Kikitangeo Romney Stud

November 2017

Breeding for resistance to parasites at Kikitangeo Stud

Northland sheep farmer Gordon Levet has spent a lifetime breeding sheep for worm resistance and facial eczema (FE) tolerance. The Levet’s first took up the land in Northland back in 1874. Gordon bought his first ram at 17 when he went to Feilding to purchase a stud sire. The Feilding Ram Fair was the top venue for selling stud Romney rams. He says the Romney breed dominated the New Zealand sheep scene at the time, being about 80 percent of all sheep. 

These days the property is focused on breeding a highly productive sheep that can thrive in what is a challenging region to farm sheep. High humidity and warm temperatures are an ideal breeding ground for parasites and fungi which can challenge sheep health. Gordon says his grandfather used to regularly lose half of his lamb crop to barber's pole worms.

Gordon began breeding for worm resistance in 1987, recognising that there was a genetic component to a sheep's ability to tolerate worms. In the early years of breeding for worm resistance, there was much scepticism and even ridicule at this departure from normal practice. Gordon says criticism included the comment  "it is just a gimmick to sell rams".

In 1990, after scientists proved that breeding for resistance was possible, a national programme was established to enable ram breeders to breed for this trait.

Over the next four years, about 30 ram breeders joined the programme. However, some soon left when they realised the amount of work that was involved.

At that time, parasitologists believed that it would take about 25 years to breed a flock that had a reasonable degree of worm resistance 

After over 30 years of breeding for parasite resistance, Gordon is keen to put together a group of breeders specialising in worm resistance. 

He says what has prompted this move is a number of factors. The national flock is becoming more susceptible to worms; climate change has encouraged worm population growth and the danger period for a worm challenge is now extended. Drench resistant worms are also becoming a major problem and with consumers looking for chemical free food, a sheep needing fewer drenches would have marketing potential

Today, 80 per cent of the stud Romney rams are undrenched and he believes it will take another four or five generations of rams before he has a sheep that is totally bullet-proof against internal parasites.

No Romney ewes at Kikitangeo have had any form of drench for at least 15 years. Gordon’s aim is to breed a flock with an early- developing immune system that protects them from any worm challenge after weaning.

Gordon says that by using reasonably resistant sires, rams will reduce faecal egg counts in their progeny by about 50 per cent when compared with the rest of the flock.

He believes using another round of resistant sires over their progeny could at least halve a farmer's drenching programme, and that in areas of New Zealand where the challenge is less, eliminate drenching altogether.

Over the last 50 or so years Gordon believes ram breeders have fallen into two groups following different breeding philosophies. First, there are those who are conservative.  They still believe that such traits as structural soundness, including feet and jaws; constitution and wool quality are essential in breeding good productive sheep.  In addition, these breeders also consider computer generated figures and rankings are an essential part of the selection process.

The second group of breeders make their selections based mainly or solely on computer figures and rankings for productive traits and perhaps FE tolerance.  Gordon believes the progress they have made in these areas is impressive.  However he says those relying on computer rankings have in some cases paid a heavy price for those gains in the form of physical faults that have developed.  “The genetic engine we are trying to breed into our sheep must be matched by a chassis and infrastructure that can support it.  This principle is understood in the motor industry, but is not always recognised by those engaged in animal breeding.”

Gordon believes that in the future the new DNA system of identifying the traits that an animal possesses, will hopefully eliminate the environmental influences, and allow an animal's true genetic value to be recognised.