In order to control the offensive odor from swine feces composting equipment, deodorization of gas produced in composting swine feces by activated sludge aeration method was examined on a practical scale. An existing swine wastewater store was converted into deodorization tank by modifying it to have no inflow from the outside and by installing a tube diffuser on the bottom. About 31.5 m³ of activated sludge was sent to the deodorization tank so that aeration depth would be 2 m. There was 2.03 m³ of activated sludge per 1 m³ of raw swine compost materials. A blower and duct to draw and treat the gas from composting were installed in ventilation type composting equipment. The odor from fermentation of swine feces was aerated to activated sludge for 15 weeks, ammonia and sulfur compounds were measured at three places : before deodorization, after deodorization, at the exhaust port. Results indicated that a high average rate of ammonia and methyl mercaptan removal was obtained at 99.8% and 83.1%, while the rate of methyl sulfide and dimethyl disulfide removal was 41.1% and 59.4% respectively. Ammonia in compost odor increased NH₄-N and NO_x-N in activated sludge, so T-N concentration ultimately reached about 4.3 times the concentration at the start of the experiment. EC rose as the time proceeds, and pH was almost steady in a range of 6.5 to 6.0. BOD and MLSS changed ; as the time proceeds, they tended to decrease gradually. During the experiment, deodorization capacity did not decline due to changes in ingredients of the activated sludge. These results suggests that deodorization by activated sludge aeration method was useful for control the odor produced by composting swine feces.

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The aim of the present study was to clarify changes in spontaneous contractility and drug responsiveness of the porcine uterus during ovarian stages. Myometrial smooth muscle strips were collected from slaughtered pigs in follicular, early luteal and functional luteal phases. Longitudinal muscle (LM) and circular muscle (CM) were mounted in organ bath and their spontaneous contractility and drug responsiveness were examined in vitro.
During the equilibration periods (90 min), all CM strips showed spontaneous contraction regardless of the ovarian stages, but the number of LM strips contracting spontaneously decreased in the functional luteal phase. Spontaneous contractility was characterized using frequency, amplitude and area under the curve (AUC). In LM strips, amplitude and AUC, but not frequency, changed during the ovarian stages. On the other hand, amplitude and frequency, but not AUC of CM strips, changed during the ovarian stages. Carbachol, fluprostenol and oxytocin caused contraction of the myometrium. LM was more sensitive to these contractile agents than was CM at all ovarian stages. Comparing the contractile responses in follicular and luteal phases, the magnitude of maximum contraction but not the EC₅₀ value decreased in the functional luteal phase. Isoproterenol (LM>CM) and BW245C (CM>LM) inhibited spontaneous myometrial contraction in a muscle layer-dependent manner. EC₅₀ values and maximum inhibition of both drugs were not different in the follicular and luteal phases.
In conclusion, a significant difference in spontaneous contractility during the ovarian stages was found in LM but not in CM. Responses to contractile drugs decreased from the follicular phase to luteal phase, but those to inhibitory drugs did not change in these two phases, suggesting that porcine uterine smooth muscle has low susceptibility to uterotonic agents in the luteal phase probably due to progesterone.

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