There are a variety of factors involved in the health and productivity of transition dairy cows. Speaking at the 2010 AABP-AVC meeting, Ken Nordlund, DVM, Dipl. ACVP-Dairy, University of Wisconsin, outlined some of the most critical areas for success. Field studies of transition cow management using Transition Cow Index as the outcome variable have shown that housing constraints are the major risk factors for fresh cow health in freestall dairies today.
Sufficient space at the feeding fence for all transition cows to eat simultaneously appears to be the most important determinant of transition cow performance in our current industry. Nordlund recommends a minimum of 30 in. of bunk space per Holstein cow in pre-fresh and post-fresh pens for a 90-minute period after fresh feed is delivered and after every milking.
Video studies suggest that lactating Holstein cows will voluntarily fill a bunk at a spacing of one cow per 30 inches. It is likely that pregnant prepartum cows would take even more space than lactating cows.
Nordlund prefers to build special needs pens to accommodate the surges in numbers of special needs cows. He recommends sizing close-up and fresh pens for 140% of the average number of calvings, which will mean that these pens are overstocked less than 10% of the time. Each stall and headlock in a prefresh pen has an impact on the start of somewhere between 10 to 15 lactations each year. Because of the multiplier effect on the start of the lactation of so many cows, it is critical that these facilities are excellent and available to all cows.
Pen moves and social stress
Each pen move requires that a cow familiarize herself with the surroundings, as well movement into a new social group also creates stress as the cow establishes rank within the group. Work with mid-lactation cows has shown reduced time spent eating, increased feed evictions, and reduced milk yield following a pen move. Minimizing the number of regroupings through the transition period is consistent with successful transition programs.
In pens where cows enter at intermittent intervals, like a week or more, extended stays in such pens are considered more desirable than in pens with entries and departures every day. Isolation from the herd creates stress for a cow and separating a single cow into a separate calving pen for more than a couple of days appears to be a practice with high risks for fresh cow health.
Dry and close-up pens
The traditional close-up pen is based upon cows entering the pen approximately 3 weeks prior to due date.
Generally, movement of single animals should be avoided as it is believed that familiarity and social bonds among 3 to 5 to five moved animals may reduce the social stress of integrating within a larger group.
Nordlund says the optimal transition cow pens would be based upon an all-in pen where a cohort of cows due to calve within a short period of time, such as a 7 to 14-day day window, are assembled with no further additions through the calving process. The usual policy would be to periodically move entire pens of cohorts intact into the next pen to keep the cows near due date in a location proximal to the calf delivery facilities. Advantages include establishing group stability, eliminating the need to lockup dry cows and remove close ups and more meaningful monitoring of dry matter intakes.
If the calving pen has a stable social structure (no additions), extended stays are fine. If new cows are continually being added, Nordlund recommends that the duration of stay be limited to 48 hours maximum. Field data shows dramatic increases in ketosis and displaced abomasums and early lactation culling of cows that stay 3-10 days in daily-entry group calving pens.
Moving cows to calving pens once calving has begun effectively minimizes the time in high turmoil pens, but requires round-the-clock labor to check and move cows. Freestall pens can be designed to facilitate this practice with the construction of two-row head-to-tail arrangements of the stall rows. With the tails of all cows visible from the central feed alley, the observer can monitor each cow without disruption. Workers should not move cows into calving pens too early. One report showed that moving cows when in labor but with only mucus showing had 2.5 times the rate of stillbirths as cows that were moved when the calf’s feet or head were showing. If cows are moved to individual box stalls for calving, the duration of stay should be limited to a matter of a few hours.
A loose, deeply bedded surface has emerged as a major factor for improving fresh cow TCI scores. In freestall herds, sand-based stalls were associated with more than a 1,000-pound TCI advantage over herds with mattress freestalls. Similarly, depth of loose bedding under shades emerged as a risk factor affecting herd average TCI scores in open lot dairies.
Studies of sand and mattress freestalls show that cows with elevated locomotion scores change their behavior on mattress stalls, but not on sand, and may explain the substantial improvement in fresh cow performance on sand surfaces.
A deeply bedded pack is the probably the preferred housing for close-up cows in confinement housing. The guideline of 100 sq. ft. of space/cow includes the bedded area only and assumes that cows have access to an external feeding alley or outside lot. If the feeding area is continuous with the bedded pack, the space should provide a minimum of 120 sq. ft./cow with good bedding covering most of the area.
Stalls for prepartum Holsteins and Jerseys should be at least 50 and 45 in. wide, respectively. Length is the distance between the outer corner of the rear curb to the point where the stall surface touches the brisket locator. If there is no brisket locator, the total stall length is the stall resting length. This distance should be greater than 70 and 63 inches for Holstein and Jersey cows, respectively.
For a stall to be considered low-risk for Holstein cows, the total stall length should be at least 9 feet long with no obstructions to forward lunge and bob. If the stall is less than 9 feet, but the lower side rail is 11 inches above the stall bed or less, it should allow side lunging and is considered an average risk for transition cows. If the stall is less than 8 feet and has obstructions to side lunging, such as lower divider rails greater than 13 inches above the stall bed, the stalls present major risks to successful transition performance. Finally, the neck rail should be approximately 48-50 inches above the stall surface.
In open lot dairies, transition cow facilities should provide at least 45 square feet of shade per cow with loose bedding at least 3 inches deep below the shade.
The practices of the herdspersons of the elite transition programs in Nordlund’s study were remarkably similar: delivery of fresh TMR while fresh cows were being milked, palpation of udders for fullness while being milked, observation of cow demeanor as the cows returned to the pen, i.e., does she go to feedbunk or does she lie down, and an assessment of appetite and attitude. Herdspersons in the elite herds knew and cared about the fresh cows under their watch.
Cows that do not lock-up, or cows that lock-up with suppressed appetite or signs of depression were examined. Other examination procedures including rectal temperature, observations for vaginal discharge, ketosis, displaced abomasum, lung sounds, etc., were conducted when primary assessments indicated further evaluation.
Formal screening procedures that lock cows up for a period of 1 hour or less per day are considered optimal. Cows are capable of compensating for a 1-2 hour change in routine; if lock-up is prolonged and in association with other stressors, the ability of the cow to compensate and catch-up on lying time may be exceeded. Extended lockup time adds substantially to the stresses of transition.
Location also has impact. If the cows have access to feed while being examined, feeding and the screening can proceed almost simultaneously. Screening time at a palpation rail, for example, must be weighted as riskier than equivalent time in lockups over feed.