Fwc. Neser et al., An investigation into possible genotype x environment interactions for weaning weight in South African Mutton Merino sheep, S AFR J AN, 28(3-4), 1998, pp. 179-184
Citations number
20
Categorie Soggetti
Animal Sciences
Journal title
SOUTH AFRICAN JOURNAL OF ANIMAL SCIENCE-SUID-AFRIKAANSE TYDSKRIF VIR VEEKUNDE
Weaning weight records available for the South African Mutton Merino breed
were utilised to investigate the possibility of a genotype by environment i
nteraction in the breed. A direct heritability estimate of 0.308 +/- 0.022
was obtained. including flock-year-season x sire interaction (FYSXS) led to
a direct heritability estimate of 0.017 +/- 0.00 and a c(FYSXS)(2) estimat
e of 0.111 +/- 0.00. Although flocks are genetically related by the use of
rams from other flocks, very few of these rams are used in different flocks
in the same year. Four flocks were hence selected where this did not seem
a problem. This led to a direct heritability estimate of 0.125 +/- 0.061 wh
en interaction was included and a c(FYSXS)(2) estimate of 0.107 +/- 0.019.
The results indicate that a genotype x environment interaction in South Afr
ican Mutton Merino exists. It is, however, impossible to quantify the effec
t of the interaction in a breed analysis because of the nature of the data
structure. This is a general problem in sheep in South Africa, partly owing
to the lack of use of Al across flocks.