Preconditioning: More Options, Same Challenges

A comprehensive preconditioning program helps calves gain weight and stay healthy through weaning and shipping. ( John Maday )

If every calf arriving at a backgrounding or feeding operation boasted a full preconditioning program and 45 days of weaning, we’d probably see significant improvements in their health and performance. Some cow-calf producers would, however, take a hit on their profit and loss statements, with market premiums failing to cover their preconditioning costs. 

Glenn Rogers, a cow-calf producer, heifer developer and retired veterinarian from Aledo, Texas, says he hasn’t seen much change in preconditioning trends among ranchers in his area over the past decade. Producers who have adopted comprehensive preconditioning systems such as VAC-45 have developed efficient weaning programs and market reputation to make the program pay. Others have stuck with more basic preconditioning systems, or none at all, depending on their facilities, feed resources, labor and other cost factors. 

On his own ranch, Rogers raises or purchases around 800 heifer calves to develop each year. He tries to purchase all VAC-45 calves from known sources, avoids commingling for an additional 30 days and has virtually no morbidity problems in his heifers. VAC-45 calves typically offer the best value for buyers, he says. 

For sellers though, that is not always the case. In his former roles as a practicing veterinarian, university researcher and technical services specialist in the pharmaceutical industry, Rogers was closely involved in annual preconditioning surveys conducted by Superior Livestock Auctions with support from Zoetis. Those analyses, he says, often show that while VAC-45 calves earn the highest premiums, the lower-cost VAC-34 program, which requires two rounds of vaccines but not 45 days of weaning, often provides the best return on investment for sellers. 


While returns depend largely on the cost structure within an individual operation, along with access to markets that reward reputation cattle, preconditioning generally pays. 

In a 2014 study, researchers from Mississippi State and Oklahoma State Universities found the probabilities for positive returns increase with more preconditioning practices adopted. Simply dehorning calves generated positive returns 57% of the time, while weaning, vaccinating and dehorning calves before selling offered positive returns around 70% of the time. A full VAC-45 program paid off about 80% of the time.

While several verification programs emphasize specific products, Rogers says he focuses more on basic good management practices for calf health and welfare. This begins with cow vaccinations to build immunity and high-quality colostrum, low-stress animal handling and weaning practices, parasite control and at least two rounds of timely calf vaccinations. 

Castration should occur “early, early,” Rogers says, meaning early in life and early in the day to avoid heat stress. Bull calves castrated post-weaning routinely experience twice the rate of respiratory disease compared with calves castrated early on the ranch. Genetics also plays a role. “A genetically inferior calf that is preconditioned is still a genetically inferior calf,” Rogers says.


Health supplements can augment calves’ health and performance while limiting antibiotic use.

But even in human health, use of dietary supplements requires a leap of faith. We know certain vitamins, minerals, fats, proteins, herbs and microbial products have health benefits, but just a few can offer data from controlled, replicable trials. 

Likewise in beef and dairy cattle, supplements including yeast-based probiotics and prebiotics, essential fatty acids can benefit rumen health, immunity and performance. Producers and veterinarians should, however, look beyond the marketing claims for credible trial data. 

VAC results
Higher levels of documented preconditioning typically earn higher premiums but also entail more production costs. 

Research shows, though, that a well-planned program of dietary supplementation could complement traditional preconditioning protocols, helping boost immunity, reducing the incidence of respiratory disease and enhancing performance Texas A&M University animal scientist Reinaldo Cooke has conducted several research projects on feed additives including yeast-based refined functional carbohydrates (RFCs), essential fatty acids (EFAs) and organic trace minerals. 

Several companies market yeast-based supplements, Cooke says. They can differ in formulation and yeast strains though, and some have more supporting data than others. Cooke and his colleagues have conducted trials with Celmanax, an Arm & Hammer RFC product derived from the cell walls of Saccharomyces cerevisiae yeast.

The RFC product contains several bioactive components, including:

  • Mannan-oligosaccharides—short sugar units of mannose.
  • Mannose—a monosaccharide. 
  • Beta glucans—sugar units from the yeast cell wall. 

Cooke says his research at Oregon State University and Texas A&M University shows feeding RFCs from weaning through receiving can improve feed efficiency and reduce BRD incidence, largely by enhancing rumen and intestinal health. 

In a research trial at Texas Tech University, receiving beef heifers were fed either a control diet or one containing Celmanax SCP for 35 days. Cattle fed Celmanax had higher average daily gains and increased dry-matter intake (DMI).

Heifers fed Celmanax also experienced 61% fewer cases of BRD when compared to the control group. In the same study, supplementing Celmanax in calves was associated with reduced Shiga toxin E.coli.

Neil Michael, DVM, a ruminant technical services specialist with Arm & Hammer Animal Nutrition, says feeding RFCs during the receiving period for stressed feeder cattle, either by inclusion in receiving rations or with a liquid drench, helps improve early intake patterns for better immunity while also reducing gut inflammatory responses, which can affect other organs such as the liver and lungs. 

Feedyards managing cattle for natural-beef programs have adopted RFCs as a tool for reducing morbidity and the need for antibiotic treatments that disqualify cattle. 

Once past the receiving phase, feedyard cattle typically have fewer health problems, but supplementing RFCs continues to improve gains and reduce the effects of heat stress.

In a recent webinar, Shelby Roberts a post-doctoral fellow with Alltech, outlined ongoing research and application of gut-health management in beef cattle. 
Roberts described how mannan-oligosaccharide (MOS), a component that is extracted from the cell walls of Saccharomyces cerevisiae yeast, bids to receptors on pathogen cells, blocks their colonization, encourages beneficial microbes and enhances production of immunoglobulin antibodies. 



Alltech also offers products with these protections, and Roberts outlines several trials to illustrate the effects. Watch the webinar. 

MOS also can benefit calves during the stressful weaning and receiving periods, Roberts says. In an Alberta feedlot trial with 900 newly weaned calves, researchers added Bio-Mos to the receiving ration for half of the calves at a rate of 20 grams per head per day. Through the receiving period in that trial:

  • Daily gains for treated calves averaged 2.07 lb. compared with 1.54 lb. for control calves.
  • Mortality rate was .44% in treated calves versus 2.66% in controls.
  • Treatment rate was 18% in treated calves versus 49.4% in controls. 

For the weaning and receiving period, Roberts suggests feeding the product in a transition mineral mix beginning two to three weeks prior to weaning and continuing for 14 to 42 days after shipping. 


Another class of dietary supplements, essential fatty acids (EFAs), can benefit reproductive efficiency in cows, calf health, and marbling and carcass quality. 

Michael says EFAs such as Omega 3 and Omega 6 improve immunity, post-calving metabolism and reproduction. Most of the research and application has been in dairy cattle; however, beef producers are increasingly adopting the concept. Arm & Hammer markets Essentiom, a rumen-inert fat with Omega-3 and Omega-6 EFAs. 

In many trials, he adds, including EFA supplements in cow and heifer diets can increase heifer weights at first breeding, reduce embryonic loss and improve overall reproduction efficiency. In a 2015 commercial trial in Florida, pregnancy rate for 300 treated heifers was 89% compared with 70% for controls.

Several applications show benefits. “Supplementing cows prior to calving improves colostrum quantity and quality, body condition and milk production,” Michael says. “Feeding EFAs through the breeding season improves cow body condition at breeding, fertility, tissue health in the uterus, ovarian function and pregnancy recognition. Most recently, Arm & Hammer research has shown feeding at weaning for 45 days and continuing through finishing can improve marbling.”

Cooke says research in human medicine has shown health benefits of dietary EFAs, particularly Omega 3 and Omega 6 fatty acids. He has done several studies on their benefits in cattle diets, particularly with Omega 6 fatty acids in Essentiom. 

“We’ve seen the best results when feeding EFA beginning around 30 days prior to shipping calves to the feedyard and continuing into the feeding period,” Cooke says. 

Beginning the supplement at arrival in the feedyard provides some benefit, but supplementing a minimum of three weeks prior to shipping allows time for the EFA to accumulate in the animal’s tissues, supporting the immune system before weaning and relocation.

Supplements such as EFAs, probiotics, prebiotics and RFCs fit in well with preconditioning programs such as a VAC-45 system, Cooke says. They support vaccines and overall health management, while helping calves endure stressful events and begin gaining weight immediately following arrival. 

Cooke says, value-added calf-marketing programs focus on vaccines and weaning protocols, and do not include nutritional supplements. However, cow-calf producers who retain ownership through finishing could benefit from using supplements during the transition period. 

Feedyard buyers, Cooke adds, are also recognizing the advantage of supplements for minimizing disease risk. Documenting a supplement program, along with traditional preconditioning protocols could enhance calf values.