高床式開放鶏舎における除糞による環境改善効果
1993 年 31 巻 1 号 p. 37-42
詳細
1993 年 31 巻 1 号 p. 37-42
In order to demonstrate the effect of removal of manure on environment in poultry house, the authors performed measurements in an open type poultry house in Ehime Prefecture from December of 1991 to April of 1992.
Cross section and ground plan of the poultry house are shown in Figs. 1 and 2. The numbers in Fig. 2 indicate measurement points. NH3 and CO2 gas generation rate from manure with relation of temperature and weight water content are shown in Figs. 3 and 4.
During the experimental period, 21, 500 White Leghorns were raised in the poultry house. Weight water content of the manure on shelf was about 68% and that at 1st floor was about 38%. The authors removed the accumulating manure on shelf using a trial machine for removal of manure on March 15. Temperature, NH3 and CO2 gas concentration, humidity and heat flux inside and outside the poultry house were measured.
Figure 5 shows the diurnal changes in temperature and NH3 gas concentration before the removal of the manure. Figure 6 shows the diurnal changes in temperature and NH3 gas concentration after the removal of the manure. Vertical distribution of NH3 gas concentration at point 5 is shown in Fig. 7.
NH3 gas concentration after the removal of the manure was lower than that before the removal of the manure, especially at 2 cm above the manure on shelf. It is considered that NH3 gas generation from the manure on shelf causes higher NH3 gas concentration in the cages and that decrease of about 10 ppm of NH3 gas concentration will be expected by removal of manure on shelf.
Furthermore, horizontal distribution of NH3 gas concentration shown in Fig. 8 was observed under condition of weak breeze. The highest concentration was 93 ppm at point 6, indicating necessity of improvement of environmental control.
