Weaning is one of the most stressful– if not the most stressful – periods in a calf’s life. Stressors affecting calves during weaning include: physical, environmental, immunological, and (some would argue) psychological. In the beef industry, there was a time when it was commonplace to “wean calves on the truck”. In this scenario, calves would be removed from the dam, possibly vaccinated and processed, weighed, and loaded on a truck to be shipped to the feedlot… all the same day. Talk about stress. We remove the calf from its mother, primary feed (milk and grass), and known environment. We place that calf with new “friends” (carrying new diseases), in a new environment (very different from pasture), with new feed sources (often changing rapidly between them), and, maybe worst of all, PEOPLE! One of the most obvious results of stress is morbidity, animals become susceptible to sickness. However, when calves are stressed, feed intake is reduced and, thus, supplying adequate nutrition to the calf becomes difficult. An old Texas A&M Ranch to Rail Summary (1999-2000) suggested that nearly 50% of the costs related to early morbidity were “hidden”, that is they were costs associated with lost performance that the sick calf never recovers when compared to the healthy calf.
While calves may still be weaned on the truck, it is imperative as cattlemen that we control the things we can to mitigate some of these aforementioned stressors. As a nutritionist, I submit that one of the things we have the most control over is nutrition. True, in many cases, the calf’s nutrition through the weaning period will largely consist of the dam’s milk and the pasture grazed. However, there are other instances when nutritional supplements of protein and energy may be provided as part of a “preconditioning” program for calves.
I love the dictionary.com definition for precondition: to “bring something into the desired state for use”. When discussing the preconditioning of cattle, we could think of bringing those calves in to a desired state of use for the feedlot. Now, preconditioning does not refer solely nutrition. Many preconditioning programs last at least 45 days and include a program for nutrition as well as vaccination. Thus, we are not only trying to provide the proper nutrients to that calf to help them grow, but we are also trying to improve health as well. Therefore, separating out solely the preweaning nutritional aspects from the scientific studies can be challenging. Interestingly enough, if you look for preweaned calf nutrition in the Nutrient Requirements for Beef Cattle (2016) there is not a plethora of information. One of the reasons for this is that nutrition prior to and through the weaning period can be highly variable, depending on the producer or nutritionist you talk to.
Variability in the cattle industry should come as no surprise. We remain successful as an industry because we can adapt to use a variety of feedstuffs and management systems. However, the variability does make it challenging to provide a rote recommendation. The appropriate concentration of energy and protein for a preweaned, continental-breed calf in Montana will not be the same as the concentration for a preweaned, Brahman-influenced calf in Florida, for example.
It is my belief, though, that the most important lesson to remember about nutrition is that the animal requires pounds per day of nutrients, not percentages or concentrations. For example, a preweaned calf consuming 5 lbs of milk per day has a very different supplemental protein requirement than a preweaned calf consuming 15 lbs of milk, all other factors being equal.
Despite this lesson, most marketed feeds for preweaned calves contain about 16 to 18% CP and are fairly energy dense. With these traditional feeds, we know that in many instances (note, I said many, not all) supplemented calves do gain more than their counterparts that are not supplemented. That said, increased pounds at weaning is not the only driver of economics in a cattle operation. Whether or not one should feed preweaned calves depends heavily on the economic climate of the cattle industry.
There are instances when feeding preweaned calves a protein and energy supplement, also known as creep feeding, will pay. For example, supplementing calves is an excellent investment when calf prices are high. How high? One general rule of thumb that has been used is that calf prices should be 10 times the cost of the feed for feeding to pay off. However, there are other times when it may be prudent to provide supplemental nutrition to young calves as well. These times include when pastures are in poor condition, or in other instances when forage may be limiting (e.g. late fall calving), and when the dams are only in first or second lactation. The goal in all of these latter situations is to provide adequate nutrition to the calves during times of limitation.
Now, just as there are times when preweaning nutritional supplementation of calves can pay, there are also many instances when it does not pay to supplement. If feed prices are up, there is less likely to be a good return (i.e. enough pounds of calf) to make up for the cost of feeding. In addition, if the dams supply adequate to good amounts of milk and/or pastures are in great condition, it likely will not pay to supplement calves because they will be receiving adequate nutrients from milk and pasture. Other instances where supplementing calves through the weaning period is generally not recommended include those systems where calves will be retained for a) backgrounding or b) heifer replacements. In both of these cases there is no sale price to make up the cost of the supplemental feed and supplying nutrients post-weaning will generally be more cost effective.
In summary, preweaned calf nutrition depends heavily on the success of the dam and the health of the pastures. While there are scenarios in which supplementing calves prior to weaning will pay the cattlemen, as always, a careful calculation of the economics is recommended.