Article By: Country-Wide Magazine. Source: Country-Wide

Progeny trials developed for a group of forward-thinking ram breeders are proving their potential is more than wool deep.

Traditionally Romneys have not been known for their carcase qualities, however, TRIGG Romneys is using science to change that perception.

TRIGG Romneys is a partnership of six of the North Island's top Romney breeders who are committed to boosting the genetics of their combined flocks and the returns to their farmer clients. To do this they have employed the research skills of Massey University.

Using a progeny test, postgraduate Massey researcher Patricia Johnson investigated the carcase value of the progeny of TRIGG's top 12 rams and found there was sufficient variation amongst the sires to mean carcase value could be improved through selective breeding. Ms Johnson presented her results at the New Zealand Animal Production Conference at Massey recently.

For the research, TRIGG's 12 top rams were identified through the Sheep Improvement Limited indexes (SIL). The indexes identified these top rams, from a total of 2300, as producing the highest number of offspring with the best body weight and 200-day weight. Each of the 12 rams was mated with 25 commercially-bought ewes. The resulting 139 lambs were born on a Massey research farm. At weaning they were moved to a commercial property where they remained until they were slaughtered in two lots at the end of 2000 and the beginning of 2001.

The lambs of the top sire produced an average carcase value of $84.93, with the lowest performing sire producing lambs averaging $76.38 a carcase, giving an $8.50 difference in the carcase value produced by the top and bottom sires.
"While Romneys are best known for their wool and maternal qualities this research shows they are also well placed to contribute to carcase characteristics," Ms Johnson says.
"In the future this will allow commercial clients to purchase rams which will contribute through the dam line to increased carcase values of their prime lambs under new proposed payment systems."
The lambs were slaughtered at Richmond's Takapau freezing works. Rather than using the current industry standard of valuing a lamb by its carcase weight and fat cover, the lambs were divided into their seven standard cuts before being valued.

While this was labour intensive and costly Ms Johnson says it meant a more accurate carcase value was obtained for each lamb. "The industry is in the process of moving towards paying based on the lean meat yield of the carcase rather than whole carcases. To ensure this research is relevant in the future when a new industry standard is introduced, it was decided this was the best way to value the meat."

Ongoing progeny testing of TRIGG rams is taking place so they are able to significantly improve the genetics of their flocks. An expanded second progeny test is currently under way, this time using 24 sires.