Despite a general appreciation that a clean, dry, comfortable place to lie down for dairy cows is associated with improved milk production and health, there is reluctance by farmers to remodel existing facilities to achieve this goal. It is very easy to understand why. Industry recommendations for stall design have not been consistent, with much debate among consultants over appropriate dimensions and size over the last few years. Also, the construction of partial budgets has been hampered by a lack of knowledge of the potential financial benefits that might accrue from stall improvements, when compared with quite substantial costs that have been relatively easy to measure.

During a period of favorable milk prices and armed with an improved knowledge over what cows need from the environments we place them in, we have been directly involved in several cow comfort improvements. This article tracks four herds over a minimum period of two years, charting improvements in milk production and health. Two barns were remodeled from mattresses to sand bedding, and two barns were remodeled to improve existing mattress stalls.

While each individual herd taken in isolation is merely an interesting story, the group of herds taken together give us insight into the actual rewards that may be realized and assist in the justification for improving stall comfort in existing facilities.

Mattress to sand conversions
We have shown that sand-bedded freestalls allow lame cows to maintain normal patterns of stall use behavior, while mattress freestalls fail to provide a surface that lame cows can rise and lie down easily upon, resulting in increased time spent standing and lower lying times. This work has stimulated several farms to remodel their mattress freestalls to sand. The decision to move to sand carries with it associated costs in converting the manure-handling system. Two herds in Wisconsin achieved this goal by converting to a flush flume system of manure handling.

In flush flume systems, manure is scraped into an 18-inch diameter pipe while a pump pushes the liquid component from a two- or three-stage settling manure pit into the top end of the line at 5 to 8 feet per second. The liquid carries the sand-laden manure to a settling lane, where the flow decelerates to around 1 to 2 feet per second along a 200- to 300-foot-long concrete settling lane. The majority of the sand is left in the lane to be recycled back into the stalls and the liquid component goes through a two- or three-stage settling process before the liquid component is used to pump back into the system.

In the fall of 2004, two herds went through these mattress-to-sand conversions.

Example Herd A
Herd A was expanding from 600 to 800 cows in November 2004. Existing housing consisted of a six-year-old 2-row tail-to-tail rubber crumb-filled mattress barn for lactating cows and a 3-row special needs barn. Bovine Somatotropin (BST) use in the herd was labeled for manure cows throughout the follow-up period. BST was used on approximately one-third of the first lactation heifers up to March 2005, and then it was used on all heifers.

The special needs barn was extended to increase capacity for dry cows and post-fresh cows. Stalls in this barn were 10 feet long against the side wall, 50 inches wide, with a PVC pipe brisket locator 70 inches from the rear curb, built to accommodate 1,700-pound special needs cows. The old barn was converted by removing the mattresses and adding a 4-inch fiberglass retaining pipe bolted to the rear edge of the stall. Approximately 4 to 5 inches of sand were maintained on the platform and no other changes were made to the stall design.

Rolling herd average milk production has increased to 26,841 pounds per cow, while turnover rate has been held at 17 to 19 percent to facilitate expansion up to 873 cows.

Mean annual average somatic cell count (SCC) has fallen from 220,000/ml with organic bedding to 158,000/ml with sand and milk per cow per day average for the year has increased by 6 pounds per cow.

The stall changes cost the herd $310,000 ($403 per cow). The positive impacts assume a $13 milk price (actual price achieved for the farm was $16.10), 3 pounds of milk per cow per day attributed to the stalls and some improvements in SCC premium, and mastitis and lameness treatments.

The financial investment was paid back within 1.5 years with an increased income of $286 per cow after feed costs. This allowed a further expansion of the herd in 2006 and the addition of a new sandstall barn. The flush flume now reclaims sufficient sand to recycle back into the stalls.

The financial aspect of this barn remodel is only part of the story. At a time when concerns over dairy cow welfare are mounting, this herd proves that we can manage high- producing dairy cows to maximize health and longevity in a large dairy.

Example Herd B
Herd B was also a mattress facility milking 700 cows, with plans to expand to 1,000 cows. In September 2004 they built new sand stalls for first-lactation heifers and by March 2005, they had removed the existing mattresses in the old barns. Herd B went one step further than Herd A and removed the concrete platform, re-pouring the rear curb to provide a deep sand bed. All other stall dimensions remained the same. Up to September 2005, cows and heifers were started on BST at 110 DIM, after which the herd reverted to label use.

In the last year, the herd has added a new section to the barn and now houses over 1,200 cows. Rolling herd average milk production has increased by 1,869 pounds per cow, with a 6-pound per cow per day increase. Somatic cell count has fallen slightly and rolling average DIM has increased by 21 days.

The changes in Herd B are remarkably similar to those seen in Herd A. Both were very well managed herds before the change, and the improvement in cow comfort has allowed both herds to achieve their potential.

Assuming an investment of $500 per cow for 794 cows, total expenditure was $397,000. An increase in milk production of 3 pounds per cow per day attributable to sand at $13 per cwt less $0.03 per pound increased feed costs yields:

(794 x 3 x 365) x (0.13 - 0.03) = $86,943 extra revenue

The reduced turnover rate yielded approximately 56 more potential dairy sales at $1,800 - $300 = $1,500 per transaction, for a total of $84,000. Increase in income per cow was therefore $86,943 + $84,000 = $170,943 or $215 per cow. The investment will be paid back in 2.3 years.

Improving existing mattress barns
While converting to sand bedding appears to carry with it some substantial benefits, it is also clear that for those herds with mattress stalls, that are unwilling to go to the expense of converting manure- handling systems, there are benefits to be accrued from improving the design of existing mattress stalls.

Example Herd C
Herd C is a 163-cow registered Holstein dairy herd. Mature cows average around 1,800 pounds and lactating dairy cows are housed in a three-year-old 6-row rubber crumb-filled mattress freestall barn. Stalls were sized for first-lactation heifers and were hopelessly inadequate for larger mature cows, proving that the concept of one size of stall fitting all cows is a fallacy. BST was used on an individual cow basis. Continual problems with poor stall use and lameness prompted the herd owners to consider a radical barn overhaul. In November 2003, the owners of the herd remodeled the mature cow pen to remove the existing loops and the concrete fill between the brisket locators. They remounted new Y2K loops 54 inches on-center, added extra foam over the rubber crumb cells, installed new mattress covers and Poly-Pillow brisket locators 71 inches from the rear curb. They then remodeled the pre-fresh and post-fresh pens and finished remodeling the first lactation heifer pen in November 2004, one year later.

Herd size and turnover rate has remained relatively stable with a small increase in cow numbers. Rolling herd average milk production has increased by 1,992 pounds per cow while the increase in milk per cow per day peaked in year three at 5 pounds and has fallen off a little in the last year to 3 pounds overall. Most of the improvement in milk production has been seen in the mature cows. Stalls were not changed for first-lactation heifers until 2004, and since then ME305 has risen 506 pounds. Mature cow MEs peaked in 2005 and have fallen back a little since then.

Despite concerns by some consultants that wider stalls lead to dirtier beds and increased udder health problems, this has certainly not been the case in this herd, where mean annual weighted SCC has fallen by 110,000/ml.

It is interesting to compare ME305 of mature cows with first- lactation heifers during the period when the mature cow stalls had been changed, while the first-lactation heifer pens had stayed the same. The mature cow ME305 climbs from 1,600 pounds below that of the first lactation heifers, to a point where it is comparable. Performance of the first- lactation heifers declined through this period and only started to improve once their stalls were remodeled in November 2004.

The cost of stall modifications was approximately $100,000, with all the labor being done by the owners. With an increase of 3 pounds of milk per cow per day, revenue after feed costs increased by

(163 x 3 x 365) x (0.13-0.03) = $17,849

SCC premium improved by an estimated $0.25 per cwt. The herd shipped 163 x 87 x 365 = 5,176,065 pounds per year at $0.0025 extra per pound equals $12,940 extra revenue per year. Total revenue increased by $30,789. Thus, the investment will be paid off in 3.2 years.

Example Herd D
This 310-cow Holstein dairy was remodeled in February 2003. Cows were housed in a 6-row mattress freestall barn with four pens. BST was used per label directions for all mature cows and heifers. The first lactation heifer pen was left unchanged, while each of the three mature cow pens were altered at low cost by increasing width from 44 inches to 48 inches on center and moving neck rails from 63 inches from the rear curb to 70 inches. All the work was done by the owners.

Each of the three mature cow pens went from 74 stalls to 68 stalls (total loss of 18 stalls) and herd size was reduced to 298 cows. 11 cows were sold as dairy sales. Herd size has remained lower than previous as stocking density has been held at around 115 percent in most pens. Turnover rate has been reduced while rolling herd average has increased by an astonishing 4,905 pounds over the last three years, and milk per cow per day has increased by 14 pounds.

Changes in ME305 by parity have been tracked. Once again, concerns over increased stall width have not been realized, with a reduction of 94,000/ml in weighted mean annual SCC.

Constructing a partial budget for this herd is complicated by the fact that the herd is milking fewer cows. Attributing 7 pounds milk improvement to stall changes and accounting for fewer cows milked, the changes make a profit of $193,232 over three years. Herd improvements in cow comfort reduced the new lameness case rate in Herd D and allowed the hooftrimmer to move to trimming cows twice a year. These improvements did not change the rate of infectious lameness but dramatically reduced the proportion of cows receiving hoof blocks for claw horn lesions to less than 5 percent of cows trimmed.

Conclusions
All four herds show that improvements in cow comfort pay. Provided the alternations are done correctly, at reasonable cost, investments have been covered within the period of six months to 3.5 years by improved milk production, lower turnover rates, higher milk quality, less lameness and an increase in the proportion of older healthier cows in the herd.

For any given herd it is impossible to predict the actual outcome of improvements in cow comfort. However, a good starting point is to compare mature cow ME305 and first-lactation heifer ME305 milk production. If there is a large gap between the heifers and the cows, model the potential benefits to the herd if mature cows achieve the same ME305 as the heifers over a three-year period.

Improvements in milk production are obviously influenced by nutrition and other management factors over time, and none of these case studies were controlled. However, it is clear that milk also comes from older cows that remain in the herd longer and stay healthy and free of hoof problems as a result of improved cow comfort. Although the improvement in dairy cow welfare has not been given a dollar value in these assessments, the owners of these dairy farms and the author believe that it is priceless. PD

—Excerpts from 2006 Vita Plus Dairy Summit Proceedings

Nigel B. Cook, Clinical Associate Professor, Food Animal Production Medicine, School of Veterinary Medicine, University of Wisconsin – Madison