New Scientific Concepts – epigenetics

Going about as I do, talking to producers, their eyes tend to glaze over when I mention some of the new concepts in our industry such as epigenetics, neutraceuticals, accelerators, nutrigenomics and so on. My apologies to those who already know what they are and what they do, but a few notes on each one may help the rest of us! I’ll begin here with epigenetics.

The prefix “epi” is very common. Of Greek origin, it means upon, near to, or associated-with. Epigenetics is a new and important area of research where pigs and poultry are concerned, and of which we’ll hear more from now on.

It’s associated with heritable changes in the way the genome works. The genome is the complete inventory of hereditary traits in a half set of chromosomes, which is boffin-speak; to me, it means all the genes in an organism. Sounds boring, sure, but epigenetic research leads into environmental and nutritional factors that can change the way genes are expressed – that is, the way they work.

Environmental influence
How an animal is managed in early life has an effect on the way its genes work for the rest of its productive life. Easy enough to understand, with vulnerable neonates and weaners that need warmth and clean surroundings, but what about sows?

Research suggests that the way the young breeding female is managed from her birth could have an effect on the many desirable (or undesirable) production traits throughout her breeding life – even up to how long she remains productive before she needs to be culled.

Could an epigenetic effect be at work when the occasional sow seems to go on and on producing good litters? At our Taymix farm, we had our “12/12 sow” that continued farrowing 12 right up to her 12th parity.

I’ve always been a firm believer in keeping sows (and especially first-litter gilts) calm and happy in those first four weeks after service, assuming this contentment (the feel-good factor) saw off most of the stress hormones likely to adversely affect embryonic development. But could epigenetics be at work too; the way she is managed at this time influencing her gene expression as to litter size for example, or longevity?

Nutritional factors
The same concept applies. The uterine environment is vital to the optimal development of the sow’s offspring, but what we feed the sow (and maybe the way we feed her – liquid gruel?) during gestation might influence the desirable traits, not only of her own subsequent performance, but that of her litter to be born – right up to the time they’re shipped.

I grew up with the idea that the poor old sow, after the essential provision of the nutrients needed in lactation to raise a large family without too much “milking off her back”, then one could ease up on the nutrients in the dry-sow period. She was on “nutritional holiday”.

This is cheaper too, but is that theory to be scotched? The effect of epigenetics is leading into an era of specially designed gestation diets to kickstart her genes into better-programmed embryos providing future benefits in her offspring, possibly even as far as disease resistance.

Far-fetched maybe, but some nutritionists/geneticists believe we’re moving from possible to probable in this and other respects.

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About The Author

John Gadd, who has spent 60 years' involvement in pig production, has had more than 2,800 articles about pigs published and has written three best-selling pig textbooks. With hands-on experience that includes managing a grow-out herd at 1,800ft in Banffshire, Scotland, and 20 years in the allied industries with Boots' Farm Department, RHM Agriculture and Taymix, he set up his own international pig management consultancy in the mid 1980s and has now visited more than 3,000 pig units in 33 countries as a pig management adviser. (Photo courtesy Bournemouth Daily Echo)