Comfortable Housing for Cattle Used in Research

Introduction
Cattle are social animals forming hierarchies based on dominance relationships among herd members. The grass field is the most species-appropriate environment for them (Figure 1).

In captivity, cattle spend 2-5 hours per day foraging and 4-8 hours ruminating, depending on the composition of the feed ration and the animals' age/size. Lying has high priority and the animals rest approximately half of the day in a recumbent position. Under unrestricted conditions, as for instance on pasture, cattle will walk 2-5 km (1-3 mi.) per day.

Laboratory cattle are mainly used for the purpose of obtaining better knowledge about their behavior and physiology. The ultimate objective in cattle research is to increase productivity and reproduction under farming conditions. Cattle in experiments are often kept on traditional farms.

Housing systems
Cattle can be housed under very different conditions. The welfare of the animals in a given system will depend on details in design.

The feed manger must be placed at least 5-20 cm (2-8 in.) above floor level to allow easy access to the food (Figure 2). The back of the manger must be low enough so that it does not hamper the species-typical range of action during feeding (Figure 3) and the forward movements of the animal when getting up (Figure 4).

In the group-housing system there must be enough feeding space so that all animals can eat at the same time. The width of the individual eating place must correspond to the size of the animals and the size of their horns. Adequate bars to separate cows and reduce competitive interactions at the manger are important. Feeding barriers which can separate and restrain the animals at the manger can be used with advantage during handling procedures. However, restraint should be avoided as far as possible (Editor's note: With patience and gentle firmness cattle can readily be conditioned to allow routine procedures such as blood collection and injection without being restrained and without showing signs of stress.)

Cows have a fairly constant need for rest (Figure 1). The resting area should be relatively soft and well heat-insulated to account for the fact that the animals spend a major portion of the time lying. Therefore, all animals should have free access to comfortable resting sites on a bedded floor at all times. Straw bedding is a species-appropriate resting material for cattle and should be used whenever possible (Figure 5).

Group-housed animals must have sufficient space allowance to avoid agonistic conflicts arising from situations in which rank-dependent social spacing is impossible. There should always be at least one lying place (e.g., one cubicle) and one eating place per animal in order to forestall competition and minimize aggression. (Editor's note: Stable social relationships are a prerequisite that members of a group/herd of cattle get along well with each other. A group's composition should therefore not be changed unless there is a specific veterinary reason).

It is extremely important to make sure that the walking areas are dry and not slippery so that the animals can walk without the risk of losing their balance and possibly injuring themselves. Walking areas used as traffic and exercise areas should be wide enough for the animals to freely pass one another. Competition exists around food and water, therefore these sites should allow enough space for avoidance.

The dimensions of cubicles and tie-stalls must meet the cow's spatial requirements when she stands and lies and when she is getting up or lying down. It should be remembered (Figure 4) that cattle need free space in front of them so that the whole sequence of the getting-up behavior can take place unhampered.

In tied cattle, the tether design must allow the animal free forward and backward movements when rising and lying down (cf. Figure 4). Furthermore, the tether must give the cow sufficient leeway to lick herself over most of the body without being forced to assume unnatural positions with the risk of falling or slipping. Also, the cow should be able to: a) eat in a natural position, b) assume a species-typical resting posture when lying as well as when standing, and c) step backwards during defecation and urination in order to avoid dung in the stall. Tethered cows should have daily access to a suitable exercise area to enhance their welfare.

Cattle have a need for social contact. Short-term social isolation of cows induces an increase in heart rate, an elevation of plasma cortisol concentration, and increased vocalization (Hopster et al. 1993) indicating that the situation is stressful. Results by Munksgaard and Simonsen (1996) suggest that long-term social isolation is also aversive to cows (Editor's note: Group-housing is strongly recommended to account for the animals' social disposition and to provide optimal methodological conditions for the collection of research data that are not biased by stress. Single-housing, e.g., tie-stall systems, should be avoided for ethical and scientific reasons.)

Nutrition
Cattle are ruminants, which means that they chew their feed twice. At first the feed is only chewed slightly and swallowed together with relatively large quantities of saliva. When the stomach is full, the animal will often lie down and start ruminating: The feed is regurgitated and chewed up again whereupon it is swallowed. Ruminants are furthermore characterized by a gastric system containing a large fermentation chamber, the rumen, where microorganisms facilitate the digestion of cellulose and other fibrous parts of the food.

This special digestive system implies that from the age of 2-3 weeks calves need fibrous feedstuffs (grass, hay, silage, straw, etc.). When the rumination process is fully developed at the age of eight weeks, the feed for cattle ought to include at least 20% fibrous material and preferably more. The lack of structural feed or extremely restrictive feeding may cause the development of oral stereotypies such as tongue rolling and bar-biting due to frustration or thwarting of foraging and ruminating behavior (Redbo 1992; Saville 1985). Free access to roughage is therefore essential for the welfare of cattle.

The requirements for fluids in cattle are relatively high. Even calves given milk during the first 6-12 weeks of life need free access to water. The young calf has a very high suckling motivation which is particularly stimulated by the taste of milk (Passillé et al. 1992). Hence, it is preferable that the milk is given from a sucking pail or that the calf has "access" to a dry teat (Figure 6). The opportunity to suckle milk reduces the incidence of non-nutritive suckling on equipment and pen mates, and hence decreases the risk of the formation of bezoars (hair balls) and the development of behavioral disorders (Sambraus 1985; Wierenga 1987).

References
Hoffmann H, Rist M 1975. Tiergerecht und arbeitswirtschaftlich günstige Anbindevorrichtungen für Kühe. Schweizer Landwirtschaftliche Monatshefte 53: 119-126.

Hopster H, Blokhuis HJ 1993. Consistent stress responses of individual dairy cows to social isolation. Proceedings of the International Congress on Applied Ethology, 3rd Joint Meeting, Berlin, pp 123-126.

Mortensen B 1971. Forsøg med bindsler til køer. 1.33. SBI-landbrugsbyggeri. Statens Byggeforskningsinstiut, pp 156.

Munksgaard L, Simonsen HB 1996. Behavioral and pituitary adrenal-axis responses of dairy cows to social isolation and deprivation of lying down. Journal of Animal Science 74: 769-778.

de Passillé AMB, Metz JHM, Mekking P, Wiepkema PR 1992. Does drinking milk stimulate sucking in young calves? Applied Animal Behaviour Science 34: 23-36.

Redbo I 1992. Stereotypies in dairy cattle. Swedish University of Agricultural Science: Re- port No. 211.

Sambraus HH 1985. Zur Beurteilung von Haltungssystemen für Kälber. Tierärztliche Umschau 40: 758-767.

Saville CA 1983. The feeding behaviour of calves in different systems of husbandry. Newcastle-upon-Tyne. Applied Animal Ethology 11: 75 (Abstract).

Wierenga HK 1987. Behavioural problems in fattening bulls. In Welfare Aspects of Housing Systems for Veal Calves and Fattening Bulls, Schlichting MC, Smidt D (eds), pp 105-123, Commission of the European Communities (CEC) Seminar, Mariensee.