Why Cattle Need Supplements in Spring and Summer

Considerations for Grass Tetany and Fly Control

It’s always a welcome sight when winter melts away and pastures begin to green up again. But the start of the new season can bring devastating disease and other harmful nuisances to your cattle. Grass tetany is a common concern in the spring, and high-quality cattle supplements should be used to help your herd stay healthy. Similarly, the transition from spring into summer means fly season has arrived – and selecting an effective fly control program is imperative. Horn flies cost the beef industry more than $1 billion each year in losses from poor performance and disease. Cattle supplements are needed to keep animals in optimal condition, and to ensure a lifetime of productivity and performance for your herd. This article explores two primary concerns for cattle on pasture in the spring and summer and how you should use cattle supplements to keep your herd safe.

What You Should Know About Grass Tetany in Cattle

Grass tetany is a metabolic disorder caused by low magnesium levels in the blood. It typically occurs in the spring when beef or dairy cattle graze on fast-growing pastures that have low levels of magnesium. It is a highly-fatal disease – but proper supplementation may aid in the prevention of grass tetany.

What causes grass tetany?

While dietary magnesium deficiency is – grass tetany, often observed in cattle on lush spring pastures is often a culmination of multiple factors. Adult cattle with functioning rumens primarily absorb magnesium in the rumen. High dietary magnesium levels as compared to blood magnesium permits passive transport across the rumen and into the blood. However, the spring pasture environment can compound a multitude of environmental factors that limit blood magnesium:

• Forage magnesium is reduced during times of rapid growth shifting the absorption of magnesium from passive absorption to the sodium-linked active transport system.
• Spring forages rich in protein and potassium, while low in sodium may interfere with magnesium absorption – reducing the solubility of magnesium and interfering with the sodium-linked active transport system.

Furthermore, the timing of high magnesium requirement due to lactation often coincides with the aforementioned dietary complications. Spring calving herds should be cognizant of this as their February calving herd may reach peak lactation and magnesium output alongside grass tetany inducing forage growth conditions. While the body has ample magnesium stores to supply blood magnesium to prevent deficient blood magnesium levels, the mobilization of those stores is limited – being tied to the release of bone calcium and not related to blood magnesium levels.

Symptoms of Grass Tetany in Beef Cattle

Grass tetany is a rapidly progressing disorder. Early signs may be difficult to distinguish, and terminal symptoms may appear before action can be taken. Cattle on lush spring forage in high risk environments for grass tetany should be monitored regularly for symptoms including:

• Isolation
• Excitability or aggression
• Disorientation and muscle incoordination and/or twitching
• Paralysis and convulsion
• Death

The transition from early to late onset and fatal magnesium deficiency can escalate rapidly. Symptoms should be addressed immediately, however prevention is often the best, and most successful plan.

What Minerals Do Cattle Need to Prevent Grass Tetany?

Cattle grazing forage that may create a grass tetany inducing diet should be offered cattle supplements that include high levels of magnesium, and added sodium (often from salt). The added magnesium and sodium will help to facilitate passive transport and/or more successful use of the sodium-linked active transport system. Other considerations are to provide a supplemental source of energy – like molasses.  The added energy in the diet may help the rumen microbes more effectively utilize the high rates of protein – aiding magnesium solubility.

Kent offers several cattle supplements to aid in the prevention of grass tetany. From loose minerals providing magnesium and sodium like Framework 365 Mineral® MG, and Framework 365 Mineral® Performance MG to EnergiLass® Super High-Mag 12 that offers a great source of magnesium and energy, Kent cattle supplements are formulated for cattle at risk for grass tetany.

When to Provide Magnesium Supplements for Cattle

High-magensium supplements for cattle are most effective when they are given at least a week before spring grazing. Continue to offer high-magnesium supplements while cattle are grazing high-risk pastures. Palatability is key to any supplement, as it does no good if cattle won’t eat it. Framework takes advantage of cattle’s internal drive to find salt, combined with other highly palatable ingredients and flavor. EnergiLass does not contain salt, but takes advantage of cattle’s taste for something sweet. Both supplements offer quality nutrition in a highly palatable form.

Fly Control: What it Means for Your Cattle

Flies are a major nuisance that cost cattle producers a lot of money. Horn flies, in particular, are the most aggressive blood feeding pests of grazing cattle. They congregate on the back and sides of cattle, drawing blood a dozen or more times a day. The discomfort and annoyance not only cause stress for your cattle, it reduces weight gains, milk production and grazing efficacy. Flies can also spread disease.

Horn flies usually stay on the back or sides of cows their whole life, with the females leaving only to lay their eggs on fresh manure. After about a week, the eggs hatch and the larvae feed and grow in the manure. They develop into adult flies within about 10 to 20 days. Adult flies can live up to three weeks.

What Do Cattle Need for Effective Fly Control?

Timing is everything when it comes to starting a fly control program for your cattle. Starting early – before you start seeing flies at all – is key. We recommend starting a feed-through fly control supplement for your cattle  30 days before the last freeze. The exact date will vary by geography, however starting this early helps get a jump on the fly population. If supplementing begins too late, untreated manure will offer a breeding ground for flies..

An effective method is to use a larvicide in the supplement provided to cattle while grazing. To be most effective, the larvicide should be added to your cattle supplement in early spring before flies begin to appear, and continued until cold weather returns and fly activity begins to lessen. Kent offers a number of Framework 365 Minerals and EnergiLass with Altosid® IGR..

In conjunction with feed-through fly control cattle supplements , an Integrated Pest Management (IPM) control system should also be implemented for effective fly control. This includes various steps in sanitation as well as the use of sticky traps and baits or sprays. Having a solid IPM system in place with larvicide controls will strengthen your defense against flies.

There are several ways to assess the effectiveness of your fly control program.

• Look for signs of discomfort: are your cows stomping, throwing their heads back or bunched together in a corner? These actions drain energy, resulting in decreases in consumption and performance.
• Do a visual check of your cattle every morning. Estimate the number of flies you see on them. Counts of 50-100 per side and back (or roughly 100-200 or less per head) are acceptable. Anything above could begin to impact the performance of your cattle.

Best Mineral Supplements for Cattle in the Spring and Summer

We already know that high-magnesium supplements will help decrease the risk of grass tetany, and feed-through fly control supplements can reduce the threat that flies bring to the performance of your herd. These are two of the biggest concerns for cattle in pastures this time of year, and having the right supplement available at the right time can keep your cattle performing at their best.

From Grass Tetany to Fly Control, Trust the Beef Cattle Experts at Kent

The right cattle supplement can make all the difference, especially when cattle comfort and performance are at stake. For grass tetany, Framework 365 Mineral MG, Framework 365 Mineral Performance MG and EnergiLass Super Hi-Mag 12  are proven choices. Kent also offers a full line of fly control supplements in Framework and EnergiLass, the most popular include Framework 365 Mineral ADE AFC and EnergiLass Cattle Mineral 8 AFC. Both are a solid line of defense in your fly control program.