The aim of the present study was to derive economic weights for 15 breeding goal traits of a Merinoland sheep population. The specific focus on novel traits including health (endo- and ectoparasite resistances) and welfare (tail length) implied the enhancement of a bio-economic modelling approach as implemented in the ECOWEIGHT software package. The newly developed subroutine enabled the consideration of disease incidences and treatment costs for health traits and consideration of the herd tail-length status. Economic evaluation criteria from the breeding goal perspective were marginal economic values (MEVs) expressed in Euro per trait unit per ewe and year, and relative economic values (REVs) standardizing the MEV to the respective genetic standard deviation and related to the sum in Euro of all 15 breeding goal traits. Highest MEVs and REVs were derived for ewe fertility traits and survival rates of lambs. In a scenario assuming 100% sheep with long tails (sheep tail below the hock), REVs comprised 27% for litter size, 24% for the survival rate of lambs until weaning, 18% for the survival rate of lambs till 24 hours after birth, and 18% for ewe conception rate. The REVs of health traits including endo- and ectoparasite resistance traits, tail length and production traits (lamb weights, wool weight) were close to zero in a range from 0% to 2%. In sensitivity analyses, we increased the percentage of short-tailed sheep in the flock by increments of 25% up to a 100% short-tailed population, but only minor effects on MEVs and REVs of all breeding goal traits were observed. The MEVs and REVs for disease resistance traits were low due to the very high health status in the research herd considered for input data generation. The newly developed software to derive economic weights for sheep breeding goal traits revealed great flexibility regarding trait pattern and sensitivity analyses in the context of environmental particularities and market conditions. • Development of a new program to derive economic values for breeding goal traits in sheep additionally considering health and welfare traits • Sensitivity analyses enabled the derivation of economic values for breeding goal traits for different scenarios reflecting the tail length status in the flock • Marginal and relative economic values were largest for ewe fertility traits and survival rates of lambs • Marginal and relative economic values for disease resistance traits and tail length as a welfare indicator trait declined with improved herd health and welfare status
Oberpenning et al. (Thu,) studied this question.