Register      Login
Crop and Pasture Science Crop and Pasture Science Society
Plant sciences, sustainable farming systems and food quality
RESEARCH ARTICLE

Effect of reproductive state and concentrate supplementation on liquid and particulate turnover in the rumen of ewes given ammonia treated straw

JF Perez, J Gasa, C Castrillo and JA Guada

Australian Journal of Agricultural Research 46(8) 1579 - 1586
Published: 1995

Abstract

Rates of passage of liquid and particulate markers (Co-EDTA, Cr mordanted fibres and Yb) were measured in ewes at late pregnancy, lactation and non-breeding status. Animals were given ammonia treated barley straw ad libitum supplemented daily with 250 and 550 (pregnancy), 550 and 850 (lactation) and 250, 550 and 850 (non-breeding) g of concentrate. The effect of the reproductive state was analysed only on ewes fed on 550 g of concentrate. Lactating ewes showed a higher voluntary straw intake (970 g/day) than pregnant or non-breeding ewes (720 and 790 g/day respectively), but there were not significant differences in the OM digestibility (OMD) among reproductive states. Increasing concentrate supplementation promoted significant decreases in the voluntary intake of straw, associated with an enhanced OMD ( P < 0.05). Fractional outflow rates (FOR/h) were higher in pregnant and non-breeding than in lactating ewes, although differences were only significant ( P < 0.01) for Chromium derived values. Ewes given 250 g of concentrate showed lower ( P < 0.05) FOR than those given 550 and 850 g/day. Results support the idea that in ruminants fed on low quality roughages, voluntary dry matter intake is mainly restricted by rumen capacity, although the energy status of the animals might influence the extent of this restriction.

Keywords: markers; reproductive state; barley straw; ewes

https://doi.org/10.1071/AR9951579

© CSIRO 1995

Committee on Publication Ethics


Export Citation Get Permission

View Dimensions