Associations between transferrin type and facial eczema susceptibility and some production traits in sheep

Abstract (1) Two groups of Romney rams from a single source, six per group, were tested for susceptibility to facial eczema (FE), by measuring 223 of their progeny. The transferrin type for one group of rams was DD, and for the other group AA, AB, or AC. There were 64% of lambs (range 42-l00%) by the DD rams susceptible to FE (tested by measuring the response to a standard oral dose of sporidesmin), compared with 51 % (range 38-72%) by the other group. The difference was not significant. (2) Transferrin types were also determined on 332 lambs born in 1986 and sired by the 12 rams above and 5 other Romney rams. Forty percent of lambs carried at least one A and/or one G transferrin gene, 40% the DD type, and 20% other transferrin types. Frequencies of the three groups susceptible to FE were 47, 61, and 60% respectively (P<0.10). Similar ranking results (31, 47, and 40% respectively) were obtained from a preliminary sample of 273 Romney lambs born in the previous year. (3) The experimental farm was in an are...