Growing Beef Newsletter
July 2024, Volume 15, Issue 1
The Zinc Advantage: Elevating your preconditioning program
Allison Baumhover, animal science graduate student and Stephanie Hansen, professor at Iowa State University
Preconditioning programs, first introduced in the mid-1960s by Iowa State University extension veterinarian Dr. John Herrick, initially faced skepticism but have since gained widespread acceptance among beef producers. Typically lasting around 45 days, these programs include practices such as vaccination, castration, weaning, deworming, and "bunk breaking" cattle. The primary goals are to enhance immune function, increase the weight of weaned calves, prepare them for transportation, and improve their success in the next phase of production.
Most feedlot producers believe that preconditioning cattle decreases morbidity and mortality, recognizing these calves often perform better in the feedlot than non-preconditioned calves. However, premiums for preconditioned cattle can vary depending on the area and certification programs available. Therefore, producers should focus on controllable factors (vaccination protocols, nutritional planning, etc.) rather than relying on fluctuating premiums to determine profitability. A long-term Purdue study (1999 to 2009) highlighted profitability was determined primarily and most consistently by additional sale weight, not just premiums. By capitalizing on cost-effective feedstuffs and maximizing growth efficiency in young cattle, the study reported an average return to labor and management of $80.70, ranging from $26.04 to $116.48 per head, and improving with manager experience.
Although the Purdue study's data is somewhat dated, its fundamental principles remain relevant, especially given today's higher cattle prices and input costs. For producers exploring or already implementing preconditioning programs, nutrition–specifically trace mineral supplementation–is an often underestimated aspect to improve efficiency. A balanced ration supports growth and can improve the response to vaccines and other health treatments. Given that feed costs comprise 50-70% of preconditioning expenses, ensuring efficient use of feed is essential.
Trace minerals are often overlooked despite their critical role in supporting cattle growth and immune function. While macronutrients like carbohydrates, proteins, and fats serve as the building blocks, trace minerals act as the essential 'mortar' that allows the body to effectively use these nutrients. Zinc (Zn), the second most prevalent trace mineral in the body after iron, facilitates over 300 enzymes and proteins essential for growth, metabolism, and immune function. Most Zn is found in skeletal muscle and bones but is not well stored in the body, requiring consistent supplementation to meet cattle's nutritional needs.
Although severe zinc deficiency in cattle is somewhat rare due to its presence in most forages, a NASEM study found 70% of forage samples from 23 states fell below the recommended zinc levels of 30 mg/kg DM for beef cattle. This deficiency can lead to a marginal or deficient status in the animal, restricting the growth potential and immune function of rapidly developing animals even without clinical signs of deficiency (see Figure 1).
Recently at Iowa State University, we investigated Zn supplementation during preconditioning on indicators of transit stress and performance during the receiving period. During the preconditioning period, all steers were on a base diet containing ~40 mg Zn/kg DM, with half receiving an additional 100 mg Zn/kg DM, supplemented as Zn sulfate (ZnSO4). After the 42-day preconditioning period, the supplemented cattle had greater DMI, ADG, and feed efficiency, culminating in an additional 13.5 lbs. over the control group, which were not deficient.
Additionally, Zn may benefit those looking to retain ownership or purchase calves for the feedlot. A study by Heiderscheit and Hansen found that steers supplemented with Zn at 70 and 120 mg Zn/kg DM for 25 days prior to transit showed improved dry matter intake recovery and greater ADG post-transit compared to the control group. All steers received a base diet that was almost double the NRC recommendation, so these differences were over Zn adequate controls.
These studies indicate that to optimize growth, supplementation above the NRC's recommended level of 30 mg Zn/kg DM is necessary, especially during the first weeks after weaning when calves have reduced feed intakes. Supplementing at levels between 75-100 ppm, the NRC recommendation for stressed calves, will better support immune function and maximize growth potential. Compared to other trace minerals, Zn is cost-effective and has a low risk of causing toxicosis, making higher feeding levels beneficial, particularly for the lightest eaters.
While preconditioning may not be practical for every producer, those aiming to maximize profitability should focus on trace mineral supplementation, especially Zn. Zinc is essential for cattle growth and immune function, offering a cost-effective and low-risk way to enhance performance. Supplementation above the NRC recommendations, particularly during the critical weaning period, supports more efficient growth and better health outcomes. Therefore, Zn supplementation stands out as a practical and beneficial strategy to improve the success and profitability of your preconditioning program.
Sources:
Duff, G. C., and Galyean, M. L. 2007. Board-invited review: Recent advances in management of highly stressed, newly received feedlot cattle. Journal of Animal Science 67: 1350-1359.
Heiderscheit, K. J. and Hansen, S. L. 2022. Effect of increasing zinc supplementation on post-transit performance, behavior, blood and muscle metabolites, and gene expression in growing beef feedlot steers. Journal of Animal Science, 100: 1-13.
Hilton, W. M. and Olynk, N. J. 2011. Profitability of Preconditioning: Lessons Learned from an 11-Year Case Study if an Indiana Beef Herd. The Bovine Practitioner 45: 40-50.
Lalman, D., Gill, D., Highfill, G., Wallace, J., Barrnes, K., Strasia, C., LeValley, B. 2017. Nutrition and Management Considerations for Preconditioning Home Raised Beef Calves. Oklahoma Cooperative Extension Service. Fact Sheet Id. AFS-3031.
Maares, M., Haase, H. 2020. A Guide to Human Zinc Absorption: General Overview and Recent Advances of In Vitro Intestinal Models. Nutrients, 12(3):762.
NASEM (National Academies of Sciences, Engineering, and Medicine). 2016. Nutrient Requirements of Beef Cattle, Eighth Revised Edition. Washington, DC: The National Academies Press. Doi: 10.17226/19014.
Olson, K. C. 2007. Management of Mineral Supplementation Programs for Cow-Calf Operations. Veterinary Clinics: Food Animal Practice 23(1): 69–90.
Pecora, F., Persico, F., Argentiero, A., Neglia, C., & Esposito, S. (2020). The Role of Micronutrients in Support of the Immune Response against Viral Infections. Nutrients, 12(10), 3198.
Thrift, F. A., and Thrift, T. A. 2011. Review: Update on preconditioning beef calves prior to sale by cow-calf producers. The Professional Animal Scientist 27:73-82.
USDA-APHIS (U. S. Department of Agriculture Animal and Plant Health Inspection Service). 2000. Attitudes Towards Pre-Arrival Processing in U.S. Feedlots. Info Sheet No. N340.1100. Fort Collins, CO: APHIS.
Vallee, B. L., and Falchuck, K. H. 1993. The Biochemical Basis of Zinc Physiology. Physiological Reviews, 73(1): 79-118.
Wikse, S. 1992. The Relationship of Trace Element Deficiencies to Infectious Diseases of Beef Calves. In Proceedings of the Texas Beef Cattle Short Course. 8. College Station, TX: Texas A&M University.
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