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Monensin concentrations measured in feeder cattle using enzyme immunoassay
M E Mount1, J S Cullor, P H Kass
1Department of Molecular Biosciences, University of California, Davis 95616, USA.
Abstract:
Thirty heifers were fed a ration containing 30 g monensin/ton. Fecal, urinary and seral samples were collected at varying intervals prior to and after initiating administration of the monensin-containing feed, and monensin concentrations were determined using a modified indirect enzyme immunoassay. Fecal samples contained measurable (micrograms/g; ppm) concentrations of monensin in most samples. The majority of sera and urine samples contained monensin at ng/ml (ppb) concentrations, which were above background levels prior to monensin feeding. Twelve head were fed monensin at 60 g/ton and 90 g/ton for 5 d with collection of similar samples. Higher concentrations of monensin were detected with increasing ration amounts in all 3 sample types. Enzyme immunoassay for monensin in these biological samples identified presence of the feed additive.
Insights
Monensin, a feed additive, was detected in fecal, urine, and serum samples from heifers. Higher monensin concentrations in feed rations correlated with increased levels in biological samples.
Area of Science:
- Animal Science
- Veterinary Medicine
- Analytical Chemistry
Background:
- Monensin is a widely used ionophore feed additive in cattle production.
- Monitoring monensin levels in biological samples is crucial for assessing exposure and efficacy.
- Accurate analytical methods are needed to quantify monensin in various matrices.
Purpose of the Study:
- To determine the presence and concentration of monensin in fecal, urinary, and serum samples from heifers.
- To evaluate the relationship between monensin feed concentration and its detection in biological samples.
- To validate the use of a modified indirect enzyme immunoassay for monensin quantification.
Main Methods:
- Heifers were fed rations containing different concentrations of monensin (30, 60, and 90 g/ton).
- Fecal, urinary, and serum samples were collected at various time points.
- Monensin concentrations were measured using a modified indirect enzyme immunoassay.
Main Results:
- Monensin was detected in most fecal samples at measurable concentrations (micrograms/g; ppm).
- Monensin was present in the majority of serum and urine samples at low concentrations (ng/ml; ppb).
- Higher monensin feed concentrations resulted in increased detection levels across all sample types.
Conclusions:
- The modified indirect enzyme immunoassay is effective for detecting monensin in biological samples.
- Monensin is absorbed and excreted, with detectable levels found in feces, urine, and serum of treated heifers.
- Feed intake and monensin concentration directly influence the levels found in biological matrices.
