Traits in Focus

Resilience to Internal Parasites.

The 1990s saw the beginning of a new and big effort to select sheep that would continue to grow while under a

summer/autumn internal parasite challenge.

Consistent with our philosophy, this selection must take place in a known parasite challenging environment. A

comprehensive program developed by Agresearch has been in place since 1993 and involves regular weighings of

undrenched Hgts through the autumn.

Most of the flock and stud rams used since 1991 have not been drenched before autumn.

Dag scoring has been a feature since 2006. In combination with resilience, dagginess has diminished substantially.

All recorded ram hgts are individually scored, all ewe hgt replacement is based on nil dags while under minimal

drench policy.

From 1970 the immediate focus was to lift fertility and develop an easy care animal, this was the same for most

modern breeding groups. For 30 years from 1969, entry into the recorded flock was only by first rearing a top set of

twins as a 2th. Including screened 2ths, the average percentage from which rams are selected has been over 190%.

Recorded 2ths average 3.2% of lambs/kg of ewe weight at tupping. Once conceived, lamb survival is essential. Most

clients report losses from scanning under 20%. Survival in twin mobs is commonly 190%.

Fertility, survival and milking ability are now strongly entrenched in the flock and due to the very low heritability of

fertility and litter size we consider that any extra fertility is of less value to us than extra resilience, therefore our

selection indexes reflect that .

Wool weight still plays an important part in our sire selection and all ram hoggets are side sampled, with the long

term aim of being able to put a true value on the key processing attributes of bulk, micron, colour, and yield, also to

identify wool with key attributes for quality apparel yarn, with the aim of taking the ‘prickle factor’ out.

This trait has always been a focus. It is more efficient to carry a high producing older ewe than extra ewe hoggets

and also allows heavier culling of replacements. Recorded ewes are not culled for age, rather just production, we

have many ewes older than 8yrs. Unfortunately SIL do not provide a breeding value (bv) for this trait nor do they

take any consideration of the fact that progeny of old ewes are generally smaller at weaning, which is not necessarily

genetic and therefore can discount their bv’s.

Facial Eczema has never been experienced at Te Whangai and therefore it has historically not been one of our

breeding objectives however a growing number of farmers want the structurally sound resilient type of sheep we

have developed over 50 years but also with tolerance to FE, which is a challenging exercise. We have initiated a

secondary flock into which we have infused high FE genetics, now testing at .45 while still maintaining our resilience

program.

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Growth rate selection continues to use the same SIL bv’s as all other flocks, however with parasite challenge being

high and feed supply always limited it appears that more robust, deep bodied animals are the top performers rather

than large framed ones.

Ultra sound muscle scanning is now being used to gather data on meat traits in order that we are better placed to

identify high Intra Muscular Fat (IMF) producing animals if that proves to be a feasible breeding opportunity.