Cows lick each other primarily to bond, reduce stress, and keep the herd socially stable. This behavior, known as allogrooming, is one of the main ways cattle build and maintain relationships. It serves practical hygiene purposes too, but the social dimension is what drives most of it.
Social Bonding and Herd Stability
Cattle are deeply social animals, and licking is their most important tool for building relationships. Preferential bonds between individual cows are established, maintained, and reinforced through mutual grooming. If you watch a herd long enough, you’ll notice the same pairs grooming each other repeatedly. These aren’t random encounters. Cows form friendships, and licking is how they express and sustain them.
Beyond individual friendships, social licking holds the broader group together. It reduces tension, calms conflicts, and reinforces group cohesion. Research published in Frontiers in Veterinary Science found that certain cows in a herd seem to take on the role of social connectors, grooming widely across the group rather than just with close partners. These individuals may function as stabilizers, keeping the herd’s social fabric intact. The behavior also operates on a kind of cooperative reciprocity: cows take turns being the groomer and the groomed, so both benefit over time.
It Physically Relaxes the Cow Being Licked
Social licking isn’t just emotionally comforting. It produces measurable physiological changes. Research measuring heart rates in dairy cows found that being licked lowered a cow’s heart rate by about 1 to 2 beats per minute on average. When cows were standing, the calming effect was even stronger, with heart rate dropping by 2.4 to 3.8 beats per minute during a grooming session. Researchers interpret this heart rate decline as a sign of relaxation and positive emotional experience.
Interestingly, the cow doing the licking doesn’t get the same benefit. In some cases, the groomer’s heart rate actually increased slightly, especially when licking the other cow’s head or neck. This suggests the act of grooming requires some effort and attention, while the receiver gets to simply enjoy it.
Where Cows Prefer to Be Licked
Cows don’t lick each other randomly across the body. The most commonly groomed areas are the ventral neck (the underside of the neck) and the withers (the ridge between the shoulder blades). These are spots a cow can’t easily reach on its own, which makes social grooming genuinely useful for hygiene and comfort. The lateral chest, by contrast, gets licked far less often.
This preference is so consistent that researchers have used it to study how cows respond to human touch. When people stroked cows on the neck or withers, mimicking where cows naturally groom each other, the animals became less fearful and more willing to approach humans. Stroking the chest, a spot cows rarely groom, had less effect. The takeaway: cows have specific “sweet spots” shaped by their social grooming habits.
Mothers and Calves
The very first licking a cow experiences comes from its mother, and it serves critical survival functions. Immediately after birth, the dam vigorously licks her calf to clear amniotic fluid from its airways, stimulate breathing, and prompt the calf to urinate and defecate for the first time. This licking also helps the calf dry off and warm up.
Just as importantly, maternal licking stimulates the calf to stand and begin nursing. This matters because a calf’s ability to absorb protective antibodies from colostrum (the mother’s first milk) is highest right after birth and begins declining within as few as six hours. By encouraging the calf to get on its feet quickly, the mother’s grooming directly supports the newborn’s immune development. Cow-calf pairs that are housed together spend roughly 10% of their time grooming each other, with the mother focusing on the calf’s head, ears, and neck, areas the calf can’t clean itself.
Hygiene and Parasite Control
The practical cleaning function of social licking shouldn’t be overlooked. Cows accumulate dirt, dead skin, and parasites in areas they can’t reach with their own tongues or by rubbing against objects. A herdmate’s rough tongue scrubs away debris, helps manage external parasites, and keeps the coat in better condition. This is especially valuable for the head, ears, and upper neck, where flies and ticks tend to concentrate.
When Licking Becomes a Problem
Normal social licking is healthy, but abnormal or excessive licking can signal welfare issues. Calves raised on liquid-only diets without access to solid feed often develop compulsive oral behaviors: sucking, licking objects, tongue rolling, and excessive self-grooming. This self-grooming leads to hair ingestion, which can form hairballs (trichobezoars) in the stomach that impair digestion and compromise the calf’s health.
Social licking can also serve as a route for disease transmission. Leptospirosis, a bacterial infection of global concern in cattle, spreads through contact with contaminated bodily fluids. Behaviors like licking and sniffing another cow’s genital area put animals in direct contact with mucous membranes, creating opportunities for the pathogen to spread. Tightly bonded groups of cows that groom each other frequently are at higher risk of passing infections within their social cluster.
What It Tells Farmers
The frequency and pattern of social licking in a herd is a useful indicator of animal welfare. Cows that groom each other regularly are generally calmer, less stressed, and better socially adjusted. A sudden drop in grooming behavior can signal illness, pain, or social disruption. Providing environments that encourage natural social behavior, including enough space for cows to interact freely and tools like automated grooming brushes, supports the kind of low-stress social environment where mutual licking thrives.
Automated brushes, increasingly common in dairy operations, promote natural grooming and scratching behaviors. They don’t replace social licking between cows, but they give animals another outlet for the physical sensation of grooming, which can reduce boredom and complement the social grooming cows do with each other.