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Beyond the Bale : September 2013
34 34 34 ON-FARM MERINOSELECT search website September 2013 BEYOND THE BALE FAST FACTS l A range of criteria can be used to select animals on the Sheep Genetics website. l Key differences exist between the sires of different wool types for the breech traits. l Indexes may offer a drafting gate to shortlist potential sires, but take a wide cast. l Understanding how genes are expressed at home is an important step for sire selection. The animal search function on the MERINOSELECT website makes it easier to search for animals that meet a range of criteria a ram breeder may be interested in. A search of the top 10 sires by wool type with more than 100 progeny gives the results in Table 1 below. The results show clear differences in fleece weight, micron, fertility, breech wrinkle and breech cover between the sire type averages selected on the three indexes. It shows greater breech wrinkle, breech cover and dag scores for the leading Super Fine type sires (greater than 0.0) and why breeding to reduce breech strike risk is slower for Super Fine sheep types. If a selection criteria for curvature is set at a minimum of +9 degrees per mm, the breech scores of the new top 10 sires remains similar as does the micron but the fleece weight falls from +3% to -3% . prior to culling on the many traits not in the index, ie polls, wool quality, availability of semen, conformation and constitution etc. As always, actual production varies across sites and between years, due to the interaction between genetic potential and the environment, ie between high wrinkle and low wrinkle country, high dag and low dag country, high micron and low micron country and between seasons. Understanding how genes are expressed at home is an important step for sire selection. A sire -2 .0 for fibre diameter can produce progeny with 17 micron wool in low micron country and 20 micron wool in high micron country. Similarly in high wrinkle country, sires may need to have a breech wrinkle ASBV of -0.5 for progeny to have breech scores of 2 or less, but in low wrinkle country sires can be as high as -0.1 . Importantly the rankings of sires remain consistent across sites. More information: The Animal Search function, explanation of ASBVs and Indexes (Pocket Guide, Understanding ASBVs etc) and a list of genetic service providers ready to assist are available on the Sheep Genetics website: http://sgsearch.sheepgenetics.org. au/?dataset=5 www.sheepgenetics.org.au/Resources/ Brochures-and-fact-sheets www.sheepgenetics.org.au/Service- providers Table 1. Average ASBVs for the top 10 sires with more than 100 progeny. Trait Adult Wt Year Fat Year EMD Adult Flc Wt Adult FD Adult Cur v Adult St Lgth Adult St Str Year WEC No Lbs Wean Breech Wkl Breech Cover Breech Dag FIBRE PROD + MERINO PROD+ DUAL PURP + Wool Type (kg) (mm) (mm) (%) (m) (D/mm) (mm) (N/Kt) (%) (%) Score Score Score Index Index Index Super Fine -1 0.2 0.1 3 - 3.0 3 -1 3 -18 2% 0.2 0.2 0.2 164 Fine 9 0.0 0.0 15 -1 .4 -5 9 3 3 13% 0.0 -0.2 - 0.2 204 Medium 9 0.1 0.6 11 -0.1 -6 6 2 -11 17% -0.5 - 0.3 0.1 197 The average of the top 10 Medium sires have lower fleece weight but higher fertility and lower breech wrinkle than the average of the top 10 Fine type sires. Yet there are individual sires in the top Fine and Medium type sires that have high fleece weight, low breech wrinkle and high fertility. (Individual ram data not listed.) The percentile table (Table 2 opposite) for the 2011 drop puts the breeding values in Table 1 into perspective for the Merino breed. Note the reduced range in dags compared to wrinkle. Breeding for low dag takes longer than low wrinkle, a significant issue for breeders and their clients in high dag country with Super Fine types. The impact of adding additional search criteria listed in Table 3 opposite can be compared with averages in Table 1. The additional criteria have reduced the average indexes but not by much. The same criteria was used across all wool types for simplicity which has led to a variable impact on the indexes. The 10 sires within each type are more balanced for the traits where the criteria was applied and highlight the importance of focusing on individual traits as well as the relevant index where greater predictability is required or individual traits are more or less important than in the index. In practice, the search criteria should vary between sheep types, indexes, environments and personal views on future markets. 30 -50 sires should also be chosen to better find the "curve benders", Note: Super Fine type sires were selected on Fibre Production Plus Index, Fine type sires were selected on the Merino Production Plus Index and Medium type sires were selected on the Dual Purpose Plus Index.