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
Calf mortality has been reported to range between 2–20% [3,4]. In one study, 48.7 – 72.5% of three groups of 120 calves were treated with antibiotics ,
and about 50% of farmers in North America have reported to use milk
replacers containing antibiotics when raising dairy calves .
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 .
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 . 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 "Welfare and husbandry of Calves" ,
with the aim of preparing more acceptable methods of calf husbandry.
However, most dairy calves are still segregated from adults and
artificially fed, although it is generally agreed that the environment
offered an animal should allow the physiological functions within a
normal range. In EU (Directive 91/630/EØF), farmers are not allowed to
separate piglets from their mother earlier than 21 days of age. A
newborn piglet and a newborn calf are comparable concerning development
and immune status at birth.
Cattle are social animals that under natural conditions live in
groups. The cow leaves the group before delivery and keeps her calf
isolated the first days, and then introducing the calf to the group.
The cows may start to leave their calves for longer periods from about
2 weeks of age, and calves are gradually weaned at approximately 6–8
months of age [10,12].
In a private Norwegian dairy herd, the calves were, for animal
welfare reasons, allowed to stay together with their mothers for 6–8
weeks after birth. This management started in 1999, and has been
performed since then. The present study was performed to get knowledge
about weight gain, health and slaughter weights in this herd performing
natural milk feeding.