University of Arkansas, Fayetteville Division of Agriculture


Beef calves (n = 88) were purchased from regional auction barns and delivered as a single group. Upon arrival, cattle were assigned to eight pens. Pens were assigned randomly to one of three treatments; two pens received 3 mL of a nasal spray solution (10.8 mg Zn/mL) into each nostril using a single-use nasal atomizer; three pens received 40 mL of an oral drench (16.25 mg Zn/mL), and three pens received no Zn at processing (negative control). Appropriate treatments were administered at processing on d 0 of the 43-d study. After treatment, cattle were worked and housed so they did not have fenceline contact with any other pens. Cattle were observed daily and rectal temperatures were taken to monitor morbidity. Nasal membranes of four randomly selected calves/ pen were swabbed prior to any treatment on d 0 and then on d 1, 2, 4, and 7. Those treated with intra-nasal Zn at processing had lower average daily gain for the first 28 d as compared to controls (P = 0.02) or oral Zn (P = 0.07). Final body weight did not differ. Treatments had no effect on percentage of morbid calves. Treatments had an effect on bacterial cultures from swabs; fewer (P ≤ 0.04) Escherichia coli, -Streptococcus spp., and Staphylococcus spp. colonies were cultured from cattle receiving the intra-nasal Zn. Bacterial cultures indicated reduced numbers of microbes in the nasal passages after treatment with intra-nasal Zn, but Zn treatments did not benefit overall morbidity or growth rates of stressed cattle.