We should design barns for cows and not for people. If cows can lie down comfortably, they will be more likely to stay in the herd. Stalls are usually designed for the cows to defecate outside the lying area, which is beneficial for the people maintaining the barn, but not conducive to the cows’ natural lying behavior. Most of the free-stalls are too short for the cow to lie down comfortably. The width of the stalls is also problematic because cows can cannot lie on their sides or stretch their legs. Bedding should be soft, clean, dry and, if possible, inorganic. It is the sum of all the different parts that creates an environment for good animal welfare, which can improve productivity.
Free stall design
The free stall cubicles should allow for normal resting positions. They must provide cows with enough space to:
- Stretch their front legs forward
- Lie on their sides with unobstructed space for their neck and head
- Rest their heads against their sides without hindrance from a partition
- Rest with their legs, udders and tails on the platform
- Stand or lie without pain or fear from neck rails, partitions or supports and
- Rest on a clean, dry and soft bed
- The slope of the floor, which is important to keep the stall clean, should be between 4-7°
Free stall dimensions should be selected based on the largest cows in the herd. To determine the right dimensions for free stalls, a careful look at the cows (behavior/posture, condition, bruises and injuries) and the cleanliness and shininess of dividers and neck rails should confirm that the chosen dimensions are the right ones. A uniform size of the herd is a prerequisite to get the right size for all animals.
Dividers should meet the needs of the cows
The size or spatial arrangement of bars etc. within the stall may be reducing lying time by around 2.5 h/d or result in cows that lie in the (dirty) alleys. Bad design or placing of dividers can induce bruises on the sides and backs of the cows. The partition should be firm, smooth, without sharp bolts or nuts sticking out. The form should be such that the cows cannot get stuck under the divider and that there is enough (side) lunge space.
Neck rail position should be adjusted properly
The neck rail of the free stall should be positioned in such a way that the cows cannot defecate/urinate in the stall in a standing position. A general recommendation for Holstein Friesian cows is to place the rail >210 cm diagonally from the rear curb and >122 cm above the stall bed. It should not hinder the cow when it wants to lie down. This implies that the cow should be able to stand with all four feet in the stall without touching it. Cows may tell us whether the position is right. If the free stalls are clean and the cows don’t have injuries or abrasions on the withers it is okay. If the neck rail is shiny and/or the cows have abrasions on the withers, the distance to the curb is too short. If the free stalls are dirty and the neck rail is not clean, the distance to the curb is too large. Too much restriction by the neck rail increases the amount of lameness. A properly designed and positioned brisket board may reduce some of this restriction because it positions the cows better when they are lying.
Cows should have enough space to lunge forward or sideways
The lunge space is the space taken up by the head of the cow as it moves forward to stand up. Analysis of standing up movements indicates that dairy cattle use between 260 and 300 cm of total longitudinal space. The space needed for the lateral movement range from 60 to 110 cm at the hips.
Bedding serves two purposes: firstly it softens the floor in order to improve comfort and welfare of the cow, and secondly, it keeps the cows and their lying area clean. Cows strongly prefer dry bedding over wet material. Bedding should also be dry in order to prevent growth of bacteria. It is important to cover soft cow mattresses with 2-3 cm of sawdust. Adequate ventilation will also help keeping the bedding dry. It has been shown that a more comfortable bedding reduced lameness compared to other surfaces and that tie stalls over all had less lameness than free stalls. Studies have shown positive results for sand bedding, where cows with non-sand bedding lay down less than those in stalls bedded with sand. However, sand bedding can involve other issues, such as high maintenance cost and sand availability, as well as difficulties with manure handling.
Cows standing idle < 15%
An easy way to assess general cow comfort in the stalls is the cow comfort index or quotient. It is defined as the number of cows lying properly divided by the number of cows with one foot or more in stalls, times 100, measured 1 - 2 hours before milking (not applicable in AMS). No more than 15% of cows should be standing idle in stalls at this time. Cows that are standing when they would like to be lying down will get stressed. The mammary blood flow is increased during lying with 25-50%, which is correlated with milk yield. Time spent ruminating is also maximized if cows are lying down.
Climatic conditions in the barn
Climatic conditions have to be checked at multiple spots in the barn, it is not enough to rely on the average of the measurements. Every single spot in the barn has to meet the reference values, otherwise cows will avoid sites with lower quality, thus reducing their available area. This has not only implications for cow comfort but also for the overall performance of the herd.
Compared to human standards cows prefer a relatively cool environment. The optimal temperature range to house high producing dairy cattle is between –5 and +15˚C. Lactating, high-producing dairy cattle have a lower critical temperature (LCT) of between -16˚C and -37˚C , but these temperatures should be seen as indicators only, since the actual LCT can vary considerably depending on factors like housing, breed type and nutrition as well as air movement and precipitation. To obtain optimal conditions for cows, people and equipment, it is therefore important to do an accurate heat balance calculation when designing the barn. The LCT for dry cows is higher and lies between –5˚C and 0˚C. At environmental temperatures above 15 ˚C, lactating cows will reduce their Dry Matter Intake in order to reduce their basal metabolic level. As a consequence, they will produce less milk.
Since cows prefer a cool climate, ventilation needs to be maintained also at temperatures below 0˚C, but the level of ventilation might need to be adjusted to remove moisture and CO2 whilst maintaining an indoor temperature suitable for the equipment, cows and staff. The temperature inside the barn should not exceed 5 ˚C above the outside in order to prevent draft. The relative humidity in the barn should be between 50-80%. Cows on a high production level produce around 10 kg of moisture per day, which is released in the barn, so humidity need to be controlled.
- Free stalls should be designed according to the needs and size of the cows
- Bedding should be soft, clean and, if possible, inorganic
- Cows should have sufficient grip in the stalls
- Floors should provide sufficient traction.
- Floors should be clean and dry.
- Floors should be smooth and in a good condition.
- Rubber will improve walking
- There should be no dirty smell inside the barn.
- The temperature inside should not be >5 °C above the outside
- There should be no draught or dead spaces
- The relative humidity in the barn should be between 50-80%
- Dust and cobwebs are an indicator for poor ventilation
- Cows produce more milk in a more comfortable environment.
- Cows may live longer in a more comfortable environment.