Browsing by Author "Pääläinen, Eeva"

A goal of a livestock farmer is to get the best possible profit by rearing heifers for replacement with the lowest possible cost. On the other hand, the environment must be taken into account in production. In 2015, agriculture produced 12 per cent of Finland's greenhouse gas emissions. Breeding choices can affect production costs and the environmental impact of production. Rapid growth shortens the rearing time of slaughter animals, allowing the resources being released quickly to the following animals. A rapid growing animal will produce less emissions during its lifetime compared to a slow-growing animal. However, the weight of an adult animal should not rise because increase of weight will increase the animal's feeding costs and if the animal eats more it will produce more emissions. This study investigated the relationship between the growth of young bulls and heifers and weight of adult cows in Ayrshire breed. Research material was provided by The Finnish Animal Breeding Assocation (Faba Osk). The materials were edited and analyzed using the R software. Growth observations ranged from 16 to 24 months old bulls and from 14 to 22 months old heifers. Weight observations were from cows which were more than 600 and under 2190 days old. Variance components were analyzed using the AI-REML method. The repeatability animal model was used for predicting heritability of live weight, as several observations were available for cows. The animal model was used for predicting heritability of growth and a genetic correlation between growth and weight. Heritabilities were quite high for both characteristics; for growth 0,36 to 0,37 (standard error SE 0,018 to 0,019) and for live weight 0,43 to 0,44 (SE 0,0094 – 0,010). The repeatability of weight was 0,63. A correlation between the characteristics was 0,57 (SE 0,0296). The correlation was lower than in previous studies. Based on this research, adding growth to the total merit index would be possible. Thus, breeding of growth would be possible and it would also be economically profitable and environmentally friendly. The results can be utilized in the development of the breeding program.