Staying connected - SIL-ACE joins the dots

Staying connected - SIL-ACE joins the dots

Within a few minutes and mouse clicks, sheep breeders can objectively and fairly compare rams from different flocks. Beef + Lamb New Zealand's (B+LNZ) SIL-ACE is the largest genetic evaluation of sheep in the world.

It takes the guesswork out of ram selection between flocks, by accurately assessing the performance of animals in different flocks. This is made possible by the flocks within SIL-ACE being "connected" through use of a common ram in two or more flocks.

B+LNZ Geneticist Dr Mark Young says "connectedness" is not as complicated as it sounds.

"For flocks to be included in SIL-ACE, a breeder needs to use a 'link' ram - a ram that another SIL-ACE breeder has used - over about 40 ewes. In this way, that ram has offspring in two or more flocks and the performance of the resulting progeny is used to separate out genetic effects, from flock effects.

These performance measures provide the benchmarks for making valid comparisons of animals from different flocks." The team at SIL uses this information to determine how much of a sire's progeny performance is by virtue of his genetics, how much is by virtue of the ewe flock's genetics and how much is due to management or other environmental influences.

Dr Young says the connectedness principle is also used by ram breeders to remove year effects and so provide an assessment of genetic gain over time - as seen in SIL genetic trend graphs. "Sires used in more than one year give 'connectedness' between years, allowing year effects due to management or the environment to be removed." However, connectedness between flocks, gained from using a common ram, is progressively lost as the years pass, so breeders need to share rams regularly - ideally every year, but at least once every two years.

Involvement in the SIL-ACE evaluation is growing, with more ram breeders consciously using a SIL-ACE-friendly ram over a portion of their flock. This allows comparisons to be made of sire progeny performance over a wide range of flocks and gives breeders a wider gene pool in which to search for the genetics they want to use.

Dr Young says new ram breeders joining need to make sure they collect all the measurements they record on progeny of link sires. "We need at least 25 progeny within each flock with performance measurements for the key traits to contribute to the across-flock connectedness calculations.

"Without good flock connectedness, top genetics will not show their true superiority. Building the genetic connections is the best way to identify top genetics. And it provides breeders with more options than those they have within their own flock or flock groups." When it comes to capitalising on the gains SIL-ACE breeders are making, commercial farmers can use the online tool, "FlockFinder", to locate rams from flocks recording traits the farmer is aiming to improve.

"SIL-ACE breeders have the biggest and best characterised gene pool in the world from which to select breeding stock to produce rams for sale." Farmer Steve Wyn-Harris says he has always kept a close eye on the SIL-ACE evaluations. "They assist me in my selection of outside genetics, as I will always use at least one new ram each year. There is no point in using someone else's rams if I can't be sure they are better than my homebred Marlow rams.

"I have been aware since the evaluations began that good connectedness is critical and I consistently either buy, borrow, swap or lease rams from right near the top of the lists, but also from other flocks that are well connected themselves." Mr Wyn-Harris says he's also had the bonus impact of selling several stud rams - two of which have been used extensively in other flocks, thus further significantly increasing his stud's connectedness to the industry.

"I measure every trait, except FEC, and - other than FEC - I see from the connectedness graphs on the web site that the Marlow stud is about as connected for all the other traits as is possible to get. This gives me the confidence to continue to target outside genetics from above my own listed rams." SIL-ACE is run every two months and results from the April 2011 evaluation are available at www.beeflambnz.com and www.sil.co.nz.

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