Changing ram source may not be the answer to an under-performing flock. Vet Trevor Cook looks at sheep breeding priorities.
When a farm is struggling with flock performance one of the most common questions I get asked is “where should I get my rams from?” Changing the ram source is so often seen as the key change necessary to lifting flock outputs.
Although I work with a number of ram breeders, I cannot be seen to be aligned with any of them. I never attempt to answer that question at the beginning and very often not by the end of the discussion.
My response always begins with getting the areas of flock under-performance defined. This then must be put into the whole-farm context such as the stocking rate, the stock mix and the environment. Are the breeding objectives defined or appropriate for the farm? What is the priority of the sheep breeding enterprise?
I then look at what it looks like at the key points of influence times.
Ewe lamb replacement weights pre-winter, the body condition score of ewes at mating and lambing, the feed conditions from pregnancy scanning on are few of the areas I explore. By then I usually am getting an idea of what might be the obstacles.
What is interesting to me in these discussions is that I will never be talking about things the flock manager has not heard before. So in finding solutions the focus needs to be on why these things are limiting. This is another big discussion because it will follow a different path every time.
Terrain, feeding background, animal health support and mob sizes will all impact on performance and therefore on the relevance of any selection.
If after all of this the ram source is still seen as an important change, I will tread carefully and talk about selection priorities and being aware of environmental background of any rams being considered. I often will refer my client to SIL flock and ram rankings but always warn of the importance of that selection background.
Terrain, feeding background, animal health support and mob sizes will all impact on performance and therefore on the relevance of any selection.
Investigation into poor flock performance most often does not result in a ram source change.
A forum I was at recently was focused on the genetics of sheep and cattle. New technologies intruding into this world were discussed and there is no question they are adding to the ability to make genetic gain.
A term used a lot is genomics which by definition is “the branch of molecular biology concerned with the structure, function, evolution, and mapping of genomes”. It is very much the world of DNA technology being used in genetic selections.
It was very comforting that in this forum there was recognition of the importance of environmental factors influencing genetic selection outcomes. Selection tools and rules used since 1865 with Mendel’s discoveries have been hugely successful and we need only look at how that has been applied to the New Zealand sheep population.
This has been based on individual breeders manually collecting data from individual sheep to make selections based on performance. The biggest gains were made before modern technology appeared. Computer analysis of data was probably the first technological aid enlisted which added massive power to onfarm selections. But these selections were all being made in an environment which impacted on the outcome.
Fancy DNA selections cannot do this and must sit alongside traditional methods. The challenge the industry has is who pays for onfarm selection which is necessary to make gains and to validate “laboratory”-generated data. This is a better allocation of funds than giving me the ability to make sire ram selection capability on my cell phone.
Attendees at that same forum were exposed to the power of a tiny manipulation of the genome altering animal performance. Of particular interest though was that performance being in disease tolerance or resistance, feed conversion efficiency or methane production.
That same technology could provide the tools needed to have any hope of reaching the predator free target by 2050. The technology is well developed and proven, but the community acceptance is the barrier in NZ. It is still a discussion hampered by polarisation of views but homosexuality and same-sex marriage acceptance were once hampered by polarisation so there must be hope.
