Variations and extremities in climatic conditions can result in cold stress for dairy calves during the preweaning period. The objective of this study was to investigate the effect of calf jackets on the health, performance, and skin temperature of dairy-origin beef calves. This study took place in a designated calf rearing unit, spanned for a duration of 1 yr, and consisted of five batches of calves. Calves (30.9 ± 1.68 d of age; 55.9 ± 0.20 kg live weight) were assigned to one of four treatment groups on arrival at the rearing unit. Treatments consisted of control (no jacket), arrival (jacket for 2 wk postarrival), weight (jacket for a minimum of 2 wk and until 65 kg live weight), and wean (jacket until 5 d postweaning). Ambient conditions differed significantly (P < 0.001) during each of the five batches; batch 4 was the coldest with a mean ambient temperature of 6.16 °C. Significant differences were observed between the five batches for day 50 weight (P < 0.01) and disease incidence (P < 0.05). However, treatment had no significant effect on calf health or performance (P > 0.05) during any of the five batches. Skin temperature was significantly greater (P < 0.001) for calves wearing a jacket. Furthermore, there was a significant (P < 0.001) relationship between ambient temperature-humidity index and skin temperature for calves with and without a calf jacket. Therefore, although calf jackets had no benefit in terms of health or performance, they did act as a barrier to environmental conditions.
Student thesis: Doctoral Thesis › Doctor of PhilosophyFile