Using test station ans on-farm data for the genetic evaluation of Piétrain boars used on Landrace sows for growth performance
- Dufrasne, M. , Rustin, M. , Jaspart, V. , Wavreille, J. & Gengler, N. (2011). Using test station ans on-farm data for the genetic evaluation of Piétrain boars used on Landrace sows for growth performance. Journal of Animal Science, 89: 3872-3880.
|Using test station ans on-farm data for the genetic evaluation of Piétrain boars used on Landrace sows for growth performance
|Journal of Animal Science
|crossbred progeny, genetic paramters, growth potential, Piétrain boars, reliability, variance heterogeneity
|The aim of this study was to develop a new genetic evaluation model to estimate genetic merit of boars for growth based on 1) performance of their crossbred progeny fattened in test station and 2) their own performance or those of relatives from the on-farm testing system. The model was a bivariate random regression animal model with linear splines and was applied to Piétrain boars from the Walloon Region of Belgium mated with Landrace sows. Data contained 1) 12,610 weight records from test station collected on 1,435 crossbred pigs from Piétrain boars and Landrace sows, and 2) 52,993 weight records from on-farm testing system collected on 50,670 pigs with a breed composition => 40 % Piétrain or Landrace. Since 2007, 56 Piétrain boars have been tested in station. Data used to estimate variance components and breeding values were standardized for the age in order to take into account heterogeneity of variances and then pre-adjusted at 210 d of age to put all records on the same scale. Weight records from test station and from on-farm testing system were considered as two different traits. The heterosis effect was modeled as fixed regression on the heterozygosity coefficient. As all test stations animals were similarly crossbred, smaller variation in heterozygosity caused the sampling error of the regression estimate at 210 d to be larger in test station than in on-farm data with estimates of 28.35 kg +/- 14.55 kg and 9.02 kg +/- 0.67 kg respectively. Therefore, the most likely reason for the large differences in estimates is sampling. Heritability estimates ranged from 0.37 to 0.60 at 210 d and 75 d, respectively, for test station weights and from 0.42 to 0.60 at 210 d and 175 d, respectively, for on farm weights. Genetic correlation decreased when the age interval between records increased, and were higher between ages for test station than for on-farm data. Genetic correlations between test station and on-farm weights at the same age were high: 0.90 at 175 d and 0.85 at 210 d. For the 56 boars tested in station, average reliability of their EBV for ADG between 100 and 210 d was improved from 0.60 using only test station data to 0.69 using jointly test station and on-farm data. Based on these results, the new model developed was considered as a good method of detection of differences in growth potential of Piétrain boars based on test station and on-farm data.
|Dufrasne, M., Rustin, M., Jaspart, V., Wavreille, J., Gengler, N.