Genotype by environment interactions of claw health in Swedish dairy cattle in tie stalls and loose-housing
Genotype by environment interactions (GxE interactions)Genetic correlationsDairy cattleClaw healthClaw diseaseHousing systemTie stallsLoose-housing
Claw diseases are common diseases in modern dairy production. They are painful for the cow and costly for the producer. Differences in the prevalence of claw disease depending on housing system have previously been observed. This raises the question if there are genotype by environment (GxE) interactions for claw diseases in different housing systems. To investigate this claw trimming records for Swedish Red dairy cattle (SR) and Swedish Holstein cows (SH) were retrieved from the Swedish Dairy Association. The data contained information concerning hygiene-related claw diseases; dermatitis (interdigital and digital), heel horn erosion and skin proliferation (interdigital hyperplasia and warts), and feed-related claw diseases; sole hemorrhage, sole ulcer, corkscrew claws and the combination of white line separation and double sole. The data also contained information about housing; tie stalls or loose-housing. Disease frequencies were studied depending on breed, lactation number and housing system and genetic parameters were estimated for the same breed-lactation-housing-combinations. To investigate the presence of a GxE interaction, genetic correlations between the same claw disease in different housing systems was estimated. The results showed lower frequencies of claw diseases for the SR compared to the SH. There was an increase in disease prevalence with increasing lactation number for the hygiene-related claw diseases in both breeds. For both breeds there was a higher prevalence of hygiene-related claw diseases in loose-housing, while there only was a tendency towards the same for feed-related claw diseases. Despite the smaller differences in disease frequency depending on housing system indications of GxE interactions for claw diseases in different housing systems were found mostly for the feed-related diseases.