Ultrasonic selection for divergence in loin fat depth in
Southdowns and Suffolks
G.L. Bennett, H.H. Meyer, A.H. Kirton
Ruakura Animal Research Station, Ministry of Agriculture and
Fisheries, Hamilton
Proceedings of the New Zealand Society of Animal Production.
1983, 43: 115-118
Suffolk and Southdown rams were selected on the basis of high
(H) and low (L) ultrasonic fat depths over the loin, adjusted for live
weight. Rams were mated to Romney ewes and progeny were slaughtered at
2 ages. Loin fat depth (C) adjusted for carcass weight by 0.31 ± 0.09
mm between progeny from H and L sires. Differences in fat depth over
the rib (GR) and kidney fat weight were small but favourable.
Southdown crossbreds responded more favourably at C and Suffolk
crossbreds more favourably for kidney fat weight and at GR; however,
these differences were not significant. Average differences between H
and L sired progeny in gains between slaughter ages indicated that fat
differences were established by 20 weeks of age and maintained through
to at least 30 weeks of age. Differences between breeds in favour of
Suffolk crossbreds for growth and carcass leanness were similar to
previous reports.
Keywords: NZSAPAB;
Ultrasonic; fat; selection; sheep; carcass
Download abstract in text format
Last Updated 03-05-1997
