Facial eczema in Jersey cattle: heritability and correlation
with production
C.A. Morris, N.R. Towers, H.J. Tempero, N.R. Cox, H.V. Henderson
MAF Technology, Ruakura Agricultural Centre, Private Bag,
Hamilton
Proceedings of the New Zealand Society of Animal Production.
1990, 50: 255-260
During the serious outbreak of facial eczema (FE) in 1989, blood
samples were obtained from first-lactation heifers born in 1986, in
order to study any genetic influence on the incidence of FE. Heifers
were located in 60 herds in Northland (14 herds), Auckland (25) and
Taranaki (21). The herds were members of the New Zealand Dairy Board's
1985 Sire Proving Scheme for young Jersey bulls. Samples were collected
from 1523 heifers, the daughters of 57 young Jersey sires and 19 other
Jerseys including reference sires from previous years. Blood samples
were analysed for gamma-glutamyltransferase (GGT), an indicator of liver
damage such as due to FE. Overall, 28% of animals had elevated GGT
values (>=30IU/1), and 72% (43) of herds had 2 or more animals with
elevated GGT. After setting aside data from the 17 herds where no
elevations of GGT concentration were recorded, the heritability of log e
GGT was 0.31±0.10 (sires with >10 daughters each, and the ancestry data
on sires included). The correlations of first-lactation milkfat and
protein breeding indexes with log e GGT were -0.32 and -0.16.
Corresponding regressions were -2.1 (fat) and -0.9 (protein) breeding
index units per genetic standard deviation change in log e GGT. Results
from three serum minerals are also reported.
Keywords: NZSAPAB;
Dairy cows; facial eczema; heritability; correlation; milkfat;
gamma-glutamyltransferase
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Last Updated 25-01-1997
