Relationship of lameness in Holstein cows to other diseases and selection index traits

ZAVADILOVÁ, Ludmila, KAŠNÁ, Eva a KRUPOVÁ, Zuzana., 2024 Relationship of lameness in Holstein cows to other diseases and selection index traits. In Aktuální směry ve šlechtění hospodářských zvířat. Praha Uhříněves: Výzkumný ústav živočišné výroby, v.v.i., s. 92-104. ISSN
Year2024
CathegoryOthers
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Abstract

The study analysed the relationships between lameness, various diseases, and traits related to the selection index. The dataset included 98,444 lactations from 42,426 Holstein cows across 24 herds that monitored lameness between 2017 and 2024. Alongside lameness, the study also monitored clinical mastitis (CM), total claw diseases (NPC), metabolic diseases (METAB), and reproductive disorders (REP). Lameness, CM, and NPC were defined as diagnoses, while METAB encompassed conditions such as ketosis, parturient paresis, and displaced abomasum. REP included retained placenta, metritis/endometritis, and cystic ovarian disease. All diagnoses were reported following the Diary of Diseases and Treatments web application guidelines. The incidence of diseases was categorised as 0 (no incidence) or 1 (incidence) per lactation. A linear model was employed, incorporating fixed effects for herd, year, season of calving, and parity combined with calving age, alongside random effects such as the cow’s permanent environment, the animal’s pedigree and genomic matrix, and residual effects for evaluation. Genetic parameters and genomic breeding values for lameness were estimated and used to calculate genetic correlations with traits in the selection index. The single-step genomic prediction method, ssBLUP, was used to estimate these genomic breeding values. A total of 14,439 animals were genotyped using the BovineSNP50 chip. The lactation incidence of lameness in the analysed dataset was 8.79%. The heritability coefficients were highest for lameness (8.44%) and lowest for METAB (4.87%). The approximate genetic correlations of lameness with selection index traits were positive: 15.52% for protein production in kg, 29.48% for longevity, 17.97% for heifer fertility, 10% for NPC, 25.41% for exterior traits, and 27.53% for udder exterior traits. Given that most of these correlations are positive and relatively low, we conclude that incorporating lameness resistance into the selection index would not significantly impact the overall breeding goal.