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Out to Pasture: Overcoming Spring Health Challenges in Cattle

Spring weather is unpredictable. One day it’s raining, one day it warms up and the next day it’s a spring blizzard. Tremendous environmental swings can wreak havoc on cattle, predisposing them to life threatening health challenges and poor nutrient conversion that costs beef producers time and money.

Spring Health Challenges Cattle Face

Ranchers are often on high alert in the spring ready to intervene on health challenges as soon as possible. Weather shifts, fresh grass, wet ground, mud and flies are a recipe for disaster that can lead to grass tetany, foot rot and parasite infestations. Once challenged, cattle begin directing vital nutrients away from gain and growth to repairing infections and activating immune systems.

So, what’s the best approach to avoiding spring health challenges and poor nutrient conversion? Prevention.

How to Prevent Grass Tetany in Cattle

Grass tetany is caused by low blood magnesium in cattle. Grass tetany is often more common in the spring as cattle begin grazing on lush immature forages that are high in potassium. High levels of potassium can decrease the absorption of magnesium, thus causing low blood magnesium in cattle.

Grass tetany typically occurs in beef cows during early lactation and is more prevalent in older cows. Older cows are thought to be less able to mobilize magnesium reserves from bone compared to younger cows. Grass tetany is also more prevalent on cool, cloudy days ranging between 40-60 F.

Out to Pasture: Overcoming Spring Health Challenges in Cattle

Related: 5 Things to Know About Grass Tetany

Grass tetany symptoms include lack of coordination, salivation, excitability, and, in the final stages, tetany, convulsions and death. Grass tetany is occasionally encountered on meadow pastures, but the incidence is much lower than on small grains like wheat.

Wheat pasture poisoning is also a form of tetany caused by calcium deficiency on wheat pastures. Often thought to be a magnesium deficiency, wheat pasture poisoning is predominantly caused by deficient levels of calcium causing low blood calcium.

When tetany is suspected, always consult with your local veterinarian. Typical protocols for treatment include an IV injection of calcium-magnesium and a mineral supplement containing a high level of magnesium (10%) and calcium between (15-20%). For prevention, mineral containing highly available magnesium and calcium should be provided with daily intake ranging from 2-4 ounces.

How to Manage Flies in Cattle

Flies begin hatching in the spring and agitate cattle shortly thereafter. According to the Journal of Entomology, the economic loss due to flies for U.S. beef producers ranges from $1-2 billion annually.

The most common flies that impact beef cattle are horn flies, face flies and stable flies. Horn flies are small black bloodsucking flies that are known to bite cattle between 20-30 times per day per fly. Stable flies are painful blood feeder flies that are more irritating to cattle and mainly attack the front legs. Face flies are nonbiting but known for contributing to the spread of pinkeye and infectious bovine rhinotracheitis (IBR) in cattle.

At peak times of the summer, there can be between 1,000-4,000 horn flies per cow causing significant blood loss estimated at 10 lbs. per cow per summer. Additionally, it can take less than 4-6 stable flies per cow to cause significant economic impact.

The goal with fly control in cattle is to keep fly populations below the economic threshold. Meaning, instead of 1,000-4,000 horn flies per cow, it’s suggested to keep flies below 200 per cow with fly control methods.

How to Manage Flies in Cattle

The horn fly population on this cow exceeds the economic threshold of 200 Flies.

Various fly control programs exist today including ear tags, sprays, oilers, dust bags, vet guns and feed additives. Often beef producers must take a multifaceted approach to fly control using more than one tool. Adding garlic to cattle mineral is another effective strategy for fly control.

Related: How to Control Flies in Cattle with Garlic

How to Manage Parasites in Cattle

Parasites are only a problem for grazing animals. Parasites grow in grazing forages that are less than 2-3 inches tall. This is why parasites are more prevalent in spring as the grass begins to grow and temperatures warm up allowing eggs to hatch.

According to Kansas State University, economic losses from internal parasites have been estimated to cost the U.S. livestock industry over $3 billion annually. Parasites, also called internal nematodes, impact cattle performance by robbing nutrients from the animal, reducing nutrient absorption and feed intake and overstimulating the immune system.

The most common cattle parasites are Ostertagia, Trichostrongylus, Haemonchus, and Cooperia. Cattle become infected when parasitic eggs become L3 larvae. As eggs hatch and develop into L3 larvae, they wiggle/crawl up short blades of grass and even live in water droplets. Cattle then graze the forage infected with the parasite larvea starting infestation.

Related: 5 Management Tips to Overcome Parasites

After ingestion, L3 larvae make their way to the digestive tract where they latch onto the gut wall and begin robbing cattle of nutrients. Parasites then produce eggs that pass through the animal in manure and the lifecycle starts all over again. Furthermore, parasites are hardy and can become inactive in the digestive tract if environmental conditions are too hot or too cold for survival. They become active again when conditions improve.

The Lifecyle of Parasites in Cattle

The Lifecyle of Parasites in Cattle

Source: MWI Animal Health

According to Texas A&M University, the clinical signs of parasites or wormy cattle include pale mucous membranes, bottle jaw, pot belly, diarrhea, not grazing, not chewing cud, rough and dry haircoat, thinness, weakness and inability to stand. These signs are similar to those caused by malnutrition and liver flukes.

Similar to fly control, the goal of any parasite program is to maintain the economic threshold of the cow, not reach zero. Cattle will eventually build an immunity to parasites, but younger calves with weaker immune systems are more susceptible.

Discussing deworming protocols with your veterinarian is critical. Every farm has different dewormer programs but developing a strategy can help avoid parasitic resistance. Meaning, not every grazing animal requires dewormer every spring, every fall or every 6 months. Dewormers should be administered strategically to infected animals in order to reduce reinfection, parasite resistance and pasture infestation. Recent research suggests that essential oils may help manage parasites without developing resistance.

Related: Are Essential Oils a Solution to Parasites?

How to Prevent Foot Rot in Cattle

Foot rot in cattle is caused by the bacteria Fusobacterium necrophorum and results in lameness and swelling.

In the spring, cattle are subjected to mud and soft ground that weakens the structural integrity of hooves which are made out of keratin similar to skin, hair and fingernails. As spring weather makes hooves soft, they become more susceptible to tears and damage from rocks and hazards on the ground. Once the hoof is split, bacteria enter and begin infection.

Symptoms of foot rot can range from obvious to ambiguous. The obvious first signs include lameness, swelling and leg favoring. As foot-rot progresses foul smells, separation of the claws and loss of appetite can follow.

Again, treating foot rot begins with your veterinarian. According to Oklahoma State University, veterinarians often prescribe antibiotics and anti-inflammatory products for pain relief to infected cattle with foot rot. If possible, infected animals should be kept in dry areas until healed.

Prevention of foot rot is multidimensional. It’s recommended to keep cattle in environments with minimal mud and manure. Additionally, foot baths, mineral supplements with zinc and vaccinations can all help reduce incidences of foot rot.

Related: Foot Rot: How Trace Minerals Can Help

Overcome Spring Health Challenges with Ralco

Spring is an exciting time on every ranch but comes with its challenges. For the last 50 years, Ralco has been helping beef producers keep their cows and calves focused on converting nutrients to growth instead of waste.

Vital nutrients are often lost and underutilized, especially during times of challenge, silently eroding the health and performance of your livestock and operation. We work with you to keep your nutrients focused on production and your bottom-line.

From high-quality mineral to essential oil feed additives and animal health products, we have solutions to help keep your cattle healthy this spring.

To learn more, reach out to Ralco’s ruminant specialist Dr. Jeff Hill by calling 507-337-6916 or emailing