The injections contained zinc, manganese, copper and selenium intended to immediately boost circulating levels of these minerals.
Injectible trace minerals were beneficial in improving performance and health parameters of shipping-stressed stockers in a University of Arkansas (UA) receiving trial.
Crossbred heifers averaging 438 lbs. were purchased from auction markets in Arkansas and Oklahoma and shipped to UA’s receiving and stocker cattle research facility. Upon arrival, the heifers were processed and separated into one of three experimental treatments – two different trace mineral injections (TMI) and a non-injected control. The injections contained zinc, manganese, copper and selenium intended to immediately boost circulating levels of these minerals. All calves were fed a standard receiving ration during the 55-day study.
Heifers receiving the TMI treatment consumed more feed (13.2 vs. 12.4 lbs./day) and gained faster (2.41 vs. 1.99 lbs./day) than the control heifers. Morbidity was high in the control heifers and was reduced by the TMI (87 vs. 61% first pulls; 52 vs. 19% second pulls and 32 vs. 10% third pulls), respectively. Antibiotic cost was less in the TMI heifers, $8.77 vs. $13.66/head.
There were no health or performance differences between the two TMI products, which each cost about $1.50/head.
Plasma zinc and copper levels rose substantially in all heifers from the day of processing to day 28 (0.6 vs. 1.7 mg/L) and (0.8 vs. 1.4 mg/L), respectively. No differences were detected in day 28 plasma concentrations between the control heifers and the TMI heifers. Injectible trace minerals are intended to provide short-term responses. By day 28, supplemental mineral provided by the feed equalized the plasma effects.