Housing, Feeding and Management of Calves and Replacement Heifers in Swedish Dairy Herds
By K. Pettersson
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C. Svensson
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P. Liberg
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Department of Animal Environment & Health, Faculty of Veterinary Medicine, Swedish University of Agricul- tural Sciences
,
Skara
,
Sweden
Pettersson K, Svensson C, Liberg P: Housing, feeding and management of calves and Replacement heifers in Swedish dairy herds. Acta vet. scand. 2001, 42, 465478. - A questionnaire was sent to 1500 randomly selected dairy herds in Sweden, asking for general information about the herds, including routines from birth to first calving and also routines at breeding, calving and during the grazing period. Fifty-eight percent of the questionnaires were returned. The preweaned calves were kept in individual calf pens in 68% and in group housing systems in 28% of the herds. Pens with slatted floors were the main housing system for replacement heifers from weaning to breeding, and tie stalls from breeding to first calving. Whole milk was used in 44% and milk replacements in 42% of the herds. The calves received, as a median, 2.5 litres of milk per meal and 2 meals per day. The median age at weaning was 8 weeks. Age was the single most common criteria used for deciding both weaning and breeding time. The median age when the heifers were first turned out to pasture was 6 months. Prophylactic anthelmintic treatment was used by 65% of the herds. The most common diet for replacement heifers before calving was a combination of grain, hay and silage.
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In modern milk production, calves are often
overlooked. Increased knowledge about their
situation is important for offering these animals
rearing conditions in which they can maintain
good health and adjust to milk production. A
link between housing and health during the
rearing period has been established by several
authors; Goodger & Theodore (1986), Curtis et
al. (1988), Perez et al. (1990), Olsson et al.
(1994) and Svensson et al. (2000a) found group
housing to be a risk factor for disease, while
Simensen (1982) reported conflicting results.
Furthermore, it has been shown that heifers
suffering from a high incidence of disease as
young calves have an increased risk of disease
later in life, as well as a higher age at first
calving (Waltner-Toews et al. 1986a). Correa et al.
(1988) found that heifers that were healthy as
calves were twice as likely to calve and calved
6 months earlier compared with calves that had
suffered from respiratory disease during their
first 90 days of life. Raising replacement heifers
in such a manner that they will give birth for the
first time around 24 months of age has been
found to reduce production costs (Radostits et
al. 1994). Mourits et al. (2000) estimated the
optimal average age at first calving, from an
economic point of view, to be 20.5 months in
Holstein animals in Pennsylvania. None of
these rearing aims are possible without optimal
rearing conditions. It has been shown that
management throughout the rearing period
influences the longevity of the dairy cow and
thereby the total herd economy (Drew 1998). In
order for veterinarians and other advisors to be
able to adapt their guidance to the situation on
the individual farm, it is important to know
which routines are used for management of
replacement heifers on that farm. The aim of this
study was to provide a comprehensive view of
the housing systems and the feeding and
management routines used for replacement heifers
in Swedish dairy herds.
Materials and methods
A questionnaire was sent to 1500 dairy herds,
randomly selected among all herds in Sweden
that had 28-94 cows and were registered in the
official milk-recording programme. A cover
letter explaining the purpose of the project was
enclosed. The letter assured the farmers that
they answered anonymously and that the
answers were to be treated confidentially. To those
not returning the questionnaire, a first reminder
was sent after one month and a second and final
reminder after another month.
The questionnaire comprised 71 questions, and
dealt with 7 sections. All questions referred to
the routines used in the herds during 1998. The
first section gathered general information about
the herd, sections 2 to 4 information about
routines from birth to first calving, and the last 3
sections emphasised routines at breeding and
calving, and during the grazing period. The
questions were of multiple-choice type (46) or
were semi-closed questions (25). Before the
questionnaire was mailed it was examined by 5
veterinarians and one agronomist. The
questionnaires returned were individually examined
for aberrant results, and the answer was
marginally excluded when a question seemed to
have been misunderstood. Geometric means,
standard deviation (SD) and range or median
and 80% central range (CR, i.e. excluding 10%
at each end of the distribution) were produced
using Microsoft Office Excel 2000.
were returned. Despite all questionnaires not
being completed by all farmers, most questions
(79%) were answered by most of the responders
(98%). The lowest answer (...truncated)