Sanidade e comportamento de bezerras leiteiras em sistema de aleitamento automático.

Abstract

The early life stage of dairy calves is characterized by important physiological, nutritional, and behavioral changes that directly influence their development, health, and future productive performance. In this context, automatic feeding systems have been increasingly adopted in modern dairy farming, making it essential to evaluate the adaptation of animals to this technology. Therefore, this study aimed to assess the development, health, and behavior of dairy calves during the milk-feeding period in an automatic feeder system through weekly monitoring over four consecutive weeks. The theoretical framework addressed aspects related to the physiology and behavior of dairy calves, digestive system development, the importance of automatic feeding systems, and the factors influencing growth, health, and animal welfare during the first weeks of life. The study was conducted on a dairy farm located in the municipality of Iguatama, Minas Gerais, Brazil. Dairy calves housed in group pens and managed under an automatic feeding system were evaluated. Assessments were performed every seven days, corresponding to average ages of 16.8, 24.8, 32.8, and 40.8 days. Body weight, rectal temperature, health and diarrhea scores, as well as behavioral variables related to concentrate intake, rumination, social interaction, idleness, and automatic feeder use were analyzed. Data were subjected to statistical analyses using the Kruskal–Wallis test, F-test, Pearson’s correlation, and linear regression, adopting a significance level of 5%. The results showed a significant improvement in health scores throughout the evaluation period, associated with increasing calf age. Body weight increased over time, while rectal temperature remained within normal physiological ranges. Regarding behavior, there was a significant increase in concentrate intake and rumination time, indicating progressive ruminal development. Social interaction decreased with age, whereas the use of the automatic feeder became more efficient, characterized by a reduction in visit duration and an increase in the number of visits to the system. Correlation analyses revealed associations between age, improved health status, and increased activities related to digestive development. It was concluded that the automatic feeding system provided suitable conditions for calf development, promoting adaptation to management practices, improved health status, and the expression of behaviors consistent with growth and digestive system maturation.