|
By Sarah Whyte
The following projects are budgeted to receive up to $25,000 in research funding
from the Ontario Cattlemen’s Association’s Research committee
Antimicrobial resistant bacteria are a serious and growing concern. As more
disease-causing bacteria are becoming resistant to multiple antibiotic drugs,
doctors are being left with few treatment options for controlling infections.
Agricultural and medical uses of antibiotics are both suspected contributors to
the problem of antimicrobial resistance, and each has come under considerable
scrutiny from the scientists, policy-makers, and the public.
In addition to using antimicrobial drugs for disease treatment, beef producers
use them to prevent illness, promote weight gain, and increase feed efficiency.
These sub-therapeutic uses have been the subject of criticism, but the precise
link between agriculture and antibiotic resistance remains unclear.
One of the greatest obstacles to determining if and how agricultural drug use
contributes to the evolution of antimicrobial resistance is a simple lack of
information. Adequate records are also needed for demonstrating to the public
that the cattle industry is actively addressing concerns about antimicrobial
resistance.
The Ontario Cattlemen’s Association has responded proactively to these issues.
Over the past year, producers have worked with researchers on OCA-funded studies
aimed at gathering information about aspects of antimicrobial drug use.
OCA Survey
The first study had a pair of objectives: to gather information about how
antibiotics are currently being used in Ontario and to solicit producers’
opinions about antibiotic drugs. The study involved one survey, distributed
widely to beef farmers in Ontario.
A total of 632 surveys were filled out, representing about of five percent of
beef cows and 11 to 13% of steers and heifers marketed in Ontario.
Respondents demonstrated some clear consensus when it came to questions about
antibiotic drugs:
- 99.1% agreed that clear instructions on labels were important
- 95.4% felt that the use of antibiotics in feed can lead to antibiotic resistance
in bacteria
- 94.4% agreed that it is important to reduce the use of antibiotics
- 94.2% agreed or strongly agreed that bacterial infections cause serious economic
losses
- 92.1% agreed that it was necessary to reduce the use of antibiotics in order to
slow the development of resistance in bacteria, while only 5% strongly disagreed
- 81.5% disagreed or only slightly agreed that the use of antibiotics in feed
resulted in significant weight gain
- 78.0% agreed to some extent that a controversy in the media would change their
current antibiotic use practices
- 53.3% reported they had heard of hygiene practices designed to decrease the need
for antibiotics
- 48.1% agreed that the cost of antibiotics in feed was low, compared to 51.9% who
disagreed
Almost all respondents were aware of the issues surrounding drug resistance.
They believed that using antibiotics responsibly, and generally reducing their
use, was important. At the same time, the respondents were just as aware of the
economic cost of bacterial infections. Perhaps surprisingly, few of the
respondents felt that antibiotics in feed truly achieved the goal of increasing
weight gain.
Antimicrobial use practices and antimicrobial recording
The second project is currently underway. Larger in scope than the first study,
it has four objectives:
- to find out how Ontario beef farmers are using antimicrobial drugs
- to quantify the amount of antimicrobial drugs being used
- to develop a treatment diary designed for keeping track of veterinary drug use,
and
- to get producers’ input on the design of the treatment diary.
A total of 29 farms are currently enrolled in this ongoing project; 16 are
feedlot operations and 13 are cow-calf operations. Producers are actively
participating in the research by keeping track of their drug use, saving all
receipts and medicine containers, and, importantly, providing information and
feedback to the researchers.
Complete quantitative data is not yet available for this study. General
antibiotic use profiles have been determined and are summarized in Table 2.
Table 2. Overview of findings: Antimicrobial use practices and antimicrobial
use recording among Ontario beef producers
|
Variable |
Feedlots |
Cow-Calf Farms |
|
Range of herd sizes |
55 to 10 000 head |
9 to 200 cows (excluding heifers) |
|
Average number of cattle |
1822.2 head |
91.4 cows (excluding heifers) |
|
Medication records kept prior to implementation of study |
11 of 16 feedlots |
3 of 12 farms |
|
Three most common disease problems treated with antimicrobials |
Shipping fever, Other respiratory illness,
Pink eye |
Cows: foot rot, pink eye, retained placenta
Calves:
Respiratory infections, undifferentiated
diarrhoea, bacterial and viral
diarrhoea |
|
Routine use of prophylactic injectable antibiotics |
5 of 15 feedlots |
3 of 13 farms |
|
Antibiotics used for prophylactic injections |
oxytetracycline, tilmicosin |
oxytetracycline, penicillin |
|
Use of ionophore antibiotics in feed |
16 of 16 feedlots |
8 of 13 farms |
|
Use of in-feed antibiotics (excluding ionophores) |
6 of 16 feedlots |
0 of 13 farms |
|
Antibiotics (excluding ionophores) used in feed |
tylosin, chlortetracycline, oxytetracycline |
None |
The number of producers who reported they had kept
records before the study began was low, further supporting the
researchers’ efforts to develop a usable treatment diary. After
beginning the study, some producers requested a pocket-size version of
the diary and others thought a clipboard version would be more useful.
Two sizes are now available.
The study also gathered some useful opinion data that is consistent with
the results of the first OCA survey. Producers are aware of
antimicrobial resistance and regard it as an important problem: 83.3%
view withdrawal periods for antimicrobials as extremely important, and
75% feel that following label instructions regarding dose is extremely
important.
In practice, however, dosing is often imprecise. According to the study,
66.7% of producers say that they would use greater amounts of
antibiotics than listed on the label. Because ionophores are purchased
as a component of feed, many producers do not consider them as a drug.
And only 25% of producers weigh their animals before administering
treatment; the others make an educated guess to determine the
appropriate dosage. |