respect to leg injuries located in the tarsal joints. q 2000 Elsevier Science B.V. All rights reserved.
Keywords: Cattle housing; Cubicle system; Soft mats; Cow comfort; Lying behaviour; Leg injuries
1. Introduction
In Switzerland, direct payments are given to farmers keeping dairy cows in housing systems that are especially adapted to the animals’ behavioural needs. The government
Ž .
has launched two programmes Meier, 1999 for housing systems corresponding to defined standards which exceed the minimal requirements for the housing of farm
animals as laid down in the Swiss animal welfare legislation. The first programme Ž
. promotes regular access to pasture and outside yards in wintertime for both cows kept
in loose housing systems and cows kept in tie stalls. The second programme focuses on indoor housing systems that are divided into at least two areas with different floor
qualities and provide the animals with a comfortable lying area. The participation in the second programme requires that the cows have access to a lying area with a high-quality
Ž .
straw bedding i.e. a compact mattress composed of straw and cow dung or with another surface equivalent to such straw bedding for them. In this context, farmers and
manufacturers raised the question whether soft lying mats in cubicle systems can be considered equivalent to straw bedding.
It is well known that dairy cows given a choice between different types of lying area Ž
surfaces prefer soft materials Lasson and Boxberger, 1976; Natzke et al., 1982;
. Gebremedhin et al., 1985; Jensen et al., 1988; O’Connell et al., 1992; Herlin, 1997 . If
Ž cows are forced to lie on hard surfaces, they spend less time lying per day Andreae and
. Papendieck, 1971; Natzke et al., 1982; Oertli et al., 1995 and show a reduction in the
Ž .
number of lying bouts per day Oertli et al., 1995 . A less comfortable lying area surface also results in an increase in the preparation time required by the cows to lie down
Ž .
Ž .
Herlin, 1997 and in a longer duration of lying down movements Oertli et al., 1995 . Finally, the quality of the lying area surface was found to be related to the incidence of
Ž leg injuries in dairy cows kept in cubicle systems Molz, 1989; Zerzawy, 1989; Oertli
. et al., 1995 .
The aim of the present study was to investigate whether, in cubicle systems for dairy cows, soft lying mats can be considered equivalent to straw bedding regarding animal
Ž . welfare. To assess this, we collected data on 1 lying down and standing up behaviour,
Ž . Ž .
2 total duration of lying behaviour per 24 h, 3 the number and duration of lying bouts Ž .
and 4 the incidence of leg injuries in dairy cows kept on commercial farms.
2. Methods
2.1. Animals and housing conditions The study was carried out on 18 farms with cubicle systems for dairy cows. There
Ž were five farms with a compact mattress composed of straw and cow dung straw
. bedding and 13 farms using four types of soft lying mats consisting of different
Ž .
materials Table 1 . The proportion of farms with straw bedding and soft lying mats, respectively, chosen for our study does not reflect the proportion of Swiss farms with
straw bedding and soft lying mats. Straw bedding is widespread in cubicle systems whereas lying mats were rarely used at the time of data collection. When designing the
study, we decided that a given type of soft lying mat would only be included if the manufacturer could indicate at least three farms using his product and that we would
collect data on five farms using straw bedding. Brown Swiss was the prevalent breed Ž
. Ž
. Ž
. 77 of the cows , other breeds were Holstein-Friesian 9 , Red Holstein 8 and
Ž .
Ž .
Swiss Simmental 6 . Herd size Table 1 did not differ significantly between farms Ž
with straw bedding and farms with soft lying mats Mann–Whitney U-tests: N s 5,
1
. N s 13, U s 18.5, P s 0.16
2
To be included in the study, the lying area in the cubicles of a given farm had to be at least 120 cm wide and 185 cm long, and the cubicles had to provide ample additional
Ž .
space minimum 45 cm in front of the lying area allowing unhindered lying down and standing up behaviour of the cows. The number of cubicles in the stable had to be at
least equal to the number of cows present in the housing system. In addition, the lying Ž
area surface in all cubicles of a given farm had to be of the same defined type see Table .
1 and had to be provided to the cows at least 3 months before the beginning of the data-collection period. There was no systematic difference in the cubicle dimensions
between farms with straw bedding and farms with soft lying mats. On most farms, small Ž
. amounts of litter chopped straw or sawdust were provided on top of the soft lying
mats. To exclude that access to pasture had an influence on lying behaviour and leg
Table 1 Description of the lying area surfaces tested, number of farms involved in the study and average number
Ž .
range of cows per herd Lying area surface
Description No. of farms
Average herd size Ž
. Straw bedding
Compact mattress 5
33 24–42 composed of straw
and cow dung Ž
. CowComfort
Foamed polyurethane 3
19 16–24 Ž
. thickness 20–30 mm
Ž .
Kraiburg Conventional rubber
4 20 14–28
Ž .
mat thickness: 18 mm underlaid with foam
Ž .
rubber thickness 25–30 mm Ž
. Ž
. Mouflex
Tubes diameter: 16 cm 3
26 20–33 made of nylon and filled
with granulated rubber Ž
. Ž
. Pasture
Tubes diameter: 5 cm 3
44 34–53 made of polypropylene
and nylon, filled with granulated rubber
and covered with a layer of polypropylene
Ž .
injuries, data were collected in the winter from December to March . Cows suffering from a disease and cows kept for less than 3 months in the cubicle system were not
considered.
2.2. Lying down and standing up behaÕiour On each farm, focal animal observations of the behaviour of at least 20 cows lying
Ž .
Ž .
down range 20–30 movements and 20 cows standing up range 20–30 movements in a cubicle were made. Cows were chosen as focal animals in the sequence they showed
such movements during the data collection periods. As a consequence, a given animal could be recorded more than once. Cows which were to give birth within a few days or
had given birth a few days ago were excluded from data collection. Both the frequency
Ž of behavioural elements indicating difficulties in lying down intention movements
before lying down, standing up again after the start of a lying down movement, slipping .
Ž while lying down or standing up crawling before standing up, breaks in the standing up
. movement, slipping while standing up and the duration of these two types of behaviour
were recorded. Lying down started when the cow descended to one of the forelegs and ended when the whole body touched the ground. Standing up started when the cow
made a first movement to raise the forelegs and ended when she stood on all four legs.
2.3. Lying behaÕiour On each farm, the lying behaviour of 10 cows chosen at random was recorded
automatically during 3 days by means of a pneumatically operated resting sensor fitted Ž
. in a belt Hauser et al., 1999 . Cows not in lactation and cows in heat were excluded
from data collection. The belt was fixed around the front part of the cow’s body, just Ž
. behind the forelegs. During a period of 72 h, the position of the cow standing or lying
was recorded automatically every 16 s by means of a switch reacting to changes in the Ž
. air pressure in a tube PVC fitted in the belt. Recordings of all 3 days of data collection
were stored in a data logger fixed to the belt. To habituate the cows to the belt, it was put on 4–6 h before the programmed start of data collection. On all farms, recordings
started in the evening with the beginning of the milking period. Data were transferred to a PC and analysed by means of MS Excel. For each cow, the average number of lying
bouts per 24 h, the mean duration of lying bouts and the average total duration of lying behaviour per 24 h was calculated.
2.4. Leg injuries Ž
On each farm, the skin of the foreleg joints and the hind leg joints of all cows except those suffering from a disease and those kept for less than 3 months in the cubicle
. system; see above was checked once for leg injuries. The following four categories of
injuries were differentiated: hairless patches less than 2 cm in diameter, hairless patches more than 2 cm in diameter, scabs or wounds less than 2 cm in diameter, scabs or
wounds more than 2 cm in diameter. A total of 463 cows were examined on all farms. In
the analysis, the sum of injuries found in all cows checked on a given farm was calculated separately for each joint. As the number of cows differed between farms, data
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were standardised incidence per 100 cows for the statistical analysis. 2.5. Statistical analysis
The farms were treated as independent observational units. As a consequence, average values per farm were calculated regarding lying behaviour and leg injuries.
Ž . Nonparametric statistics were used. It was tested a
whether farms using cubicle systems with straw bedding differed significantly from farms using cubicle systems with
Ž .
Ž . soft lying mats Mann–Whitney U-tests; Siegel and Castellan, 1988 and b whether
there was a significant inhomogeneity in the data collected on farms using different Ž
. types of soft lying mats Kruskal–Wallis tests; Siegel and Castellan, 1988 . The alpha
Ž .
level was therefore adjusted to 0.025 Bonferroni correction .
3. Results
