Under one of its priority research
programs, the Canadian Poultry Research Council (CPRC) has provided
funding for a number of projects relating to the Environment. Below are
summaries of the final reports for two of them:
Under one of its priority research programs, the Canadian Poultry Research Council (CPRC) has provided funding for a number of projects relating to the Environment. Below are summaries of the final reports for two of them:
VETERINARY PHARMACEUTICALS AND THE ENVIRONMENT
When animals are given medications such as antimicrobials and coccidiostats (collectively referred to as veterinary pharmaceuticals, or VPs), residues can sometimes be found in their manure. These residues are introduced into the environment when manure is applied to agricultural land. Drs. Shiv Prasher and Xin Zhao at McGill University, and Dr. Ciro Ruiz-Feria of Texas A&M University have been investigating the fate and transport of VPs in soil and water. There has been relatively little work done in this area, especially specific to Canadian environmental conditions; more information is therefore required to determine the extent to which VPs persist in agricultural soil and runoff, and what risks are posed by their presence.
Dr. Prasher’s team took manure from Quebec poultry farms feeding one of three coccidiostats (monensin, narasin or salinomycin) and applied it to soil at an equivalent of 10 mg of manure per hectare (~4.5 ton per acre). The soil was previously free of poultry manure for 10 years. The research was conducted in specially designed devices, known as lysimeteres, which were used to track the movement of these VPs through the soil and into groundwater. Rainfall was simulated to represent the 50-year maximum in the area over three months (July to September). Soil samples were collected from the surface and at three depths (0.1, 0.3, 0.5m), and leachate (groundwater runoff) was collected 0.9m below the surface throughout the experiment.
Persistence in Soil
The researchers found that the VPs varied in their persistence in the soil and in the rate at which they moved into groundwater. Monensin persisted the longest in soil and was detectable at all depths throughout the 60-day experiment. A small amount of monensin was found in the drainage water until day 15. The amount of narasin found on the surface declined over a 30-day period, while subsurface levels declined below detection limits by Day 15. Levels of salinomycin declined quickly at the soil surface and were undetectable by Day 3. Below the surface, salinomycin was only detectable until Day 7. It was detectable, however, in drainage water throughout the entire experiment. These results suggest that while monensin can persist in soil over a longer period, salinomycin is more mobile and may present a greater threat to water resources.
Predicting VP Movement
The data collected in this study are being tested against a mathematical model designed to predict movements of VPs in soil and water. It is hoped that information gathered during ongoing work will lead to Best Management Practices designed to minimize any negative effects of VPs in the environment.
Biological Significance
Work is also underway to determine the biological significance of VP residues in soil and water. Preliminary information in one study, for example, indicates that half-lives of three herbicides (atrazine, metolachlor, and metribuzin) increased with the presence of VPs in soil. One of the primary mechanisms of pesticide degradation in soil is by microbial action; the presence of VPs in soil may be affecting microbial survival in soil. However, more work needs to be done in this area before any concrete conclusions can be drawn.
CALCIUM AND PHOSPHORUS FROM LAYERS
Drs. James France and Steve Leeson at the University of Guelph and Dr. Ermias Kebreab at the University of Manitoba have developed a mathematical model to describe and predict calcium (Ca) and phosphorus (P) flows in layers.
The first step in this project was to perform a literature review to collect relevant data regarding the many inter-actions of Ca and P in layers. Data collected were entered into a database that was used to develop the model. Once developed, a functional model was tested using data from the literature and was shown to accurately predict outcomes that matched those measured in real experiments. A working mathematical model of Ca and P flows in layers will help industry (producers, nutritionists, etc.) make dietary and management decisions to optimize Ca intake and reduce P excretion in manure. This has the potential economic impacts of saving dietary input costs while maximizing layer productivity, and will help reduce the environmental impact of commercial layer production.
Funding for both of these research projects was provided by the CPRC and the former joint Natural Sciences and Engineering Research Council/Agriculture and Agri-Food Canada matching fund program.
For more details on any CPRC activities, please contact Gord Speksnijder at The Canadian Poultry Research Council, 483 Arkell Road, R.R. #2, Guelph, Ontario, N1H 6H8, by phone 289-251-2990, fax: 519-837-3584, or e-mail: info@cp-rc.ca , or visit us at www.cp-rc.ca .
The membership of the CPRC consists of the Chicken Farmers of Canada, Canadian Hatching Egg Producers, Canadian Turkey Marketing Agency, Canadian Egg Marketing Agency and the Canadian Poultry and Egg Processors’ Council. CPRC’s mission is to address its members’ needs through dynamic leadership in the creation and implementation of programs for poultry research in Canada, which may also include societal concerns.
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