Tag: "skin"

  • Can Selection for Skin Traits Increase the Rate Of Genetic Progress in Merino Breeding Programs?

    There is widespread interest in the use of skin properties for the selection of superior Merino genotypes. This is despite the fact that no selection experiments to date have demonstrated beneficial effects on production traits from selection based solely on skin traits. Two studies have examined whether the inclusion of skin traits in a realistic selection program improves the rate of genetic progress towards a breeding objective emphasising fleece weight and fibre diameter. Both indicated little benefit from including the skin traits. However the impact of the skin traits will depend on their heritabilities and their genetic associations with one another and with the traits in the breeding objective. There is increasing evidence that the genetic parameters differ between the Merino strains so results from one strain cannot be extrapolated to another. In this paper we examine the effects of including classer assessed skin quality and two objectively measured skin characters, skin biopsy weight and follicle density, on the genetic and economic gain made over and above that made using a standard selection index in South Australian Strongwool Merinos. The results indicate that substantial additional genetic gain can be made by including the skin traits. This was particularly true at low micron premiums where addition of all three skin traits increased the economic gain by 25%. The genetic improvement in adult clean fleece weight by including all three skin traits at this premium, was increased from 0.9% per annum to 1.4% per annum with a corresponding slight reduction in the decrease in mean fibre diameter. At higher micron premiums the benefit of including the skin traits was substantially less, again reflecting the tendency for skin trait inclusion to influence fleece weight to a larger extent than fibre diameter. Inclusion of the skin traits had little impact on coefficient of variation of fibre diameter, staple strength and staple length. Our results suggest that consideration of some skin traits may lead to moderate genetic gains and be worthwhile including in breeding programs for Strongwool Merinos, but they do not lend support to notions that consideration of skin traits will produce dramatic increases in fleece weights with concomitant large decreases in fibre diameter. more »
  • Phenotypic Links Between Skin Thickness, Follicular Density, and Fiber Growth Rates in Alpacas

    One of the benefits of objective measurement of phenotypic alpaca traits is that the resulting measurements can be collected and analyzed for additional insights that can benefit the industry as a whole. Breeders who commission these analyses of their animals, as well as the organizations that provide them, play an important role in advancing the understanding of alpaca trait relationships and their possible underlying genetic links. more »
  • Herdsire Line-Up

    An example from two alpaca breeders looking for generational fleece trait improvements using skin biopsy data as an aid to making better breeding choices. more »

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