After a cow gives birth, she starts sniffing and licking her newborn calf. In this bonding process, she learns to recognize her calf, and commits to caring for it and protecting it. Her actions are a complex blend of hormonal-induced and learned behavior. Mature cows that have had calves before are more apt to quickly and successfully mother their offspring than first-time heifers. It's important to understand maternal behavior and how to help prevent confusion or stress at calving time.
Experience is part of the equation, since older cows tend to be more consistent mothers than heifers, but hormones are the key factor.
"A cow is most receptive to wanting her newborn calf at the time of birth," says Dr. Joseph Stookey with the Western College of Veterinary Medicine, Saskatoon, Saskatchewan.
"Some cows become receptive up to a week before they calve. Their hormone pump is already primed, and reaching a level that makes them receptive to any new calf, even if it's not theirs," he says.
"At the other end of the spectrum are cows that don't have proper hormone profile or levels, and they don't want their calf. We see this most often in first-calf heifers, or in some of the females we assist with birth, or those with calves delivered by C-section. If it's a rodeo getting the cow in for assistance, or she undergoes too much trauma, she may be less interested in the newborn calf. Other hormones may be overriding the system due to stress, pain, or some of the drugs used during a C-section," Stookey says.
Changes in progesterone and estrogen levels initiate the birth process, but rising oxytocin levels trigger maternal behavior. Oxytocin is released in the brain during birth. "Its presence in the olfactory bulb of the brain helps explain the role of smell and the importance of odor in the bonding process," he says.
"Cervical stimulation is crucial for proper hormonal triggers," Stookey explains. Release of oxytocin is caused by stretching/stimulation of the cervix and birth canal. Gradual dilation of the cervix as the feet and head of the fetus push against it with each uterine contraction, and passage of the fetus through cervix is one of the main triggers for oxytocin release.
"If you do a C-section there isn't much cervical stimulation, since the fetus doesn't come through it. This could be a factor when the cow doesn't mother her calf very well. Analgesic drugs used during a C-section to block pain can also interfere with oxytocin release," Stookey says.
First-calf heifers produce less oxytocin than cows that have had previous calves. This may be why some heifers reject or abandon their calves. "Giving birth seems to prime the system and allows for release of larger quantities of oxytocin with subsequent births. Heifers are less experienced than cows, and also have lower levels of oxytocin release in the brain during calving," he says.
A few heifers seem indifferent to their calves, but within 12-24 hours become motherly. In some instances, a heifer may not have much milk, and then as her milk starts to come in, she becomes interested in her calf. Oxytocin is associated with milk let-down, and is also closely tied to maternal behavior. If a heifer is indifferent, or rejects her calf, she may become more receptive to motherhood by assisting the calf in nursing. The act of suckling stimulates release of oxytocin.
"If you stimulate milk let-down a few times by helping the calf nurse, the hormone comes on board and improves maternal behavior. Oxytocin can switch off aggression, reluctance or fear, and turn it into interest and mothering," Stookey says.
The cow or heifer reacts to sensory clues provided by the calf and birth fluids. If she's lying down as the calf slides out of the birth canal, she will generally raise her head to get a glimpse of the calf.
"Any movement of the calf at this stage (raising its head or shaking its head) is a strong stimulus to the cow to get up and turn around to smell the calf and start licking it. Calves that are vigorous elicit a stronger response in the cow; they are more attractive to the cow than a weak or dead calf," Stookey says.
"The smell and taste of birth fluids is another strong attractant that stimulates the cow to lick the calf. If the mothering process is interrupted before she licks the calf, the likelihood for rejection increases," he says.
If the calf is pulled, birth fluids should be smeared across the muzzle and tongue of the dam following delivery. "This seems to jump-start the maternal response. Simply putting the newborn in front of the mother may not be sufficient stimulus to start maternal behavior, especially for first-calf heifers. Pouring feed onto a newborn calf may entice some reluctant mothers to approach the calf and come in contact with birth fluids as they eat the feed. Any attractant that stimulates the cow to lick the calf would be useful," Stookey says.
Cows too closely confined don't get a chance to leave the herd and find a private place to calve. Dr. Jack Whittier, extension beef specialist at Colorado State University, says allowing cows and heifers plenty of room can help prevent problems. "Then the calf and its mother are not distracted by herdmates or dominant individuals that might disrupt the bonding process," Whittier says.
"There are always a few, particularly heifers, that don't have a strong mothering instinct right away. Allowing them to calve out in the field by themselves is best, and then moving them into a pen by themselves with their calf if they don't bond quickly, can sometimes work - so they can continue the bonding process without interruption by herdmates. Getting from point A to point B can be a challenge, however, and may confuse a heifer more and make it worse than if you'd left her alone," he says.
If weather necessitates confinement for shelter, diligent monitoring and quietly moving each calving female to a private place to calve - her own barn stall - will prevent problems. It's best to move the female before she calves. Trying to move her and the calf afterward can be disruptive, especially for a heifer. Older cows are more likely to follow their calf, while heifers may become confused, especially if they haven't had much time to lick and bond with the calf. Often the heifer or cow will run back to the birth site, looking for the calf.
"There many tricks to get a cow to claim a calf," Whittier says. "Proximity is important, keeping them close to one another. Often if you just give the heifer a little time, things work out."
"If a cow is very aggressive, kicking or hitting the calf with her head, restraint may be needed so she won't hurt the calf. This is better than beating on her. I've seen cows overly abused when they kick the calf. Hurting the cow does more harm than good." It won't improve her attitude, and may make her harder to handle.
If a first-time mother is confused or aggressive, ignoring her calf or attacking it, she will often change her mind after nursing. It may be necessary to tie her or put her in a headcatcher, with a side that swings away, for restraint while the calf finds a teat.
Often it just takes one nursing to change her mind. But some heifers are still determined to attack the calf. The calf should be protected during the transition period, in a small pen next to the cow's pen, or a paneled off corner of her stall - letting it out to nurse while the mother is supervised.
Feed the cow only at nursing time so she'll focus on eating rather than attacking her calf or moving away from it. Stand guard while the calf nurses, then put it back in a safe corner. It may be necessary to hobble the cow so she can't kick the calf.
If the cow won't stand still, leave a halter on her, dragging the halter rope. She can then be tied or held while she eats hay, enabling the calf to catch up with her and nurse. After dragging the rope and stepping on it a time or two, she quickly learns to respect this restraint.
It may take two days or two weeks to change her mind about being a mother, but she will eventually accept the calf. Once she starts showing interest in it, mooing at it or licking it as it nurses - no longer trying to hurt the calf - the pair can be left together. Keep the cow hobbled, however, until its clear she won't kick the calf.
Another trick that often works with an aggressive heifer is to lightly tranquilize her during the first day. This may change and mellow her attitude enough that the calf will be able to nurse. Ask a veterinarian about proper use of tranquilizers.
For a heifer that ignores her calf, sometimes bringing a dog to her pen or stall will stimulate her mothering/protective instinct and she'll suddenly become interested in protecting the calf. This may jump-start more motherly behavior.
"Patience, good husbandry, astute observation and being in tune with the cattle are key. Look for ways to overcome the various problems," Whittier says. Sometimes a physical problem is the reason a cow or heifer is slow to mother the calf. A heifer with a swollen, painful udder (with hard edema or "cake") may kick at her calf because it hurts. An injured teat or frostbitten teats may be too sore for the cow or heifer to allow her calf to suckle.