It can be difficult to gain the momentum needed to change seemingly productive long-time practices. Sometimes there may not be a necessity for the change or enough information and initiative to propel it.
Needle-free injection technology, or NFIT, is such a practice. Variations of it have been around since the 1940s when it was first used to vaccinate people. Subsequently, the hog and sheep industries have used the method to deliver antibiotics, iron and vaccines, while the cattle industry has not yet adopted it on a large scale.
Dr. Kim Ominski, professor and associate head in the Animal Science Department at the University of Manitoba has conducted several studies and explored the use of this technology in cattle. “Although this technology has been adopted by the hog industry, we weren’t sure if it could deliver an effective immune response in cattle given hide thickness and cold temperatures associated with winter conditions in the prairies. The needle-free (NF) system offers several advantages for all livestock species including removal of the risk of broken needles and the transmission of disease from animal to animal.”
Needle-free injections are just as they sound—injections administered into the body without the use of a typical needle and syringe. Models include those using compressed air, carbon dioxide or nitrogen to provide the pressure required to inject the vaccine. When the device is held perpendicular to the animal, it is triggered by mechanical compression as the nozzle touches the skin, producing a high pressure stream to penetrate the epidermis and place the vaccine at the desired tissue depth.
Both intramuscular and subcutaneous products can be administered. NFIT models are typically connected to a backpack where the vaccine and power source are carried. They usually weigh approximately 12 pounds but vary by device.
Benefits and disadvantages
Several benefits of needle-free injection systems include:
• Although infrequent, needles that break off inside an animal present a food safety issue;
• Removing needles from the workplace represents a safer environment for those handling the injection tasks. The chances of being poked or stuck by a stray needle are non-existent for workers;
• Less waste is involved. The need to properly dispose of dirty and contaminated needles is eliminated;
• Since no needles are used, the potential to transmit organisms or blood-borne diseases such as anaplasmosis between animals is reduced when compared to injecting multiple animals with a single needle;
• NF injections are equally effective in vaccine delivery, dispersing it evenly throughout the body which enhances cellular contact and product efficacy; and
• Comparable, or in some cases, enhanced immunity responses have been reported between NF and needle syringe (NS) injection devices.
Disadvantages of needle-free injection technology systems include:
• Systems have greater complexity than their counterparts, requiring calibration, maintenance and training for the workers;
• A small amount of vaccine residue may be present after injections;
• Systems are designed to contain one vaccine. They are not usually equipped for large doses like antibiotics; and
• Producers who wish to inject multiple vaccines would have to purchase several units, (at a cost of $2,500 to $5,000/unit) or move the cattle through the chute a second time to administer subsequent vaccines.
Research trial details
Several trials using NFIT have been completed by Ominski and her colleagues at the University of Manitoba. Two separate commercial cow-calf beef herds were included in the trial which saw 86 spring-born crossbred beef calves weighing approximately 230 pounds vaccinated from July to November and a similar group of fall-born calves vaccinated from October to March.
“We compared body weight presence of skin reactions and antibody response in calves following vaccination against BVDV (bovine viral diarrhea virus) and C. chauvoei using NF and NS vaccination techniques. We also wanted to determine if season of vaccination affected the ability of a NFI device (NFID) to effectively vaccinate cattle given that hair coat and hide thickness could change the penetration of the vaccines.
“We found no differences between the two injection systems in terms of the immune response generated in either the spring-born or fall-born calves. Trends in immune response between the 2 seasons suggested the NF device can be used in the cold temperatures of western Canada.
“Although a small amount of vaccine residue was present on some of the animals following the needle-free vaccinations, the antibody response was not compromised because of it,” said Ominski. “NF vaccination also caused a greater number of skin reactions at site compared to the use of a typical needle and syringe. However, this may not necessarily be a bad thing as it might simply indicate an immune response is occurring. A second study following vaccinated calves through to slaughter examining injection site reactions indicated they were no longer present at slaughter and NF systems did not result in tissue damage in the carcass.”
The study concluded NF and NS injection deliveries were equally effective in the vaccination of spring- and fall-born calves, and an NFID could be successfully used in colder climates.
Although the use of needle-free technology is feasible and still an option, adoption by cattle producers will be based on benefits and disadvantages for individual circumstances and requirements. Cost, practicality of work processes and animal handling will play a large role in whether the decision is made to part ways with a long-time practice and invest in the needle-free technology. — Bruce Derksen, WLJ correspondent