Effects of Zelnate® and zoledronic acid on immunity in goats infected with Haemonchus contortus

TitleEffects of Zelnate® and zoledronic acid on immunity in goats infected with Haemonchus contortus
Publication TypeJournal Article
Year of Publication2018
AuthorsYang, Q, Wang, Z, Tilahun, Y, Merkel, RC, Goetsch, AL, Liu, H, Sahlu, T, Dawson, LJ, Campbell, M
JournalJournal of Animal Science
AbstractThirty-six 6.5-month-old Alpine wethers (28±2.4 kg initial BW) were used to determine effects of Zelnate® (Z) and zoledronic acid (ZA) on immunity of goats infected with Haemonchus contortus during a 5-wk period. Wethers were housed in a confinement facility, supplemented with 400 g/d of a concentrate-based pellet, and offered alfalfa and grass hay free-choice. Thirty wethers were given 2 doses of 5,000 L3 H. contortus by gavage on 2 sequential days, and the other 6 were the noninfected normal control (NI-C). The infected control wethers (I-C) were not treated with Z or ZA. Other treatments were 1 injection of Z (2 ml/goat) on d -1 of L3 infection (Z1), 2 injections of Z on d -1 and 13 (Z2), 5 injections of ZA (75 µg/kg BW each time) on d -6, 2, 6, 13, 20 (ZA), and 1 injection of Z and 5 injections of ZA (Z1-ZA). Infection reduced ADG (P = 0.05), which was alleviated by Z and ZA (54, 14, 23, 23, 32, and 40 g for NI-C, I-C, Z1, Z2, ZA, and Z1-ZA, respectively; SEM=13.5). Although FEC was similar among treatments (P > 0.05), the percentage of female adult worms in the abomasum was lower in wethers treated with Z or ZA (P < 0.01). The hematocrit and concentrations of hemoglobin, WBC, and neutrophils were lower for I-C vs NI-C (P < 0.05) but concentrations of neutrophils for treatments with Z or ZA were similar to that for the NI-C. The percentage of female worms was negatively correlated with concentrations of neutrophils (r = -0.55, P < 0.01) and lymphocytes (r = -0.65, P < 0.01). The findings imply that H. contortus infection alters the immunity in goats and that effects may be reversed by immune modulators such as Z and ZA.