Water quality is critical for poultry farming. This study assessed the physical, chemical and microbiological quality of drinking water in small-layer farms in Southern Mozambique and identified potential risk factors for total coliform (TC) and Escherichia coli contamination of drinking water. In 20 farms, 57 samples were collected and examined for pH, nitrate content (NC), nitrite level (NL) and total hardness contents (TH). Furthermore, TC and E. coli growth were assessed at 37 °C. One hundred per cent of the drinking water was of acceptable quality in terms of pH (6.5-8.5), NC (50 mg/L) and NL (3 mg/L). Total hardness contents exceeded the recommended standard in 37.5% of borehole water samples and 91.7% of tap water samples, respectively. Total coliform and E. coli were found in 40% and 15% of water samples. Tap water samples had the greatest contamination, with TC and E. coli levels of 41.7% and 16.7%, respectively. Although not statistically significant, sampling from the beginning of the nipple line (p = 0.101, OR = 7.357, 95% confidence interval [CI]: 0.678-79.886) and not cleaning the rearing equipment regularly (p = 0.098, OR = 3.966, 95% CI: 0.766-20.280) were factors affecting the TC growth. Sampling from the tank water source (p = 0.001, OR = 0.005, 95% CI: 0.000-0.121) and borehole water source (OR = 13 585) and not cleaning the equipment consistently (p = 0.073, OR = 9.682, 95% CI: 0.810-115.68) were all factors affecting E. coli growth. It is concluded that the TH and microbiological quality of the drinking water of the study region are inadequate. Regular water quality assessments should be incorporated into Mozambican layer farm management to limit the potential for health concerns, and farmers should thoroughly clean and disinfect their rearing equipment. CONTRIBUTION: We should incorporate regular water quality assessments into Mozambican layer farm management to limit the potential for health concerns, and farmers should thoroughly clean and disinfect their rearing equipment

Administration of higher dosage of chlorine leads to a concern about proper dosage determination for shrimp hatchery operations. Hence, the dosage application needs to be reworked at the present context. Accordingly a Completely randomized design experiment with 6 treatments (control, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm of active chlorine content) with 3 replications was conducted. The water quality and the bacterial load were monitored once in 3 hours continuously. The salient observations of the study was that the exposure time for residual chlorine to be nil for the tank with chlorination of 10 ppm concentration was 6 hours, for 20 ppm and 30 ppm it was 18 hours and for 40 ppm and 50 ppm it was 21 hours. Also the results shows that bacterial load was nil in all the treatments viz. 10 to 50 ppm. The pH of the water gets increased and then stabilized. It could be concluded from the study that the chlorination is required in shrimp hatcheries. But the optimum dosage is 10 ppm for ensuring better water quality in shrimp hatchery which is very much less when compared to the general dose of upto 30 ppm for other purposes. Another experimental trial with three replications was conducted to ascertain the survival of post larvae of P. monodon from PL5 to PL 20 with the 10 ppm active chlorine. The study showed that survival was high in 10 ppm.