Animal Industry News Update - December 2014

Theresia Lavergne, Page, Timothy G., Walker, Neely, Pruitt, J. Ross, Johnson, Rodney  |  12/17/2014 1:33:19 AM

Equine Enteric Coronavirus

horse biosecurity

Dr. Neely Walker


A horse in Port Allen, Louisiana, has been diagnosed by the LSU School of Veterinary Medicine with Equine Enteric Coronavirus (ECoV). Coronaviruses are part of a large group of ribonucleic acid (RNA) viruses that can cause both respiratory and intestinal distress in a variety of species, including but not limited to birds, dogs, cats, swine, cattle and humans. While the Equine Coronavirus is very similar to Bovine Coronavirus, which displays both respiratory and intestinal distress, the Coronavirus that affects horses currently only presents as an enteric (intestinal) disease. This infection spreads in horses via fecal-oral transmission, which may occur when horses are stabled together or during transport, and is more common during the colder months of the year.

Horses affected with ECoV tend to have fevers above 102o F, have a loss of appetite and may appear depressed or lethargic. Typically these symptoms will disappear in one to four days with minimal treatment. Less commonly, horses may experience one to two days of diarrhea or loose feces and signs of mild colic. In rare cases additional complications can occur, such as septicemia (bloodstream infection), endotoxemia (endotoxins from bacteria released into the bloodstream) and neurologic abnormalities.

Equine Enteric Coronavirus is highly infectious. However, only very rare cases will result in death. Typical treatment will include supportive care, such as intravenous fluids, fever-reducing medications and gastrointestinal support. Once a horse has been diagnosed with ECoV, that animal must be isolated and strict biosecurity measures must be put into effect. Keep in mind horses that are no longer showing clinical symptoms can still shed the coronavirus through their manure for up to three weeks, and some horses may shed the virus without showing any signs of the virus at all. Encourage horse handlers to use disinfectant footbaths, disposable gloves and individual equipment for horses diagnosed with ECoV. Limiting traffic into and out of the barn and the use of veterinary-grade disinfectants will help reduce the chance of spreading the virus.

While diagnosis of ECoV is not typically a fatal event, special attention is required to prevent and control the disease in horses. Effective biosecurity principles must be followed to prevent the spread of infection. Currently there is no vaccine available for ECoV; therefore, supportive care is necessary to reduce the impact of the disease. If you are concerned your horse may have ECoV, contact your veterinarian immediately.

Swine Trailer PEDV Disinfecting Methods

swine trailer

Dr. Tim Page


In a recent study at Iowa State University, researchers evaluated various disinfectants and disinfection techniques to assess how effective they are in inactivating porcine epidemic diarrhea virus (PEDV) in hog trailers. Several trailer sanitation programs were evaluated. These included thermo-assisted drying and decontamination (TADD) systems, along with multiple disinfectants. They reported that some disinfectants may work well against PEDV even when feces are present.

The study verified previous methods of fighting the virus. In the presence of feces, PEDV was inactivated by heating to 160o F for 10 minutes or by maintaining room temperature at 68o F for at least seven days. No other combinations of time and temperature evaluated were shown to be effective at inactivating PEDV.

Accel disinfectant was found to be effective at inactivating PEDV in the presence of both heavy and light fecal contamination within 30 minutes of contact time at room temperature. Accel was found to be effective at both concentrations evaluated (1:16 and 1:32).

Stanlosan F disinfectant powder alone, with one hour of contact time at room temperature, did not inactivate PEDV in feces. Complete trailer sanitation protocols that included a wash with detergent, disinfection with Synergize at a concentration of 1:256 and heating were effective at inactivating PEDV. Synergize alone with 10 or 60 minutes of contact time following a wash with detergent and disinfection was effective with or without heating after disinfection.

The investigators do not propose that TADD-only or disinfectant-only approaches to trailer sanitation are preferred alternatives to thoroughly washing, disinfecting and drying trailers. Rather, they recommend the value of including washing, disinfecting and TADD in a trailer-sanitation protocol. This work demonstrates the value of possible alternatives when all of the steps cannot be accomplished as a means to reduce the risk of transmitting PEDV between groups of animals during transport.

(Source: Thomas, P., L.A. Karriker, A. Ramirez, J. Zhang, J.S. Ellingson, and D.J. Holtkamp. 2014. Methods for inactivating PEDV in Hog Trailers. Twenty-second Annual Swine Disease Conference for Swine Practitioners, November 13-14, 2014.)

Reducing Cold Stress on Cattle

calves

Dr. Tim Page


Winter and cold weather play a big role in overall cattle health. Stressed animals always are more susceptible to stress-related illnesses, and cold and/or wet weather is even more challenging for cattle. Wind can add another compounding stress during cold stretches. In fact, it is recommended that windbreaks and even bedding be provided during times of high winds with cold.

Young calves, especially newborn calves, are at the highest risk during cold weather. Also, calves that are two weeks of age or less and sick calves are at risk in severely cold weather. Young calves handle cold temperatures fairly well once they are dry and have the insulating effect that a dry hair coat provides.

Colostrum always is important, but during cold weather it is even more vital for newborns. Colostrum is high in fat, with approximately two to three times more fat than in regular milk. This can really help boost the calf’s energy and get it going. A calf that has nursed a full feeding of colostrum can stay warmer, and its chance of survival is vastly improved. Once the calf has nursed colostrum it usually has the energy needed to keep warm since a newborn calf is born with less than a day’s worth of energy in the form of brown fat to burn for body heat. If the newborn does not get colostrum, once the brown fat is depleted, there is no energy available for the calf to maintain or regulate body heat.

The lower critical temperature (LCT), which is the temperature below which the calf or cow must burn extra energy to keep warm, is higher for calves than for cows, especially if the animal is wet. The LCT for calves is close to 60o F, but with a little rain or sleet, the LCT moves closer to 70o F. As little as 0.10 inch of rain on the day the calf is born can increase calf losses by 4 percent.

As calves get older they usually become more resistant to cold stress as long as proper nutrition and health care are provided. It is critical for calves to have quality nutrition that meets or exceeds their requirement for nutrients to deal successfully with cold weather. With the correct nutrition, the calves will be in good body condition and have more insulation against cold and enough energy to keep warm. Many producers focus on protein (which is important), but energy for cattle is crucial to reduce cold stress.

Record Prices and Reevaluating Your Operation

cow calf pairs

Dr. Ross Pruitt


With what has been a very memorable year for livestock producers coming to a close, many are likely reluctant to see it end. Numerous records have been set throughout the supply chain from the retail and wholesale levels down to the farm level, often at breathtaking speed. Additional records are likely to be set in 2015, but maybe not with the frequency that has occurred this year. These record levels of prices have altered not only the outlook for the U.S. livestock industry as a whole for the next few years but also what is possible for individual livestock operations right now.

Current price levels change what is possible for livestock operations because the relative returns have changed. As an example, higher prices combined with lower grain prices have resulted in higher dressed weights for steers and heifers since September, as additional returns for extra pounds exceeded the additional costs to feed the animal to those weights. This has resulted in an additional 24 pounds of beef per steer (18 pounds for heifer) since September. This is one example that happens in markets when relative returns change, providing incentives for market participants to alter their actions.

The above example highlights how dynamic the market can be and how economically sound decisions change over time. To borrow briefly from economic theory, there are three stages of economic production. The first is where additional spending can result in additional production and revenues, the second (and optimal stage) is where additional spending is equal to the additional returns, and the third stage is where additional spending results in lower production and revenues. In the feedlot example, lower grain prices resulted in a shift back to stage one, resulting in additional production to get back to an optimum situation.

While a cow/calf operation is not nearly as dynamic as a feedlot in terms of the frequency and number of head marketed, there are still similar changes in the relative costs and returns that may have shifted an operation outside of the optimal second stage of production. Retaining heifers is one possibility as current forecasts suggest they will pay for themselves in only a few years’ time. While expansion is certainly worth analyzing, what about increasing the productivity of existing animals within the operation? For a 50-cow operation, increasing the calving and weaning percentages an additional 5 percent results in an additional two to three calves per year. With each calf worth approximately $1,500, the potential revenues add up quickly from increased productivity of existing animals within an operation. The cost associated with carrying the cow throughout the year does not change whether it has a calf or not, only whether the cow covers her costs with a calf to sell for revenue. This option also does not result in foregone revenue by holding heifers back to expand or the cost to develop those retained heifers. The additional cost to increase cow productivity is minimal compared to the total annual cost of owning the cow. In the current market setting, the additional effort and cost of increasing productivity are well-rewarded.

No two operations are exactly alike, but the changes seen in the livestock markets this year warrant a re-examination to determine if your operation is getting the biggest bang for its input spending. The above examples highlight the possibility that an operation may need to slightly increase spending to optimally use its resource base, which can result in additional production. The opposite also is true; that which was once overspending may have landed the operation in a temporarily optimal situation. The current market environment of high cattle prices will not last forever, but it will likely be with us the next few years. Understanding how relative changes in prices and costs impact your operation can aid in making the good times slightly better now and aid the transition back to a new “normal” when it occurs in upcoming years.

Goat Production: Preparing for the Breeding Season

boer kids

Rodney Johnson


Breeding is a very important aspect of any goat operation. Preparing does for the breeding season can have a large influence on the success of the operation. Goats are seasonal breeders. This means that beginning in late summer and early fall, the amount of daylight decreases, which signals the does to come into heat.

Doe Management

One to two months prior to breeding:

  • Provide additional feed to does. This is called flushing. Supplement the females with 0.5-1.0 pound of grain per head per day to improve body condition and ovulation rates. Does with extremely good body condition scores (BCS = 7) will tend not to respond to flushing. Does with internal parasites (i.e. worms) may not increase their body condition during the flushing period, and therefore, flushing may not increase ovulation rate.
  • Vaccinate the females with Clostridium Perfringens Types C & D + Tetanus toxoid vaccine.

Two to three weeks prior to the breeding season:

  • Deworm the does using a targeted, selected treatment such as FAMACHA or fecal egg counts.
  • Vaccinate the females with Clostridium Perfringes Types C & D + Tetanus toxoid vaccine. This vaccination prior to kidding will allow some immunity to be passed to the newborn baby.

At Breeding:

  • Breed meat type goats at BCS between 5 and 6 and dairy goats at BCS between 3 and 3.5. Place the buck with the does for two estrous cycles (or 42-45 days) and then remove him, or artificial inseminate (AI) them.
  • At least 10 days after the last AI, put a “clean-up” buck in with the does to breed the does that did not get pregnant from AI.

Early Gestation (First 100 days):

  • There is very little fetal growth during early gestation.
  • Good quality forage should meet their nutritional requirements.
  • Feed at a rate of 2 percent of body weight.
  • If no pasture or limited forage is available, feed grass hay and a 16 percent protein diet at 1.5 percent of body weight.

Late Gestation (Last 50 days):

  • During late gestation 70 percent of fetal growth occurs.
  • Poor nutrition at this stage causes low birth weight and low milk production.
  • Utilize forages and supplemental feeding at this time.
    • Feed at a rate of 4 percent of body weight.
    • Feed two to four pounds of good hay and two pounds of grain per doe.

Lactation:

  • Doe nutrition is key to early kid growth.
  • Lactation peaks at three to four weeks after kidding.
  • Utilize pasture and supplemental feeding during lactation.
    • Feed does at a rate of 4-5 percent of body weight.
    • Feed three to four pounds of good hay and three to four pounds of grain.

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