Nutritional evaluation of a copper-methionine complex for chicks

Area of Science:

• Animal Nutrition
• Trace Mineral Metabolism
• Poultry Science

Background:

• Copper (Cu) is an essential trace element for poultry, vital for various physiological functions.
• Methionine (Met) is a crucial amino acid for growth and feathering in poultry.
• Evaluating the bioavailability of mineral complexes is key to optimizing animal feed formulations.

Purpose of the Study:

• To assess the relative bioavailability of copper (Cu) and methionine (Met) from a novel Cu complex, Cu-Met, in young chicks.
• To compare the efficacy of Cu-Met with standard copper sources (CuSO4·5H2O) and other copper complexes (Cu-Lys, CuCl).
• To validate the liver Cu concentration assay for evaluating copper bioavailability.

Main Methods:

• Three chick experiments utilizing bile Cu and liver Cu concentration assays to determine Cu bioavailability.
• Common-intercept multiple linear regression (slope-ratio) method applied to supplemental Cu intake.
• Relative bioavailability of Met assessed separately using feed-grade DL-Met as the standard.

Main Results:

• Cu-Met exhibited relative Cu bioavailability of 96% (bile assay) and 88% (liver assay), not significantly different from the CuSO4·5H2O standard (100%).
• Cu-Lys (114%) and CuCl (145%) showed significantly higher Cu bioavailability via the liver assay compared to the standard.
• Relative Met bioavailability of Cu-Met was 100%, matching the DL-Met standard.

Conclusions:

• Cu-Met demonstrates comparable copper bioavailability to inorganic copper sulfate and high methionine bioavailability.
• The liver Cu accumulation assay is a reliable method for assessing copper bioavailability, consistent with bile Cu assays.
• Cu-Met presents a viable alternative for supplying both copper and methionine in poultry diets.