Suftex is one of several terminal sire breeds involved in a FarmIQ genetics project that aims to produce genetic and genomic breeding value predictions for growth, yield and eating quality in terminal sires.
AgResearch scientist John McEwan is one of 11 researchers working on the project and says the outcomes of this work will benefit the wider sheep industry.
“It brings science-based meat quality measures into sheep breeding and is developing methods that make them accessible to the commercial breeder.”
Now in its final phase, the project team has worked with 11 flocks that produce Texel terminal sires or composite-type genetics derived from Suffolk, Texel and Poll Dorset breeds.
The first part of the project was developing a SNP chip that enabled the scientists to predict an animal’s breeding value for meat quality traits using DNA only.
The second part involved measuring eating quality and carcase yield traits in more than 15,000 progeny from 839 terminal sires.
Indicators of eating quality such as tenderness, pH, marbling, colour and colour stability were measured along with meat yield and these measurements havebeen used, along with the SNP chip, to probe 600,000 variants from each animal.
This has given scientists the ability to develop prediction equations for meat yield and quality traits. Further testing has shown breeding value accuracies are equivalent to the potential sire animal having been killed and tested for the actual trait.
This means accurate breeding values for meat quality traits can be available for terminal sire ram lambs at weaning.
An interim index of desired traits has been constructed and this was used for ram lambs used for mating in 2015 and 2016.
The science team is testing results in commercial terminal sire breeding flocks to ensure the system is accurate, practical and cost-effective.
Development of a much lower cost SNP-chip will be more practical to use as part of an expanded parentage test.
In the New Zealand genetic evaluation trend, data showing animals that are part of the Premier Suftex Group are well-ahead of any other terminal sire breed.
Recent SIL-ACE terminal sire analysis has four Suftex rams among the top eight. Southland-based Suftex breeder Andrew Tripp says the Premier Suftex Group started 13 years ago and has 10 members throughout the country.
Accurate breeding values for meat quality traits in terminal sires will benefit the wider sheep industry.
Sire referencing is one of the group’s key goals and members link at mating time, sharing rams to establish good genetic linkages.
Based on sire summaries, the best ram across the group has been made available for the central progeny test, where Suftex have consistently been among the top performers for terminal sire traits.
Tripp says the group brings together like-minded people who are keen to progress the breed.
He says the group’s involvement in the FarmIQ genetics programme has allowed them to generate breeding values for tenderness and intra-muscular fat in their ram lambs, so they can use these values in the selection process from a young age.
Another group member, Southland breeder Russell Welsh has bred Suftex since 2000. He says the group’s focus is on producing fast-growing animals with outstanding carcase characteristics.
Strong terminal yield
Eketahuna farmers Brad and Jackie Anderson have used Suftex rams over half their 4400 ewes for four years now and are very happy with the results.
Last year 65% of the terminal sire lambs were finished off their mothers at weaning, which was pleasing given the particularly dry season and unforgiving terrain.
Only 4% of the Andersons’ 780ha farm is cultivable, so finishing lambs can be a challenge in tough seasons.
ViaScan results showed the finished Suftex cross lamb yielded very well, Brad says, and he will continue to use these genetics.
Cameron and Robert Grant find using fast-growing Suftex genetics allows them to finish 40-60% of their terminal sire lambs off their mothers at weaning, which frees up pasture for their white-faced lambs.
The pair, who farm near Mandeville in central Otago, use a Suftex over 9350 ewes or 45% of their ewe flock.
These include full and failing-mouth ewes, so early weaning allows them to have these ewes sold before Christmas, further freeing up feed for their Romney lambs.
Last year was a particularly good season for clover and this, coupled with good genetics, allowed the Grants to sell about 7000 lambs prime at weaning, at an average carcaseweight of more than 18kg.
Weaning is split, with a proportion of terminal sire and white face lambs weaned from December 10 and the balance after Christmas.
