Modern dairy herd management practices have increased the frequency with which animals must be handled. Animals must be isolated and restrained for physical examination, vaccination, artificial insemination, pregnancy checks, treatment, dehorning, calving, etc. on a regular basis. Animal handling is critical because each cow in the herd may be handled 40 to 50 times per lactation.

Self-locking manger stalls (headlocks) allow the producer to have several pens of animals ready for support people, who need access to the animals. Headlocks offer flexibility in arrival time and an efficient way to observe, identify and service animals. Dairy facilities need to be designed to optimize the performance of both the animals and humans managing them. Animal-handling options The sorting and restraining activities are independent and can be performed in different sequences.

Dairy producers can sort animals using manual or electronic sort gates or headlocks. With headlocks, animals are restrained in random order and then identified, whereas, sort gates are used to select animals that are then restrained in palpation rails, parlor return lanes, treatment chutes or headlocks. The options selected influence work routines, labor requirements and animal stress levels associated with animal-handling activities.

One person should be able to isolate and restrain an animal safely and conveniently. Animal flow, the path followed by the cow as she is moved around the dairy for milking, feeding and treatment should be considered. Rough or prolonged handling of cattle can be a major source of stress. Stressed animals produce less milk, and milking efficiency is reduced. Stressed cattle are difficult to handle, posing an increased risk of accidents and injuries for handlers and animals.

Possible animal-handling systems

Animal-handling systems can be classified as “home-based,” where the animals are restrained and treated where they are housed; or “treatment area-based,” where animals are restrained and treated in some special area away from where they are normally housed. Home-based systems normally utilize headlocks, where cows lock themselves in place upon returning to a manger full of fresh feed after being milked. The self-locking feature is activated when the animal puts her head in a stanchion to eat.

Treatment area-based systems often use sort gates to separate selected animals from their group as they leave the milking parlor. These sort gates can be manually controlled by the parlor operator or controlled automatically by a computer if animals are electronically identified. Animals sorted in this manner may be directed into a palpation rail (management rail) system or placed in a holding pen and handled using a head chute or some other restraint system.

Headlock-based animal-handling systems

Dairy managers selecting an animal-handling system should compare the cost of headlocks to the cost of a separate treatment area, plus any labor differences over time.

The following are some advantages of headlock-based animal-handling systems:

• There is less traumatic handling of cows since they are treated in familiar surroundings.
• Cows may eat their proper ration while waiting to be treated.
• No time is wasted returning animals to their pen after treatment because they were restrained in their own pen.
• It minimizes the risk of mixing pens of animals following treatments.
• Manger uprights decrease feed wastage and minimize the effect of boss-cow domination of a large section of the feedbunk.
• Large numbers of cows can be automatically restrained.
• Manure from restrained animals is handled with normal procedures.
• Locking cows after milking allows teat sphincter muscles to close before the cow lies down, thereby decreasing the risk of mastitis.
• Parlor efficiency is improved, since animals leaving the parlor do not need to be channeled through a narrow sort lane. • Workers perform several different activities simultaneously while cows are locked.
• Two people can quickly identify and treat a large number of animals.
• Animals not automatically caught in headlocks may be directed into an open headlock or wedged between animals in a row of headlocked cows for treatment.
• It allows flexibility of arrival time for veterinarian and other workers handling cows.
• Animals become conditioned to consistent restraint method that should reduce stress on treatment days. • Animals restrained as a group are much calmer than animals that are separated from the group for individual treatments.
• Animals can be locked away from feed. This can improve animal movement past feedbunks and allows producers to delivered fresh feed to animals.
• Headlocks support the daily heat detection and A.I. of custom breeding programs.

As with all animal-handling options, producers report some concerns with headlocks:

• Initial cost can be a concern, but care needs to be taken to evaluate the “annual cost” (i.e. of all initial costs adjusted for life expectance and all associated labor costs) of each system.
• The noise that some brands of headlocks make as cows access them can be a problem for some producers.
• Since animals are locked along the length of a feedbunk, the walking distance can be extensive for large herds and treatment supplies must be taken to the animal.
• Finding an animal may be difficult since animals are caught and restrained in a random order.
• Heifer housing cost may increase slightly since headlocks should be present to train heifers to access feed through them.
• Workers must handle animals that are not automatically caught differently. Handling these animals can be time-consuming, dangerous and stressful on the animal.

Where have headlocks been used?

Headlocks have been installed and used many different ways. Some of the more typical are:

• Complete pens: The complete feedbunk of a freestall barn is lined with headlocks, and all animals in the group are locked simultaneously. Desired animals are identified, treated or moved before the remainder of the animals are released. This is the most typical use of headlocks and very common in large herds.
• Partial headlocks: Headlocks are only placed on a portion of the feedbunk length and gates used to isolate a sub-pen. Selected animals are pre-sorted and placed in this subpen to be caught and treated, then the gate separating this sub-pen is opened, allowing animals to rejoin their group. This technique can decrease the initial expenditure for headlocks but may complicate animal management.
• Treatment holding pens: Animals are held after being sorted, treated and then returned to their permanent pen. • Removable headlocks Gangs of headlocks can be placed at the feedbunk on treatment days and removed the remainder of the time.
• Individual pens: Workers can use gated pen sides to direct an animal into a headlock to be restrained during calving, treatment, etc.

Recommended headlock management practices

Headlocks, like any other tool, are more effective if incorporated into a complete animal management system that capitalizes on its strengths and avoids weaknesses. If headlocks are to be used, the producer should:

• Allow animals time to learn to access feed through headlock openings. If possible, raise heifers so they are exposed to headlocks at an early age. Purchased animals or mature animals should be given time before calving to adjust. It is not recommended to start this training process with close-up cows.
• If headlocks are to be used in the just-fresh pen to support early lactation health monitoring, animals should be conditioned to their use before calving.
• Avoid selective use of headlocks. A major advantage of headlocks is the ease with which animals access them if they become part of the animal’s normal routine. Removing routine headlock access may decrease the effectiveness of animal catching or feed intake.
• Minimize overcrowding of freestall barns. If there are more animals in a group than headlock openings, dry matter intake may be reduced.
• Animals should not be locked longer than necessary to minimize the time they are forced to stand on concrete away from water and freestalls. Under normal conditions, having cows locked 1.5 to 2 hours periodically should not impact animal health or performance.
• Producers should consider mounting headlocks above the manger in a 10- to 20-degree sloped position. Research has shown that barriers placed at a 20-degree sloped position provided the cows better access to the feed manger and caused less impact on the cows or pressure on the feed barrier than when placed in a vertical position. Sloping headlocks more than this amount may affect the automatic closing ability of the headlock and increase the possibility of damage from equipment moving through the center feed alley.
• The inclusion of headlocks, like the investment in other barn features, should be evaluated and prioritized based on the producer’s circumstances. If the initial cost of headlocks is a concern, because of budget constraints, designs can be selected that allow their inclusion later or placed in only those pens which house animals with high management needs (just-fresh, breeding, etc.).
• Feedbunk management is extremely important to maximize intake and milk production. Whether headlocks are used or not, care should be taken to keep fresh feed in front of animals and to maintain stocking rates which allow animals to access it.

Selecting a headlock brand

The following is a list of features that may be considered when selecting a brand of headlocks:

• Can animals remove their head from the top and bottom of the opening? This helps animals that fall to exit the stall.
• How easy and safe is it to release individual animals? Can fingers get caught when animals are released?
• If a few animals are to be locked in place, how can the remainder of the animals be released, individually or as a group? What is the status of these unoccupied stalls after cows are released? Can other cows enter them, or will they be locked?
• Do uprights have counterweights or some other feature to insure the stall stays open when empty? Will they function correctly considering the slope of the barn and the feed fence slope?
• Can animals be easily released from behind the animal?
• How easy and safe is it to release a downer animal?
• Does the design prevent two animals from entering a single opening and getting caught together?
• How wide is the head opening?
• Are the stalls made of materials that will wear well over time? Is the self-locking control mechanism durable enough not to require regular maintenance and adjustment?
• Is the product made of new materials and been galvanized?
• Do the headlocks catch, do they ride back and forth on the rail causing long-term wear?
• If parts of the stall are removable, how difficult is it for the removable part to be dislodged and get into the manure-handling system?

Conclusion

Knowing how animal management activities will be performed is very important when designing a new or modifying an existing facility. When animal management systems are evaluated, it is important to determine the effects each system will have on the animals, management, facility layout, work routines and labor requirements. All initial costs should be prorated and added to the expected ongoing labor costs to arrive at an estimated annual cost of using each system. Whatever animal-handling system is selected, it should be flexible enough to support daily disruptions and future animal management changes that will inevitably occur. Putting a value on the convenience and flexibility is difficult, but substantial when considering the implications of a structure that will last 10 to 20 years.

References omitted but are available upon request by sending an email to the editor.

Roger W. Palmer is a dairy systems management specialist with University of Wisconsin – Madison.

—Excerpts from University of Wisconsin Extension website