Although cows are social animals, they compete for access to resources, such as food and lying areas. This competition can lead to stress responses, and dairy cows, especially high-producing cows, may find themselves in a trade-off situation between lying and eating if they are under time constraints. If the total lying time is below 10 hours per day the cow might be in lack of time. She will eat less when pressed for time, and consequently produce less milk. To provide the high-yielding dairy cow with proper working conditions she should have free access to feed and resting areas, and it is important to limit waiting time before milking. Farmers seem to have little knowledge of the cows’ time budgets. However, there are tools available on the market for recording of lying behavior.
To increase the production life time yield of the cow there will most likely be a need to respond to an increased demand for space, less competition for access to resources and ways to avoid that cows spend too much time standing and waiting for access to the milking parlour.
Optimal working conditions – for the cow
The critical factors of the cow’s well-being are relate to whether or not she can fulfill high priority behavior like resting, lying and social contact, and whether she can avoid fear, pain and discomfort. During the working day, the dairy cow has to convert feed resources into milk, and the efficiency of this process is central to both profitability and sustainability. The time budget – the allocation of time to different activities - can vary considerably depending on the environment, management and status of the cow. The cow has only 24 hours available per day, so it is important to make sure that she has enough time to do her work, to convert feed into milk.
Time budgets and priorities
The ranked priorities for the various behaviours of the dairy cow are: lying, then eating, followed by social contact. As an example, cows in an average free stall commercial herd in Denmark spend their 24 hours per day on the following activities: 10,8 hours lying down, 5 hours feeding, 2,9 hours standing in the aisles, 2,9 hours standing in the cubicles 1,9 hours in feed areas, and 0,5 hours milking.
A high feed intake, particularly in the first part of the lactation, is very important in order to obtain high milk yield and to avoid production diseases. Time spent feeding typically varies between 3 to 6 hours per day in lactating dairy cows. The composition of the diet, particularly the energy density, strongly affects the time needed for consuming any given amount of food.
Lying behaviour is a high priority behaviour for the dairy cow, and if her lying behaviour is constrained it can lead to both behavioural and physiological stress responses, for instance a reduced growth hormone level. If the total lying time is below 10 hours per day the cow might be in lack of lying time and get stressed. There is also a relationship between lameness and long lying bouts, where lame cows tend to lie longer.
Milk yield and time budget
A high-producing cow has an increased need for energy intake. This can be obtained by increasing the energy density in the diet, but in order to keep a healthy digestive system cows need some structure in the diet and there is a limit to how concentrated the diet can be. High producers need more time for feeding, and consequently there is less time left for other activities such as lying. Under time constraints, cows are willing to give up some feed intake in order to maintain lying time, showing that constraints on the high priority behaviour can lead to a reduction in feed intake and milk yield. This can in turn lead to increased loss of body weight and consequently an increased risk of production diseases.
Competition and access to resources
Cost of buildings can be a limitation to the amount of space and other resources like cubicles and feeding places that are available per animal, with the result that the cows have to compete for access to resources like food, water and resting areas. Social stress or a combination of social stress and restricted access to important resources, can affect both the welfare of the animals and the production, including the efficiency of converting feed to milk.
In a group of cows there is a hierarchy based on dominance relationships between pairs of cows. On larger farms cows are often moved between groups to optimize feeding or monitoring. Such regroupings are usually associated with increased aggressive interactions in order to establish new dominance relationship. This can also increase the risk for injuries and it can also lead to decreased lying time. Several studies have reported a decreased milk yield lasting for days to several weeks. There is a large individual variation between cows and there seems to be less strong response when cows were regrouped later in lactation. More space and easy access to resources are expected to reduce the negative effects of regrouping.
Access to lying area
Lying behaviour has high priority in dairy cows, and lying takes up almost half the 24 hour time budget. A number of studies have shown that increased stocking density to more than one cow per cubicle leads to reduced lying time, increased aggression, increased abnormal behaviour and increased risk of especially low ranking cows lying in the alleys. Short lying time and increased time spent in the alleys can increase the risk of claw diseases.
Access to feed
If feed is delivered in restricted amounts, there should be at least one feeding place per cow, otherwise there is a great risk that some cows will not get access to the feed at all. Although many dairy cows have free access to feed, a number of studies have shown that competition at feeders leads to increased displacement and reduced times spent eating. Cattle can compensate for a shorter eating time by increasing the feeding rate, so stocking density can be more than one cow per feeding place without decreasing feed intake, but subordinate cows might in this case have a reduced feed intake.
Measure effects of changes
Farmers have very little knowledge of the cows’ time budgets, as it can be difficult to make an assessment. However, there are tools available, e.g. devices for recording of lying behavior.
There is a lot of existing knowledge about cows’ time budgets and behavior, and if there can be a development towards a system where even more knowledge from the large amounts of data available on a farm can be processed, this kind of system could be a good support for farmers in making management changes. It could for instance be possible to measure the effects of changes in the energy density in the diet on lying behaviour, or the effect on waiting time of moving from milking twice per day to three times.
- Limit waiting time before access to the milking parlor for high producing cows
- With increased milk yield cows have less spare time; the barn design should allow easy access to food and lying area
- Total lying time below 10 hours per day suggest that the cow is in lack of lying time
- Devices for on-farm automatic recording of lying behavior are available