The effect of miscellaneous oral dosage forms on the environmental pollution of sulfonamides in pig holdings

Abstract

Background: Due to antibiotic treatment of humans and animals, the prevalence of bacterial resistances increases worldwide. Especially in livestock farming, large quantities of faeces contaminated with antibiotics pose a risk of the carryover of the active ingredient to the environment. Accordingly, the aim of the present study was the evaluation of the benefit of different oral dosage forms (powder, pellets, granula) in pigs concerning the environmental pollution of sulfadiazine. Two subtherapeutic dosages were evaluated in powder mixtures to gain information about their potential to pollute the pig barn. Furthermore, a new group of pigs was kept in the stable after powder feeding of another pig group to determine the possible absorption of environmentally distributed antibiotics. Pigs were orally treated with three dosage forms. Simultaneously, sedimentation and airborne dust were collected and plasma and urine levels were determined.

Results: All formulations result in comparable plasma and urine levels, but massive differences in environmental pollution (powder > pellets, granula). Pigs housing in a contaminated barn exhibit traces of sulfadiazine in plasma and urine.

Conclusion: Using pharmaceutical formulations like pellets or granula, the environmental pollution of sulfonamides can significantly be diminished due to massive dust reduction during feeding.

Keywords: Antibiotic residues; Dust; Environmental pollution; Pigs; Sulfonamides.

Fig. 1

Scheme of the pig stable. The numbers indicate the 5 areas of sedimentation dust sample withdrawal (1. window sill, 2. grid above the tub, 3. grid above the lying area, 4. gutters in front of the tub and 5. bay barrier on the other side of the stable), and “P” shows the positions of air samplings. Bay 1 was used for all experimental setups

Fig. 2

Plasma concentration of sulfadiazine (SDZ; mean) in six pigs after powder feeding of sulfadiazine in three dosages: 2.5 mg/kg BW (body weight; grey box), 5 mg/kg BW (black box) and 25 mg/kg BW (black triangle) and after pellet (dark grey triangle) and granula (bright grey triangle) feeding in a concentration of 25 mg/kg BW; feeding was performed twice daily (asterisks)

Fig. 3

Urine concentration of sulfadiazine (SDZ; mean ± standard deviation) in six pigs after powder feeding of sulfadiazine in three dosages (2.5 mg/kg BW (body weight), 5 mg/kg BW and 25 mg/kg BW) and after pellet and granula feeding; feeding was performed twice daily on day 1–4

Fig. 4

Urine concentration of sulfadiazine (SDZ) in six untreated pig, all of which were housed in the stable after removing orally treated pigs (25 mg/kg BW over four days) and after dry cleaning; data are shown as mean + standard deviation; LOQ = 0.1 μg/ml