Department of Environmental and Preventive Sciences, University of Ferrara, Corso Ercole I d’Este 32, 44121 Ferrara, Italy
Dyan Meuwissen
Division of Animal and Human Health Engineering, Department of Biosystems, KU Leuven, Campus Geel, Kleinhoefstraat 4, 2440 Geel, Belgium
Ilaria Prosepe
Unit of Biostatistics, Epidemiology and Preventive Sciences, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Via L. Loredan 18, 35131 Padova, Italy
Ali Zidi
Department of Animal Medicine, Production and Health (MAPS), University of Padova, Viale dell’Università 16, 35020 Legnaro, Italy
Giulio Cozzi
Department of Animal Medicine, Production and Health (MAPS), University of Padova, Viale dell’Università 16, 35020 Legnaro, Italy
Early predictions of cows’ probability of survival to different lactations would help farmers in making successful management and breeding decisions. For this purpose, this research explored the adoption of joint models for longitudinal and survival data in the dairy field. An algorithm jointly modelled daily first-lactation sensor data (milk yield, body weight, rumination time) and survival data (i.e., time to culling) from 6 Holstein dairy farms. The algorithm was set to predict survival to the beginning of the second and third lactations (i.e., second and third calving) from sensor observations of the first 60, 150, and 240 days in milk of cows’ first lactation. Using 3-time-repeated 3-fold cross-validation, the performance was evaluated in terms of Area Under the Curve and expected error of prediction. Across the different scenarios and farms, the former varied between 45% and 76%, while the latter was between 3.5% and 26%. Significant results were obtained in terms of expected error of prediction, meaning that the method provided survival probabilities in line with the observed events in the datasets (i.e., culling). Furthermore, the performances were stable among farms. These features may justify further research on the use of joint models to predict the survival of dairy cattle.
