Genetic association between longevity and linear type traits of Holstein cows

Longevity is a desirable trait in the dairy industry because of its relationship to profitability. The aim of this study was to estimate genetic parameters for longevity measurements related to productive life, or life in the herd, and linear type traits of Brazilian Holstein cows born between the years 1990 and 2008. The (co) variance components were estimated by the restricted maximum likelihood method. The heritability for measurements of longevity and linear type traits ranged from 0.05 to 0.07 and 0.08 to 0.39, respectively. The genetic correlations between measurements of longevity and linear type traits ranged from -0.39 to 0.31. Direct selection for longevity does not necessarily lead to long-lived cows, due to low heritability. Indirect genetic selection for udder depth, bone quality, udder height, rear teat placement and conformation traits showed the highest genetic correlations with measurements of time between birth and last milk record and time from first calving to last milk record

Mature body weight and profit selection in Spanish dairy cattle

Individual mature body weight (BW) and profit were obtained from type, milk yield, and economic data from 42,401 Spanish Holstein cows. The economic value of BW was estimated in order to consider it in the breeding goal and to compare the importance of BW to other traits related to profit. Also, relationships between predicted breeding values (BV) of BW with actual profit, functional herd life, and calving interval by regression analysis were estimated. Body weight obtained an economic value of - 0.84 euros per cow per year. Inclusion of BW in the breeding goal by considering stature in a new economic index was shown to have 10% importance in genetic merit of profit. Reliability increased from 0.33 to 0.47 with respect to the old index that only included production and longevity. A significant positive quadratic relationship between body weight BV and profit BV was found (R2 equals to 0.54) but heavier animals had shorter herd lives and longer calving intervals. Influence of Holstein genes and selection for production increased body weight BV and reached a plateau at year 1994, while profit BV trends were still rising. Results suggest that selection for actual profit should be made maintaining a constant BW. © 2005 Elsevier B.V. All rights reserved

A bio-economic model to improve profitability in a large national beef cattle population

A bio-economic model was developed for estimating economic values for use in improving profitability in a large national beef cattle population from birth to slaughter. Results were divided into fattening costs, production costs and income. Economic values were derived for 17 traits for two regions, mature weight (- 0.43 € and - 0.38 €/+1 kg of live weight), age at first calving (- 0.13 € and - 0.11 €/+1d), calving interval (-1.06 € and -1.02 €/+1d), age at last calving (0.03 € and 0.03 €/+1d), mortality 0-48 h (-5.86 € and -5.63 €/1% calves per cow and year), pre-weaning mortality (-5.96 € and -5.73 €/+1% calves per cow and year), fattening mortality (-8.23 € and -7.88 €/+1% calves per cow and year), adult mortality (-8.92 € and -7.34 €/+1% adult cows per cow and year), pre-weaning average daily gain (2.56 € and 2.84 €/+10g/d), fattening young animals average daily gain (2.65 € and 3.00 €/+10g/d), culled cow in fattening average daily gain (0.25 € and 0.16 €/+10g/d), culled cow dressing carcass percentage (3.09 € and 2.42 €/+1%), culled cow price (4.59 € and 3.59 €/+0.06 €/kg), carcass conformation score (16.39 € and 15.3 €/+1 SEUROP class), dressing carcass rate of calf (18.22 € and 18.23 €/+1%), carcass growth (9.00 € and 10.09 €/+10g of carcass weight/d) and age at slaughter (0.27 € and 0.44 €/+1d). Two sample herds were used to show the economic impact of calving interval and age at first calving shortening in the profit per slaughtered young animal, which was 178 € and 111 € for Herds A and B, respectively. The economic values of functional traits were reduced and production traits were enhanced when fertility traits were improved. The model could be applied in a Spanish national program