28 March 1997

Acceptable way to better pig genetics

IMPROVING pig genetics using non-invasive biotechnology is the way forward for pig breeding.

Andy Coates, US-based technical services director with the Pig Improvement Company, told pig producers at a meeting in Oxfordshire that the latest genetic techniques were not invasive and should be acceptable to consumers and the welfare lobby.

"Growth rate improvements of up to 80g a day over the past six years, now worth £1.57 a pig a year, have already been ach-ieved using traditional breeding programmes.

"But genetic improvement has now entered a new phase with molecular genetic techniques used to boost classical breeding methods," said Mr Coates.

He explained that the identification of genes with big effects on prolificacy, growth rate, feed conversion and meat quality brought many advantages.

They helped the breeder to improve selection accuracy and intensity by the early identification of superior animals of either sex.

Underlying genotypes

"Geneticists can now look at the underlying genotypes like the ESR marker gene influencing litter size which confers 0.4 pigs a litter.

"A second marker for litter size has also been found. This could be worth an extra 0.4 pigs a litter, coupled with a favourable effect on teat numbers, and further progress is expected," said Mr Coates.

"The raw material for marker gene study is just a sample of hair plucked from the pig, a technique which should be acceptable to the general public."

He said current targets for marker gene identification included the meat colour, marbling fat, firmness and drip loss.

"Traditional breed names have given way to numbers at PIC nucleus level. And numbered lines in turn could be replaced by pigs carrying their own genetic bar-codes in the near future."

He also considered that semen sexing, single sex litters and genetic selection for disease resistance were feasible developments in the near future.

"Disease resistance would probably not be specific but based on a general improvement to the pigs immune system," he added. &#42