Department of Animal Sciences
University of Florida
Range Cattle Research and Education Center
Ona, Florida

Study Overview

This study evaluated the effects of a commercial feed additive containing mastic gum on the growth performance and feed efficiency of beef steers over a 70-day feeding period.

During the initial phase of the trial, feed intake was below maintenance requirements, resulting in weight loss across all steers. Despite these early challenges, cattle receiving the Product demonstrated improved performance outcomes compared to Control steers over the course of the study.

Early Trial Conditions

• During the first 42 days, steers exhibited low feed intake and lost weight.
• The cause of reduced feed consumption was not definitively identified.
• Anaplasmosis was suspected but not confirmed.
  

On Day 42, all steers were administered an antibiotic. By Day 44, feeding behavior changed noticeably, with bunks consistently slick by the end of the day — a marked difference from prior observations where feed refusals were common.

Additionally, the ration was transitioned to Diet 2 on Day 47, which may have contributed to improved feed consumption and performance during the final phase of the trial.

Performance Outcomes

Despite poor performance early in the study, steers receiving the Product showed measurable improvements compared to Control steers:

• Average Daily Gain (ADG):
  Product steers gained 0.24 lb/day more than Control steers over the 70-day period.
• Final Body Weight:
  Product steers weighed approximately 20 lb more at the conclusion of the trial.
• Feed Intake:
  Similar between Product and Control groups.
  

Feed Efficiency:

Product steers demonstrated improved feed efficiency, gaining approximately 0.025 lb more per pound of feed consumed compared to Controls.

Key Conclusions

The results of this study indicate that the commercial product containing mastic gum was associated with improved growth rate and feed efficiency in growing beef steers.

While the magnitude of improvement observed in this trial may not fully reflect outcomes under typical commercial conditions — due to unusually poor early performance — the findings suggest potential benefits when the product is included in the diet.

The study also highlights the importance of:

• Consistent formulation
• Proper ratios of bioactive compounds
• Rigorous quality control of mastic gum ingredients
  

These factors are critical for achieving reliable and repeatable results in commercial beef production settings.

Summary Takeaway

Even under challenging early conditions, steers receiving the Product demonstrated improved growth and feed efficiency relative to Controls, supporting further exploration of mastic gum–based feed additives in beef cattle nutrition.