科研之友
微信
新浪微博
Facebook
分享链接
摘要
In most dairy herds in North America and European countries, calves are separated from their mothers immediately or few hours after birth. During the first weeks of life, the calves are usually kept in individual pens, which prevent calves from suckling one another, minimize the spread of disease, and simplify feeding and disease detection. The calves are fed milk artificially, either by bucket or a teat feeding system. It is recommended to feed dairy calves milk twice daily an amount equivalent to 10% of their body weight, until weaning at about 6 weeks of age [1,2]. Normal oral and ingestive behaviour pattern is prohibited by separation of newborn calves from their mothers. The segregation eliminates the maternal care and the influence of adults on calf behaviour, and the individual penning restricts movements and social interference with other calves.Calf mortality has been reported to range between 2每20% [3,4]. In one study, 48.7 每 72.5% of three groups of 120 calves were treated with antibiotics [5], and about 50% of farmers in North America have reported to use milk replacers containing antibiotics when raising dairy calves [6].Artificial teat feeding allows dairy calves to express their natural suckling behaviour, and feeding milk ad libitum has been observed to improve both health and weight gain [7,8]. Separating calves and cows 4 days after birth has been associated with health advantages for the calf, compared to separation at birth [9]. Calves allowed to suckle their mother for 14 days gained weight at more than three times the rate of those separated during the first 24 hours [10]. However, the later separation was observed to increase the separation stress for both cow and calf.The public concern to animal welfare is increasing. Already in 1981, the Commission of the European Communities, Brussels, arranged a seminar on %26quot;Welfare and husbandry of Calves%26quot; [11], with the aim of preparing more acceptable methods of calf husbandry. However, most dairy calve
