While dramatic signs like animal deaths capture attention, the greatest economic damage from copper deficiency is often silent - a "hidden hunger" that quietly erodes profitability through poor growth, reduced fertility, and weakened immunity across the entire herd or flock.³

This deficiency can be either primary, where soils and forages are naturally low in copper, or secondary, which is far more common and complex. Secondary deficiency occurs when an otherwise adequate diet contains antagonists that block the animal from absorbing the copper it consumes.3 Understanding and managing copper is therefore not just about what is in the feed, but what the animal can actually use.

The Absolutely Critical Functions of Copper

Copper is not just another mineral; it is a fundamental component of enzymes that drive the most basic life-sustaining processes. A deficiency in copper creates a cascade of failures that manifest as poor performance on your farm.

• Energy Production: Copper is the cornerstone of the enzyme cytochrome C oxidase, which is essential for generating ATP - the main energy currency of every cell.4 Without enough copper, an animal's cellular engine sputters, leading to poor growth, reduced milk production, and general unthriftiness.⁵

• Immunity and Health: A robust immune system depends on copper. It is a key component of antioxidant enzymes like Cu-Zn Superoxide Dismutase (SOD), which protect immune cells from damage as they fight off pathogens.4 Copper-deficient animals are more susceptible to disease, show a poorer response to vaccines, and have a reduced resistance to parasites.8

Copper has been directly linked to the ability of immune cells to engulf and kill bacteria³⁷. 

Source: Image generated by Gemini Pro

• Fertility and Reproduction: Few things impact the bottom line more than fertility. Copper is essential for enzymes involved in hormone synthesis and regulation.⁹ Deficiency is directly linked to delayed or silent oestrus, poor conception rates, early embryonic death, and an increased risk of retained placentas.¹¹ Studies have shown that supplementing copper can improve pregnancy rates and reduce the number of services required per conception.¹²

• Structural Integrity: The copper-dependent enzyme lysyl oxidase is responsible for linking collagen and elastin fibers, which provide strength to bones, cartilage, and blood vessels.4 Deficiency can lead to lameness and spontaneous fractures. In severe cases in cattle, it can cause aortic rupture, a condition known as "falling disease".⁴

A trial conducted in 1980 studied the effect of a copper deficiency in sheep. The control group received no MULTIMIN whereas the other group received MULTIMIN. A clear difference can be seen in the bone density of these sheep:

Copper is a key player in helping ruminants recover from intestinal insults, such as episodes of diarrhea. It plays an important role in ensuring optimal gut health - from laying the structural foundation for new tissue and promoting the growth of blood vessels, to quenching inflammatory damage and supporting a robust immune response⁴⁴.

• Coat and Wool Quality: The classic sign of copper deficiency - a faded, reddish coat on black cattle or "steely," straight wool on sheep - is due to a lack of the copper-containing enzyme tyrosinase, which is needed to produce pigment.⁴

The Challenge: Why Your Animals May Be Copper Deficient

Even with what seems like a good mineral program, ensuring adequate copper status in ruminants is uniquely challenging. The complex environment of the rumen, coupled with the intense demands of production, creates several hurdles.

The Rumen Antagonists

The primary reason for copper deficiency on modern farms is the presence of antagonists in feed and water. These elements effectively "steal" copper in the rumen, preventing its absorption.

• Molybdenum and Sulphur: This is the most potent combination. High levels of molybdenum (Mo) and sulphur (S), often found in lush forages, certain water sources, or co-products like distillers grains, combine in the rumen to form compounds called thiomolybdates.¹⁵ These thiomolybdates bind to copper with incredible affinity, forming insoluble complexes that the animal cannot absorb and simply pass out in the manure.¹⁶

A major problem we are facing in South Africa, is the emission of sulphur from coal-generated power stations. Water and pasture around these power stations are contaminated with sulphur, which affects not only copper absorption, but selenium absorption too. A study conducted by Arthington in 2023, clearly shows low (deficient) levels of copper and selenium in the livers of animals grazing near these power stations:

Liver analysis shows significantly lower selenium and copper in (impacted) cattle grazing near power stations. 

• Iron: High iron (Fe) is another common and powerful antagonist18. Many of South Africa’s pastures and water sources are known to be high in iron. In the rumen, iron reacts with sulphur to form compounds that can also bind copper, rendering it unavailable for absorption.20

High Demand and Stress

An animal's copper requirement is not static. It skyrockets during "critical windows" of production, creating a gap between supply and demand.

• Pregnancy and Lactation: During the last trimester, the dam transfers large amounts (approx. 30%) of copper to the fetus to build up its liver stores for life after birth, placing a huge drain on her own reserves.⁸ Moreover, fetal demands for copper significantly increase during the last trimester of pregnancy⁴¹. Adequate copper status is crucial for fetal development, contributing to the immune system, bone and connective tissue formation, cardiac function, keratinisation, and spinal cord myelination⁴⁰. An adequate copper status during the breeding season is critical, as copper is essential for embryo survival, oocyte viability and optimal functioning of the corpus luteum^38,39.

Milk is a poor source of copper, so the calf is born relying almost entirely on the liver stores it acquired in utero.⁸   

• Stress: Events like calving, weaning, and transport are major stressors. Stress not only reduces feed intake - meaning less copper is consumed - but the release of stress hormones like cortisol has been shown to impair the intestine's ability to absorb copper.23 This combination of reduced intake and impaired absorption can cause an animal's copper status to crash precisely when its immune system needs it most.

Research has shown major losses in copper and zinc following a disease challenge⁴² and a 266% reduction in copper retention in the body following a stressful event⁴³.

Copper and zinc losses following an infectious bovine rhinotracheitis virus challenge (Orr et al., 1990)

Ineffective Supplementation

Traditional salt-based blocks and licks often use inexpensive forms of copper, like copper sulphate, which have extremely poor bioavailability (1-5%) in ruminants25. Furthermore, intake from free-choice licks is notoriously variable, with some animals consuming too much and others, often those who need it most, consuming none at all.²³

Assessing and Solving the Copper Problem

Diagnosing copper status requires a multi-faceted approach. Testing forage, soil, and water can identify high levels of antagonists and reveal your farm's baseline risk.²⁷ 

Blood tests for copper status can be misleading. An animal will drain its liver reserves to keep blood levels normal, so a "normal" blood test can mask a severe underlying deficiency.¹⁴ In an experiment conducted by Virbac in 2022, livers were collected from slaughter cows and analysed for both liver and blood copper levels. These animals were highly stressed and it clearly showed that their livers were deficient in copper, while blood copper levels were high. 

Liver biopsies remain the golden standard for assessing the copper status of an animal and will give a general idea of the herd’s copper status. There are a few things to keep in mind: it should be carried out and interpreted correctly and done at the right time of the production cycle with a sufficient number of samples. It is important to remember that copper levels do not remain static throughout the production cycle. 

Swenson (1998) showed a decrease in copper status precalving, continuing through to the breeding season:

Changes in Liver and Serum Copper Concentrations For Beef Cows (Swenson, 1998)

The most definitive diagnostic tool to evaluate a trace mineral product’s efficacy is through response-to-supplementation. Farm trials are not an option, as there are too many variables that can affect the outcome. Thankfully, there are over 50 scientific trials which have been conducted with MULTIMIN^®. These trials have been peer-reviewed and published in well-known scientific journals, giving you peace of mind that the independent research community has approved the reliability of the trials’ outcomes.

For periods of peak demand and stress, an evidence-based injectable trace mineral like MULTIMIN^® offers a powerful tool. By delivering copper directly into the animal's system, it completely bypasses the rumen and its antagonists, ensuring a rapid and guaranteed dose.²³ Blood levels of the minerals in MULTIMIN^® peak within hours, making it ideal for use at critical times like precalving, prebreeding, and weaning to help bridge the "deficiency gap" that often occurs even in well-fed animals.²³ While not a replacement for a quality daily oral program, it is a strategic intervention to boost mineral status precisely when it is needed most.³⁶

During critical times when demand for trace minerals exceeds intake, a study by Hartman (2018) showed how MULTIMIN^® can be beneficial when an immediate replenishment of trace minerals is required. The study also showed what effect organic trace minerals play in ensuring that basal daily requirements for trace minerals are replenished, which happened more rapidly than inorganic trace minerals alone. This emphasises the importance of a quality daily oral nutrition program in combination with strategic MULTIMIN^® administration during critical times:

A product like MULTIMIN^®, formulated with a scientifically validated copper concentration of 15 mg/ml, is designed to rapidly elevate liver copper stores to therapeutic levels. This is critical for supporting cattle during periods of high physiological stress, such as calving, breeding, or weaning.

Peer-reviewed research substantiates the benefits of this specific copper dosage. Studies have directly linked this concentration to significant improvements in herd health, including enhanced immune responses to vaccines, lower incidence of disease in calves, and better reproductive outcomes in cows. By providing a potent, bioavailable source of copper, such a product ensures the mineral can support essential enzymatic functions tied to antioxidant defence and energy metabolism.

Ultimately, having the correct amount of copper in an injectable trace mineral is not arbitrary. It is a key factor that enables farmers to proactively manage nutritional gaps, ensuring their herds have the necessary reserves to thrive. This leads to improved fertility, stronger immunity, and better overall health, which are fundamental to a productive and profitable operation.

Conclusion

Effective copper management is fundamental to unlocking the health, fertility, and growth potential of your herd or flock. It requires moving beyond simply providing a mineral lick or block and adopting a proactive, two-pronged strategy:

1. Provide a high-quality, highly bioavailable oral mineral year-round to build and maintain a strong foundation.

2. Use MULTIMIN^® before predictable periods of high stress and demand to ensure peak mineral status when it matters most.

By understanding the challenges and utilising modern nutritional tools, you can overcome the hidden hunger for copper and ensure your animals have what they need to perform at their best.

Please take note of the following: Sheep are highly susceptible to copper toxicity and should not be supplemented with copper unless there is an established diagnosis of copper deficiency.

^References:

1. ^{Hefnawy, A. and khaiat, H. (2015) “The Importance of Copper and the Effects of Its Deficiency and Toxicity in Animal Health,” International Journal of Livestock Research, 5(12), p. 1. Available at: https://doi.org/10.5455/ijlr.20151213101704.}

2. ^{McDOWELL, L.R. and Conrad, J.H. (1977) “Trace mineral nutrition in Latin America,” World Animal Review [Preprint].}

3. ^{Menzir, A. and Dessie, D., 2017. Review on copper deficiency in domestic ruminants. IJARP, 1, pp.101-110.}

4. ^{“Review on Copper’s Functional Roles, Copper X Mineral Interactions Affecting Absorption, Tissue Storage, and Cu Deficiency Swayback of Small Ruminants” (2016) ARC Journal of Animal and Veterinary Sciences, 2(2). Available at: https://doi.org/10.20431/2455-2518.0202001.}

5. ^{A guide to feeding copper to dairy cows - Farmers Weekly https://www.fwi.co.uk/livestock/livestock-feed-nutrition/a-guide-to-feeding-copper-to-dairy-cows}

6. ^{Saka, A.A., Adekunjo, R.K., Adedeji, O.Y., Awodola-Peters, O.O. and Yahaya, M.O., 2022. INFLUENCE OF DIETARY COPPER SUPPLEMENTATION ON GROWTH PERFORMANCES OF RUMINANT ANIMALS. Nigerian Journal of Animal Production, pp.1543-1545.}

7. ^{Palomares R., Ferrer M. and Jones L. (2024) “Role of trace minerals in cow’s reproductive function and performance: a clinical theriogenology perspective”, Clinical Theriogenology, 16. doi: 10.58292/CT.v16.10529.}

8. ^{Importance of copper for cattle fertility and health - Sweetlix https://www.sweetlix.com/research-articles/calvingbreeding/importance-of-copper-for-cattle-fertility-and-health/}

9. ^{Lou, Y. et al. (2025) “Effects of Copper on Steroid Hormone Secretion, Steroidogenic Enzyme Expression, and Transcriptomic Profiles in Yak Ovarian Granulosa Cells,” Veterinary sciences, 12(5). Available at: https://doi.org/10.3390/vetsci12050428.}

10. ^{Yatoo, M.I. (2016) “Status and Interrelation of Trace Minerals and Steroid Hormones in Heifers,” Advances in Animal and Veterinary Sciences, 4(2s), pp. 1–4. Available at: https://doi.org/10.14737/journal.aavs/2016/4.2s.1.4.}

11. ^{Verma, A. and Kumar, P., 2018. Important minerals affect the fertility of dairy animals: A review. The Pharma Innovation Journal, 7(11), pp.136-138.}

12. ^{Ahola, J.K. et al. (2004) “Effect of copper, zinc, and manganese supplementation and source on reproduction, mineral status, and performance in grazing beef cattle over a two-year period,” Journal of animal science, 82(8), pp. 2375–83.}

13. ^{Mudgal, V., Gupta, V.K., Pankaj, P.K., Srivastava, S. and Ganai, A.A., 2014. Effect of copper supplementation on the onset of estrus in anestrous buffalo cows and heifers. Buffalo Bulletin, 33(1), pp.1-5.}

14. ^{Maas, J., 2009. Copper deficiency and toxicity in ruminants (Proceedings).}

15. ^{Suttle, N.F., 1991. The interactions between copper, molybdenum, and sulphur in ruminant nutrition. Annual review of nutrition, 11(1), pp.121-140.}

16. ^{Gooneratne, S.R., Buckley, W.T. and Christensen, D.A., 1989. Review of copper deficiency and metabolism in ruminants. Canadian Journal of Animal Science, 69(4), pp.819-845.}

17. ^{Gould, L. and Kendall, N.R., 2011. Role of the rumen in copper and thiomolybdate absorption. Nutrition Research Reviews, 24(2), pp.176-182.}

18. ^{López-Alonso, M. and Miranda, M., 2020. Copper supplementation, a challenge in cattle. Animals, 10(10), p.1890.}

19. ^{Spears, J., 2013. Advancements in ruminant trace mineral nutrition.}

20. ^{Clarkson, A.H. and Kendall, N.R., 2022. X-ray absorption spectroscopy of copper and iron in sheep digesta. Journal of Trace Elements in Medicine and Biology, 72, p.126987.}

21. ^{López-Alonso, M. and Miranda, M., 2020. Copper supplementation, a challenge in cattle. Animals, 10(10), p.1890.}

22. ^{Hefnawy, A.E., Tortora-Perez, J., Shousha, S.M. and Abukora, S.Y., 2011. Effect of gestation and maternal copper on the fetal fluids and tissues copper concentrations in sheep.}

23. ^{Multimin Campaign Landing Page - Axiota® Animal Health, https://axiota.com/multimin-campaign-landing-page/}

24. ^{Guo, S., Chen, Z., Dong, Y., Ni, Y., Zhao, R. and Ma, W., 2023. Chronic corticosterone exposure suppresses copper transport through GR-mediated intestinal CTR1 pathway in mice. Biology, 12(2), p.197.}

25. ^{National Research Council, Committee on Animal Nutrition and Subcommittee on Dairy Cattle Nutrition, 2001. Nutrient requirements of dairy cattle: 2001. National Academies Press.}

26. ^{Kegley, E.B. and Spears, J.W., 1994. Bioavailability of feed-grade copper sources (oxide, sulfate, or lysine) in growing cattle. Journal of animal science, 72(10), pp.2728-2734.}

27. ^{Vermunt, J.J. and West, D.M., 1994. Predicting copper status in beef cattle using serum copper concentrations. New Zealand Veterinary Journal, 42(5), pp.194-195.}

28. ^{Copper Deficiency in Sheep and Cattle | OSU Small Ruminant Team, https://u.osu.edu/sheep/2019/10/15/copper-deficiency-in-sheep-and-cattle/}

29. ^{Cha, M., Ma, X., Liu, Y., Xu, S., Diao, Q. and Tu, Y., 2025. Effects of Replacing Inorganic Sources of Copper, Manganese, and Zinc with Different Organic Forms on Mineral Status, Immune Biomarkers, and Lameness of Lactating Cows. Animals, 15(2), p.271.}

30. ^{Why are organic sources of trace minerals important for cattle producers? - Crystalyx, https://www.crystalyx.com/blog/why-are-organic-sources-of-trace-minerals-important-for-cattle-producers/}

31. ^{SMART Hydroxy trace minerals, a top quality mineral supplement with superior characteristics, https://orffa.com/publications/smart-hydroxy-trace-minerals-a-top-quality-mineral-supplement-with-superior-characteristics/}

32. ^{Hydroxy Trace Minerals Shown to Support Cow Health, Performance - Dairy Herd Management, https://www.dairyherd.com/news/dairy-production/hydroxy-trace-minerals-shown-support-cow-health-performance}

33. ^{Spears, J.W., Kegley, E.B. and Mullis, L.A., 2004. Bioavailability of copper from tribasic copper chloride and copper sulfate in growing cattle. Animal feed science and technology, 116(1-2), pp.1-13.}

34. ^{What is Multimin®? - Specialist Sales, https://cdn.specialistsales.com.au/wp-content/uploads/2020/11/25153211/Multimin-Injection-for-Cattle-Scientific-References.pdf}

35. ^{Kirchhoff, A.A., 2015. The effect of a supplemental trace mineral injection on developing beef bull and heifer reproduction (Doctoral dissertation, Kansas State University).}

36. ^{Palomares, R., Ferrer, M. and Jones, L., 2024. Role of trace minerals in cow’s reproductive function and performance: a clinical theriogenology perspective. Clinical Theriogenology, 16.}

37. ^{Cerone, S., Sansinanea, A., Streitenberger, S., Garcia, C. and Auza, N., 2000. Bovine monocyte-derived macrophage function in induced copper deficiency. General Physiology and Biophysics, 19(1), pp.49-58.}

38. ^{Nazari, A., Dirandeh, E., Ansari-Pirsaraei, Z. and Deldar, H., 2019. Antioxidant levels, copper and zinc concentrations were associated with postpartum luteal activity, pregnancy loss and pregnancy status in Holstein dairy cows. Theriogenology, 133, pp.97-103.}

39. ^{Rosa, D.E., Anchordoquy, J.M., Anchordoquy, J.P., Sirini, M.A., Testa, J.A., Mattioli, G.A. and Furnus, C.C., 2016. Analyses of apoptosis and DNA damage in bovine cumulus cells after in vitro maturation with different copper concentrations: consequences on early embryo development. Zygote, 24(6), pp.869-879.}

40. ^{Andrieu, S., 2008. Is there a role for organic trace element supplements in transition cow health?. The Veterinary Journal, 176(1), pp.77-83.}

41. ^{Van Emon, M., Sanford, C. and McCoski, S., 2020. Impacts of bovine trace mineral supplementation on maternal and offspring production and health. Animals, 10(12), p.2404.}

42. ^{Orr, C.L., Hutcheson, D.P., Grainger, R.B., Cummins, J.M. and Mock, R.E., 1990. Serum copper, zinc, calcium and phosphorus concentrations of calves stressed by bovine respiratory disease and infectious bovine rhinotracheitis. Journal of Animal Science, 68(9), pp.2893-2900.}

43. ^{Nockels, C.F., DeBonis, J. and Torrent, J., 1993. Stress induction affects copper and zinc balance in calves fed organic and inorganic copper and zinc sources. Journal of Animal Science, 71(9), pp.2539-2545.}

44. ^{Vallet, S.D. and Ricard-Blum, S., 2019. Lysyl oxidases: from enzyme activity to extracellular matrix cross-links. Essays in biochemistry, 63(3), pp.349-364.}