Have the Years Made Your Barn Redundant?04 July 2014
A barn built 12 years ago could be falling short in providing sufficient cow comfort as operations strive for more productive cows that milk for longer.
Therefore, flooring, stall size and ventilation may require updating, Pennsylvania State agricultural engineer John Tyson has advised.
Mr Tyson has warned that a typical cow stall in 2002 may need extending so it is at least a foot longer.
This is from an insufficient four foot wide (1.21 metres) and eight feet (2.43 metres) long, he explained.
“Today, that is a heifer stall and standard cow stalls are 9 to 9.5 feet long,” he said.
“In 2002, even 7.5-foot head-to-head stalls were long stalls.”
The latest thinking is for cow stall dimensions to offer 1.8 metres (five foot) lying area and 0.7 metres (2.3) for the head.
Professor Christer Bergsten of the Swedish University of Agricultural Sciences prescribes that modern herds also require 2.1 metres (6.8 foot) between the top of the stall rail and the rear curb.
“Cows stand by lunging their heads forward as they are lifting – this can require an extra 90 centimetres,” said Prof Bergsten.
“Young cows can succeed against cramped conditions but older, heavier or lame cows struggle to stand.”
Walking surfaces may also need resurfacing or a little attention to improve traction.
Sawing grooves at a 45 degree angle to existing ones may resolve issues, as could the use of rubber, Mr Tyson advised.
“Many 10-plus-year-old concrete floors will be in need of some resurfacing,” he added.
“All those trips with scrapers are bound to smooth off the floor, leaving it slick.”
He urged farmers to consider scarifying or milling to improve tired flooring and rubber matting in areas where cows stand, such as holding areas or milking stalls.
Ventilation must also be up to the job, added Mr Tyson. Current buildings in the North East US aim to provide 11 square feet of windward opening per cow.
He also suggested that fans may need scrutinising. Air speed of a minimum or three to five miles per hour should be targeted.
“Studies and experience have taught us that fans spaced approximately 10 times their diameter, over each row of stalls, can achieve this goal,” said Mr Tyson.
“Increasing the opening of a shelter is going to increase the air exchange rate for summer weather.”