Milk Producer - December 2009 - (Page 34)

APPLIEDSCIENCE By Dan Weary and Marina von Keyserlingk Better hoof health Design plays key role in using freestalls to duplicate pasture’s curative powers for cows with ailing feet hen one of your cows is on the limp, turning her out to pasture can help her recover rapidly. Just two weeks on grass improved the gait of lame animals, while cows that stayed in a freestall barn showed no improvement, recent research has shown. Given Canada’s climate, however, year-round pasturing simply isn’t practical. So, could freestalls be modified to benefit lame cows the way pasture does? Standing outside a stall—typically on wet concrete—increases a cow’s risk of lameness. Encouraging her to remain in the stall could work, and the neck rail position especially affects where cows stand. If stalls could be custom fitted for each cow, the neck rail position would let her lie down and stand up comfortably in the stall. While standing, she would be indexed so her manure and urine would fall in the alley outside the stall. Unfortunately, cows come in a wide range of sizes, and custom-fitting each stall would be difficult. Both the neck rail height and distance from the curb affect standing behaviour. More restrictive neck-rail placements—lower and closer to the stall’s rear—prevent cows from fully standing in the stall. This may keep stalls clean, but has the unfortunate effect of forcing cows back onto the wet concrete outside the stall. In a recent study, we showed how neck rail placement affects a cow’s ability to stand in the stall. We tested cows with neck rails positioned over the range of values found on com34 | December 2009 | MilkPRODUCER W mercial farms—from a restrictive placement of 130 centimetres from the rear curb to a much more generous 190 cm. As shown in Figure 1 on page 36, cows clearly responded to neck rail position. The more restrictive the neck rail, the more time the cow spent perching—her front hooves in the stall and rear hooves in the alley—and the less time standing fully in the stall. This result gave us an idea. We knew standing outside the stall increases lameness risk. We also saw how a simple aspect of stall design can change where the cows stand. Could we create an environment that would help lame cows recover simply by moving the neck rail? Lameness takes weeks to develop, and recovery takes weeks more. In our next experiment, we observed cows for 10 weeks. We tested just the two extreme positions from the previous study, 130 and 190 cm from the rear curb. Cows were assigned to one treatment for the first five weeks, and then crossed over for testing on the alternative treatment for the next five weeks. Every week, we gait-scored cows using the University of British Columbia (UBC) scoring system. Cows with perfect gait are scored 1, and severely lame cows 5. Cows scored at 3 or greater are considered clinically lame. Again, the results were clear. When provided stalls with the more generous neck rail placement 190 cm from the rear curb, cows spent more time standing with all four hooves in the stall and less time perching with just the front two hooves in the stall. The neck rail position has a direct bearing on lamesness risk for dairy cows.

Table of Contents for the Digital Edition of Milk Producer - December 2009

Milk Producer - December 2009
Contents
Editor's Notes
DFO Chair's Message
Dairy Update
Industry Roundup
DFC Promotion
Office Management
Seven Issues That Matter
Herd Health
Research
Applied Science
Ruminations
Markets
New 'N' Noted
Back Forty

Milk Producer - December 2009