Depressing Effect of Rumen Distension on Silage Intake of the Lactating Dairy Cow

Abstract

The numerous factors involved in the control of food intake by ruminants have been reviewed in detail (Baile and Forbes, 1974.). Distension of the rumen is thought to limit the voluntary intake of hay by dry cows (Campling and Balch, 1961) and by lactating cows (Mbanya, Anil and Forbes, 1987). In more recent reports, it is thought that some of these factors which are negative feedback signals combine additively in their effects to induce satiety (Forbes, 1986). Prior to investigating the additive effects of rumen distension to those of other feedback signals on intake of silage by lactating dairy cows, we carried out a preliminary study now reported to establish a response curve to different levels of distension which will enable an appropriate degree of distension to be imposed in future experiments involving combinations of treatments.Animals and Housing - Five rumen fistulated, non-pregnant Friesian cows in early lactation (mean daily milk yield, 25.2 kg) were used in a 5 x 5 Latin square design with a row omitted.