Livestock Production Science 65 2000 131–142 www.elsevier.com locate livprodsci
Effect of sward height and distance between pasture and barn on cows’ visits to an automatic milking system and other
behaviour
a , a
a a
C.C. Ketelaar-de Lauwere , A.H. Ipema , C. Lokhorst , J.H.M. Metz ,
b c
a
J.P.T.M. Noordhuizen , W.G.P. Schouten , A.C. Smits
a
Institute of Agricultural and Environmental Engineering IMAG, P.O. Box 43, NL-6700 AA Wageningen, The Netherlands
b
Department of Ruminants ’ Health Care, University of Utrecht, P.O. Box 80151, NL-3508 TD Utrecht, The Netherlands
c
Department of Animal Sciences , Ethology Group, Wageningen Agricultural University, P.O. Box 338, NL-6700 AA Wageningen,
The Netherlands Received 9 February 1999; received in revised form 24 August 1999; accepted 1 November 1999
Abstract
Two experiments were conducted to study the effects of sward height experiment I and the distance between barn and pasture plot experiment II on cows’ visits to an automatic milking system AMS and other behaviour. The study was
carried out in a situation in which grazing was combined with fully automatic milking. The cows had to visit the system voluntarily without interference of the farmer. The AMS was continuously available in the barn adjacent to the pasture. The
pasture was divided into ten plots of 1 ha for the two experiments and the preceding habituation. The same group of 24 Holstein Friesian cows was used in both experiments. The cows were allowed to spend up to 15 h at pasture daily. The
results of experiment I rotational grazing showed that the total number of AMS visits increased from 4.4 to 7.3 and that the number of milkings increased from 2.6 to 3.0 when sward height decreased P , 0.01. The results of experiment II strip
grazing showed that a distance of 360 m between pasture and barn did not affect the cows’ visits to the AMS. In both experiments, cows preferred to lie in the pasture, when available, rather than in the cubicles, and tended to visit the barn
group-wise and to enter the AMS in close succession. As a consequence, in the period that the cows had access to the pasture there were peaks in AMS visits, and the AMS was unvisited for several hours.
2000 Elsevier Science B.V. All rights
reserved.
Keywords : Automatic milking; Grazing; Sward height; Distance; Cow behaviour
without human interference in an automatic milking
1. Introduction
system AMS with a milking robot is rising steadily Rossing et al., 1997. Many farmers considering
The number of dairy farms where cows are milked changing from milking in a milking parlour to fully
automatic milking want to be able to allow the cows
Corresponding author. Tel.: 131-317-476-543; fax: 131-317-
to graze during the summer De Boer et al., 1994,
425-670.
as this reduces feeding costs and labour and is often
E-mail address : c.c.ketelaar-delauwereimag.wag-ur.nl C.C.
Ketelaar-de Lauwere
seen as a period of recovery for the cows Hopster,
0301-6226 00 – see front matter
2000 Elsevier Science B.V. All rights reserved. P I I : S 0 3 0 1 - 6 2 2 6 9 9 0 0 1 7 5 - X
132 C
.C. Ketelaar-de Lauwere et al. Livestock Production Science 65 2000 131 –142
1996. It is known that the behaviour of cows at experiment started one month after the first. At the
pasture is affected by many factors, such as seasonal beginning of this experiment one third lactation cow
variation Krohn et al., 1992; Rook and Huckle, had to be culled for reasons of udder health.
1996, either very warm Muller et al., 1994; Mader The experimental facilities consisted of an open
et al., 1997 or very cold weather Dunn et al., 1988; barn with a lying area with 30 cubicles and a
Prescott et al., 1994, sward height Phillips and separate feeding area with 12 feeding places Fig. 1;
Hecheimi, 1989; Rook et al., 1994, concentrate for more details, see Ketelaar-de Lauwere et al.,
supplementation Rook et al., 1994 and forage 1999. The barn was adjacent to a pasture of
supplementation Phillips and Leaver, 1986; Phillips approximately 10 ha, which was divided into ten
and Hecheimi, 1989. However, little is known about plots of 1 ha. All plots were connected to a 4-m wide
factors affecting the behaviour of dairy cows in a central alley, leading to the barn. The plots differed
situation in which grazing is combined with fully in distance to the barn, which was measured from the
automatic milking. The novel element in such a centre of the plot to the entrance of the barn Fig. 2.
situation is that cows at pasture have to return to the The central alley of the plots led to a collecting area
2
barn by themselves several times per day, to be of approximately 48 m
in front of the barn. To milked in the AMS. It seems likely that the amount
reach this collecting area, cows had to pass through a of grass in the pasture and the distance between the
one-way gate. From this area, they could enter the barn with the AMS and the pasture may play a role
barn. Cows wishing to leave the barn had to pass in a situation in which grazing and fully automatic
through a selection gate with its entrance in the milking on a voluntary basis are combined. It can be
feeding area. When a cow arrived at this selection expected that cows will return to the barn more often
gate, she was identified by computer. If she had been if the sward is short, and extra forage is sup-
milked more than 6 h ago, the selection gate plemented in the barn. Conversely, if there is plenty
automatically moved in such a position that the cow of grass in the pasture, cows may be reluctant to
was diverted back to the lying area, giving her a new return to the barn, so there will be fewer visits to the
chance to visit the AMS. If she had been milked AMS. Distance between the barn and the pasture
more recently, she could leave the barn via a passage may also influence frequency of AMS visits. This is
along the barn to the central alley of the plots. Water a point of concern in practice because on many farms
troughs were located in the barn, but not in the plots the barn and the pasture are not adjacent.
Fig. 1. In the experiments described in this paper, the
Throughout both experiments, the cows were fed effects of the sward height and the distance between
at a constant level. They daily received 440 kg maize the barn and the pasture on the cows’ visits to the
silage on a dry matter basis in the barn. The forage AMS and associated behaviours were tested, in order
was supplied at 08:30 and 20:15 h and raked up at to determine the feasibility of combining AMS with
13:00 h. Concentrate was dispensed during milking grazing for both the farmer and the cow.
in the automatic milking system AMS. First lacta- tion cows received 1 kg of concentrate, and multi-
parous cows 1.5 kg per milking. The system con-
2. Material and methods sisted of two milking stalls and a robot arm equipped
