Mineral and nitrogen balance in lambs implanted with zeranol

Area of Science:

• Animal Science
• Nutritional Physiology
• Ruminant Metabolism

Background:

• Zeranol is a non-steroidal anabolc agent used in livestock production.
• Understanding its impact on mineral and nitrogen metabolism is crucial for optimizing animal growth and health.

Purpose of the Study:

• To evaluate the effect of zeranol implantation on the apparent absorption and retention of essential minerals (Ca, P, Mg, Zn, Mn, Cu) and nitrogen (N) in wether lambs.
• To determine if zeranol influences nutrient balance in lambs fed a high-concentrate diet.

Main Methods:

• Fourteen crossbred wether lambs were assigned to either zeranol implantation (12 mg) or a control group.
• Lambs were fed an 86% concentrate diet, followed by a metabolism trial involving total collection of feces and urine.
• Analysis of feed, feces, and urine for Ca, P, Mg, Zn, Mn, Cu, and N content.

Main Results:

• Zeranol significantly decreased fecal excretion of Ca, P, Mg, and Zn, leading to increased apparent absorption of these minerals.
• Apparent absorption of Ca, P, Mg, and Zn increased by 88%, 193%, 9%, and 45%, respectively.
• Zeranol enhanced the retention of Ca (98%), Mg (138%), and Zn (60%) and improved nitrogen balance by reducing urinary N excretion by 24%.

Conclusions:

• Zeranol implantation positively impacts nutrient utilization in lambs.
• The anabolic agent enhances the absorption and retention of key minerals (Ca, P, Mg, Zn) and improves nitrogen balance.
• These findings suggest zeranol can be a valuable tool for improving nutritional efficiency in lamb production.