Multi-trait selection for body weight, egg production and total fat in the Chinese and Synthetic strains of geese

Abstract

The Chinese and Synthetic (assembled from Pilgrim, Chinese and Hungarian) strains raised at the Greenbelt farm of the Centre for Food and Animal Research (formerly Animal Research Centre, and Animal Research Institute) located in Ottawa, Canada, had been subjected to 12 yr of random mating. From 1982 onwards, these two strains were selected for five generations in order to increase egg production over a 24- wk laying period and body weight at 16 wk of age, and to simultaneously decrease total fat (abdominal and intestinal). At the same time, Randombred Chinese and Synthetic strains were maintained during the course of selection to monitor year-to-year trends in the production traits. In both the Randombred strains, body weights at 9 and 16 wk of age remained stable (P > 0.05) during the course of the study. In the Selected Chinese strain, five generations of selection increased male and female body weight at 1 6 wk of age by 0.181 ± 0.024 and 0.165 ± 0.009 kg/generation, respectively, (P < 0.05), while egg production increased by 1.3 ± 0.73 eggs/generation (P > 0.05). Concurrently, in the Selected Synthetic strain, male and female body weight at 16 wk of age increased by 0.085 ± 0.028 (P < 0.10) and 0.084 ± 0.024 kg/generation (P < 0.05), respectively, while egg production increased by 1.1 ± 0.87 eggs/generation (P > 0.05). In Generation 6, measures of the abdominal, intestinal and total fat increased significantly in the Selected Chinese strain when compared to the Randombred Chinese strain, whereas the Selected and Randombred Synthetic strains were similar (P > 0.05). Correlated responses to selection were observed for body weight at slaughter, eviscerated carcass weight, dressing percentage, weights of the liver and neck, as well as fertility and hatchability traits. In the Selected Chinese strain, the genetic response to selection estimated as a deviation from the Randombred Chinese strain from Generation 2 to 6 for male and female body weight at 16 wk of age were 0.17 ± 0.03 and 0.13 ± 0.02 kg/generation, respectively (P < 0.05). Corresponding estimates of genetic response in the Selected Synthetic strain as a deviation from the Randombred Synthetic strain were 0.04 ± 0.01 and 0.05 ± 0.01 kg/generation, respectively (P < 0.05). In light of the variable results on fatness in the two Selected strains assessed, there is a need for further studies on response to selection for reduced abdominal and intestinal fat. Therefore, selection studies based on a larger number of geese are warranted to sustain goose breeding. Nevertheless, it is evident that multi-trait selection for egg production and body weight offers one of the most practical means for rapid and permanent improvement of economically important production traits in commercial goose breeding. Key words: Chinese strain, Synthetic strain, selection, body weight, egg production, abdominal and intestinal fat