Minerals Matter

The Invisible Link Between Nutrition and Fertility

Nutrition and fertility often go hand in hand, but while plenty of attention is given to energy, protein and body condition, one piece of the puzzle can easily be overlooked.

Minerals.

They may only be required in tiny amounts, but their influence on reproductive performance is anything but small. From supporting healthy ova and embryo development to maintaining immune function and improving calf survival, trace minerals work quietly behind the scenes every day.

When mineral levels are right, cows simply get on with the job.

When they're not, fertility can begin to unravel—often without obvious warning signs.

The challenge is that mineral deficiencies rarely announce themselves. Instead, they quietly chip away at reproductive performance until empty rates creep higher, calves become weaker or cows take longer to get back in calf.

Fertility Depends on More Than Feed Quantity

A cow may appear to be receiving plenty of feed, yet still lack the micronutrients needed for optimum reproductive performance.

Pasture quality varies throughout the year, soil types differ from region to region, and environmental conditions all influence the mineral content available to livestock. Every farm is different. What works well on one property may not provide the same balance on another.

That's why understanding what's happening beneath the surface is becoming just as important as measuring pasture covers or body condition scores.

“Minerals may be measured in grams and milligrams, but their impact is often measured in conception rates, healthy calves and the future productivity of the herd.”

Selenium: Small Mineral, Big Impact

Selenium has long been recognised as one of New Zealand's most important trace minerals.

Its role extends well beyond preventing deficiency.

Adequate selenium supports immune function, assists recovery after calving and helps protect developing reproductive tissues from oxidative stress. Healthy immune function also reduces the likelihood of conditions that may delay the return to normal cycling.

While selenium alone won't guarantee higher conception rates, cows with an appropriate selenium status are generally better equipped to recover from calving and establish pregnancy successfully.

Like many minerals, however, more isn't always better.

Excessive supplementation can become toxic, making careful management essential.

Copper Supports More Than Growth

Copper is often associated with growth and coat colour, but its contribution to fertility is equally important.

Healthy copper levels help support immune function, enzyme activity and tissue repair.

Cows entering mating after battling infections, inflammation or poor recovery from calving are naturally at a disadvantage. Maintaining adequate copper status helps support overall health, allowing cows to direct more energy towards successful reproduction.

Again, balance is critical.

Too little copper can reduce performance, while excessive supplementation can create its own set of health challenges.

Healthy Calves Start Before They're Born

Iodine rarely attracts much attention until problems begin appearing in newborn calves.

Yet it plays an important role in thyroid hormone production, regulating metabolism and supporting normal foetal development throughout pregnancy.

When iodine levels are inadequate, calf vigour at birth may be compromised, making those valuable first hours of life even more challenging.

Healthy pregnancies don't simply produce live calves. They produce calves that are ready to stand, suckle and thrive.

Zinc Helps Keep the Whole System Working

Most farmers think of zinc during facial eczema season. However, its importance extends much further.

Zinc contributes to healthy skin, hoof integrity, tissue repair and numerous enzyme systems involved in reproduction.

It also supports immune function, helping cows recover more efficiently after calving and reducing the impact of health challenges that can interrupt reproductive performance.

Healthy cows cycle sooner. Healthy cows conceive more readily. Sometimes the difference begins with trace minerals working quietly in the background.

Don't Forget the Bigger Players

While trace minerals receive much of the attention, macro minerals such as magnesium and phosphorus remain equally important.

Magnesium plays a vital role in muscle and nerve function while supporting many metabolic processes occurring throughout early lactation.

Phosphorus contributes to energy metabolism, skeletal strength and normal reproductive function. Neither should be considered in isolation.

Successful mineral programmes look at the complete nutritional picture rather than chasing individual elements.

Test Before You Treat

Perhaps the biggest mistake in mineral management is assuming. Every farm has different soils, pasture species, supplementation programmes and seasonal influences.

What appears to be a deficiency may not be one at all. Likewise, adding extra minerals "just in case" can create unnecessary expense or, in some cases, lead to toxicity.

Blood testing, liver sampling where appropriate, pasture analysis and professional nutritional advice provide a far clearer picture than guesswork ever can.

Knowing where a herd stands allows supplementation to be targeted, measured and effective.

Balance Is the Real Goal

It's tempting to think that if a little mineral is good, more must be better.

Nutrition rarely works that way.

Many minerals interact with one another, meaning excessive levels of one element can interfere with the absorption or utilisation of another.

The goal isn't maximum supplementation.

It's achieving the right balance for that particular herd, on that particular farm, at that particular time of year.

The Small Details That Make a Big Difference

High-performing herds are rarely built on one major breakthrough.

More often, they are the result of dozens of small management decisions made consistently over time.

Mineral nutrition is one of those details.

It may not be visible every day, but its influence reaches into conception rates, calf survival, immune function and the long-term productivity of the herd.

When fertility performance starts to drift, looking beyond mating management alone can reveal opportunities that have been quietly hiding in the feed trough all along.

Because sometimes, the smallest nutrients have the biggest impact.