Whose Cow Is It Anyway?
Many years have now passed since the RASE organised a meeting at Stoneleigh to discuss the way forward for cattle breeding. Geneticists took the stage, declaring that, in future, they would be in charge! So perhaps it is timely to take a look at the results of the not inconsiderable body of work from the Geneticists (a veritable industry in itself).
Various composite figures such as, PIN, ITEM and PLI have been used over the years to produce a ranking Index, the aim being to deliver further improvement in profitability for the next generation of cattle.
The original Index was based on increasing yield for the general black and white population, mainly British Friesians. The introduction of the Holstein cow made a substantial contribution to that aim. Angularity was found to be strongly correlated to this increase in yield, so it was factored in to a composite Index, until it was later realised that the loss of body condition was having a negative impact on fertility.
The question is, has the cost of poorer fertility and loss of body condition, which also affects lifespan, outweighed the profit obtained from the increase in yield? This yield, of course, has to be fed for, not forgetting that the cow has grown a massive 16% in twelve years, and there is evidence that feed efficiency has reduced. Much will depend on the milk contract as to whether the higher yielding cow, with all its support mechanisms, will hold as much attraction as it has in the past.
The effect of resetting the base every five years, from which Index is calculated to take into account ‘Improvements’ during that period, is questionable. Under this system, the PLI of older cows with higher mature yields making valuable contributions to profit are devalued, sometimes by more than one base change. To discourage breeding from these good cows flies in the face of the evolutionary principle - survival of the fittest. Instead, farmers have been encouraged to breed from their younger higher Indexing animals using high Index bulls to speed up ‘genetic gain’. Has this promise of profitability actually been delivered?
The PLI formula and the eagerness of the AI companies to source top ranking bulls reduces the biodiversity of the population, as ever narrowing selection passes down the generations. By disregarding fundamental principles it was inevitable that, eventually, the gradual increase in inbreeding would lead to the emergence of genetic faults, as a quick glance at the ‘Genetic Codes Explained’ page on the HUK / NBDC website demonstrates. For example, we now have over 400 known carriers of CVM and, most recently the serious problem of Cholesterol Deficiency in calves.
Genomic selection has done nothing to arrest the problem of inbreeding, as the same goals of ever higher Index are pursued except, of course, to screen out known defective gene carriers. To try to move cattle breeding forward in such a way is purely experimental and we should beware the law of unintended consequences. It should be noted that the generational turnover has now reduced from 15 to 4-5 years.
Considering there is much encouragement the world over to ensure biodiversity, so essential for survival of whatever species, it seems extraordinary that this principle has been ignored. This should be of major concern to the Breed Societies as the geneticists’ ultimate solution is to cross with another breed for heterosis, thereby abandoning pedigree and valuable data. Surely an admission of failure!
Critical to biodiversity is the major histo-compatibility complex (MHC) set of genes, important components of the immune system and also playing a role in fertility. The wider the range of MHC genes in the population, the better the health and fertility. Cross breeding between the two black and white breeds would maximise the effect with the ability to stay pedigree within the herd book, surely a win-win for the Breed Society.
If the UK is to avoid the inbreeding percentages seen in the USA, we need to make use of the various independent mating programmes on offer. However, now might be a good time to review the evaluation system, both in the light of the changed circumstances in the Dairy Industry and the need to arrest the decline in biodiversity.
The long term success of any Breed depends ultimately on its suitability for the commercial market. It should be the ‘raison d’être’ of any Breed Society. We, in the British Friesian Breeders Club, are determined to follow that goal.
After all, it is our cow!