Mineral Solutions to
Better Cow Fertility
Eliminating mineral deficiencies is a proven approach to preventing cow fertility problems. Before you look at synchronisation protocols or vet bills — ask if your cows are mineralised correctly.
Transition: Where Fertility is Won or Lost
Ensuring that the cow transitions correctly from dry cow to production is one of the most important steps you can take to improve fertility outcomes across your herd. The three weeks before and after calving — the transition period — set the stage for everything that follows in the breeding season.
Care is needed to ensure the uterus is in the best condition to start a new reproductive cycle. By reducing the risk of milk fever and metritis, and minimising any retained cleanings, the cow is positioned to go back in calf as quickly and efficiently as possible.
The national average calving interval in 2025 was 385 days — 20 days over the 365-day target. The top 10% of Irish herds are hitting 364 days; the bottom 10% are at 418 days. That 54-day gap between best and worst represents a significant and recoverable profit difference, and mineral management is one of the most direct levers available to close it.
The Four Key Fertility Minerals
Not all minerals are equal when it comes to reproduction. Eliminating mineral deficiencies is a proven approach to preventing cow fertility problems. The minerals with the biggest impact on cow fertility are Copper, Iodine, Selenium and Phosphorus. Low levels of these minerals in cows can lead to:
- Undetected or poor heats — cows fail to show visible signs of oestrus
- Poor conception rates on first and subsequent services
- Early embryonic loss in the first three weeks after conception
- Delayed return to cyclicity post-calving
- Increased incidence of retained placenta and metritis
Copper
Trace ElementCritical for immune function, glucose metabolism and cyclicity. The hidden challenge: copper can be "locked up" by iron, sulphur and molybdenum in the rumen — a cow can appear sufficient on paper but be functionally deficient. Liver sampling is the gold standard. A February 2026 Teagasc study confirmed that nutritional management, including mineral status, directly impacts uterine recovery speed after calving.
Iodine
Trace ElementDrives thyroid hormone production, which regulates metabolism and has a direct link to reproductive function. Iodine deficiency causes suppressed oestrus, stillbirths and weak calves at birth. Closely linked to selenium through thyroid enzyme activity.
Selenium
Trace ElementFunctions as an antioxidant enzyme (glutathione peroxidase) with a direct role in ovarian health and immunity. Deficiency is closely linked to retained placenta, poor uterine involution and suppressed oestrus. Always pair with Vitamin E — both must be adequate for full effect.
Phosphorus
Macro MineralEssential for energy utilisation and protein synthesis, and plays a direct role in reproductive performance when severely deficient. Always assessed in balance with calcium (target ratio 1.5:1 Ca:P). Associated with PICA (cows eating stones or plastic) when very low.
Uterine Health: The Foundation of Fertility
Care is needed to ensure that the cow's uterus is in the best condition to start a new reproductive cycle. A cow that experiences milk fever, metritis or retained foetal membranes is significantly less likely to achieve conception at the desired time — regardless of how good your AI technique is.
Subclinical milk fever (low blood calcium without obvious symptoms) is far more common and damaging than clinical milk fever. When blood calcium is low, uterine muscle function is impaired — leading to difficult calvings, retained membranes, metritis, poor uterine involution and delayed return to cyclicity. All of this feeds directly into your six-week in-calf rate. A 2026 study by Teagasc Moorepark, published in the Journal of Dairy Science, found that even three extra days of uterine recovery time post-calving — the difference between elite and average-EBI cows — is enough to affect whether a cow holds her calving interval or falls behind. Correct mineral status throughout transition directly supports faster recovery.
Pull out a problem cow group — any cow that had milk fever, retained cleanings, twins or illness since calving needs examination before breeding begins. Don't let transition failures silently sink your in-calf rate.
The TERRA NutriTECH System
The TERRA NutriTECH system helps deliver precisely what the herd needs each day. Key minerals can be dosed separately, and all systems dose accurately as they monitor water consumption patterns. This precision increases animal health and helps farms become more profitable, reduce waste, lower emissions, and reduce labour.
Our Fertility Mineral is available in 20kg, 200kg and 1000kg options and contains the full complement of key reproductive minerals: Copper, Iodine, Selenium, Phosphorus and Vitamin E — formulated for bioavailability and consistent daily delivery through your water supply.
Mobile System
Flexible, farm-to-farm or paddock-to-paddock dosing. Ideal for grass-based systems where cows move regularly. Quick to install and relocate with no fixed infrastructure required.
In-Line System
Permanently installed in-line dosing through your existing water supply. Set, monitor and forget — every cow at every trough gets a precise dose, every single day.
Water is the most reliable daily intake vehicle on any dairy farm. Unlike boluses, buckets or TMR blending, a correctly calibrated water dosing system guarantees that every cow — including shy feeders and fresh calvers — receives a consistent, precise mineral dose each day.
Top Tips for a Successful Breeding Season
- Blood or milk mineral analysis — carry out at least 6 weeks before planned mating start date
- Body condition scoring — thin cows will not cycle reliably; OAD milking for 3–4 weeks can help recover BCS
- Transition management — prioritise pre- and post-calving mineral support to reduce milk fever, metritis and RFM
- Problem cow group — identify and examine any cow with a difficult calving or post-calving illness before breeding
- Pre-breeding heat detection — start at least 3 weeks before your mating start date
- Bull fertility testing — test all bulls before the season begins; don't assume they're ready
- Consistent mineral delivery — start 4–6 weeks before breeding and maintain through the season via a reliable system
- Record everything — heats, repeats, cows not seen bulling; act on the data weekly
© 2026 · Every Animal. Every Time. Proven.