When health issues are carefully managed, early weaning calves offers a lot of benefits in good years, as well as drought-stricken years.

Many people are talking about the economic benefits of weaning calves early: the increased productivity for the dam, the high efficiency of a young calf. But what are the health issues at stake for the calf?

Some see early weaning as a technique to resort to when a producer has run out of resources or needs to get thin cows rebred – not one that could be of benefit to the calf. “From the calf standpoint, there is no health advantage,” says Keith Lusby, PhD, PAS, University of Arkansas. “The health implications are probably the major factor to consider – the calves have to have extremely good health. It also has to be coordinated with a nutritionist and a veterinarian.”

Lusby says the first question is: How early is early? “There have been many successes, but there have also been disasters, usually when calves were weaned too young, and too many were weaned at the same time,” he notes. “It is easier for a university to wean 60 calves than for a ranch to wean 400 head.”

But J.J. Hovde, DVM, of Hovde Veterinary Clinic in Sidney, Mont., has seen some health advantages to early weaning in dry years. “In some drought years, we’ve seen an increase in respiratory disease in calves on pasture,” he says. “It’s an advantage if you get them vaccinated and have them in a pen where you can do a better job of pulling and treating.”

At Western Livestock Consulting in Bridgeport, Neb., Phillip Kesterson, DVM, has been working with a client on early weaning, even in good, non-drought years, and thinks the health advantages are there. “Younger calves, 120 days ballpark, seem to adapt to the weaning process and feedlot environment more easily,” Kesterson says. “They appear more resilient to change and less dependent on their mothers.” He’s been weaning winter-born calves in July and August. “We thought heat would be a problem, but it’s been a benefit. You don’t have the fluctuations you’d have in October, and it’s easier on the calves. All the things we thought would be difficult haven’t proven to be.”

 

Phillip Kesterson, DVM, (right) here with early-weaning client Kirk Laux, says as they grow, early-weaned calves appear more resilient to change and less dependent on their mothers.

Passive immunity
Younger calves still have passive immunity from their dams, and there are two sides to that fact. “One thing this means is that they may not respond to vaccines like an older calf would,” Lusby says.

But passive immunity might also work in favor of early weaning. “We feel the immune system is helping us more at that age,” Kesterson says. “Immunologists tell us they have high passive transfer from their mothers. That hits a low at six to seven months of age, when they get their own active immunity. We have fewer pulls and less mortality in the first 30 to 60 days than with 600-pound calves.” When there is sickness, he adds, treatment costs are less because less medicine is needed for a small calf.

Hovde finds the younger immune system doesn’t behave a lot differently from that of a 6-month-old calf. “On a proper vaccination program, they do well,” he says. Normally, he gives a Pasteurella, a 4-way and a 7-way vaccine at branding and then the same treatment at preconditioning, three to four weeks before weaning, early or not. “You always worry about response to vaccines the closer they are to birth because of colostral interference,” Hovde says. “But even if they don’t respond well at the branding vaccinations, they’ll respond better at preconditioning.”

Deworming is crucial as early-weaned calves appear to be especially susceptible to intestinal worms, and getting rid of the parasites will help them respond to vaccines. “We might worm them two or three times over 200 days,” says John Arthington, PhD, University of Florida.

There’s also an economic argument for it. “A lot of programs have gone away from implants; this is a way producers can pick that loss up. It’s as much an economic as an immune system issue,” Hovde says. “We’ve seen a minimum of a 10-pound increase – and an all-around healthier calf.”

Dry lot or pasture?
The day of early weaning needs to be well planned. “Have it all coordinated to go like clockwork,” Lusby says. “Keep them as comfortable as possible. They are too brittle to leave them standing out in the sun all day.”

Afterward, it’s preferable to keep them on the ranch. “The producer can just sell the calf; there’s always a market for lightweight calves,” Arthington says. “But they are so highly efficient if kept on the ranch and reared to the normal weaning age, we recommend keeping them.”

The primary disadvantage to this is that the producer has to set up a system to care for those calves. “When you first wean, they’re better off in a small dry lot pen where they can learn to eat,” Lusby says. They should be spread out in their pen, about 20 head per – grouped by size and age. Crowding makes it difficult to evaluate their health. “After about two weeks, it’s good to get them out into pasture, ideally a grass trap, to get them away from the dust and mud, where they can eat hay and mixed feed. In a large grass pen, they’ll walk the fence – they’ll walk themselves sick.”

When they go onto pasture, that pasture needs to be fenced well. “We call them calf nurseries because it helps to get people to think about them a little differently,” Arthington says.

     

J.J. Hovde, DVM, says when starting early weaning, it’s important to feed calves a good quality concentrate with no fermented feed for three to four weeks.

John Arthington, PhD, says deworming is crucial as early-weaned calves appear to be especially susceptible to intestinal worms.

Keith Lusby, PhD, says producers must have a system in place to properly care for early-weaned calves.

In Florida, there is pasture year round. “Gulf Coast states – assuming fall calving – can utilize winter annuals,” says Arthington. “With a small amount of supplement, 1.5 percent of body weight, the calves do well.”

In one study, calves on winter perennial pasture were provided with self-feeders with soybean hulls and cottonseed meal blended to 16 percent crude protein. “There, they tend to eat 2 percent of their body weight,” says Arthington. “Some people think grazing on winter annuals is difficult. But these 200-pound early-weaned calves only eat 6 pounds of dry matter a day; they are much gentler on a fragile forage base.”

What they don’t have in Florida are feedlots, so all market calves are shipped out of state. “We have become interested in early weaning because of the health and stress on the transported calf,” Arthington says. One of his first early-weaning studies showed that early-weaned calves had much better feed efficiency in the yard, compared to their normally weaned counterparts. No calves showed any illness, but when blood samples were taken, the inflammatory response was greater in the conventionally weaned calves. “That has an energy cost to it, which could be going to something else,” Arthington says. “The differences in efficiency were greatest in receiving and growing periods, but also carried out throughout the entire feeding period.”

In the feedyard
When early-weaned calves go to the feedyard, Kesterson says, “Less is done on arrival. We’ve focused on making sure they get dewormed. A lot of calves just get dewormed and get an intranasal vaccine, and then go in the pen. Then in several weeks or a month, you can go ahead with the traditional program.

We have delayed branding at the feedlot until a later trip through the chute. It’s stressful; we do it once they’re acclimated.”

In the pen, early-weaned calves have the same disease challenges as older calves, but they have greater ability to withstand it. “The early-weaned calf is incredibly resistant,” Arthington says.

Most any feedyard is adequate, though there might be a problem with them trying to crawl through the bunk. Some people find it helpful to shorten the depth of the pen, as smaller calves need less square footage to feel comfortable and having them in a smaller space helps to keep dust down. For best results, there should be adequate facilities to sort into groups of similar size and age.

Hovde’s clients early wean when calves are about 4 months old, but because the calving season is 50 to 60 days, some of the calves will be only 2 months old. “They do fine, but at that age, they don’t have great rumen function,” Hovde says. “But once you get them on feed, it kickstarts rumen function. It’s important to feed them more like a monogastric animal, with a good quality concentrate with no fermented feed for three to four weeks.”

Two months, Lusby says, is about the youngest an early-weaned calf should be, so their diet is not totally milk. “At the university, when they say they will wean at 2 months, they know when the calves were born. They never wean at less than 6 weeks,” Lusby says. “At the ranch, they’re going to be tempted to bring in the whole calf crop. It’s difficult to know how old the youngest calves are. I think this is why ranches aiming at a 120-day-of-age early program have fewer health problems.” This may be the major obstacle for producers wishing to use early weaning.

A carefully designed ration is essential. “The calves don’t eat much,” says Kesterson. “That could be a problem if you don’t have the right nutritionist.” They need a very palatable mixed ration with protein and very good trace mineral balance and energy level, one that they can eat quickly but won’t make them sick. “The total pounds of ration is low; it’s hard to get used to feeding that little amount of ration in the bunk space,” he adds.

Producers need to be willing to grow calves a little longer than they normally would and to beware of the danger of getting them too fat before they’re grown.

Who shouldn’t wean early
Seedstock producers probably should not early wean, Arthington says. “It’s impossible to put together accurate EPDs on weaning weights or maternal values of the mother on early-weaned calves,” Arthington says. “Also, people in the business of raising replacement heifers might not want to. There is very little data on whether her fertility is normal in subsequent years. We don’t see any reason it wouldn’t be. Some current research even suggests they might be more fertile. I think we need more research in this area.”

For his clients who lease grass, there may be no argument for early weaning. There’s no advantage to pulling the calves off,” Kesterson says. “It costs the same whether they have an animal in there or not.”

Calves that show any indication of being unwell should be left with their mothers. “Have someone take a good look at the calves to see that they’re healthy,” Lusby says. “Don’t wean them if they look sick.” As far as sickness goes, it’s usually the same things expected with lightweight stocker cattle: respiratory disease and diarrhea. “The same things happen as happen with stockers, but faster,” Lusby says. “And when you get problems, they tend to linger longer.”

Those are the factors that have slowed the broader acceptance of early weaning. “If it weren’t for the health problems, we’d be doing this nationwide,” Lusby says. “Little calves are extraordinarily efficient, almost like a pig.” Early weaned calves usually get slaughtered earlier as well, and data from the
University of Illinois and The Ohio State University show that a younger slaughter age goes with a higher percentage of upper Choice carcasses.

Some see great promise in the practice of early weaning. “I’d say all producers should consider early weaning as it applies to their operation,” Kesterson says. “The cow can utilize grass better than the calf; the calf can use a grain-based diet better. But changing people’s paradigms is the single biggest factor.

Immunology and the early-weaned calf

Most research related to early weaning has been in the realm of production parameters. As a result, very little is known about the effects of early weaning on the postnatal development of the immune system.

That system is competent at birth, but immature; changes continue to occur until puberty. At weaning, whether early or not, calves are still responding to endemic agents in the herd. “Many calves are probably immunologically ‘primed’ by mucosal exposure to various agents early in life, while they are still protected from disease by maternal antibodies,” says John Ellis, DVM, PhD, University of Saskatchewan. “This may be altered by early weaning. But there are not many controlled studies to assess that.”

The effect of weaning stress is also unknown. “I’d predict that any additional stress could impact ongoing immune responses. We know that the primary organs of B-cell and T-cell development, the ileal Peyer’s patches and the thymus, respectively, are very susceptible to the physiological effects of ‘stress,’” Ellis says. “But again, the long-term implications of damage to these organs
early in life are unknown.”

There are also few data available on vaccine response in young calves. And most studies of early weaning have been in low-challenge situations, or else the effects of disease have not been monitored, making conclusions about the immune system response uncertain.

 

Metal sheets serve double-duty in both raising the feed so even small calves can reach it, and discouraging calves from climbing through and out of the feedbunk.

An early-weaning success

Beef producer Kirk Laux, a client of Phillip Kesterson, DVM, manages Laux Feedyard in Bridgeport, Neb., and also owns a cow-calf operation. Three years ago, in response to drought, he and Kesterson started an early weaning program.

This year, they weaned in June, at 110-135 days of age, before the calves reached 450 pounds. Weaning early doesn’t change castrating, which is done at birth, or branding, which is done in April when the calves get an intranasal and a 4-way modified-live vaccine.

Arrival at the feedyard is a simple process. “The calves are given an intranasal vaccine and are dewormed and poured for flies,” Laux says. “Normally, we would give a 4-way on arrival, but we’ve thrown that out for the early-weaned calves,” Laux says. “We can work them without a needle, depending on what dewormer we use. We can run them through quickly, and they don’t have a bad experience at the chute. We wait until normal weaning time to implant them.” An added bonus is that Laux has found that calves at this age are easier to handle and easier to get out of the pens. 

In the feedyard, Laux uses Kesterson and Jon Maxcy’s design of sheets of metal to go in the bunks and raise the feed up, so even the smallest calves can reach it. They’ve seen how efficient those small calves are. “At traditional weaning time, they weigh as much or more than with traditional weaning, so we’re not giving anything up in terms of performance,” Laux says. “They’ll gain 2-2.5 pounds a day for the first couple of months. Their conversion seems to be quite a bit better; they’re in the upper 4s or low 5s right off the bat.”

An added benefit is that the cows go into fall in better condition when the calves are weaned early.

Laux has been pleased with the results. “We’ll continue to do this even in good years,” he says.