One of the most important challenges facing feedlot operators, and the consulting veterinarians who service them, is the development of on-arrival strategies to maximize health in the most economic fashion. Many products are available to producers, including vaccines, antimicrobials, parasiticides, nutritional supplements and rumen modifiers. It is vital for producers to work closely with a veterinarian to determine which products are most applicable to achieve the best overall health possible.
However, a few certainties apply to every load of cattle coming into the feedlot. First, research during the past 30 years has consistently revealed that a solid deworming program is crucial to getting cattle started right. Failure to control internal parasites can result in a decrease in feed intake and general immunosuppression leading to increased sickness during the feeding period.1,2 The injectable avermectin products, such as doramectin, provide superior efficacy at controlling internal parasites, while pour-on products provide the best control for external parasites. Since internal parasite control is far more critical in starting cattle, injectable products are recommended for feedlot cattle. Inexpensive, permethrin-based topicals can be used to control biting lice in affected geographies at peak times.
Second, producers should take advantage of the respiratory protection offered by viral vaccines on-arrival or shortly thereafter. Many vaccines are available providing protection against the following diseases: infectious bovine rhinotracheitis (IBR) virus, bovine viral diarrhea (BVD) virus Types 1 and 2, bovine respiratory syncytial virus (BRSV) and parainfluenza virus 3 (PI3). The level of protection a given vaccine offers against these diseases is clearly stated in the label indications. Every producer should have regular discussions with a veterinarian regarding which vaccine should be used.
Third, proper nutrition is critical to the success of any arrival program. High- to moderate-risk, lightweight cattle need a higher forage concentration in the ration and plenty of available protein, vitamins and minerals to ensure adequate feed intake and optimum immune response to vaccines.
In addition to these certainties, some loads of cattle are candidates for metaphylactic or control therapy with an antimicrobial on arrival. Several antimicrobials are labeled for control of bovine respiratory disease in high-risk cattle. Whether or not to medicate cattle on arrival and which product to use can be a complicated decision. Factors that affect the decision are:
- Cattle source
- Historical risk associated with the source/supplier
- Impending weather
- Age of the cattle
- Vaccination history of the cattle
- Labor availability