Abstract:
Animal manure is commonly being applied to agricultural land to improve soil fertility and organic matter content. Animal manure however, is the main organic fertilizer that contains heavy metals as contaminants, Residues of heavy metals in pigs’ manure can be accumulated in surface soils as a result of long-term agricultural use and may also find their way into the food chain, Pig production and consumption of pork in Uganda is increasing at a high rate. Increase in pig production comes with increased manure production, the heavy metals found in pigs’ manure are derived from the feeds on to which 'the pigs are fed. Kyambogo University farm, and other farms within its environs in Nakawa sub, county is producing pigs fed on commercially purchased feeds. The manure generated by these pigs is being used as fertilizer in the university and the neighbouring crop gardens. This practice or applying pig manure in agriculture has the potential of causing serious environmental problems resulting from lead (Pb) pollution. A cross sectional quality assurance study was carried out to investigate the presence of Pb in pigs, manure fed on commercial rations in the 6 selected farms in Nakawa Sub County.
The study which lasted three weeks, profiled the presence of Pb in feed concentrates, water supplied and manure generated by pigs of Kyambogo University, Kabanda, Kasana, Moses Steven and Katushabe farms. The samples collected were analyzed using atomic absorption spectrophotometer at Wandegeya chemotherapeutic laboratory.
Ten (10) pigs were sampled from each of the 6 farms and their fecal material used to make 6 composite samples one for each or the six farms. The samples were recovered fresh from the rectum with no fecal material picked from the ground. Concurrently, one water & one feed concentrate sample from each of these farms was-taken to the laboratory for analysis. The data was analyzed using the Statistical Package for social scientists (SPSS) version 16 and results interpreted at p<O.05. All the samples tested positive for Pb in the feeds, water and manure. Kabanda farm had the highest concentration of lead in feed concentrates (O.277mg/g) while Katushabe farm topped the list for Pb in water (3.453mg/g) and manure (O.2644mg/g).
