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PO Box 116, Graaff-Reinet, 6280 South Africa or E-mail: pspcc@global.co.za Lionel Tel: +27(0)49 8930577 or Mobile 084 4877979: Jean +27(0)49 8450153 |
ACHIEVEMENTS* International Guest Speaker, New Zealand 2012– Genetics Technology & Logic * Top Breeder Karoo Region 2009 and on numerous previous occasions * Twice Winner of the IVOMEC TROPHY, the prestigious National Award * Long serving Breed Society Council Member * Embryos exported to Australia and the Falklands.
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ORIGINSThe Normandy Stud is one of the oldest registered with the Dohne Merino Breed Society. Norman de la Harpe (uncle of the present owner) established the stud in 1957 from breed material acquired from the well known Wauldby Foundation Stud (est. 1948). Lionel de la Harpe, assumed control of the Stud in 1972 since when it earned international recognition. The Stud is now under the management of Lionel’s son, Jean. The Stud and commercial flock are run on a mountainous grassveld farm “Grassdale”, situated between Graaff-Reinet and Murraysburg in the harsh Sneeuberg area of the Eastern Cape. |
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THE NORMANDY STUD Our stud and flock have produced outstanding lamb crops and wool clips for 55 years. We breed animals for production and profit that are in balance with the environment. To achieve this, we are using phenotypic carcass evaluation that uses ultra-sound technology to scan live animals and produce an accurate index value through a developed formula. This highly successful system is interfaced with skilled appraisal of the animal. Whilst adhering to the requirements of the Dohne Merino Breed Society, we do not base our selection priorities on “Performance Figures”. We are not blinded by ‘so-called’ REV’s (Relative Economic Values). Instead we subscribe to the Genetics of Profitability. Our strict dedication to sound breeding principles in a large stud, complemented by the annual addition of highly selected young ewes from the commercial flock, has earned the stud a reputation for sheep of the highest quality that adapt and produce everywhere.
SELECTION METHODS: A LEARNING CURVE Over the past few years, which included a conference and farm visits in New Zealand during 2012, and since making an in-depth study of epigenetics and inheritance, it is absolutely clear that current selection systems that focus and rely heavily on BLUP EBV’s for Body Weight, have produced unintended and undesirable consequences. What is required is a better understanding of selection methods to enable the breeding of animals that are better adapted to their environment thus generating an increase in profit.
PERFORMANCE VERSUS PRODUCTIVITY : A BRIEF EXPLANATION The generally accepted current animal selection system that is heavily geared to BLUP figures and Selection Indices is resulting in animals being selected on performance rather than holistically based and economically sound productivity. Let’s take a motor vehicle. If selected for size, speed, power etc, it will be able to PERFORM very well - i.e. without consideration to cost of production, fuel consumption, versatility and specific usage etc.To prove profitable, the motor vehicle must PRODUCE holistically – i.e. be affordable, suited to the terrain (environment), functional, have low fuel consumption and running costs etc. So it is with livestock. Why are we producing “racing car” animals with extreme performance figures when what we should be looking at is a cost-effective animal that is adapted to its environment, is hardy and fertile and suited to the required end-product or marketplace. Profit comes from OPTIMUM not MAXIMUM. i.e. production per hectare or per farm unit – NOT per animal.
THE CHALLENGE The challenge to animal scientists and breeders is to adapt to scientific advances, improve our understanding, and to develop new and improved systems so as to limit our mistakes. It is Thomas H Huxley who said “Science commits suicide when it adopts a creed”. In his influential book, “The Structure of Scientific Revolutions”, Thomas Khun, said “Science does not proceed in an orderly, linear and polite fashion, with all new findings viewed in a completely unbiased way. Instead, there is a prevailing theory which dominates a field. When new and conflicting data are generated, the theory doesn’t immediately topple. It may get tweaked slightly but scientists can and often do continue to believe in a theory long after there is sufficient evidence to discount it”.
MEET THE EPIGENOME At its most basic, epigenetics is the study of changes in gene activity that do not involve alterations to the genetic code but still get passed down to at least one successive generation. These patterns of gene expression are governed by the cellular material, the epigenome that sits on top of the genome, just outside it (the prefix epi means above). It is the epigenetic “marks” that tell your genes to switch on or off, to speak loudly or whisper. It is through epigenetic marks that environmental factors like diet, stress and prenatal nutrition can make an imprint on genes that is passed from one generation to the next.
BREEDING GOALS AND BALANCE Dr Rolf Beilharz, Univ.of Melbourne and Independent Higher Education Professional, stated:- “Before we started to breed intensively for production/performance, animals tended to be in balance with their environment. There is no doubt in my mind that the technology which is now available for animal breeding has been taken to extremes. To some extent we have lost respect for what nature has already done, and as it turns out, we have done too much. When we focus exclusively on improving a particular characteristic, we unbalance that which natural selection has given us, which was optimal for surviving and reproducing. If we regained that respect, then it would put the whole context of animal breeding into a much better position, and it would also tell us what we ought to be doing in the future. Quantitative genetics and the breeding for maximums is being applied as though animals are not limited by their natural environment.”
Consider that natural selection has been continuously active adapting organisms / animals to their natural environment. When adaptation is complete, (as indicated in fossil records when species have not changed much over long evolutionary periods) organisms are utilising all the resources available to them in the most efficient way. In this state, organisms / animals are limited completely by the resources of their environment. Many animal breeders have been pushing for genetic maximums rather than optimums. In the case of body mass, by the indiscriminate use of EBV’s, many sheep and cattle have become too large. This emphasis on largeness is neither necessary nor desirable and has resulted in negative effects. These animals not only require more food for maintenance and production, but conversely, fewer animals can be kept on the available food resource. In biologically adapted animals, every increase in a production trait or characteristic (using resources) will reduce biological fitness (as the increased production uses resources that earlier were used to maximise fitness).
We should be asking ourselves these questions: Are our selection goals still relevant? Are our methods serving our best interests?
“Animals that, phenotypically, show efficient economic production and satisfactory reproduction in the available environment, must have a good set of genes for the particular environment. Common sense suggests that the best procedure then is to select, as breeders, these animals with phenotypes expressing the economically best combination of production and fitness over a suitably long productive life on each farm Farmers should beware of introducing stock which is “genetically better” (on EBV’s) from more productive areas. Selecting animals on the genotypic level by for example selecting animals with high body mass EBV’s, has led to big responses as environments and feeding has improved, but there are signs that phenotypes in many of these populations are also now limited. More and more unwanted side-effects are appearing. What has happened is that breeding programs based on EBV’s have successfully produced animals whose genes demanded more resources than the environment could provide. A result of the inappropriate definition of breeding objectives.
It would be far better if:- 1. Every breeding program was restricted to a specific population in a specified, preferably uniform, environment. The total lifetime pattern of production to be achieved was to be reflected accurately in the breeding objective
Extremes should be avoided and genetic traits should be in balance with one another AND with the environment. The genetic goal therefore should surely be to maximise economic fitness.”
ASSOCIATED PROBLEMS The following are examples of typical problems associated with ever-increasing body-mass:- Animals with higher nutritional requirements and thus fewer animals per hectare or per farm Slower maturity Poorer carcasses Lower slaughter percentages Fewer quality meat cuts Lean, lanky and lacking animal types – so-called “draadkarre”
Why then focus on high Body Mass EBVs? Why draw up Elite Sire Lists emphasizing extremes of performance? Why rank animals on non-holistic performance?
As stated some years ago by Chris Cummins of Breakout River Meats, Australia: “Sheep have grown bigger but haven’t put on meat. What had been a necessary reform years ago, was now producing lambs that couldn’t be effectively finished, with good loin, eye-muscle and hindquarter. These animals don’t present well or yield well, so there is less cutting and fewer dollars.”
Zimbabwean, Dr. Johan Zietsmann, BSc. Animal Science (Cum laude), cattle farming expert / consultant on Sustainable Ranch Management, speaks of “inappropriate breeding and management practices that cause farmers to discriminate against those characteristics in their animals that make livestock farming profitable”. Eg: a major problem arises in the case of EBV’s of criteria e.g. average daily gain and feed conversion ratio being diametrically opposed to veld productivity. In such a case, BLUP accelerates the achievement of an undesired end-point”.
Dr Irvin Lazlow, who holds 4 PhD’s and was twice nominated for the Nobel Peace Prize, says: “The prevailing model of biological evolution, which has given so much emphasis to the centrality of genes, needs to be radically reconsidered. Instead we now need to examine the entire organism (or animal) as a coherent entity in constant and dynamic multi-level interaction with its environment. While the DNA code may be unchanged in some cell types, differences may arise in the way the genes are expressed. These differences are transferred to the cells of offspring – a phenomenon called ‘epigenetic inheritance’.”
As put by Christine Couldrey, PhD Cambridge., now Senior Scientist at AgResearch’s Animal Productivity Section & Centre for Reproduction and Genomics, Univ. of Otago, NZ :- “Epigenetics is a layer of information that lies on top of genetic information, effectively bridging the gap between nature and nurture because the epigenetic info that cells carry has been built up in response to the environmental conditions that animals have experienced throughout their lifetimes, starting as early as egg and sperm formation.”
In her recent book “The Epigenetic Revolution”, Nessa Carey, PhD, Former Senior Lecturer in Molecular Biology, Imperial College, London, states: “Animals will NOT always keep reproducing / replicating according to their genetic code or DNA. Scientists have now discovered and proven that trans-generational inheritance of non-genetic phenotypes does occur.”
How long are breeders going to continue to use a selection system that is inappropriate? It is indeed unfortunate that the overuse of single trait selection has had many unforeseen and negative consequences.
Consider: It is easy to breed sheep with good figures – it is far more difficult to breed good sheep.
Article shortened to fit onto the webpage - For a copy of the presentation as delivered at the Inaugural Falkirk Conference, New Zealand, May 2012 Tel: Lionel de la Harpe on 084487 7979 or email pspcc@global.co.za |