“Because of our unusual amount of snow, animal health is also a concern this winter,” says North Dakota State University Extension veterinarian Gerald Stokka. “For cattle operations that begin calving during this time, cows must have access to some type of confinement facility with the capability to provide bedding. Newborn calves will need space inside a bedded barn or shed, or cows with newborn calves will need to be moved to confined space facilities.”
Typically, confinement facilities should have room for the dams predicted to calve during the first two weeks of the calving season, as gestation periods vary widely, says Dr. Stokka. In confined spaces, it is important to separate first-calf heifers from the mature cow herd. Calves born to first-calf heifers are considered to be at a higher risk of disease during the first three to six weeks of life. This is primarily due to the relatively lower quality of colostrum produced by first-calf heifers and potentially a lower absorption rate due to the risk of poor dam-to-calf bonding and greater calving stress. These factors combine to inhibit colostrum consumption, decrease absorption, increase the risk of failure of passive transfer, and increase the risk of disease, especially neonatal calf scours, and the chance of pathogen exposure to other calves. In addition, when working with higher-risk groups, it is important to remember that pathogens can be spread by human and mechanical (loader tractors) contact. In outdoor pens connected to confinement barns, cows should be provided a minimum of 250 to 500 square feet per head, and it is beneficial to the health of the cow and calf to bed these pens.
Dr. Stokka advises ranchers to design a system to reduce the risk of disease spread to the pregnant cow and newborn calf. A calving barn can be used as a gateway to reduce exposure from winter weather. All cows observed to be close to calving in a 24-hour period should be moved into the calving barn. Pens can be constructed out of panels if working with first-calf heifers or mature cows, as these cows may need some assistance with establishing the cow-calf bond. The calving barn must be supplied with clean bedding midway and later into the calving season, as new bedding decreases the spread of pathogens to calves moving through the facility.
Depending on weather, herd size and barn size, the entire barn and all cows calving within the 24-hour period can be moved to sod or clean, dry ground with some type of wind breaks. Evaluate each calf for well-being prior to the move to outdoor space. If the ground is still covered with snow, the removal of snow, the addition of wind protection and the application of bedding can be sufficient for newborn calves, says Lisa Pederson, NDSU Extension livestock specialist.
Without a calving barn and under extreme cold and snowy conditions, providing protection from wind and finding sod that can be cleared of snow is an option. Each cow close to calving should be provided at least a quarter to a half acre per cow to calve, reducing the risk of pathogen exposure. The practical nature of this is difficult, as cows do not stay in their own areas, and feeding cows in the same space complicates all of this. After two weeks of calving if conditions are still less than ideal, clear snow, bed and move to another area and leave behind the contaminated area. In extreme weather conditions, calf shelters can be utilized, however they should be moved often to reduce the risk of pathogen exposure to the calf crop.
“In every condition, monitor calf health, look for symptoms associated with calf scours, bloody diarrhea and depression,” says Dr. Stokka. “Also monitor calves that express lethargic behavior, lack of nursing and increased respiration. If calf scours develop, it may be advisable to separate the calf and dam from the group to limit spread.”
Newborn calves have a higher amount of bodyweight related to fluid volume. It is estimated that up to 75% of their body weight is fluid from blood, tissues and cellular spaces. This extra fluid volume does not protect them from dehydration when losses occur due to diarrhea. For example, a 100-pound calf that is 10% dehydrated due to fluid losses will require 10 pounds of fluid to replace the loss. This is 1.25 gallons, which does not include the amount required for maintenance. Mild dehydration can be detected visually in neonatal calves. A dehydration of 2% body weight is associated with slight sunken eyes, dry mucous membranes, and a prolonged skin tent duration of three seconds. In severe cases, intravenous administration of fluids may be necessary. Reductions in cardiac output in dehydrated calves is associated with decreased blood flow and therefore cooler extremities such as ears, feet and legs.
Oral replacement products are important to have on hand, says Dr. Stokka. There are a number of products available, such as Entrolyte HE and Resorb. They are balanced, with the main electrolytes being sodium, chloride and potassium, as well as varying amounts of dextrose for energy. High energy electrolytes are especially important if the calf has lost weight or is going to be on electrolytes for an extended period of time. If the calf seems confused, dopey or wobbly, it may be due to metabolic acidosis due to loss of fluids. Adding sodium bicarbonate (baking soda) to oral fluids can help to correct this condition. Recommendations vary as to the amount of baking soda added to oral solutions, but 2 tablespoons of baking soda to 2 quarts of oral solutions would be appropriate.
According to Dr. Stokka, antibiotics are not needed to treat most cases of calf scours, as dehydration and electrolyte loss are the principle issues for the calf to overcome. In cases of calf scours, there often are multiple causative etiologic agents involved, including viruses such as rotavirus and coronavirus, protozoa such as cryptosporidium, and bacteria such as E.coli. Only in cases with suspected systemic infections or sepsis would the use of antibiotics provide a potential benefit.
“This winter has been difficult and may not be completely over, but spring is coming and with it, drying weather and a new calf crop,” Dr. Stokka says. “Remember as you are taking care of your livestock to take care of yourself too. Your health is as important as that of your herd.”
Source : ndsu.edu