Ja. Archer et L. Bergh, Duration of performance tests for growth rate, feed intake and feed efficiency in four biological types of beef cattle, LIVEST PROD, 65(1-2), 2000, pp. 47-55
Data from the centralised performance tests for young beef bulls in South A
frica were used to determine the minimum test duration required to obtain a
n accurate measure of feed intake, growth rate and two measures of feed eff
iciency: feed conversion ratio and residual feed intake. Five breeds from f
our different biological types were used to investigate whether different d
uration tests are required for different types of cattle. The results indic
ated that a test of between 42 and 56 days is sufficient for measurement of
growth rate when a linear regression equation is used to model weight vs.
time. Feed intake required approximately 56-70 days to measure accurately,
while feed conversion ratio and residual feed intake both required around 7
0-84 days. There was little evidence of consistent breed differences in the
time required to measure the traits, and it was concluded that the duratio
n of performance tests could be shortened from 112 days to between 70 and 8
4 days for all breeds with no loss in accuracy of the test. (C) 2000 Elsevi
er Science B.V. All rights reserved.