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Bottlenecks in the milk factory: The ABCs of cow comfort

Gordon A. Jones, DVM, Falls Animal Health, Inc. Published on 18 December 2008

Dairy operations can be subdivided into sets of tasks. When these tasks are thought about individually, they are very simple. Collectively, these tasks represent the overall operation of successful dairy production.

Think of the dairy as a factory that manufactures milk and the producer as the CEO of the factory. But never think of the cow as a piece of machinery. Dairy operations have many inputs, such as labor and feed, which ultimately result in profit or loss.



A dairy can be thought of as a pipeline, inputs in one end and profit out the other end. In the middle of the pipeline are tasks and processes which produce milk. Unfortunately, there can be bottlenecks (dents in the pipeline) that restrict the flow of milk (profit). A producer’s or manager’s job is to identify the limiting bottleneck and eliminate it. In regard to dairy facilities, potential bottlenecks can be subdivided into three major areas:

1. air

2. bunk space

3. comfort


Ventilation must be maximized for cows to achieve top performance. The cow comfort range for temperature is between 10°F and 70°F. When temperatures are below this comfort range, the cow will need to consume more feed to produce heat needed to remain comfortable (maintenance). But when temperatures rise above the cow’s comfort range, she must use lots of air to reduce or maintain her body temperature (maintenance needs). The cow’s only way to cool herself is to use her respiratory system to exchange heat. Without air movement, heat stress increases, dry matter intake decreases and, therefore, milk production drops. Dairy facilities need to be designed to enable cows to have access to an unlimited fresh air supply.


To enhance performance, the first place to increase the air flow is where cows eat and spend the majority of their time. Fresh air increases appetites. Take a critical look at the inside environment. The side height of the barn should be 12 feet and the sides open to allow air to flow freely. All obstructions on the sides of the building, such as boards, should be removed to encourage air flow. Bird netting used on the sides of buildings can reduce air flow by as much as 15 percent. When needed, use open, narrow bird netting.

Another area where good ventilation is critical is in the holding area, where cows can be subjected to the single-largest source of heat stress. Here, cows are held closely together, potentially for long periods of time. The most important place to locate fans is in the holding area. Next, producers should install fans over feedbunks and, when needed, over freestalls. The exact amount of air (cubic feet per minute) needed by dairy cows has not been determined, but it is the author’s experience that it is better to error with air on the high side – more air movement makes more milk.

Look outside buildings to observe the surrounding environment. Beware of wind shadows, such as an empty field that will have 12- to 14-foot-high corn during the summer. A corn field located close to a barn can obstruct air flow into the barn.

Bunk space

Usually, the first limiting factor (bottleneck) to milk production is dry matter intake. It is important to realize the last one pound (lb) of dry matter intake (DMI) consumed will yield 2.5 to 3 lb of milk. In terms of feed cost and resulting milk yield, this means that 8¢ of feed (1 lb) will yield approximately 36¢ worth of milk. Troubleshooting dairies for a DMI bottleneck is simple – just look at factors that limit feed intake. Bunk space should be adequate to allow every cow to eat at the same time. Allow 2 feet of bunk space per cow, except when milking three times per day (then 1.5 feet of bunk space per cow is sufficient).

The major feeding periods are after each milking. The first cows out of the parlor will be the first ones to eat and will be finished at the feedbunk before the last cows exiting the parlor come to the bunk. The largest error one can make when feeding cows is to not have feed in the bunk when cows exit from the parlor.

The bunk surface must be smooth and should be 4 inches higher than the cow’s feet. This keeps the cow’s head down in a natural grazing position, which increases saliva production by 17 percent. Saliva buffers the rumen. Another factor to consider in feedbunk height is higher feedbunks increase feed tossing. Provide 5 percent to 8 percent extra feed (weighback) in the bunk every day. This helps ensure that every cow receives sufficient nutrients.


Water is vital to milk production. Provide at least two waterers per group and at least 2 feet of waterer space for each 10 to 15 cows. To maximize production, water should be available immediately upon exiting the milking parlor. This is extremely important as cows consume 30 percent of their water requirement within the first hour after being milked.


Comfort includes lying down space, floors and heat. When cows lay down, they increase the blood flow to the udder by approximately 28 to 30 percent. This means the lying cow makes more milk compared to the standing cow. Lactating cows should be allowed to do only three things daily:

1. stand to be milked

2. stand to eat

3. lay down, chew her cud and make milk

Freestalls need to be inviting for the cow to choose to lay in them. Freestalls that are not used by cows usually fail in one of four areas:

1. lunge space

2. neck rail position

3. cushioning

4. air and vision

Lunge space

The first reason a freestall fails is lack of lunge space. A cow needs forward or side lunge space. That means the freestall should be 8 feet long if the cow is alone. If the cow is nose-to-nose with another cow, then the freestall can be shorter and each stall can share lunge space as long as there is no obstruction above the height of the brisket board. If using short (7 or 7.5 feet) freestalls, use a divider that allows sideward lunging.

Neck rail

The neck rail must not interfere with the cow entering the stall. That is, it should be far enough back (66 inches) and high enough (44 inches) that the cow can enter the freestall completely with all four feet. Then, the cow can kneel forward and lay down. If the neck rail is too far back, the cow cannot bring her back feet into the stall, and she then lays half-in and half-out of the freestall. If the neck rail is too low, the cow hits her neck on the rail as she tries to rise.


Cushioning is also very important to encourage freestall use. If the stall floor is hard, there is very little incentive to lay in freestalls over the alleys. The bedding of choice is anything which provides 4 inches of cushion, absorbs moisture, prevents friction and does not promote the growth of bacteria.

Sand is the ideal cow bedding but not the ideal manure additive. Cows show a preference for sand bedding over other bedding options. Sand depth should be at least 4 inches. Sand must be free of clay or dirt, and it must not pack or become firm. Mattresses for cows are great if one remembers that they only provide cushion. Bedding needs to be provided on top of mattresses for moisture absorption and friction prevention. Other bedding choices could include chopped straw, sawdust, dried manure or corn stalks.

Air and vision

A cow also needs air movement while laying down. If freestall walls are not open down to the cow’s face level while laying, she may refuse to use the stalls during hot weather. The cow would choose to remain standing in better air flow areas than to lay down facing a wall with limited air movement. And, due to the cow’s unique vision (320° view), she prefers a freestall or position that does not limit her view of the surrounding environment.


Bottlenecks in the milk production pipeline can be avoided by carefully evaluating the cow’s environment. Ensure facilities have good ventilation, provide sufficient bunk space and waterer space and make an environment conducive to cow comfort and higher milk production. PD

—Excerpts from ADM Alliance Nutrition Dairy website