Weight gain and reproductive performance of spring-born beef heifer calves intraruminally administered oxfendazole

• Published in: Journal of animal science Vol. 72; no. 4; p. 817
• Main Authors: Purvis, H.T, Whittier, J.C, Boyles, S.L, Johnson, L.J, Ritchie, H.D, Rust, S.R, Faulkner, D.B, Lemenager, R.P, Hendrix, K.S
• Format: Journal Article
• Language: English
• Published: United States 01.04.1994
• Subjects: Animals; ANTHELMINTHIQUE; Anthelmintics - pharmacology; Anthelmintics - therapeutic use; ANTIHELMINTICOS; Benzimidazoles - pharmacology; Benzimidazoles - therapeutic use; BOVIN DE BOUCHERIE; Cattle - growth & development; Cattle - physiology; ESTADOS DEL CENTRO NORTE (EUA); ETATS DU CENTRE NORD (EU); ETE; FECES; Feces - parasitology; Female; FEMELLE; FERTILIDAD; FERTILITE; Fertilization - drug effects; GAIN DE POIDS; GANADO DE CARNE; GANANCIA DE PESO; GENISSE; HECES; HEMBRA; HIVER; Intestinal Diseases, Parasitic - drug therapy; Intestinal Diseases, Parasitic - physiopathology; Intestinal Diseases, Parasitic - prevention & control; INVIERNO; MADUREZ SEXUAL; MATURITE SEXUELLE; NOVILLA; Parasite Egg Count - veterinary; PERFORMANCE DE REPRODUCTION; Reproduction - drug effects; REPRODUCTIVIDAD; Sexual Maturation - drug effects; TERNERO; VACA; VACHE; VEAU; VERANO; Weight Gain - drug effects
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/1994.724817x

The effect of oxfendazole (Synanthic) on weight gain and reproductive performance of spring-born heifer calves was evaluated at five locations (IL, IN, MI, MO, ND). Three hundred thirty-eight mixed-breed beef heifers (293.4 kg) blocked by weight and age were randomly allotted to one of two treatments. Treatment 1 heifers were dewormed via intraruminal injection of oxfendazole. Treatment 2 heifers served as a control. Heifers were commingled during the winter phase in semi-confinement during the period from late January to late May (winter phase). Heifers were sorted by treatment at the beginning of the grazing season (approximately May 24, 1991) and remained separate until the end of the study (approximately July 31, 1991; summer phase). Dewormed heifers received oxfendazole (4.5 mg/kg BW) in late January and again 28 and 56 d after the beginning of the grazing season. Fecal samples were taken every 21 d from January through September and assayed for gastrointestinal parasite eggs. Fecal egg counts were similar across treatments at the beginning of the trial (P = 0.34). Deworming decreased fecal egg counts throughout the trial. Twenty-eight days after initial deworming a significant treatment effect on fecal egg counts was observed (P 0.01). Winter ADG was significantly higher (P 0.01) for dewormed heifers than for controls (.60 vs 0.52 kg, respectively). Summer ADG was not different between treatments. Dewormed heifers were 7.4 kg heavier than controls (P 0.05) at the end of the trial. Age of puberty was not affected by treatment (P