Toxicologic studies with sheep fed colored magazines and newsprint

Area of Science:

• Animal Nutrition
• Toxicology
• Environmental Science

Background:

• Dietary inclusion of recycled paper products in animal feed is a growing concern.
• Potential risks associated with heavy metal accumulation and metabolic changes in livestock are not fully understood.

Purpose of the Study:

• To evaluate the effects of feeding paper containing colored inks on sheep health and metabolism.
• To assess lead accumulation and hepatic enzyme activity in sheep consuming paper-based diets.

Main Methods:

• Sheep were fed rations with 23% paper (magazines, newspapers) or oat hulls for 175 days.
• Feed intake, feed efficiency, tissue lead levels, and hepatic microsomal mixed function oxidase activity were measured.
• Histopathological examination of liver and kidney tissues was performed.

Main Results:

• Paper-fed sheep consumed 29% more feed, with comparable feed efficiency to controls.
• Lead accumulated in animal tissues.
• Hepatic microsomal mixed function oxidase activity was significantly higher in paper-fed sheep.
• No diet-induced lesions were found in liver or kidney tissues.

Conclusions:

• Sheep can tolerate diets containing 23% colored paper without apparent histopathological damage.
• However, lead accumulation and altered liver enzyme activity indicate potential subclinical effects warranting further investigation.