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THE USE OF SHEEP FITTED WITH OBSOPHAGEAL FISTULAE IN GRAZING STUDIES
Author(s) -
Hodgson J.
Publication year - 1969
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/j.1365-2494.1969.tb01089.x
Subject(s) - grazing , biology , morning , zoology , evening , diurnal temperature variation , ruminant , agronomy , botany , pasture , physics , atmospheric sciences , astronomy , geology
Studies were carried out on the effects of diurnal variation, fasting before sampling, and acclimatization to a sward on the chemical composition and in vitro OM digestibility of samples of extrusa collected from sheep fitted with oesophageal fistulae. The N content of extrusa samples increased markedly during the morning, and tended to decline again in the evening. The diurnal changes in digestibility were similar, but the variation was much smaller. There was no significant correlation between either N content or OM digestibility and grazing speed measured in bites per minute. There were no significant changes in either the N content or OM digestibility of successive samples of extrusa collected after over‐night fasting, or after the sheep were introduced to a sward to which they were not accustomed, though the concentration of ash in the extrusa was significantly lower when the sheep were hungry than when they were not. The OM digestibility of the diet selected was approximately two units lower on the first two days after introduction to a new sward than the mean value of samples collected over the next 12 days.