Date of Graduation


Document Type


Degree Name

Master of Science in Animal Science (MS)

Degree Level



Animal Science


Elizabeth B. Kegley

Committee Member

Jeremy G. Powell

Second Committee Member

Paul A. Beck

Third Committee Member

Jiangchao Zhao


Biological sciences, Bovine respiratory disease, Microbiome, Morbidity, Pathogens, Zinc


The objective of this study was to determine if using an intranasal zinc (Zn) solution would impact health and growth performance of high-risk stocker cattle. Male beef calves (n = 239; 3 arrival dates [block]; initial BW = 276 ± 2.4 kg) were stratified by arrival gender and BW and assigned to 1 of 2 treatments: 1) treated with 3 ml of a Zn solution containing 36.24 mg of Zn administered intranasally, or 2) control, in which calves were not treated. Calves were observed daily and if exhibiting signs of morbidity and a rectal temperature ≥ 40° C they were treated with an antibiotic. If rectal temperature ≥ 40° C persisted cattle were re-treated according to pre-planned protocol. Body weights did not differ (P ≥ 0.22) across treatments throughout the duration of the study. Calves treated with Zn had a lesser (P < 0.01) ADG from d 7 to 28 and d 14 to 28 compared to the control. Control calves tended (P = 0.06) to be treated with 3 antibiotics more often than Zn treated calves. Overall treatment antibiotic costs did not differ (P = 0.64) across treatments. There were no differences (P ≥ 0.10) for rectal temperature of calves across treatment. Overall, Zn treated claves were similar in growth performance parameters and minimally different in percentage morbidity compared to the control. With the exception of Bacillus spp. and Pseudomonas aeruginosa the prevalence of bacterial pathogens were not different (P ≥ 0.14) across treatments. The presence of Pseudomonas aeruginosa was greater (P ≤ 0.04) in the control compared to the Zn calves, and Bacillus spp. tended to be greater (P = 0.09) in control calves. There were no differences due to Zn treatment in microbiome analysis; however, differences were found in healthy versus sick cattle.