Effects on Stocker Steer Performance While Consuming Essential Oil or Ionophore Minerals

Alternative methods to reduce the use of synthetic products in cattle production, as well as reduction in feeding antibiotics to cattle, have been a growing preference in consumer opinions. The objective of this study was to determine if essential oils produce the same performance for stocker steers as consuming an ionophore.

Steers (n = 281 head; 641 ± 10.3 lb) were assigned to one of two mineral treatments and grazed on tallgrass native range on eight pastures. Treatments consisted of the “positive” control of ionophore (lasalocid at 3.6 lb/ton) and essential oil (garlic oil at 3 lb/ton and essential oil blend at 6 lb/ton) in free-choice mineral. Steers were weighed at the beginning and end of the 92-day grazing period. Pasture biomass production and mineral intake were monitored weekly.

Effects of mineral types on growth performance, average daily gain, average daily mineral intake, and pasture biomass

Item	Ionophore1	Essential oil2	SEM3	P-value
Initial weight, lb	629	653	10	0.16
Final weight, lb	833	856	9	0.12
Total gain, lb	204	203	8.8	0.92
Average daily gain, lb/day	2.15	2.13	0.09	0.92
Pasture biomass, lb dry matter/acre	1180	1229	79	0.67
Average mineral intake, oz/head/day	5.18	5.63	0.54	0.58

¹Ionophore mineral (Bovatec 91 included at 18 lb/ton to provide 3.6 lb/ton lasalocid; Zoetis, Kalamazoo, MI).

²Essential oil mineral (3 lb/ton garlic oil and 6 lb/ton Solace; Wildcat Feeds LLC, Topeka, KS).

³Standard error of means.

The Bottom Line: Growth performance produced by essential oils in mineral and ionophores are similar when fed to growing stocker steers grazing tallgrass native range.

The complete report is available at https://doi.org/10.4148/2378-5977.8672. Jones, Tatiana M. and Farney, Jaymelynn K. (2025) “Effects on Stocker Steer Performance While Consuming Essential Oil or Ionophore Minerals,” Kansas Agricultural Experiment Station Research Reports: Vol. 11: Iss. 1.