Effect of large doses of zinc bacitracin on voluntary intake, mastication and digestibility of hay in adult ruminants

Authors

• Liisa Syrjälä University of Helsinki, Department of Animal Husbandry

DOI: https://doi.org/10.23986/afsci.71787

Abstract

Two cows were used in the trials. They received timothy hay as their only feed. As the antibiotic doses were increased during the experiment, the cows’ hay consumption decreased. The maximum zinc bacitracin doses were 80—100 mg per kg live weight. Sieve fractionations of the faeces were made to investigate the efficiency of the mastication of the feed. The crude faeces fractions increased with increases in the zinc bacitracin doses, indicating that the mastication of the food was depressed. Lignin was used as an indicator when investigating the digestibility of the food. The results show that zinc bacitracin depressed the digestibility of the plant cell wall substances. There was also a decrease in the digestibility of the other constituents of the hay.