Much research has examined the effect of different environments on milk production and dry matter intake (DMI) of small groups of cattle over relatively short periods of time. It is our view that many of these studies have inadequately demonstrated the true impact of environmental factors on cow health by failing to monitor low rank sub-groups of the population.

In simple terms, compromised environments do not affect all animals equally. Ill health does not affect all of the individuals in a pen at the same time; rather, some cows are unaffected and perform well, while a few succumb to disease and perform poorly. Monitors based upon group average DMI and milk production are likely to miss the adverse effects on outlier cows unable to compensate in a compromised environment.

We believe to improve the health and well-being of dairy cattle in modern freestall facilities we must provide for the needs of each cow so she can behave as a herding animal - eating with the herd, resting with the herd and socializing without fear.

Grouping cows
The replacement of old tiestall barns with freestall housing has brought with it a change in the lifestyle of the dairy cow. Traditionally, the tiestall cow was milked in the stall, fed in the stall, drank water from a cup in the stall and stood and lay down in the stall, as she required. In most situations, cows were allowed outside of the barn for two to four hours per day for exercise and to display signs of heat. Her production level and ration might change, her pregnancy status would change and she might receive treatment for injury or disease, but she would remain in the same stall with her herdmates in place on each side. In essence, management was brought to the cow in her tiestall.

In contrast, the cow in the large freestall barn moves to management groups. She is moved to different pens for special rations, breeding, dry-off, treatment and other management practices. From the far-off dry cow group, a cow is typically transferred to the close-up dry cow group at 14 to 21 days prior to the expected calving date. From here, she is often moved to a bedded-pack maternity pen at around three days before the expected calving.

After calving, she is moved to a pen for cows with non-saleable milk to stay for two days, then to a fresh cow pen for 14 days and then to a high group pen. This plan completes five pen moves in a period of less than five weeks. Essentially, the cow moves to management and finds herself in a different space, surrounded by different herdmates and subject to the management change for which she was moved. As investigators of problem herds, we have become increasingly concerned about the frequency and character of these pen moves on the well-being of the transition cow.

Effect of pen move on the group
Moving cattle between groups brings about a period of increased social interactions, many agonistic (aggressive), before stabilization and development of a social hierarchy. For lactating cows, Grant and Albright report social impacts of moves last around three days and almost always less than seven days. Kondo and Hurnik conducted a study on the behavior of lactating dairy cows after pen changes where two groups of 16 lactating dairy cows each were assembled in freestall pens and monitored for five weeks, after which half of each group were randomly selected and reassembled into a third group.

Agonistic interactions between cows were characterized as physical (which included bunting, pushing and fighting) or non-physical (which included threatening and avoidance behaviors). The frequency of agonistic interactions was high for the first 48 hours after grouping, averaging over 300 events per two-hour recording session. After 48 hours, the frequency had stabilized at about 100 events per session. During the first 48 hours, approximately 65 percent of interactions were physical and 35 percent non-physical. After the second day, this ratio had reversed to around 40 percent physical and 60 percent non-physical.

When cows are moved into stable groups, the moved cows are involved in more agonistic interactions than the stable cows. Brakel and Leis showed that during the first day after regrouping, the average moved cow was involved in 9.6 interactions per hour, approximately double the rate of the other cows in the pen. Obviously this increase in physical interactions during the first 48 hours of joining a new group may have an effect on other behaviors performed during the day - feeding and resting time in particular, which may in turn influence milk production.

Research on the milk production effect of pen moves on the average cow in the group has found mixed results. Generally, a pen move has a negative effect on milk yield of the transferred cows of the order of 2 to 5 percent for a short period, but not in all situations. For example, Brakel and Leis found a 3 percent decrease in fat corrected milk yield of the transferred cows on day one of the move. It should be noted that many of these studies were conducted with mature cows in mid-lactation and not with cows in the transition period.

Studies on the effect of the number of cows moved at one time have generally found that movement of single animals should be avoided, as it is believed familiarity and social bonds between three to five moved animals may reduce the social stress of integrating within a larger group.

Effect of pen move on individual cows
While the effect of pen moves on the average cow appears to be modest, the effect appears to be more significant on low-rank cows. The subject of rank and social dominance is complex. Lamb describes three different ranking orders in cow herds (dominance, leadership and parlor entrance order) and reports the rankings for each are not the same. For example, the “leader” cow is not likely to be the most dominant cow. Dickson reported that cows form dominance hierarchies strongly associated with age, body size and seniority in herd.

Changing conditions for individual cows such as weight gain or loss result in rank changes. Arave reports a trial of individually-fed cows, some receiving a ration that exceeded energy requirements and others receiving an energy-deficient diet. Rank within the group changed continually as some cows gained weight, strength and social dominance, while cows on the low-energy diet lost weight, strength and rank.

Pen moves are also responsible for changes in rank. Dominance relationships between pairs of cows are gradually learned, but once formed, they tend to last for a long time. Cattle moved to a new pen will tend to maintain their rank relative to the cows that were moved but occupy a low rank with respect to the other cows, even first-lactation, that already occupy the pen. However, the situation may become more complex. Hook observed a complete reversal of the social rank of a group of six heifers with the removal of the high- rank individual and the simultaneous introduction of a new heifer.

Primiparous (first pregnancy) cows are usually subordinate to multiparous (multiple pregnancy) cows. Phillips and Rind studied behavior and milk production of mixed and unmixed parity groups on pasture after assembly of the groups. Unmixed groups of either primiparous cows or multiparous cows produced 3 percent more milk in the first week than equivalent cows in the mixed group. Both primiparous and multiparous cows spent more time standing and less time grazing in the mixed group. The primiparous cows spent more time grooming, a submissive action, while the multiparous cows increased pasture biting rates, an aggressive action, compared to their contemporaries in unmixed groups.

Hasegawa et al. described the effect of pen moves on dominant, middle-rank and subordinate primiparous cows. Dominant animals showed little change in behavior and production, but middle-rank and subordinate cows produced 3.8 and 5.5 percent less milk in the second week after movement to a new pen. Subordinate individuals spent more time eating than dominant cows, spent more time standing (especially on day two after the move) and had a greater frequency of short lying bouts of less than 15 minutes in duration, suggestive of disrupted lying behavior.

Robinson et al. found no difference in subsequent early lactation milk production following exposure to either 11.7 or 14.4 percent crude protein pre-fresh rations. However, the time for which primiparous cows had access to the diets was significant. Close-up primiparous cows that spent nine or more days on the control ration produced significantly more milk in the subsequent lactation than those that spent eight or fewer days on either ration. In contrast, there were no significant differences in response of multiparous cows to either ration or duration of exposure.

We are, therefore, starting to question the need for multiple dry cow diets and suggest the requirement for the cow and the rumen to adapt to a new diet in dairy herds feeding predominantly total mixed ration (TMR)-based rations has been overstressed. Indeed, some progressive dairy owners are now feeding high-fiber, lower-energy straw-based diets throughout the dry period with apparent success.

Our focus has shifted from concern over rumen adaptation to concern over social disturbances around calving time. Think for a moment about how close-up pens and maternity pens are managed. The close-up pen consists of a group of cows which spend about two to three weeks together. Additions to the pens are made usually on a weekly basis, which means there will be social turmoil for two to three days, followed by four to five days of stability.

We would suggest subordinate animals - first-lactation heifers, for example - would be more affected by these social challenges. Thus, when we look at the data from Robinson et al., we might suggest there is an alternative point of view. Benefits to heifers of a longer exposure to the close-up ration and pen may be due as much to stabilization of rank and social order as to the acclimation to the ration. Stays of four days or less will be characterized by social disruption through most of the entire stay, whereas longer stays allow for acclimation to both rations and herdmates.

Effects of confinement

Normal stocking density
Confinement appears to increase levels of conflict, even in established groups of cows. Miller and Wood-Gush monitored conflict interactions in a herd of 190 high-yielding cows on pasture during a grazing season and through the following winter confinement in a freestall barn. Agonistic interactions averaged 1.1 per cow per hour on pasture but increased to 9.5 per hour in a confinement barn stocked at a rate of 0.9 cows per stall. Low-rank cows spent approximately 15 percent of their time in submissive or avoidance behavior in confinement, and their movements were frequently blocked by dominant cows in their paths.

Galindo and Broom observed three dairy herds through a five-month study of social rank, behavior and lameness. In all herds, the stocking density was one cow per stall. Low-rank cows spent less time lying and more time standing still and standing half in the freestalls than middle and high-rank cows. By 25 weeks into their lactations, more than 60 percent of the low-rank cows had become lame compared to 18 percent of the high-rank cows, suggesting a link between social rank and health in confinement conditions.

Overstocked conditions
When confinement barns are overstocked, social tension increases. Primiparous cows spent more time walking and lying outside of freestalls and showed a greater cortisol response to adrenocorticotropic hormone (ACTH) challenge than multiparous cows in a mixed group stocked at two cows to one stall, indicating an elevated level of stress in these animals.

Overstocking can also refer to situations where the number of cows exceeds the number of eating spaces. Ethologists describe cattle as allelomimetic, meaning they like to perform the same activity at the same time. This can apply to resting behavior, eating, drinking and other activities. Overstocking, by definition, frustrates allelomimetic behavior.

Most modern freestall pens are constructed with either two or three rows of stalls. Stalls are approximately 48 inches wide, while headlocks are located 24 inches on center. Thus, in a two-row configuration there are two feeding spaces for every two stalls. In contrast, in three-row pens, feeding space per cow is reduced by one- third.

Studies of the effect of limiting feedbunk space have produced mixed results. Using 24-hour video monitoring of high-producing cows in three-row barns, Menzi and Chase showed that periods when the feedbunk was occupied to capacity were few and of short duration, suggesting there was much alternative time available when other cows could gain access to the feed.

However, recent work has demonstrated changes in feeding behavior following fresh feed delivery in overstocked conditions. In one study, when feedbunk space per cow was reduced from 1 meter to 0.5 meters, spacing between cows decreased, there were increased aggressive interactions and, most importantly, subordinate cows reduced feeding activity within the 90-minute period after fresh feed delivery. In contrast, dominant cows showed no change in feeding activity with either spacing regimen.

Although dry cows generally have a low DMI compared to lactating cows, they may reduce intake when allelomimetic behavior is frustrated. Field data collected by Kenn Buelow from two herds with dry cows maintained in dry-lots being fed a blended ration from a common source demonstrated a significant reduction in group DMI when cow numbers exceeded 92 percent of headlocks. Pregnant dry cows are wider than the typical 2-foot spacing of headlocks, and the maximal filling rate of the feedbunk is likely achieved at less than one cow per headlock.

Data collected by Gary Oetzel demonstrates an effect of overstocking on mixed primiparous and multiparous groups during the pre-fresh period. Stocking densities greater than 80 percent of stalls in the pre-fresh group in a 2-row pen adversely affected milk production of the primiparous cows through the first 83 days of the subsequent lactation. Modeling of data demonstrated that for each 10 percent increase in pre-fresh stocking density above 80 percent, there was a 0.73 kilogram per day decrease in milk production.

Limited access to feed prepartum may also impact health. Cameron et al. showed dry cow feedbunk management had a negative impact on the incidence of displaced abomasum in a herd level model on 67 farms. Management was scored negatively if bunk space was less than 11.8 inches per cow or if bunk space was 11.8 to 23.6 inches and the ration was limit-fed.

Interactions of rank and overstocking also influence stall access. Wierenga and Hopster showed no significant effect of stocking densities of between 125 and 133 percent on stall access and resting time, but mean resting time for the group was adversely affected at 155 percent. However, when rank was evaluated there were changes in behavior of low-rank cows even at 125 percent stocking rates. As stall access was reduced, low-rank cows shifted lying behavior from night into early evening hours when competition for stalls was less. At 155 percent stocking rates, this compensatory mechanism was overwhelmed as stall access in the evening also became reduced and total daily lying time could not be maintained.

Management of transition cow pen moves and stocking density
Very few behavior studies have been conducted using cows in the transition period. However, extrapolation of the findings suggests effects on low-rank individuals and, in particular, primiparous cows in mixed age groups, could be of great significance. A pen move introduces a period of social disruption lasting two to three days. Residency within a pen confers some elevation in rank of animals already in place.

Small heifers will usually be subordinate to larger mature cows; however, cows losing weight, a common occurrence around calving time, may change rank. In any of the several pens that a cow visits during the transition process, agonistic interactions within a group will be amplified wherever overstocking occurs.

Grummer et al. point out that the most important nutritional factor in determining metabolic disease in transition cows may not be the absolute level of DMI, but rather the change in DMI at the point of calving. Therefore, the risk of reduced intake following pen moves and competition in overstocked pens may well be key determinants of transition cow success. Two critical control points for transition management are, therefore, to control stocking density changes in the pre-fresh, maternity and post-fresh accommodation and to limit the number of pen moves around calving time.

Control of stocking density
The size of the pens in a transition cow facility are usually based on some estimate of the proportion of the lactating herd that will be in a certain stage of the lactation cycle, depending on the target duration of stay in each group. As the close-up dry pen consists of a small number of cows grouped together for a short period of time, it is continually in a state of flux. Control of stocking density in this group is difficult, despite adequate planning, and may relate to occurrences during a few months in the summer in warm climates.

It is common for fertility to be very depressed through July and August in many parts of North America. Following return to cooler conditions, the cows recover body condition and reproductive performance rebounds. This has a major impact on throughput in the transition cow facility which may be understocked during April and May and extremely overstocked during July and August - right at the time when these cows will face the next round of heat stress.

Adequate heat abatement measures for both lactating cows during the breeding period and transition cows are, therefore, vital for the control of throughput during the transition period. Sizing of pens for the transition period is, therefore, helped by reviewing documentation of the historical calving pattern of the herd. It is helpful for expanding herds if pens are constructed which may be used for a variety of purposes, one of which would be carryover space for pre-fresh cows, should the need arise. We recommend the allocation of at least one stall per cow and, because of the increased girth of the pregnant cow, a minimum of 30 inches of linear bunk space per cow.

Limiting the number of pen moves for transition cows
Moving cattle between groups is inevitable on modern dairy farms. However, we suggest the number of moves be limited as much as possible. Currently, most dairy advisors recommend a two-group dry period where cows are exposed to a close-up ration for the last 14 to 21 days before calving. However, Varga argues that a minimum of five weeks of feeding a given ration may be required to establish a new metabolic plateau for liver and intestinal tissues. Shortened dry periods that use a single ration for the entire time are growing in popularity among progressive farmers, and benefits from this strategy may also accrue from a reduction in the number of group changes.

As calving becomes imminent, Mee suggests the ideal time to move the cow is 24 hours prior to calving. Unfortunately, a growing amount of field data and experience suggests this timing is difficult to manage. Predicting calving time is unreliable, and cows may remain in the maternity pen for a week or more rather than one to two days as expected.

Although the cows in a spacious maternity pen, lying down on a deep bed of clean dry straw, may appear to be in an ideal environment for freshening, this may not be the case. Our field investigation experiences, based upon data from farms that maintained excellent records of pen move dates, suggest that non-esterified fatty acid (NEFA) concentration is elevated in a greater proportion of cows that have spent three or more days in the maternity pen than in cows that stay in the pen fewer than three days. The same farm records show there is more than a two-fold greater risk for ketosis and displaced abomasum (DA) for cows that stay on the maternity pack for three or more days compared to cows that calve within two days on the pack.

A calving management strategy which is finding favor in a growing number of medium to large size dairies involves moving the cow to a calving pen when the calf’s feet begin to show. The practice presents some disadvantages; it requires around-the-clock monitoring of the close-up dry cow group with approximately hourly checks and moving at this time may interrupt the calving process, particularly in heifers. Once the calf is delivered and the cow has returned to her feet and is able to walk without ataxia, she is transferred to the post-fresh pen and the calf moved to the neonatal housing area. The duration of maternity pen stay is measured in hours rather than days.

Another possible strategy is to maintain several large bedded-packs and practice an all-in, all-out policy for the close-up cows. A group of cows expected to calve within a two- to three-week period would be moved into the pre-fresh pen, where they would remain until they calved. Subsequently, another group representing the following two to three weeks of calving cows would be moved to another similar pen, from which they, too, would calve and move into the post-fresh accommodation. This strategy, which maintains small stable groups throughout the dry period, has been made more feasible by the advent of shortened dry periods of 40 to 50 days.

The approach does not obviate the need for regular checking of the pen so the calf can be removed promptly without sucking. Cows could freshen in the pen or be moved to a calving pen as previously described. No new cows would be added until the pen is emptied, cleaned and re-bedded, completing the cycle. This strategy would almost completely remove the stresses of continually mixing cows.

In traditional grouping systems, the cow may be transferred from the calving pen to a nonsaleable milk pen for two to four days or moved straight to a post-fresh monitoring pen for 10 to 21 days. We prefer the latter strategy as it removes a pen move, but it does mean the milk must be diverted from the bulk tank when cows still under milk withdrawal are milked through the main parlor.

Some cows that have suffered milk fever or calving difficulties may benefit from a short period of time in a smaller group away from more aggressive cows, however. Primiparous cows are uncommonly split from multiparous cows during the immediate post-fresh period, primarily due to the convenience of health monitoring in a single group. However, there are undoubted benefits to grouping primiparous cows separately from multiparous cows after calving. Frequent milking of multiparous cows for 21 days or more after calving is facilitated by separating them from the primiparous cows, but in some herds, both are milked frequently in the same group for ease of management.

With these alternative strategies, the cow can proceed through the transition period with fewer pen moves and rank changes. However, for the strategies to work, the facility must be well designed, and the management must be excellent. We recognize five critical control points for these strategies to succeed:

1. Bedded-pack management and hygiene must be excellent, necessitating the need for a plentiful supply of clean, dry, fresh bedding material on a well-designed, comfortable lying surface with excellent drainage.
2. The close-up pen must be checked frequently by a well-trained person hourly, 24 hours per day.
3. The close-up pen must be located immediately adjacent to the individual cow calving pens so the move at the time of delivery, if used, is easy and stress-free.
4. The calving pens must also be located in an area away from cow traffic.
5. Cows, and in particular heifers, must be allowed to progress through the stages of labor, without repeated disturbance, following the guidelines for intervention.

Problems will occur if a poorly trained individual is responsible for monitoring the close-up pen or if it is done infrequently. Calves sucking the wrong dam may lead to failure of passive transfer problems and breakdowns of disease control programs. If animals must be moved the length of the barn to the calving pen and not given time to deliver undisturbed (especially in the case of heifers), increased rates of dystocia and fetal death may occur.

Controlled data have yet to be collected to support the changes suggested, and this is an area in much need of research. However, several large farms are experimenting with these strategies with apparent success in many cases.

Conclusion
Improved building designs come from a better understanding of the behavioral needs of the dairy cow. The costs to provide for these needs in the facility must be offset by improved milk production, health and longevity. Research is still required to more fully understand the health implications of many building design considerations and their impact on disease.

Perhaps the most important end result of an improved environment for the transition cow, however, is an improvement in animal well-being. Better buildings that accommodate the behavioral needs of cows present “win-win” situations where dairy cattle thrive and work is more enjoyable. This results in an improved image for the industry, greater consumer confidence in the quality and safety of the final food product and a prosperous dairy industry. PD

References omitted but are available upon request.

—Excerpts from 2005 Cornell University Fall Dairy Conference Proceedings