Best scan for New Zealand ewes in INZAC flock

The results of pregnancy scanning in the Irish and New Zealand Across Country Comparison (INZAC) flock trial show New Zealand (NZ) Suffolk and Texel ewes continuing to outperform their Irish counterparts.

Speaking at last week’s ASA sheep masterclass held in UCD Lyons Research Farm, Teagasc geneticist Noirin McHugh said the pregnancy rate in the NZ Suffolk and Texels was helped by a combination of factors. As detailed in the table below, the ewes had a slightly higher conception rate to first service and a significantly lower barren rate.

This, combined with a higher litter size for ewes in lamb, resulted in a scan rate of 1.82 lambs per ewe joined to rams, 0.13 lambs higher than elite Irish Suffolk and Texel ewes, which scanned 1.69 lambs per ewe joined and significantly ahead of the low genetic merit group, which scanned 1.51 lambs per ewe joined. The higher breeding performance of the NZ ewes could also have been helped by breeding programmes in New Zealand for Texel sheep incorporating high-prolificacy genes.

Late-pregnancy feeding

Noirin says that attention in the flock is now turning to late-pregnancy feeding. Ewes have ad-lib access to silage with a dry matter digestibility of 70DMD while the concentrate supplementation programme is detailed in this table.

The flock collects detailed lambing records, with each individual pen possessing a whiteboard on the wall. Every time a ewe and her lamb(s) needs attention a mark is placed on the whiteboard. Any other factors such as poor milk yield, ewes exhibiting poor maternal behaviour or lambs requiring excessive help in suckling is recorded, which helps to develop a more robust breeding index.