Some Thoughts on Replacement Gilts
The most statistically successful breeding herds are those that include in their data a very low or zero value for re-services and a high farrowing rate. I used the word ‘include’ because of course numbers are equally important and this is a critical factor. The production of replacement gilts has, for nearly 50 years, been mainly in the hands of a few breeding companies. This has been of great benefit to the industry. It has consistently delivered increasing genetic potential, feed efficiency, and in the UK, product that conforms to the demands of processors and consequently retailers. And the economic model upon which the pig price is currently (though wrongly) predicated. I do not know which came first, the breeding companies or the historic, P2 driven pig price. Was the emergence of breeding companies, often from well-known pedigree breeders, a response to the processors or an unwitting invitation. This, of course, is just conjecture.
Breeding companies have responded to the increase in the average herd size as the UK herd itself contracted. Breeding programmes have extended into individual businesses to enable everything from closed herd, self-perpetuating grandparent (GP) populations to simple criss-cross strategies have been employed. It is very much ‘horses for courses’. This is partly because the parent gilt premium is a financial disparity in the accounting minds of some pig producers, with the on-farm cost of producing replacements. This is inevitable but it is not the fault of the economic model of the breeding companies, which is sound as far as I can see. It is more to do with decreasing return on capital and extended periods of finely balanced cash-flow.
Pig production needs a sustainable strategy for the foreseeable future and this must include consideration of what makes for success in the day to day management of the breeding herd and subsequently the feeding herd following on. The removal of failure at the point of failure and a management strategy that realises the genetic potential of the parent stock to underpin this, is critical. Where breeding programmes have been locked in behind closed doors within individual businesses it is possible to increase selection pressure. I believe that GP and parent replacement gilts selected from GP dam-line females that have achieved a third parity with no breeding failure is a worthy selection criteria and it must not compromise the other selection criteria. I am not a geneticist and I have no idea of the degree of heritability of conception. What I do know is that this selection strategy works. To avoid wastage of GP animals their productive lives can be extended by at least the two parity’s that forego gilt selection. I do not believe that the loss of genetic progress in the increase in output from numbers is an important enough issue to ignore the gains that will be made by applying this additional pressure and extending the production lives of GP’s. This should have a minimum impact on nucleus progress and over time, by virtue, it will resume normal service in the multiplication populations, returning them to parity 1 selection.
By putting pressure on breeding failure in both the nucleus and multiplication populations and then on the commercial parent population we can achieve true genetic potential that brings with it a significant improvement in cost efficiency. Commercial breeding herds can carry between ten and twenty percent of the herd size that are never actually in production statistically. This is due solely to the level of recycled failure and carries and enormous cost. Another aspect of recycled failure, in my opinion, is that these animals make up the majority of the sows that fail in the periods known as seasonal infertility, gilts, in the main, do not appear to fail in these periods.
What I am suggesting does, of course, impact on the economic model of the breeding companies, some more than others, because it means that purchased parents would be culled at the point of first failure. This failure is always, to a degree, subjective whether the replacement gilt is bought in or home produced from a breeding programme. This strategy has to be balanced to circumstance. It is however a direction that we should be giving serious consideration to if we are to make herd replacement work for us and not against us, as it currently does, often forcing us to extend the overall herd parity distribution to compensate. Compensation that comes at an unacceptable cost.