Demand for poultry meat is rising in low- and middle-countries, driving the expansion of large commercial farms where antimicrobials are used as surrogates for hygiene, good nutrition. This routine use of antimicrobials in animal production facilitates the emergence and spread of antibiotic-resistant pathogens. Despite potentially serious consequences for the animal industry, few studies have documented trends in antimicrobial use (AMU) at the farm-level in low- and middle-income countries. The objective of this study was to estimate AMU in a broiler chicken farm in Pakistan over a five-year period and to extrapolate national AMU in commercial broiler farming. Between 2013 and 2017, we monitored AMU in 30 flocks from a commercial broiler farm in Punjab, the most populous province of Pakistan. The amount of antimicrobials administered was calculated in milligram/population unit of the final flock weight (mg/fPU) and in used daily dose (UDD). The annual on-farm antimicrobial use was 250.84 mg of active ingredient per kilogram of the final flock weight. This consumption intensity exceeds the amount of antimicrobial used per kilogram of chicken of all countries in the world except China. Measured in mg per kg of final flock weight or population unit (fPU), medically important drugs such as colistin (31.39 mg/fPU), tylosin (41.71 mg/fPU), doxycycline (81.81 mg/fPU), and enrofloxacin (26.19 mg/fPU) were the most frequently used antimicrobials for prophylactic or therapeutic use. Lincomycin was the most frequently used antimicrobial used in-feed (29.09 mg/fPU). Our findings suggest that the annual consumption of antimicrobials in the broiler sector in Pakistan could be as high as 568 tons. This alarmingly high consumption estimate is the first baseline study on antimicrobial use in animals in Pakistan. Our findings call for immediate actions to reduce antimicrobial use in Pakistan, and countries with comparable farming practices.

The effects of thiamethoxam neonictinoids insecticide (TMX) commonly used in different food crops and in veterinary practice were evaluated in freshwater fish exposed to sublethal concentrations for 120 h. A total of 60 freshwater fish Labeo rohita were collected from local fish rearing center and kept in different five equal groups (A–E). Fish in groups B–E were exposed to sublethal concentrations of thiamethoxam (0, 0.5, 1.0, 1.5, and 2.0 mg/L) to determine the genotoxic potential and serum biochemical effects. Results showed significantly (p<.05) increased concentrations of urea and creatinine in thiamethoxam-treated fish as compared to untreated control fish. The concentrations of liver function tests (aspartate aminotransferase, aspartate aminotransferase, and alkaline phosphatase), cardiac functions tests (cholesterol, triglycerides), and lipid peroxidation product (malondialdehyde concentrations) were significantly increased while serum total proteins and globulin significantly (p<.05) decreased in thiamethoxam exposed fish. Furthermore, blood DNA contents significantly increased in thiamethoxam treated fish. At histopathological level, fatty infiltration, congestion, disruption and degenerations of bile ducts, abnormal sinusoids, nuclear fragmentation, condensation, and eccentric nuclei were observed in liver of thiamethoxam treated fish. Histological observation of kidneys of treated fish showed edema, degeneration of renal tubules, congestion, necrosis of renal tubular cells, glomerular degeneration, and detachment of tubular epithelium. DNA damage by comet assay was significantly increased in hepatocytes, kidneys, and blood cells. In conclusion, the results of our study indicate that thiamethoxam induces blood biochemical, genotoxic, and histopathological alterations in exposed fish.