in blood of calves from birth to week 14 of life. Calves were offered acidified milk till week 12 of life according to a defined milk feeding scheme and water throughout the whole experiment. Furthermore, calves wer fed one of four experimental diets (solid feeds) throughout the whole experiment: 100 % medium quality hay, 100 % high quality hay, 30 % medium quality hay + 70 % concentrates and 30 % high quality hay + 70 % concentrates.