Cow handling is a very important topic because of its impact on milk production, milk quality, milk composition and animal welfare. Canadian and Danish studies have demonstrated that hostile cow handling negatively affected the behavior of dairy cows. In one study, the hostile treatment consisted of striking the cow forcefully with a hand.
In another study, the hostile treatment consisted of striking the cow with a hand, use of a cattle prod, striking the cow on the horn region and flanks and shouting. Cows handled roughly had a 70 percent increase in their residual milk (milk that is not extracted from the udder), thus producing less milk.
Lost milk production is also accompanied by a decrease in fat percentage. Milk fractions in dairy cows contain different amounts of fat. Residual and last milk fractions extracted from the udder usually contain four times more fat than the first milk extracted. An increase in the amount of residual milk will consequently decrease milk fat, in addition to decreasing milk production. Hostile handling also increases defecation, which negatively impacts udder cleanliness and as a result decreases milk quality by increasing the occurrence of mastitis. In addition, cows that are stressed are more restless, moving around more during milking. This change in behavior increases the risk of injury to employees and herd milking time.
Examples of aversive handling practices that increase cows’ fearfulness and stress level include shouting, hitting the cow with a stick (even if it is plastic), using electrical prods, slapping, punching and tail twisting. In addition, dairy employees should always move the cows from the pens to the milking parlor quietly and at a slow pace. Several studies have demonstrated cows treated gently developed less fear for people and thus were easier to manage.
There is no doubt cows can distinguish their handlers, leading to generalizations for their future behavior toward humans. A cow pusher that mistreats cows will create fear in the animals, and this fear will affect their behavior against other employees on the dairy. Animals in general (including dairy cattle) avoid handlers who treat them badly and approach handlers that consistently treat them gently. Other studies have demonstrated differences in milk productivity depending on who was milking the cows on commercial dairies. Cows were most probably scared of some milkers who handled or milked them. All persons that work with cows should remember cows are creatures of habits and should always be treated the same way. Cows also experience an increase in their stress level if they don’t eat at the same time and if they are not milked consistently using the same protocol. Reducing stress on dairies will also help reduce illness and improve production by improving the immune system and dry matter intake (DMI).
Studies have also clearly shown that cows can tell people apart and that colors play a very important role in their ability to distinguish people. This could have a major impact on dairies where employees use the same type of coveralls. For example, if someone wearing a green coverall handled the cow roughly, the cow will fear all employees wearing the same color of coverall. A simple change in the colors of the coveralls might be a helpful technique that could help alleviate the fearfulness of a particular employee that has previously roughly treated the animals. It is not, however, a very practical solution if the offender or other offenders are still working on the dairy. All employees should handle cows gently and consistently all the time. Owners should have zero-tolerance policies against bad cattle handling and should set a good example by gently treating their cattle. Designing proper handling facilities should also be a priority on a dairy, because it will alleviate the stress of both cattle and employees.
So how much milk and money is a dairy losing if cows are handled roughly? Based on the studies mentioned above, we should expect a 70-percent increase in the residual milk when cows are handled roughly. Usually 10 to 15 percent of the milk will be retained in the udder in a normal, nonstressful situation. This means a cow producing 70 pounds of milk a day should have around 7 pounds of residual milk in her udder. If this number increases by 70 percent, the cow would be producing 5 pounds of milk less every day.
In the United States, this would translate into a loss of 1,825 pounds of milk per cow per year and a loss of $43,800 to $51,100 per year in a 200-cow herd, a $219,000 to $255,500 loss in a 1,000-cow herd and a loss of $876,000 to $1,022,000 in a 4,000-cow herd. Even if only 20 percent of the cows have been handled roughly and have developed fear of humans, the numbers are still staggering. The yearly loss would be $8,760 to $10,220 in a 200-cow herd, $43,800 to $51,100 in a 1,000-cow herd and $175,200 to $204,400 in a 4,000-cow herd. Those calculations do not even take into consideration the time lost in the parlor, the drop in milk fat or the premium loss associated with decreased milk quality. PD
Dr. Mireille Chahine, Extension Dairy Specialist, University of Idaho for Progressive Dairyman