Department of Animal Science


First Advisor

Andrea K. Watson

Date of this Version



A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Animal Science

Under the supervision of Professor Andrea K. Watson

Lincoln, Nebraska, December 2023


Copyright 2023, Reba L. Colin


Environmental sustainability can be positively impacted by the inclusion of feed additives to reduce enteric methane production from cattle. Methane production can be affected by feed additives that either alter the rumen environment or act as methanogenesis inhibitors. A reduction in methane from cattle can contribute to meeting carbon neutrality.

A metabolism study was conducted to evaluate Alga 1.0, a product containing bromoform, fed to cattle to evaluate the effects on gas emissions. Treatments were (0, 69, or 103 g/d Alga 1.0) fed in a corn-based diet. Headbox-style indirect calorimeters were used to measure gas emissions. Feeding Alga 1.0 linearly decreased dry matter intake (P < 0.01). There was a linear decrease in CH4 when expressed as g/d (P < 0.01) and g/kg DMI (P < 0.01). There was no effect on CO2 expressed as g/kg DMI (P > 0.20). Diet digestibility (P ≥ 0.28) and digestible energy were not affected (P ≥ 0.38) when feeding Alga 1.0. Feeding Alga 1.0 reduced CH4 emissions from cattle.

A finishing study was conducted to evaluate black seed oil plus acetic acid on beef cattle performance as well as enteric methane production. The diet consisted of Sweet Bran, high moisture corn, dry rolled corn, alfalfa hay, and supplement with the black seed oil plus acetic acid replacing 2.67% of diet DM of the corn blend. Cattle were rotated through a two-chamber emissions barn equipped with open-circuit indirect calorimeters to measure CH4 & CO2. There was no effect on CH4, or CO2 emissions (P ≥ 0.26) compared to the control diet. Body weight, dry matter intake, and ADG were not affected (P ≥ 0.34) by the inclusion of black seed oil plus acetic acid. There was a tendency for improved feed efficiency (P = 0.08) in the cattle consuming black seed oil plus acetic acid compared to control fed cattle. Feeding black seed oil plus acetic acid did not affect gas emissions.

Advisor: Andrea K. Watson