Monensin level during grain adaptation and finishing performance in cattle

Area of Science:

• Animal Science
• Ruminant Nutrition
• Feedlot Management

Background:

• Cattle finishing diets often involve high concentrate levels, requiring careful adaptation.
• Monensin is a commonly used ionophore feed additive in cattle diets.
• Understanding the impact of monensin dosage during diet adaptation is crucial for optimizing performance.

Purpose of the Study:

• To evaluate the effect of varying dietary monensin levels on cattle performance during adaptation to high-concentrate diets.
• To assess the impact of monensin on intake, gain, and feed efficiency during the finishing period.
• To investigate physiological responses, such as acid-base status, during diet adaptation.

Main Methods:

• Two finishing trials involving Hereford-Angus steers were conducted.
• A 2x3 factorial arrangement tested tylosin and monensin levels during a 28-day adaptation period (75% to 95% concentrate).
• Blood acid-base status and feed intake were monitored; performance metrics (gain, feed efficiency) were measured over the total finishing period.

Main Results:

• Digestive upset was observed in all treatments during adaptation to the 95% concentrate diet.
• Increased monensin levels linearly decreased intake during the initial 28 days.
• Over the total finishing period, higher monensin decreased intake and tended to decrease gain, with no effect on feed efficiency.

Conclusions:

• Monensin supplementation during the grain adaptation phase influences intake and gain in feedlot cattle.
• While higher monensin levels reduced intake, they did not negatively impact feed efficiency in this study.
• Further research may be warranted to determine optimal monensin levels for specific diet adaptation strategies.