Effects of Serum Levels of Copper and Zinc on Antibody Titers of Two Breeds of Stocker Calves Injected with Leptospirosis sp. Vaccine and Drenched with an Organic Mineral Supplement
Keywords:copper, zinc, Leptospirosis, antibody titer, cattle
This study was conducted to determine the effects of serum levels of copper (Cu) and zinc (Zn) on antibody titers of stocker calves administered Leptospirosis sp. vaccine that were given a balanced oral mineral drench. A total of 111 head of stocker calves were injected with Leptospirosis sp. vaccine and blood samples were taken from each calf to determine initial serum levels of Cu and Zn. Calves were blocked according to breed (Limousin or Angus based crossbred) and sex (steers or heifers) and allotted to one of two treatments. Treatments were allotted and worked on Day 0 (D 0), treatment one (Trt.-1) received a balanced mineral drench containing chelated forms of Cu and Zn, while treatment two (Trt.-2) did not receive mineral drench and served as control. Blood was obtained via jugular venipuncture on D 14 and D 28 for determination of serum Cu, Zn and titer strength to Leptospirosis. Data analysis revealed no differences (P>0.05) in mineral levels between control and drench treated calves on D 14 or D28. Pooling calves on breed revealed a higher level (P<0.05) of serum Cu levels in Limousin calves, while crossbred calves had higher (P<0.05) circulating Zn levels. These results are indicative of previous trials showing substantial breed differences in mineral metabolism and also suggest that a short-term treatment of Zn and Cu will not positively affect a calf’s ability to respond to Leptospirosis vaccines.