How do you know it’s weaning time in ranching country?
That’s easy. It’s the only time of the year that the bawling of cows and weaned calves is loud enough to drown out the howling coyotes.
But what’s music to the ears of the ranchers anticipating the arrival of their annual paycheque is actually the sound of cattle in the throes of emotional distress, according to Dr. Joe Stookey, a researcher at the Western College of Veterinary Medicine in Saskatoon.
“Weaning is the most stressful thing that we impose on our animals, no doubt,” Stookey said in a presentation on ways to minimize weaning stress at the recent Manitoba Grazing School.
Cattle, even after 10,000 years of domestication, are a herd species that want to stick together. Bulls may bellow out challenges to their rivals across the fence, but cows and calves seldom vocalize, except when under stress. That’s because prey animals have learned to avoid obvious displays of weakness which attract predators.
Calves at six months of age bawl and mill about for three to five days after separation because they fear that if they can’t locate each other, their survival prospects are dim.
“We know that they’ll survive, but the calf hasn’t gotten the memo,” said Stookey.
Temple Grandin’s famous animal- welfare audits at slaughterhouses specifically target vocalizations on the way to the kill chute, he noted, and if more than three are heard per 100 head, the whole operation flunks.
“If you fail, McDonald’s won’t buy,” said Stookey. “If three vocalizations can fail a slaughter plant, what the heck are we doing on the farm? We’re failing big time.”
The traditional method of weaning, where calves are abruptly separated from their mothers and loaded onto a truck bound for market, increases stress, which leads to immunocompromised animals.
“More calves are treated for disease and health complications at weaning than any other time in their life,” he said, adding that the term “shipping fever” should be changed to “weaning fever.”
Transportation is a stressor, but it seldom causes problems by itself, unless combined with weaning stress to create a “synergistic” effect greater than the simple sum of both.
“We can’t change the fact that we have to transport them, but we can improve on how we wean them,” said Stookey.
He showed results of a study showing that unvaccinated calves exposed to M. Haemolytica, a bug that causes acute respiratory distress, were 2.5 times more likely to die within first three to four days when weaned abruptly compared to those weaned gradually.
“What’s the disadvantage of pre-conditioning? You don’t get paid for it,” said Stookey.
That’s why an estimated 40 per cent of all calves are weaned and shipped the same day. Twothirds are also shipped unvaccinated for the same reason, he added.
“If you had a pre-conditioned calf, took it to the sale barn, and it was quiet and calm, those order buyers don’t know the difference between a calf that’s overweaning and a calf that’s sick.”
In an attempt to determine the exact cause of weaning stress, whether it is the lack of milk or the lack of mothering, Stookey and his fellow researchers tried a variety of experiments including dry “trainer” cows in feedlot pens, fenceline separation, and plastic nose clips.
There was no evidence that putting adult cows in with the freshly weaned calves helped, he said.
Two-stage weaning, where nose clips are first used to cut off the milk, and then the calves are separated from their mothers after a period of time, almost eliminated vocalizations and arguably stress on the part of both.
The calves fitted with nose clips tried to suck for the first couple of days, then gave up with a minimum of complaints. During the two days immediately after, the calves were separated from their mothers, the researchers were surprised to find very little vocalization or milling about.
“When you spend four days without nursing, you’re weaned,” said Stookey. “Weaning in the presence of their mother made all the difference.”
He concluded that taking away both the milk and mother at the same time was the true cause of weaning stress. Taken separately, they cause minimal stress, but together, the stress effectively “blows their circuits.”
Calf health and feedlot performance improved, but the downside to two-stage weaning is the need to run the calves through the chutes two times, once to install the nose clips, then again to take them out.
Critics point out that extra handling for nose clips causes stress, too, he noted.
“Running cattle through the chute is stressful, but there is no way it trumps the stress of five days of bawling and calling,” said Stookey. daniel. [email protected]
“Ifthreevocalizationscanfailaslaughter plant,whattheheckarewedoingon thefarm?We’refailingbigtime.”
– DR. JOE STOOKEY