Revisiting grass tetany and magnesium deficiency

Clifton Martin, Extension Educator, Agriculture and Natural Resources, Muskingum County

When the spring flush arrives lactating animals will be the most susceptible to grass tetany.

Managing agricultural field fertility through lime applications is a well-known practice with the goal of maximizing plant growth and productivity. One choice in the process is the decision to use calcitic lime or dolomitic lime as a source. Competing variables in the decision might be economics of short-term cost versus managing for a magnesium deficiency in the pasture. Generally, calcitic lime is cheaper to acquire and dolomitic lime is more expensive, but as we seek to manage a magnesium deficiency it may be advantageous to use dolomitic lime to deliver the needed nutrient to plants. This may be a consideration in a hedge to prevent grass tetany in a pasture. With spring just around the corner, it is a wonderful time to revisit the grass tetany challenge in forages.

What does the problem look like?

To get straight to the point, animal death is the outcome of a grass tetany problem if not properly treated. Grass tetany, also called hypomagnesemia, refers to blood magnesium concentration that is Continue reading

Winter is Here – What’s your Action Plan?

– Dr. Michelle Arnold, DVM – Ruminant Extension Veterinarian (UKVDL)

Figure 1: The UK Beef Cow Forage Supplement Tool homepage

Winter presents multiple challenges for cattle and those who care for them including cold temperatures, wind, snow, freezing rain, and mud. Unfortunately, drought conditions in the spring and summer significantly reduced the quality and quantity of hay available to feed this winter, exacerbating the difficult conditions. It is important for beef cattle producers to devise a “winter weather action plan” with the goal of maintaining cattle health, comfort, and performance despite what Mother Nature sends to KY. Many telephone conversations with veterinarians and producers confirm cattle are losing body condition this winter and some are dying of malnutrition. The cloudy, wet weather with regular bouts of rain and temperatures hovering right above freezing has resulted in muddy conditions that require diets substantially higher in energy just to maintain normal body temperature. At the UKVDL, we are beginning to see cattle cases presented to the laboratory for necropsy (an animal “autopsy”) with a total lack of fat stores and death is due to starvation. This indicates winter feeding programs on many farms this year are not adequate to support cattle in their environment, especially aged cattle, cows in late pregnancy or early lactation, or their newborn calves, even though bitter cold has not been much of a factor.

The “lower critical temperature” (LCT) is the threshold outside temperature below which the animal’s metabolic rate must increase to maintain a stable internal body temperature. If temperatures fall below the LCT, the amount of Continue reading

Posted in Health

Ensuring Healthy Herds: The Critical Role of Water Management for Livestock in Winter

Kate Hornyak, OSU Extension Program Coordinator, Delaware County (originally published on Ohio Farmer on-line)

A heavy equipment tire can be a large capacity water trough.

Water stands as an essential nutrient for beef cattle, much like it does for humans. It plays a vital role in various bodily functions, including growth, reproduction, lactation, and the regulation of body temperature. However, the winter season intensifies the challenge of providing a sufficient and accessible water supply. This difficulty is compounded by the freezing temperatures and changes in the behavior of the livestock during colder months.

Challenges in Winter Water Management

Managing water for livestock during the winter months presents distinct hurdles. The primary issue is the freezing of water sources, limiting cattle’s access to water. Cattle often increase their water consumption in colder weather to meet their heightened energy needs. This requires more focused management strategies to ensure they receive sufficient hydration.

In colder temperatures, cattle consume more feed to maintain body heat. If water availability decreases, feed intake also drops, leading to Continue reading

Buying Feeders? How “Histophilus somni” or “Somnus” is Changing the Game

– Dr. Michelle Arnold, UK Veterinary Diagnostic Laboratory

Most KY-born calves leave the farm and enter marketing channels, usually through auction markets, into stocker and backgrounding operations. Not surprisingly, late fall and winter are difficult seasons to keep feeder calves alive in KY due to major health challenges. Weather is just one of many risk factors that play a role in Bovine Respiratory Disease (BRD) or “Shipping Fever” development. Most auction market calves are sold as “high risk calves”, meaning they are lightweight (≤ 500#), young (estimated 6-8 months), unweaned (or abruptly weaned on the trailer on the way to the yards), unknown health history, never or poorly vaccinated and most are trace mineral (copper and selenium) deficient. At the auction barn, they are mixed or “commingled” with similar weight calves from multiple farms then sold, allowing respiratory “bugs” to spread prior to delivery to the stocker/backgrounder facility or feedlot. After arrival and a brief rest period, these calves are usually processed through the chute and receive multiple vaccines, deworming, are implanted and the bulls are castrated. These calves will typically break with respiratory disease within the first 2 weeks after arrival and require at least one antibiotic treatment. It is estimated that 60-70% of calves marketed through sale barns are considered at high risk for disease.

Over the last few years, the bacterium Histophilus somni (formerly known as Haemophilus somnus) has emerged as the major bacterial pathogen responsible for the rapid development of disease and death in feeder operations. While Mannheimia haemolytica, often referred to as “Pasteurella”, has traditionally been the most important bacterial species in “shipping fever” bronchopneumonia, Histophilus somni (HS) can cause similar disease symptoms but is proving very difficult to Continue reading

Nutritional Considerations Going into Calving

– Lawton Stewart, Extension Beef Cattle Specialist, UGA

Nutritional requirements change with the stages of reproduction.

As we start 2024, many beef cattle producers are about to start the calving season. Across the state, forage availability is variable. Some places have seen severe drought in late summer/early fall, causing producers to feed more hay and deplete their winter hay supply. Many producers were able to put up plenty of hay. However, we have received several emails and phone calls dealing with hay quality being lower than expected this year. Entering the peak of hay feeding season, here are a few situations we are seeing, and the potential ramifications.

  1. I will restrict feed in the last trimester to decrease calf birth weights.
  2. I need more protein to go with my hay.
  3. There is a tendency to underestimate crude protein and overestimate energy.

I will restrict feed in the last trimester to decrease calf birth weights.
Is this correct? Absolutely! The problem is that is not the only thing it will affect. Recent research has focused on fetal programming. Fetal programming is the concept that maternal stimulus or insult during fetal development has long-term effects on the offspring. One of the most critical aspects of fetal programming involves adequate nutrition, or lack . . .

Continue reading Nutritional Considerations Going into Calving

How much vomitoxin is too much for feedlot cattle?

Jerad Jaborek, Michigan State University Extension

Fusarium graminearum is one of the most common species responsible for producing vomitoxin.

The weather Michigan experienced in 2023 was quite different from the norm and created an ideal environment for fungi that can produce mycotoxins. In the Thumb region, a lack of rain and drought was experienced during the early summer followed by plenty of rain during late summer months. Weather summary data collected from weather stations in Richville/Frankenmuth and Lapeer areas, reported an average temperature of 66 degrees Fahrenheit, average humidity of 75 to 78%, monthly rainfall of 4.5 to 5.9 inches, and 11 to 13 days of rain in the month of August. The weather conditions experienced were prime for fungal and mold growth during the silking stage of corn development.

Fusarium species of mold prefer temperatures of 69 F or less with a relative humidity over 70%. Fusarium graminearum being one of the most common species responsible for producing vomitoxin and responsible for gibberella ear and stalk rot of corn. Vomitoxin, also known as deoxynivalenol (DON) is a type B trichothecene (i.e., mycotoxin) that can occur in grains such as corn, wheat, barley, oats and rye, as well as others.

The U.S. Food and Drug Administration (FDA) has set advisory levels for DON concentration allowable in grains allowed for human food consumption or animal feed consumption. The FDA has set advisory levels at . . .

Continue reading How much vomitoxin is too much for feedlot cattle?

Cattle Herd Health Seminar, register today!

Attend either location

Join OSU Extension and the College of Veterinary Medicine for the 2024 Cattle Herd Health Seminars. The seminars will be held on January 19 in Jackson and January 26 in Caldwell.

Both locations will have the same agenda covering emerging herd health challenges as well as addressing large animal veterinary shortages across greater Southeastern Ohio. Speakers and topics for the program are as follows.

Dr. Risa Pesapane – Tick Borne Diseases. Dr. Pesepane will focus on the Asian Longhorned Tick and the emerging disease Theileria orientalis that can be devasting to cow-calf and dairy production. Theileria cases are increasing in occurrence in Ohio, are you Continue reading

Caring for Beef Cattle in Winter Months

Ted Wiseman, OSU Extension, Perry County (originally published in Ohio Farmer on-line)

To help ensure a successful calving season, Body Condition Scoring has heightened significance in Ohio’s winter care regimen.

Ohio Winters can be a challenge, especially for those with livestock. Here’s a short list of five management tips to keep in mind as we prepare to manage cattle through another Winter.

Nutrition Management for Ohio Winters: Ohio’s varying winter conditions of mud to snow and back to mud, we need to be prepared for proper nutrition management for cattle. There have been numerous research studies that have shown the effects of extreme cold, mud, and wind. Producers will need to monitor and adjust feed regimens by incorporating high-quality forages rich in nutrients. Supplemental feed with a careful balance of protein and energy becomes essential to meet the increased caloric demands during colder months. This strategy ensures that Continue reading

Toxic Tall Fescue: Recommendations and Reality

– Dr. Chris Teutsch, Extension Associate Professor and Forage Specialist, University of Kentucky

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I wrote this article several years ago for the forages session at the Kentucky Cattlemen’s Annual Meeting. It is a summary of management strategies for utilizing tall fescue in grazing systems. How we approach tall fescue management in grazing systems is NOT black and white, but rather nuanced by a number of practical considerations. In some cases, replacement of toxic stands with improved novel endophyte (non-toxic endophyte) varieties does not always make sense. The objective of this article is to help you work through those considerations to determine the best path forward for managing tall fescue in your operation.

Tall fescue (Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.) is the most important cool-season grass in the transition area between the temperate northern and subtropical southern United States. In most unimproved pastures, tall fescue is infected with a fungal endophyte that imparts tolerance to abiotic and biotic stresses. While this mutualistic relationship improves persistence in low input grazing systems, it also results in the production of alkaloids that cause tall fescue toxicosis. While there are a number of grotesque symptoms associated with this syndrome such as Continue reading

Fescue Toxicosis: What is it and what does it look like?

– Dr. Michelle Arnold, UK Veterinary Diagnostic Laboratory

Summer Slump-Photo M. Arnold (University of KY) The expected response to hot summer temperatures is an increase in blood flow to the skin and extremities in order to remove heat from the body core to the skin surface. However, with fescue toxicosis, the blood flow to the skin is reduced by the constrictive effects of the ergot alkaloids on the blood vessels, severely limiting the ability of the body to cool itself.

Tall fescue (Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.) is the most important cool-season grass in the transition area between the temperate northern and subtropical southern United States. In most unimproved pastures, tall fescue is infected with the fungal endophyte Epichloë coenophiala, that imparts tolerance to abiotic and biotic stresses. An “endophyte” is a fungus or bacteria that lives entirely within the intercellular spaces of the leaf sheaths, stems, and seeds and is only visible microscopically. The grass and fungus enjoy a mutually beneficial relationship; the plant provides nutrients and a means for the endophyte to reproduce through infected seeds. The fungus, in turn, produces chemicals known as “ergot alkaloids” that function as chemical defenses, making the grass more vigorous, pest-resistant, drought-resistant, and tolerant of many adverse soil and environmental conditions. Often KY 31 tall fescue is the only grass that can survive and thrive in poor conditions or with poor grazing management. Importantly, the ergot alkaloids cause cattle to eat less, protecting tall fescue from overgrazing during its vulnerable decline in summer growth. Of the alkaloids produced by the endophyte, ergovaline is the predominant ergot alkaloid mycotoxin that significantly impacts livestock health and productivity. Ergovaline accounts for approximately 90% of the ergot alkaloids in tall fescue with the highest concentrations found within the seed head. “Fescue toxicosis” is the broad term used for the variety of clinical disorders that can affect cattle grazing endophyte-infected (E+) tall fescue. The most common and economically damaging manifestation of fescue toxicosis is “summer slump”, a syndrome characterized by Continue reading