The effects of supplementing fermented liquid feed with chocolate on the growth performance, carcass characteristics, and pork quality in finishing pigs were investigated. To elucidate the effects of differences in fatty acid composition of the added fat source, we also added soybean oil to the feed. Five pigs were assigned to receive control fermented liquid feed (Control group), five pigs were assigned to receive control fermented liquid feed supplemented with chocolate at a level of 12.2% (Chocolate group), and five pigs were assigned to receive control fermented liquid feed supplemented with soybean oil at a level of 5% (Soybean oil group). The levels of crude fat in the feeds of the Chocolate group and the Soybean oil group were equivalent. All pigs were fed ad libitum from the body weight of 67kg to 110kg and then slaughtered. There were no significant differences among the groups in average daily gain, feed intake, and feed conversion ratio. The intramuscular fat contents and iodine value of subcutaneous (inner layer) and intermuscular fat of pigs in the Soybean oil group were higher (P<0.05) than those of the Control and Chocolate groups. The level of fatty acids in the subcutaneous fat of the Chocolate group was not different from the Control group. The level of saturated fatty acids in the subcutaneous fat of the Soybean oil group was lower than that of the Control group (P<0.05). The level of mono-unsaturated fatty acids and poly-unsaturated fatty acids of the Soybean oil groups was higher than those of the Control (P<0.01). The L^* values of subcutaneous and intermuscular fat of the Chocolate group were higher than those of the Control and Soybean oil groups (P<0.05). Thus, feeding fermented liquid feed supplemented with chocolate may result in a brighter color of pork and the prevention of soft fat, which was probably resulted in the feeding by feed supplemented with soybean oil. We conclude that chocolate is an effective feed resource for finishing pigs though it is necessary to limit the amount.

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A simple form MAP reactor (200 liters capacity) was made with PVC pipe, then installed in a sequencing batch reactor of a swine wastewater treatment facility. Phosphorus recovery by struvite crystallization method was attempted using swine wastewater taken out from a feces-and-urine separate-type piggery. Hydraulic retention time of 1 hour was required with an aeration of 45m³h⁻¹m⁻³. A solution of 30% MgCl₂, 0.1% of the swine wastewater volume, was dropped into the reactor. Under these conditions, 60-69% of soluble PO₄-P was crystallized. The reactor was equipped with stainless steel nets as an MAP accumulation device, and 12.8-41.0g of MAP per 1m³ of swine wastewater was recovered as MAP. The recovered MAP had 96-98% purity, and the content of heavy metals such as copper and zinc, was comparable to that of chemical fertilizer. Estimation of mass flows of phosphorous for a 42-day period of operation in summer showed that 11% of crystallized soluble PO₄-P had been recovered as MAP, while 89% of crystallized soluble PO₄-P was discharged from the equipment with the swine wastewater. Purity of the recovered MAP was 96% or more.

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