Weaning early is a powerful drought weathering strategy.
Major droughts occurred 29 times on the Great Plains and Canadian Prairies between 1700 and 2000.
“They lasted a total of 99 years,” K.C. Olson of Kansas State University said recently during the Western Nutrition Conference in Saskatoon.
“One third of the time we are in a drought …. Having a mitigation strategy is just good business.”
Olson said cattle producers without a plan give up equity every time a drought occurs.
“Most producers can find ways to break even during drought,” he said.
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Australian consultant John Black said livestock producers in his country go through drought even more often than those in North America.
“We have found ways to reduce your exposure to drought. We have some producers that move into their mitigation plans at the first sign of drought. They are often the ones that not only break even during dry times, they quite often show small profits. So it can be done.”
Black said any strategy that saves rangeland from overgrazing has been shown to make money.
Being prepared to protect pasture is a crucial aspect of western grazing strategies, added Olson.
“You can start by reducing the load on the pasture, but that doesn’t necessarily mean you disperse the herd. First try to pull those calves off earlier.”
Early weaning can be performed on calves as young as 30 days, but 60 to 150 days is generally considered most effective.
Typically in North America, calves remain with their dams for 180 to 220 days. When lactation ceases, cows reduce their consumption of feed by 30 to 50 percent.
The cow’s condition also improves, it rebreeds sooner and forage is conserved.
“Body weights of calves at 205 days that are early weaned properly are the same as those of calves left on the dams for the same period of time,” Olson said.
“Better, the early weaned calf can often be harvested sooner and has better overall health when entering the feedlot.”
Black said the first mistake producers make when a drought hits is trying to wait it out.
“It’s going to rain. You know it’s going to rain. When it doesn’t rain you’ve already done in your forages.”
Olson said there are few disadvantages to weaning early, other than added feed for the calves, which is offset by improved forage condition.
“Use objective measures of your forage and when you reach the point where your agronomist says whoa, be prepared to wean,” he said.
The calf is a functional monogastric in the first three weeks of life, consuming only milk. It’s not long, however, before the bacteria, fungi and protozoa necessary to begin fermentative digestion begin colonizing the rumen.
Research has shown that earlier exposure to feed causes the rumen to convert to full function as early as 30 days after birth.
“A fully functioning rumen isn’t the only factor, though,” Olson said.
Despite calves having passive immunity to many diseases, recent research at the University of Nebraska has shown vaccinations can develop improved immune function in animals younger than 120 days.
“Dehorn and castrate as early as possible if early weaning is a consideration. Weaning is a major stress and lessening that load is important,” said Olson.
“You want to perform those first clostridial and respiratory vaccinations two to three weeks ahead of weaning. Booster vaccinations for viral diseases and treatments for internal and external parasites should be done the day the calves are separated from their dams.”
He said the Nebraska research also showed that fly control is beneficial at this time.
“You’re preconditioning now. That can have value later to the feedlot owner, so keep that in mind when you begin thinking about marketing.”
Olson said the preconditioning costs $25 to $45 per head, but those costs are usually recovered through reduced death and disease and increased weight gain.
Calves are able to eat two percent of their body weight on a dry matter
basis within 10 days of weaning.
Calves should be given high quality hay that can be gradually swapped for a high quality, nutrient-dense concentrate feed that maximizes palatability.
Temporary feed bunks should be added to weaning pens that are perpendicular to the fence line, interrupting calves as they move along the fence seeking their dams.
Water systems should be allowed to temporarily overflow so calves can identify the source as they move around the pen.
These methods can be abandoned once a few animals have found pen side water bowls and feed troughs, said Olson.
Calves should be sorted regularly for body weight so that mixed pens are avoided, reducing size competition issues.
While the calves consume concentrates, the cows consume less forage material. Pre-weaned calves in a conventional weaning period also consume up to two kilograms of forage per day between 30 and 150 days of age.
In an early weaning program, cows will have a day of grazing for every 3.3 days that a calf is early weaned.
“In a drought or on marginal land that will buy a lot concentrate (feed),” said Olson.
Traditional weaning
- A 1,300 lb. cow with calf at side consumes 12.3 kg/day of dry matter forage.
- Calves consume an average of 1.9 kg per day of dry matter forage in the pre-weaning period.
- No calf consumption of feed concentrates or hay.
- Cows show reduced body score while calf is nursing. A cow on drought-stressed forage can be expected to perform poorly and deliver a less than average body score.
- Cows have longer post-partum anestrous period, conception rate and increased embryo loss associated with lower body scores.
- Higher winter feeding costs as cows recover from later weaning.
- Higher mortality and morbidity rates than with preconditioned calves.
Early weaning
- A 1,300 lb. bred or dry cow consumes 10.9 kg/day of dry matter forage; 42 kg/month or 1.4 kg/cow saved on cow without calf each day.
- No calf consumption of pasture forage.
- Calf consumes two percent of body mass of a 75-85% daily feed concentrate ration. The cost of the feed ration and handling in pens is a variable cost based on farm structure and labour components.
- Cows show improved body score, conception rate and embryo retention.
- Lower winter cow feeding costs due to better condition in fall.
- Preconditioned calves in the feedlot or in backgrounding show improved health, better antibody development and exhibit less stress because they are not experiencing dam separation anxiety.
- Savings in range forage with early weaning.
- Reduced forage demand by 3.3 kg dry matter per day or 99 kg/month per cow. This provides an additional day of cow grazing for each day the calf is weaned early. A calf weaned at 50 days on a pasture grazing program of 220 days would return 51.5 days of potential grazing for each cow.
Sources: Kansas State University, University of Nebraska, Mississippi State University, John L Black Consulting, Australia, Western Beef Development Centre, University of Saskatchewan
