As political pressure intensifies and focuses some uncomfortable attention on how cattle feeders use antibiotics, researchers have been engaged in a constant quest to find some useful alternatives to them, alternatives that can not only keep the politicians happy but also still work as well as antibiotics do. In that spirit, British Columbia researchers will report in an upcoming issue of the journal Research in Veterinary Science on the practical—and apparently successful—use of nitric oxide at receiving to help protect calves against Bovine Respiratory Disease Complex, or BRDC.
Naturally produced by the body (and not to be confused with the nitrous oxide gas you used in your gearhead days), nitric oxide serves the primary function of permitting the cells of the body to communicate chemically, facilitating many of its physiological processes. For instance, a dose of it can quickly and powerfully cause the circulatory system to dilate, opening up otherwise restricted blood flow; that’s why doctors give some newborn babies with poor lung function a dose of nitric oxide gas or give heart attack victims nitroglycerine or amyl nitrate--nitric oxide is the functional molecule those drugs release once they’re ingested.
But in addition to those physiological functions, the British Columbia researchers note, scientists also know nitric oxide has some antimicrobial properties against not only bacteria, but also yeast, fungi and viruses, both in the lab and in the animal. It also provides cell-signaling functions that can encourage the growth and function of immune cells to naturally protect the body from those pathogens. When other Canadian research from 2006 gave it over a period of three days by nasal tube to calves they had purposely infected with BRDC, they found it proved an effective treatment.
The problem with that earlier study was the necessary delivery device was a bulky and cumbersome patchwork of multiple gas tanks, regulators, heaters and humidifiers inherent in gas delivery, in addition to requiring 20 minutes daily to treat each calf. This latest study eliminated that problem by creating a simple nitric oxide spray that could be shot into the nose much like a nasal vaccine in under 5 seconds. The British Columbia team tested the safety and effectiveness of that spray for its potential to prevent BRDC in crossbred, multiple-sourced, commingled commercial feeder calves when given at arrival processing. Rather than purposely infect the calves as the 2006 study did, this one actually bought the 85 calves through a conventional auction system, shipped them for four to six hours, put them in a typical commercial feedlot—with the exception of providing them an under-roof area with straw bedding—and processed and fed them as most commercial feeders would. By re-creating the real world of feeder calf procurement and handling, they hoped to achieve a typical BRDC incidence rate of between 30 percent and 60 percent in the experimental calves.
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