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A comparison of indirect methods of estimating feed intake on pasture
Author(s) -
WANYOIKE MARGARET M.,
HOLMES W.
Publication year - 1981
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.1365-2494.1981.tb01558.x
Subject(s) - chromic oxide , pasture , feces , sampling (signal processing) , zoology , agronomy , coefficient of variation , nitrogen , mathematics , biology , chemistry , statistics , ecology , filter (signal processing) , computer science , computer vision , organic chemistry
The data from 12 individual cattle grazed on a uniform sward were used to compare field sampling of faeces with three time‐schedules for rectal sampling of faeces. Estimates of digestibility from a faecal nitrogen equation were compared with estimates based on in vitro digestibility, or modified acid‐detergent fibre determinations, on clipped herbage samples. Field sampling gave a lower coefficient of variation (8%) in chromic oxide content than did grab sampling (14%). Grab sampling introduced an upward bias in estimates of faecal output compared with field samples. The estimate of digestibility based on the faecal index was intermediate to those based on clip samples from the upper and lower horizons of the sward. There was no difference in the mean digestibilities estimated from in vitro or MAD fibre.