A Relationship between some Bacteria, Protozoa and Diet in Early Weaned Calves

Abstract

EARLY weaning of calves on to a solid diet is now becoming more common, and investigation of the establishment of ciliate protozoa in calves reared according to Preston's system¹ indicated that although numerous ciliates might be established by the end of the second week when only milk and roughage were being fed, these disappeared immediately a large proportion of concentrates was included in the diet. Microscopic observations suggested that the numbers of ciliates were inversely related to the numbers of Lactobacilli, which were directly related to the proportion of concentrates in the diet. It thus seemed of interest to investigate the influence of diet on the flora and fauna of early weaned calves, as the establishment of an adult rumen population might aid in the digestion of an adult diet. Some preliminary results on two calves fed widely different ratios of hay and concentrates are given here. The organisms selected for cultural study were those which previous results had suggested might be related in numbers.