The Rules Still Haven't Changed
By: John Tyson, Agricultural Engineer Educator, Penn State Extension
What makes good housing for cows with a robotic milking system? The simple answer is, the rules haven’t changed! Every dairy shelter, no matter the style, needs to provide good ventilation, ready access to high-quality water and feed, a clean, dry, comfortable resting area, and confident footing. It doesn't matter how she is milked, the measures of what makes good housing and husbandry don't change.
So start with the basics. What a cow really needs is air, water, feed, and a resting area. How well we as caretakers do at providing for those basic needs will determine how well the cow does at paying us back with milk production.
Ventilation
The goal of ventilation in a dairy shelter is to provide that clean, dry air to the cow, while removing excess moisture, heat and other pollutants. The key thing to remember here is that dairy cows are much more cold-loving animals than us humans. 50°F is often quoted as the ideal temperature for mature cows, and at 70°F they begin to feel the effects of heat stress. So while we may think those warm spring days feel really good, our cows may in fact be headed toward heat stress. Even in the dead of winter the shelter must have some ventilation to provide fresh air and remove moisture. The general rule of thumb for naturally ventilated, cold housing is the temperature within the shelter should be within 5°F to 10°F of the outside ambient air temperature. Any greater difference than that and there is a risk of buildup of excess moisture. Natural ventilation is largely dependent on local wind speed and the size of the opening in the shelter. We can select a site and building orientation that allow for the best possible exposure to those winds, but whether or not the wind blows on any given day is not up to us. Therefore the designer’s best option is to maximize the available openings to promote summer ventilation. The rule is to have the openings of one sidewall and one endwall add up to 11 square feet per cow within the shelter.
Water
The second necessity to the cow is water. Water is the single largest feed ingredient on the farm. A high producing cow is drinking 250 to 330 pounds of water per day. That’s more than twice what she eats in feed per day! Remember milk is really 87% water, and all that water needs to come from somewhere. While cows may drink large quantities of water in a day, they don’t spend much time doing it. On average a cow only spends about one hour per day drinking, but can drink 3 to 5 gallons per minute. So a watering system must be designed to handle this large flow in a short time period. The general recommendation is to provide at least two watering stations within a group, and a total of 3 inches of water trough perimeter per cow.
Feed Space
One of the larger areas of discussion in robotic shelters is feed space. In the past 24 inches was the rule of thumb used, but with the lack of group flow of animals out of and into the shelter, it is speculated that the required feed space could be less in a robotic system. I think the jury is still out on this point, but what we do know is that having the physical design of that feed space so cows can easily access the feed is important. So rather than focus on the inches of space, perhaps we should focus on how easily a cow can reach under, through and/or over the feed barrier, and whether high quality feed is in fact there. Simply put, what must a cow do to get a bite of feed?
Resting Area
At last we make it to the resting area. As time goes on and we better understand cow behavior and therefore design resting areas for the cow herself, we have greatly improved cow comfort. Those same rules of body space, head space, lunging area, etc. that are used to design a non-robotic freestall shelter need to be used here. Why would a robotically milked cow rest any differently than her non-robotic cousin?
Finally overseeing these four basic needs is the management of the system. Resting area maintenance, feeding frequency, manure scraping, system evaluation and adjustment can never be overlooked. The need for good husbandry skills never changes!
For more on Robotic Milking Facilities check out the Penn State Extension Dairy Team’s achieved webinar at: http://extension.psu.edu/animals/dairy/courses/technology-tuesday-series/webinars/facility-design-for-robotic-milking-dairies.
