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ANIMAL BREEDING IN THE CONTEXT OF MODERN AGRICULTURE FROM SCIENCE TO PRACTICE 21-22 May 2009. PERINATAL MORTALITY IN DAIRY CATTLE Szűcs, E., Gulyás, L., Cziszter, L. T. Demirkan, I. STATE OF THE ART. Consumer concern towards ethics and animal welfare have been increasing
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ANIMAL BREEDING IN THE CONTEXT OF MODERN AGRICULTURE FROM SCIENCE TO PRACTICE 21-22 May 2009 PERINATAL MORTALITY IN DAIRY CATTLE Szűcs, E., Gulyás, L., Cziszter, L. T. Demirkan, I.
STATE OF THE ART • Consumer concern towards ethics and animal welfare have been increasing • Socio-economic issues have to be taken into account in animal production • High perinatal mortality is unacceptable in animalproductionincludingbovine species • Finding the way for reducing prevalence • Develop instruments to attain the targeted goal
STATE OF THE ART • Calving is the most stressful part of life cycle in cows • Stillbirth and calving difficulty may result in direct and indirect losses • Direct losses such ascalf and dam mortality • Premature culling • Additional veterinary service • Extra labour and treatment
FACTORS / RISKS • Genetics • Inbreeding • Breed differences • Gender and multiple births • Calving number • Age at first calving • Gestation days
Genetics • Several QTL affecting direct and maternal traits identified in Denmark • Multitrait and multiple variance components detected pleiotropic QTLs for 1) direct and maternal stillbirths 2) direct calving size and difficulties • Opportunity genetic progress for calving traits
IMPLICATIONS • Due to variation among sire families recording scheme should cover direct (sire of calf) and maternal (sire of cow) aspects for perinatal traits • Info gained has to be used in selection programs • Direct and long term costs have to be evaluated
IMPLICATIONS • Direct costs: loss of calf, death of dam, labour, veterinary assistance • Cost of longer term: culling rate, milk yield, fertility • Non genetic factors: parity, sex of calf, age at first calving, season, level of nutrition during gestation
IMPLICATIONS • Effects of non-genetic factors mentioned abovehave to be considered • In genetic model for calving trait estimates direct, maternal, and direct maternal interaction should be included into the model to understand the contribution of sire traits in terms as birth weight, gestation period, body dimensions