CALF scours should be a top concern for dairy producers because even when a calf survives a bout of scours, its future performance may be diminished.
"Scours is actually a clinical sign of a disease caused by many different bacteria and viruses infecting the lining of a calf's small intestine," said Dr. Mike Moore, a professional services veterinarian with Novartis Animal Health. "Scours is highly contagious and can spread rapidly."
Prior to its onset, producers may notice that calves have a dry muzzle with thick mucus appearing from the nostrils, very firm feces, a decline in feed intake, a tendency to lie down and a high body temperature.
Once scours begins, Moore said feces will be more watery and may appear bright yellow or white. In some cases, blood and mucus may be seen in feces.
Calves will exhibit signs of depression. Their eyes may appear sunken, and their skin may remain peaked when lifted. Abdominal distention may be present. Calves may become weak or collapse.
"Immediately isolate scouring calves if your facilities allow, and address electrolyte loss and dehydration with fluid therapy immediately," Moore said. "Pathogens may not directly cause death of the calf but will contribute to dehydration, electrolyte loss and acid-base imbalance, which is responsible for the calf's death."
Moore said the cause of scours is complex and stems from calf management, nutrition, the environment and the presence of pathogens. Moore said producers can reduce the risk by following these management strategies:
* Provide quality colostrum. Quality colostrum begins with good nutrition of the cow during the second half of gestation. Proper immunization of the cow at dry-off, including vaccinating for scours, passes antibodies to the calf in the first colostrum.
Up to 40% of calves do not consume enough colostrum and are more likely to develop infectious scours. Colostrum should be fed within two to four hours of birth, with the same volume fed again four to six hours later. If milk replacer is used, it should be added slowly to reduce digestive upset. Provide adequate protein and energy to allow the calf to produce optimal immunity.
* Manage facilities. Environmental stress brought on by sudden changes in the weather (particularly cold, wet, windy weather) as well as cold, damp, drafty or humid calf hutches can increase the chances of scours. Keep hutch bedding clean and dry, and provide young calves with individual hutches to slow disease spread.
* Train and limit staff. Different staff members have varying hygiene and handling methods that can lead to calf stress. Ideally, the same person should handle calves every day. Staff should always clean and sterilize feeding utensils and facilities. Workers should wash their hands thoroughly and wear waterproof boots that can be washed and disinfected. Staff should always handle healthy calves before sick calves. Ideally, the worker treating the sick calves should not handle the healthy calves.
"Although calf scours is a serious and costly condition, much can be done to minimize the risks through facility management, diet, immunization, genetic selection and management practices," Moore said.
Calf raisers take many steps to prevent their calves from getting sick. However, despite taking these preventative measures, one of the first frustrations heard when doing a walk-through of calf facilities is that calves are still getting scours between seven and 10 days of age, according to Devin Hyde, a calf and heifer specialist for Purina Animal Nutrition.
Having sick calves despite having taken all of the proper actions to support calf health can be one of the most discouraging challenges calf raisers must overcome, Hyde said.
She noted that it is not uncommon for calf raisers to overlook their calf facility cleaning and sanitation protocols, which play a vital part on any dairy.
Scours is typically caused by a bacterial overload on the feeding equipment and/or the environment. Calf raisers should address their equipment sanitizing protocols to limit bacterial exposure as much as possible.
Skipping these steps can allow disease and illness to quickly spread from calf to calf, negatively affecting the overall health and profitability of the herd.
Hyde recommended that calf audits be done frequently to evaluate what the cleaning procedures are and what type of disinfectant is being used.
Hyde suggested that calf raisers use the following six steps, developed by Dr. Don Sockett of the University of Wisconsin Veterinary Diagnostics Laboratory, when cleaning milk feeding equipment:
1. Rinse the equipment using warm, 90 degrees F water.
2. Soak the equipment in hot water, greater than 130 degrees F, with 1% chlorinated alkaline detergent.
3. Make sure wash water is greater than 145 degrees F. Using a brush will help eliminate any other residue.
4. Rinse the equipment using a cold water solution that contains 50 parts per million of chlorine dioxide.
5. Let the equipment drain and dry completely before reuse to prevent the growth of bacteria.
6. Finally, spray the inside and outside of calf equipment with a 50 ppm chlorine dioxide solution two hours or less before the next use of the equipment.
Hyde also emphasized that cleaning shouldn't stop with milk feeding equipment. Milk bottles and buckets should be cleaned daily, while calf starter and water buckets should be cleaned and disinfected between calves, at a minimum.
Feeding calves the correct amount of grain can be a challenge, and one particular challenge with managing large calf groups of varying ages and sizes is that they don't all eat the same amount of calf starter.
There is a delicate balance between not overfeeding calf starter to younger calves while not letting older calves run out of starter, according to Christie Underwood, a calf and heifer specialist with Purina Animal Nutrition.
It is important for calf feeders to be aware of how much calves eat at varying stages of life to avoid wasting feed and to help improve calf growth performance. According to Underwood, keeping calf starter and water fresh and readily available are vital to maintaining optimal calf growth.
Underwood highlighted the following benchmarks for specific periods in a calf's development:
* The young calf (first two weeks of life). Within the first two weeks of life, calves often consume very little calf starter and are more dependent upon liquid nutrition.
"One common mistake I see on farm is that calf feeders tend to offer a large amount of feed to young calves," Underwood said. Ideally, calf starter should be changed every day, and old feed should be discarded. Unfortunately, this doesn't always happen, and uneaten calf starter goes to waste.
This may also interfere with calf starter consumption because the starter becomes stale. Stale calf starter may look okay to eat but is no longer palatable to the calves.
* Three to four weeks of age. According to Underwood, by the time calves are three to four weeks old, noticeable increases in calf starter intake should be seen. During this time frame, it is important that employees monitor feed intake closely as this increase can often go unnoticed, and calf growth could be hindered due to inadequate nutrition.
Calf feeders should pay attention to how much feed is left. If calves are finishing their feed on a regular basis, then their daily allotment should be increased.
* Weaning (four to eight weeks). By the time calves reach weaning age, they should be consuming greater amounts of calf starter. Underwood pointed out that calf starter intake may even double. Employees need to be aware of potential spikes in consumption and be ready to meet calves' increased appetite.
* Grain-only phase (8-12 weeks). After calves are weaned, they rely on complete feeds as their sole source of nutrition.
"Some operations I work with leave calves in a hutch or pen for up to 12 weeks of age," Underwood said. Once calves reach 12 weeks old, these calf raisers begin introducing a calf grower feed so that their calves can transition more easily to a diet higher in fiber.
As calves continue to grow, starter consumption increases significantly; it is important to not limit intake at this stage of development. It is also important not to let calves go for periods of time without starter. Some animals may slug feed when feed does become available, and this could lead to bloat.
To help achieve optimal growth, calf starter should always be fresh, dry and readily available.