In house handling of pig waste in bacteria-assisted deep litter under tropical conditions 
Two experiments were conducted in tropical Malaysia to study the effects of keeping pigs on deep litter without washing on growth, behavior, pen hygiene and pig health. In Experiment I, forty-eight growing pigs were allocated to three treatments with 16 pigs per treatment and 8 pigs per pen. Treatment A was a control in which pigs were washed twice a day. In Treatment B, pigs were kept unwashed in deep litter consisting of sawdust. In Treatment C, pigs were kept unwashed in deep litter consisting of sawdust supplemented with a bacterial product. The elimination of washing in Treatment B and C was to eliminate wastewater discharge. Pigs under Treatment B and C exhibited depressed growth rate, having an average daily gain of 477 and 492 g, respectively compared with 600 g in the control group. Average daily gain of pigs under Treatment B and C were 79.5 and 82.0% respectively of that of the control group. In Experiment II, pigs were again kept on litter versus traditional method, but under different housing conditions. Another 48 pigs were allotted to three treatments namely, I, pigs on concrete floor washed twice daily; II, pigs on 20 cm of sawdust litter supplemented with bacterial product; III, pigs on pens where only two-thirds of floor area are covered with litter supplemented with the same bacterial product. Aluminium roofing materials were added on existing asbestos roof and ceiling fans were introduced. Pigs bathed twice a day again showed superior performance compared with those kept unwashed on litter. Poor performance of pigs kept on litters was attributed to heat stress conditions caused by increased litter temperature resulting from bacterial activities coupled with the fact that the pigs were not bathed. Pigs kept on litter showed increased respiratory rate compared with those washed daily. The concentration of ammoniacal nitrogen was least in litters of sawdust supplemented with bacterial product. However, results indicated that lung consolidation, snout deformities and endoparasites could be potential problems for pigs kept on litter.