Effect of Inverdale gene (FecX) on fleece characteristics in
Romney sheep.
T. Wuliji, G.H. Davis, K.G. Dodds, R.N. Andrews, R. Wheeler and
P.R. Turner
AgResearch, Invermay Agricultural Research Centre, Private Bag
50034, Mosgiel.
Proceedings of the New Zealand Society of Animal Production. 1997,
57: 29-32
The effect of the Inverdale gene (FecX) on wool production
traits was measured in a trial where Romney carrier rams (I) were
crossed and backcrossed with high fleece weight-selected (HF) Romney
ewes, and Romney non-carrier rams (+) with unselected (RC) Romney ewes.
The trial generated 248 female progeny in five genotype subgroups:
non-carrier (++)½RC and ¼RC; heterozygous (I+)½HF and ¼HF;
and homozygous (II) ¼HF. The live weight, fleece weight, wool
characteristics and reproductive performance of these genotype subgroups
were compared, and from corresponding genotype subgroups of male progeny
(n = 307) were also evaluated for early growth and fleece traits. No
differences were found for birth, hogget shearing and two-tooth live
weights among genotypes. Greasy fleece weight was significantly (P<0.05)
higher for I+½HF ewes shorn as lambs (9%), hoggets (8%) and
two-tooths (10%) compared with ++½RC. The important wool
characteristics of yield, fibre diameter, bulk, staple length and staple
crimp did not differ significantly between genotypes. The ovulation rate
(combining subgroups with the same Inverdale genotype) was significantly
(P<0.05) higher for I+ (2.3) than ++ (1.5) progeny (SED: 0.3). The
results suggest that introgression of FecXI into fleece weight
selection flocks will improve prolificacy in these flocks while ensuring
high fleece weight.
Keywords: NZSAPAB;
Inverdale; FecX, crossbreeding; ovulation; fleece weight.
Last Updated 12-09-1998
