Keeping cattle healthy without antibiotics
December 27, 2013
Good health depends on many factors; keeping cattle healthy can sometimes be a challenge. With the advent of vaccines and antibiotics, it became easier, and for many decades cattle producers routinely addressed the issue of disease by using vaccination for prevention, and anti-microbial drugs for treatment. The use of pathogen-killing drugs is being questioned today however, due to increasing numbers of drug-resistant pathogens. Microbial resistance diminishes the effectiveness and benefit of some of the drugs we've come to rely on.
There is also the issue of drug residues in food animals if drugs are not used appropriately or withdrawal times are not carefully observed. Consumers are concerned about the safety of meat products. For these reasons, a growing number of beef producers and veterinarians are looking at alternatives to antimicrobial use in dealing with disease. The key factors in this goal are reducing exposure to disease while at the same time keeping immunity strong.
Andy Allen, DVM, Assistant Professor, Washington State University, says the number one thing a producer can do to minimize use of antibiotics is make sure cattle have good nutrition. "This enables the immune system to fight off infections. The diet must include adequate protein, energy, vitamins and trace minerals–with copper, selenium and zinc being the main ones. This may require testing feeds, and the producer may need a custom trace mineral mix that fits specific needs. One mineral mix won't fit every situation," he says.
“Keep records on the animals treated – the conditions you treated, when and what you treated them with and how they did. You may find you are using fewer antibiotics and only using them on the animals that really need them.”
–Andy Allen, DVM
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Know what you are feeding. "Just because the hay is green doesn't mean it has enough protein and energy. You also don't know the trace mineral levels." Some soils are deficient in copper. Many areas are deficient in selenium–while others have too much selenium.
Other elements in soils and feeds can bind up copper, making it unavailable for the body. "Even if you are giving cattle the required amount of copper, it may not be enough if there is too much molybdemum, sulfur, iron or zinc that might be binding to it. Understanding these mineral relationships is important. We recommend working with a nutritionist to figure out the proper levels of trace minerals for each ranch," says Allen.
"Looking at body condition score is crucial throughout the year, making sure cattle are somewhere near the ideal range of five or six. You don't want them going into winter thin. There is a big push today for cost-effective ways to feed cattle, but you need to balance this with body condition. A certain method might be the cheapest way to feed, but there can be long-term adverse effects for those animals and the immune system if they lose too much weight." It might cost more in the long run if cattle become thin, causing higher incidence of disease and the need for more antibiotic use.
"Monitor body condition score or weight, to tell if cattle are gaining or losing. Weight loss can happen pretty fast; then you are behind the 8-ball before you know it, and you'll have to feed more to catch up," he says.
Allen works with the Field Disease Investigation Unit at WSU. "We investigate disease outbreaks and increased incidence of disease within herds. The second most common thing we see associated with increased disease incidence (and more use of antibiotics) is high stocking density. This is important to think about, along with nutrition. In many situations where there is increased disease incidence, we find there are too many animals in too small an area."
This is particularly important before and during calving. Management of cows pre-calving is crucial for preventing sickness in baby calves, keeping the environment clean. Don't calve in the same area where you fed cows through winter.
"If you leave cattle in the same area too long, pathogens build up–there will be higher numbers of bacteria, viruses and protozoa that cause calfhood diseases," he points out. The calves are more vulnerable than cows because they don't have an experienced immune system yet.
"There are ways we can keep the calving area cleaner, such as the Sand Hills Calving method. We recommend this management program to many ranches where we've gone to investigate disease outbreaks. This involves moving the pregnant cows to new calving grounds every seven to 10 days," he explains. This leaves the calved-out pairs behind, in small groups according to age. Those young calves, in their most vulnerable state, don't have to contend with older calves that might be sick and shedding pathogens. The calving cows have clean ground to calve on–that hasn't already been contaminated by sick calves. Sick animals concentrate the pathogens at a much higher level.
Stress hinders immune function, so it pays to reduce stress as much as possible. "Weaning time is a big stress, so preconditioning programs may be helpful, setting up a program that's appropriate for your ranch and working with your veterinarian. If you plan to vaccinate them ahead of weaning it should be done several weeks ahead," says Allen.
There are various ways to reduce stress at weaning, such as fenceline weaning, nose flaps, etc. Decide what will work best for your own situation, finding ways to keep calves' immunities strong rather than weakened by stress.
"It also helps to train calves to eat out of bunks, and drink from water troughs before or during weaning, before they are shipped, so it won't be an unfamiliar situation. You don't want multiple stresses at the same time. We see a lot of people pulling calves off cows and putting them onto a truck and this is usually a recipe for disaster regarding incidence of disease," he says.
Make sure working facilities flow well. The less time cattle must be confined, and the quieter they are moved and handled, the less stressed they will be. "If they move through easily and there's not a lot of whooping and yelling and hot shot use, those animals do better. During stress their cortisol levels go way up, and when that happens their immune system drops. Keep stresses to a minimum. If you can practice with a group of calves, putting them quietly through the facility without being worked, they are not as upset and stressed when you put them through again," says Allen.
Having cows that don't get upset when you move them through the facility will be easier on them. They can be trained to tolerate being worked and handled if you keep stress levels low. "There are always ways to improve cattle handling to keep it less stressful," he says.
"Another thing people often don't think about is how dystocia stresses the cow and calf. A high rate of dystocia is a risk factor for higher rate of diseases (diarrhea and respiratory) in the calves," says Allen. Calves experiencing difficult birth may be fatigued and short on oxygen, and may not get right up and nurse. A calf that's been stressed during birth, or severely chilled soon after birth, is acidotic and unable to absorb antibodies from colostrum as readily as a strong healthy calf.
"A cow that's just gone through difficult labor is less likely to have enough antibodies and less likely to mother the calf. He's slower to get up, and may need to be force-fed. Using calving-ease bulls and selecting cows for easy calving can be a help in preventing these problems." Having less stress at calving time helps ensure higher rates of colostrum absorption in the calves, and better immunity.
Understanding when to use antibiotics and when not to
"Many producers give antibiotics to cattle that don't really need them. It may be a condition that antibiotics won't help; we're just increasing the chances for development of resistant bacteria. We want our antibiotics to work well, and for a long time. Talk with your vet and come up with protocols for using antibiotics," says Allen.
Sometimes antibiotics are administered unnessesarily. "Some ranchers may treat animals the way their father did, or give antibiotics for situations like retained placenta–where antibiotics are generally not needed. Talk to your vet about calf diarrhea, and such, and what the protocol should be. Take the calf's temperature, monitor how the calf is suckling, how dehydrated it is and use fluid therapy. Determine at what point the calf might need antibiotics. Often a calf just needs good supportive care," he says.
"Keep records on the animals treated—the conditions you treated, when and what you treated them with and how they did. You may find you are using fewer antibiotics and only using them on the animals that really need them. That way you are not wasting money or causing more antibiotic resistance," he says.