Dairy cow

The working day of a dairy cow

Although cows are social animals, they compete for access to resources, such as food. This competition can lead to stress responses, day of high producing cows. They may find themselves in a trade-off situation between lying and eating if they are under time constraints. They will eat less when pressed for time, and consequently produce less milk. It is important to try and limit waiting time before milking for high producing cows.

With increased milk yield cows have less spare time. To provide the high producing dairy cow with proper living conditions, she should have free access to feed and resting areas. If the total lying time is below 10 hours per day the cow might be in lack of lying time.

Milk yield based on very simple aspects cow 50% + Feed 25% + comfort 15% + milking 5% + others 5%

There is a relationship between lameness and long lying bouts, where lame cows tend to lie longer. 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.

(This article belongs to the proceedings from the Ref=”http://www.delaval.com/en/About-DeLaval/Cow-Longevity-Conference/”>Cow Longevity Conference 2013; that took place at Hamra farm, Sweden in August 2013)

Day of Dairy cow

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 suggests that the cow is in lack of lying time. Devices for on-farm automatic recording of lying behavior are available. With a cow’s eye view of barn design, critical factors are most likely related to whether or not the cow can fulfil high priority behavior and avoid fear, pain and discomfort.

Behavioral priorities depend on both internal and external factors, and in dairy cows’ internal factors such as milk yield and age can affect both feeding and lying behavior. The yield of cows increases with age, especially from first to second and third parity. Thus, increased production life time yield is expected to increase the proportion of cows in second and later lactations and this may change the demand to the barn design and management.

Cattle are light-active animals; therefore, foraging and social behaviors occur mainly during daytime while they show less activity during the dark hours. However, cattle also rest during the daytime; typically, the activities alternate between eating and lying with shorter periods of search for the most attractive food and resting areas as well as social behaviors in between periods of eating and lying.

Dairy cows are social animals and many dairy cows live in groups either in loose housing systems or at pasture. Therefore, cows have to compete with the group members for access to resources like food and lying areas. The time budget – the allocation of time to different activities – can vary considerably depending on the environment, management and status of the cow. However, time is a limited resource for the cow, and like all other living creatures, the dairy cow has only 24 hours per day to allocate to different activities.

During the working day, the dairy cow has to convert feed resources into milk. The efficiency of this process is central to both profitability and sustainability. In this paper, I discuss how cows prioritize their time; how the level of milk yield and the time budget interact and how competition can affect the time budget.

Important activities in the day of dairy cow

Feed intake

A high feed intake, particularly in the first parts of lactation, is very important to obtain high milk yield. To avoid production diseases (Ingvartsen et al., 2003). 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. One kg of concentrate is typically consumed within 3 to 4 minutes while it takes about half an hour to eat one kg of hay. Likewise, cows fed a low concentrate diet for ad libitum intake spend more time eating compared to cows fed rations with higher energy density.

TMR

TMR is formulated with a vitamin mineral supplement based on alfalfa grass, sweet potato, cornmeal, soybean meal, molasses and dry matter (DM) in a ratio of 40:30:18:9:2:1, respectively. Total mixed ration moisture was then adjusted to 60% humidity (medium, M-TMR) TMR and 75% (high, H-TMR) TMR by adding sterilized water content.
However, high moisture content and prolonged storage time can cause excessive acidification of TMR, which reduces palatability and reduces livestock intake. TMR’s high moisture content also promotes the growth of unwanted microbes, including aerobic bacteria and molds.

Lying behavior

Lying is a high priority in dairy cows, and thwarting of lying can induce both behavioral and physiological stress responses, for instance reduced growth hormone level and changes in the sensitivity in the hypothalamus-pituitary adrenal axis (Munksgaard & Simonsen, 1996; Munksgaard & Løvendahl, 1993; Fisher et al., 2002).

Lying requirements of dairy cattle have been studied in a series of experiments by estimating demand functions based on price elasticity. The results suggest that dairy heifers of about 400 kg have an inelastic demand for lying at about 12-13 hours per day. In another study, time constraints were used to estimate the relative priority between lying, eating and social behaviors; i.e. dairy cows were deprived of lying, eating and social contact for either 9 or 12 hours per day compared to a control treatment.

Time constraint reduced the absolute amount of time spent on each of the behavior’s measured. However, the proportion of time spent lying increased, whereas the proportion of time spent eating remained similar to non-constrained cows. This result suggests that the ranked priority for the various behaviors would be: first lying, then eating followed by social contact. This is based on the assumption that compensatory mechanisms for each activity under time constraints are similar. However, food intake can be maintained under constraints by a variety of mechanisms (e.g., increased intake rate, increased bite size). whereas it is more difficult to imagine alternative mechanisms for maintaining rest or social contact under constraint. Previous studies have shown that both competition and restriction of the amount of food offered can increase the rate of feed intake in dairy cows (Nielsen, 1999).

Milk Yield and Time Budget of Day of dairy cow

Milk yield based on very simple aspects cow 50% + Feed 25% + comfort 15% + milking 5% + others 5%

When the cow produces more milk, she has an increased need for energy intake. To some degree, increased energy intake can be obtained by increasing the energy density in the diet. However, in order to keep a healthy digestive system, cows need some structure in their diet. Thus, there is a limit to how concentrated the diet can be. Furthermore, cows may become more effective in consuming their feed. For instance, there is some evidence that with increasing yield cows become more effective at eating; e.g., Bao et al. (1992) found that grazing time and biting rate correlated positively with genetic merit, and in another Irish study, high merit Holstein cows had higher biting rates (O’Connell et al. 2000).

Even though there are different strategies that cows may use to cope with an increased need of energy, it is likely that high producers need more time for feeding and consequently, there is less time left for other activities such as lying.

Under housed conditions, both in tie-stalls and in cubicles houses, there is some documentation that increased yield leads to a reduced lying time (Norring et al., 2012; Fregonesi and Leaver, 2001; Bewley et al., 2010). Under commercial conditions in Denmark in a loose housing system with cubicles (one cubicle per cow, one eating place per cow), we found a negative correlation between lying time and eating time and also that lying time as well as time in cubicles were negatively correlated with yield in first lactation Holstein cows (Løvendahl & Munksgaard, 2004). This suggests that high producing dairy cows may be in a trade–off situation between eating and lying.

Genetic selection for milk yield alters the need for nutrients and thereby increases the need for time to eat, but the need for lying time is probably not affected. Thus, with further genetic increase in milk yield, cows may face an increasing deficit in their time budgets.

Increased production life time yield will most likely lead to increased demand for space, less competition for access to resources and ways to avoid cows spending too much time standing and waiting for access to the milking parlor.

Cost of Being in a Tradeoff Situation

In the study the cows compensated for the time constraint by increasing the rate of feed intake, and, therefore, the reduction in feed intake was less than the reduction in eating time. However, even though the cows increased the rate of feed intake, they did not fully compensate for the time constraint.

In fact, the cows allocated relatively more time to lying at the expense of feed intake. This was not due to limitations in physical or metabolic capacity, since in another experiment using a similar total mixed ration, cows that were not restricted in resting and social contact-maintained feed intakes when restricted to 12 hours access to feed. Thus, these results suggest that under time constraints, cows are willing to give up some feed intake in order to maintain lying time. Therefore, constraints on the high priority behaviors can lead to a reduction in feed intake and milk yield. Furthermore, this may lead to increased loss of body weight and thus an increased risk of production diseases.

Furthermore, when cows are in a trade-off situation between two important behaviors such as lying and feeding, this may lead to frustration, which can induce stress responses. It is well known that stressors induce changes in the metabolism towards energy mobilization. Activation of the hypothalamic-pituitary-adrenal axis (HPA-axis) is one of the primary adaptive mechanisms in response to stressors, and there is growing evidence for a close link between metabolism and stress responses especially in rodents (Dallman et al., 2003

Increased HPA-axis activity during stress induces gluconeogenesis, resulting in more glucose being available for metabolism in the CNS (Moberg, 1985, Peters, 2011). Repeated deprivation of lying in dairy cows changes the functioning of the HPA-axis (Fisher et al., 2002 Munksgaard & Simonsen, 1996), but there is a lack of knowledge on the effects of stressors on energy metabolism in dairy cows. Traditional measures of energy metabolism are difficult to obtain simultaneously with observations of behavior, as frequent blood sampling affects the time budget of the animals. However, new studies (Larsen, personal communication) have identified milk iso-citrate and free glucose as promising biomarkers for physiological imbalance; milk β-hydroxybutyrate also increases significantly during feed restrictions in early lactation (Bjerre-Harpøth et al., 2012). These milk-based measures of energy metabolism can be collected non-invasively, without disrupting the cows, thus providing insight into physiological changes associated with behavioral trade-offs.

COMPETITITON AND ACSESS TO RESOURCES

Cattle are social animals. Therefore, cows prefer to stay in a group of conspecifics, and social isolation induces both behavioral and physiological stress responses. However, cattle also need social space; they attempt to keep an individual distance from other animals.

Competition for access to resources is a much more common event in dairy production than social isolation, since the cost of buildings typically limits the amount of space and number of resources (cubicles and feeding places) available per animal so 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, such as feed and resting areas, can affect both the welfare of the animals and production, including the efficiency of converting feed to milk.

REGROUPING

In each group of cows, there will be a hierarchy based on dominance relationships between pairs of cows. In modern dairy production with larger farms, cows are often moved from one group to another group of cows to optimize for instance feeding or surveillance. However, due to the organization of social behavior in groups of cattle, such regroupings are usually associated with increased agonistic interactions in order to establish new dominance relationships. This can also lead to an increased risk of injuries caused by butting and claw lesion due to sudden movements or slipping (EFSA, 2009). Furthermore, regrouping can lead to decreased lying time (Hasegawa et al. 1997, Phillips and Rind, 2001)

Several studies have reported a decreased milk yield lasting for days to several weeks (Arave & Albright, 1976, Brakel & Leis, 1976, Hasegawa et al, 1997, Phillips and Rind, 2001) although some studies did not find any effect on milk yield. In a newer study, in a robotic milking system at the Cattle Research Centre in Foulum, we found that regrouping one cow at the time in early lactation decreased milk yield during the first three weeks after relocation (Munksgaard & Weisbjerg, 2009). Furthermore, we saw very large individual variation between cows, and a less strong response when cows were regrouped later in lactation.

The effects of regrouping on both behaviors and milk yield are most likely affected by the status of the cow(s) that are regrouped, space allowance and ease of access to resources. More space and easy access to resources are expected to reduce the negative effects of regrouping. However, even though one could argue that regrouping should be avoided whenever possible there can be other factors that advocate for regrouping such as homogenizing the group with respect to nutritional or housing requirements. There is only very limited information for balancing the pros and cons in terms of profitability and cow longevity when farmers have to take decisions on whether or not to regroup cows.

ACCSESS TO LYING AREA

Lying behaviors 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 behaviors and increased risk of especially low ranging cows lying in the alleys (Friend et al., 1979; Short lying time and increased time spent in the alleys can increase the risk of claw diseases (Dippel et al., 2005). In one older study, the stocking density was reduced to less than one cow per cubicle (0,5 cow/cubicle), and the lying duration increased by 20 to 30 minutes

ACCSESS TO FEED

Feeding behavior is synchronized, and when fresh feed is delivered, most if not all cows will approach the feeders or feed bunk. If feed is delivered in restricted amounts, there should be at least one 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 are fed ad libitum, a number of studies have shown that competition from feeders leads to increased displacement and reduced times spent eating. However, as cattle can compensate for a shorter eating time by increasing the feeding rate, stocking density can be more than one cow per feeding place without decreasing feed intake. However, subordinate cows might have reduced feed intake.

Furthermore, when all cows are not able to eat at the same time sorting in the food may change the composition of the diet for those cows that do not have immediate access to the feed.

Even though it is relatively well documented that stocking density can have substantial effect on the behavior of dairy cows, much less information is available on the effects on profitability.

SUMMARY day of dairy cow

Cows are social animals but they compete for access to resources. Competition can induce stress responses, and under time constraints especially high producing dairy cows may be in a trade-off situation between lying and eating. To provide the high-producing dairy cow with proper working conditions she should have free access to feed and resting areas. Furthermore, regrouping should be avoided or at least balanced against positive effects of regrouping.

References of Day of dairy cow

• Arave, C.W. & Albright, L.L. 1976. Social rank and physiological traits of dairy cows influenced by changing group membership. J. Dairy Sci. 59, 974-981.
• Bao, J., P.S. Giller and J.J. Kett, 1992. The effect of milk production level on grazing behavior of Friesian cows under variable pasture conditions. Irish J. Agric. Food Res. 31: 23-33.
• Bewley, J.M., R.E. Boyce, J. Hockin, L. Munksgaard, S.D. Eicher, M.E. Einstein, and M.M. Schutz. 2010. Influence of milk yield, stage of lactation and body condition on dairy cattle lying behavior using an automated activity monitoring sensor. J. Dairy Res. 77: 1-6.

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