PRECONDITIONING VITAL PART OF CALF HEALTH PROGRAM

by: Lee Jones
MS, DVM, University of Georgia


If you have sold a calf recently, I don't have to tell you that calf prices have dropped significantly from 2015. Last year, you could sell about anything and get good money for it; but now, you have to have a good calf to bring the best price. In the right market, preconditioned calves still bring the most money, and there is a good return on healthy calves. Besides a health premium, farmers also sell a heavier calf.

The basic principle of preconditioning is to prepare or "condition" calves to move from the cow-calf operation to backgrounding, grazing or finishing stages. The goal is to improve calf health (decrease sickness and mortality by enhancing the calf's immune system and resistance to disease) while increasing growth, carcass performance and profitability of calves. This article serves as a general overview of the process and will mention the importance and profitability of an effective preconditioning program. There is not a one-size-fits-all program that will work for every operation. The main components of a preconditioning program are: preventive management, including vaccination and deworming; low stress weaning; minimizing effects of painful procedures; and facilitating diet transition.

Vaccinations

Vaccination to enhance the immunity and resistance to various disease agents is a common practice in veterinary medicine. The type of vaccine, selection of antigens and timing of administration are important. Vaccines stimulate the immune system by mimicking the natural infection. Typical antigens included in calf vaccination programs include the viruses most commonly associated with BRD, including: bovine herpes virus-l (infectious bovine rhinotracheitis, IBR); bovine viral diarrhea virus types 1 and 2 (BVD 1 and 2); bovine respiratory syncytial virus (BRSV); and parainfluenza 3 (PI3). These are often combined in a multivalent vaccine that contains either killed (KV) or modified live virus, or a combination of modified live (MLV) and killed or attenuated virus. It is important to follow the label recommendations and instructions when vaccinating calves with an MLV vaccine. MLV are not recommended for calves nursing pregnant cows, or pregnant cows that have not been vaccinated with a MLV vaccine.

Research has shown that calves can respond to vaccines as early as the first month; but there is concern that maternal antibodies might neutralize the vaccine. Also, working very young calves with bigger cattle increases the risk of injury. Vaccinating the calves at the same time as vaccinating the cows in the pre-breeding period is an effective, convenient and safe time to use a MLV vaccine. It is common practice to vaccinate calves at three to five months of age and again at weaning. Vaccinating calves two to three weeks prior to weaning is also an effective, low-stress way to vaccinate calves. Current recommendations include two doses (initial and booster or re-vaccination) of most vaccines two to four weeks apart for the best protection. Research has shown that calves that had been vaccinated twice as calves (once at two to four months of age and again at weaning) with an MLV vaccine had no more morbidity in the feedlot than calves that received two doses of MLV two to three weeks apart at weaning.

Clostridial pathogens cause various diseases in cattle - ranging from tetanus and blackleg, to digestive disorders caused by different types of C. perftingens, to botulism. Cattle acquire clostridial organism spores from their environment while grazing. Ideally, calves should receive a multivalent clostridial toxoid vaccine by two months of age before the calves begin to experiment with grazing. Giving a booster about a month before weaning will ensure that the calves have the best protection against the diseases caused by Clostridium spp. Bulls castrated by banding should be vaccinated against C.tetani two weeks prior to banding. It is a common practice to vaccinate at the time of banding and also administer tetanus antitoxin.

Deciding on a vaccination protocol begins with the knowledge of expected exposure. It is important to follow the label instructions and handle vaccines carefully. Vaccines need to be kept cool and out of sunlight. If they require mixing, mix only enough to use within one hour of mixing. Always use a new needle when filling the syringe, and be careful not to contaminate the bottle of vaccine. All injections should be given in the neck area, and most should be given under the skin (SQ). Just because there is a vaccine for it, doesn't mean that it needs to be used. While protecting against the clostridial diseases and respiratory diseases such as BVD, IBR, PI3, and BRSV is extremely important other vaccines might be beneficial depending on the farm and health history. Pasteurella and Mannheimia might be beneficial, depending on a known history of this disease in the cattle; or it may be a required component of a verified program for marketing. A Moraxella, or Pinkeye, vaccine can help, when added as a part of a Pinkeye control program. However, it is recommended to give Pinkeye vaccine alone, and also control face flies and other eye irritants for best results. Other vaccinations such as Leptospirosis, Histophilus somnus and Mycoplasma spp may not be economically important in a feeder calf program; but Leptospira and Campylobaeter foetus are commonly included in vaccine programs for replacement cattle.

Parasites

Parasites have a large impact on health, immunity and performance of young calves. Control efforts should target both internal and external parasites. Parasites affect growth; they can also act to suppress the immune system, making cattle more susceptible to disease. Strategic deworming involves considering the time of year the parasites are most active, cattle movement between pastures, and management events such as weaning. This approach will help to decrease the parasite load and reduce pasture contamination. The anthelmintic to use is somewhat of a herd-specific decision. When evaluating an anthelmintic, consideration should be given to the class of drug, the stage of the life-cycle it targets, and which parasites are susceptible. A good deworming protocol can increase weaning weight by 20 to 30 pounds. Strategic deworming can also help replacement heifers reach puberty earlier and at lighter weights. It is important to avoid overusing products, in order to reduce the development of resistant internal parasites. Periodic fecal testing to determine parasite infestation will help to verify the effectiveness of the parasite program.

Weaning

The weaning event typically occurs around seven to nine months of age; but the preconditioning program begins even before this time period. It is essential to begin preparing the calves for weaning, in order to reduce stress and its effects on health and performance or growth.

Castration and Dehorning

Another element of the preconditioning program involves castration and dehorning. These processes can be stressful to calves, and can result in discounts if not performed prior to marketing. Bull calves sold through auction markets are often discounted as much as $10/cwt or more, compared with steers, in some regions of the country. Castration is a time-proven practice to improve behavior and management of male cattle. Preferably, castration should occur between birth and four months of age. Castration can be accomplished by: surgical removal of the testes; Burdizzo (crushes cord while leaving skin intact); or using an elastic band, which obstructs blood flow to the testicles and scrotum. Age of calf, available facilities, time of year, and experience of the person performing the procedure may determine the method selected. Calves castrated at weaning or later often have decreased performance and increased morbidity in the two to three weeks following the procedure. Calves castrated early (birth to three months) may be implanted to aid in weight gain. Some producers believe that later castration will aid in weight gain; but recent research from Florida doesn't show a weight benefit to delaying castration - and it increases pain, stress and hemorrhage, reduces feed intake, and increases risk of morbidity associated with the procedure. It is best to castrate in a clean and dry environment - and in the spring or fall, when flies are less irritating - to decrease the risk of infection. When using the knife method of castration, adequate drainage from the wound should be provided. Elastration/banding is a bloodless procedure in which the blood supply is obstructed and the scrotum and testicles shrivel and falloff in time. With this method, there is higher risk of tetanus, so proper vaccination is essential; and both testicles must be below the band, or the calf will have an incomplete castration.

Ideally, dehorning should be done genetically by using polled bulls. Dehorning/disbudding is recommended from birth to two to three months, while the horn buds are small and before the horns are connected to the frontal sinuses. Dehorning older calves can lead to exposure of the sinuses, which predisposes to infection and maggot infestation. Dehorning should be avoided during fly season and cold weather, if possible. Pain management techniques can decrease stress from dehorning and castration, and can reduce the stress and risks associated with painful procedures. A local anesthetic, such as lidocaine, has been shown to reduce the immediate pain response in calves to dehorning. Meloxicam administered orally at 1 mg/kg BW 24 hours before surgery reduced pain and morbidity on castrated bulls compared with nonmedicated bulls.

A good calf health program has several important parts. Vaccination is an important part, but there are other considerations if we want to produce healthy calves.

http://www.bqa.org/CMDocs/bqa/NationalManual.pdf







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