Abstract

One hundred and eighty three embryos were collected from 29 donor Merino ewes and transferred as either a single or twins to Merino (MR), Coopworth (CR) and Romney (RR) recipient dams. A total of 107 lambs were weaned from these implants. A control group (MN) of 24 naturally conceived single and twin lambs were included for comparison. Follicle fibre diameters at birth were 16.7, 17.2, 17.7 and 17.6 mm (SED 0.4) for MN, MR, CR and RR respectively; while the fibre diameter of wool samples at birth for all dam groups was 16.5 mm (SED 0.3). Follicle fibre diameters at weaning were 16.5mm, 15.9, 16.3 and 16.1 (SED 0.6) for MN, MR, CR and RR respectively while the corresponding wool FDs at weaning were 16.3 mm, 16.1, 16.0, and 16.0 (SED 0.4). Weaning weight was similar in CR and RR, while CR weaned significantly heavier lambs than Merinos (recipients or naturally bred). The results suggest that crossbred dams improve weaning weights of Merino lambs born to embryo transfer but do not affect their wool follicle character-istics.

T, Wuliji, KG Dodds, RN Andrews, J Aspinall, and T Harrison

Proceedings of the New Zealand Society of Animal Production, Volume 59, , 19-22, 1999