Absorption in calves of amoxicillin, ampicillin, and oxytetracycline given in milk replacer, water, or an oral rehydration formulation
Palmer, G.H.; Bywater, R.J.; Stanton, A.
American Journal of Veterinary Research 44(1): 68-71
1983
ISSN/ISBN: 0002-9645 PMID: 6824227 Document Number: 218315
Oxytetracycline, amoxicillin or ampicillin suspended in milk replacer, water or a glucose-glycine-electrolyte solution (GGES) was given orally to 64 calves. Oxytetracycline suspended in milk replacer gave lower relative bioavailability than when suspended in water (P < 0.01) or in GGES (P < 0.001). The 63% binding (only partly reversible) of oxytetracycline suspended in milk repalcer was responsible for low serum concentrations; the greater water absorption from the GGES was responsible for improved uptake of antibiotic. Amoxicillin suspended in milk replacer had a delayed absorption compared with the antibiotic suspended in water; the relative bioavailabilities from milk replacer and water were similar. Peak serum concentration and bioavailability were higher (P < 0.05) when amoxicillin was suspended in GGES than when suspended in water. Binding of amoxicillin with milk replacer was comparatively low (16%) and was reversible. Ampicillin suspended in GGES gave a higher peak serum concentration (P < 0.05) than when suspended in milk replacer. Apparently, these antibiotics were more bioavailable when suspended in GGES than when suspended in water or especially in milk replacer. Oxytetracycline was bound particularly strongly to milk replacer.