Copper is an essential micronutrient for animals. It is involved in cellular respiration and connective tissue development as well as being an essential component of several enzymes. High doses of copper—about 20 times the nutritional requirement—have been shown to improve growth performance in pigs. This may be because copper has an antimicrobial effect in the intestinal tract.

When supplemental copper is added to pig diets, it is usually in the form of copper sulfate. However, another form called tribasic copper chloride (TBCC) has been shown to be equally effective and may be  more bioavailable, but it is not yet known how much TBCC should be fed to optimize performance. Therefore, an experiment was conducted to determine the effects of adding 100 or 200 mg/kg TBCC to diets fed to weanling pigs.