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Grading system for replacements & culling

Discussion in 'Breeds & Breeding - Sheep' started by ohiogoatgirl, Feb 2, 2019.

  1. Feb 2, 2019
    ohiogoatgirl

    ohiogoatgirl True BYH Addict

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    I was watching some webinars and came across trait performance ratio.
    Indv performance
    -------------------------------------------- x100
    Avg performance of group

    Example..
    45lb
    ----------- x100 = 108%
    41.7lb

    So that lamb did 8% over the average. And you can do it for any measurable trait.

    Then later they talked about the EBVs and all the different systems used to determine how good a sheep is against the group average.

    So that got me thinking about writing down a sort of score card for picking replacements and culling decisions. I'd like to know what you think and what kind of systems you use for these decisions.

    *Litter size 20
    *Weaning weight 20
    *ADG (birth to wean & wean to market time) 20
    *rams- scrotal size. ewes- teat placement and extra teats. 20
    *Fleece weight 10
    *staple length 5
    *wool cover of face/legs 5

    My reasoning...
    *Litter size isn't that high of heritability but selecting for it won't hurt. 2018 my lambing was 140%. Not terrible but not fantastic.
    *Weaning weight is a good representative of the mom's milkability and mothering. Milk yeild is 30% heritable. As well as selecting quick growing lambs.
    *Avg daily gain will show who is better at turning food into gain. Weaning to market time represents on the indv lambs genetics for growth.
    *Rams with higher scrotal size have higher fertility and produce ewes with higher fertility. Extra teats.
    Teat size is 20% heritable, teat placement is 25% heritable. Extra teats can be problematic for newborn lambs. Several of my sheep have extra teats and I'd like to nip that trait right off.
    *Grease fleece weight is 35% heritable. Fleece yeild is 40% heritable. CV of fiber is 50% heritable.
    *Staple length is 55% heritable. If having yarn milled it's important to have fiber that is within an inch staple length to prevent issues.
    *Wool cover of face is 56% heritable.
     
    mysunwolf likes this.