The Influence Of Tunnel Ventilation To Environment Of Fattening Pig House And Fattening Pig’s Growth In Winter

In view of the current large scale pig production in China, existing equipmenthumbly, environment control ability poorly and influenced by external environmental factorsgreatly, especially the ventilation system is unscientific, unreasonable and leading to thedeterioration in pig growth environment, welfare, the incidence increasement and the level ofproductivity decline, this paper designs a new type of piggery ventilation system——tunnelventilation system, and through the comparison with natural ventilation mode and mechanicalventilation modes pigsty fattening pig house in winter conditions and pig growth situation todetect its use effect. Selecting36fattening pigs with satisfying experiment in weight、healthdegree、body form from50pigs aged92~94days random divides into3disposes, and eachdispose is divided into3groups with4pigs in every group rearing in different hutchs. The pigs in3disposes are reared in3different ventilation modes, and the experiment deadline is28days (4weeks).Obtaining the results through the experiment:1) The environment temperature of hoggery in winter is different obviously in3differentventilation modes, and the temperature of hoggery in tunnel ventilation is higher than it in theother two traditional ventilation modes, and lowest higher than natural ventilation and mechanicalventilation respectively is1.37℃(P=0.024<0.05)and1.11℃(P=0.065)(at16:00), the upper higherrespectively is2.81℃(P=0.000<0.01)and2.05℃(P=0.000<0.01)(at10:00),and the highertemperature is good for keeping warm; During the experiment, the natural ventilation mode、mechanical ventilation mode and tunnel ventilation mode temperature change range is11.2~21.9℃,11.4~22.2℃,14.4~25.2℃r espectively; The relative humidity diversity in3differentventilation modes is different with different time, the diversity isn’t obvious during0:00~4:00,andduring8:00~14:00, the relative humidity in tunnel ventilation is slightly higher than the other twotraditional ventilation modes, the diversity is obvious(P<0.05),and the relative humidity in tunnelventilation is obvious different with the relative humidity in mechanical ventilation in the othertime, but isn’t obvious different with it in natural ventilation, the relative humidity variation rangeof3different ventilation modes is50~65%. The variation of NH3concentration and wind speedin3different ventilation modes are obvious (P=0.014<0.05； P=0.000<0.01), the NH3concentration of tunnel ventilation mode is obviously lower than the other two traditionalventilation modes, respectively lows5.39mg/m3and4.72mg/m3; and the wind speed is high0.12m/s and0.13m/s respectively. In addition, temperature difference of pig skin in three kinds of ventilation modes isn’t obvious, this may be the result of adopting to the environment by theirmetabolic regulation.2) The growth rate of pigs in tunnel ventilation mode is obviously faster than those intraditional ventilation modes. The ADG of fattening pigs in tunnel ventilation mode is higher thanit in natural ventilation and mechanical ventilation, respectively improves93.91g (P=0.047<0.05)and56.5g (P=0.078), and the F/G respectively respectively falls11.07%and7.66%, and the FCRrespectively respectively improves4.59%(P=0.039<0.05) and3.23%(P=0.058), and theaccumulative dynamiting is more2.25kg (14.85%) and1.36kg (8.48%) respectively. Supposing100kg is the crop goal, the pigs in tunnel ventilation mode will shorten5~9d in fatten period,and it speeds up the enterprise capital turnover rate, improving the economic benefit. This has adirect relationship with the good environment by tunnel ventilation.3)Uncomfortable environment will give undesirable stimulation, making the speed ofadopting to the environment slowly. The fattening pigs in tunnel ventilation mode can quicklyadopt to environment from the undesirable stimulation by uncomfortable temperature、hazardousgas, making the Na+、K+、Ca2+、CL—concentration recover quickly, but the pigs in traditionalventilation mode recovers slowly;4)The tunnel ventilation mode can provide more comfortable environment to pigs, makingpigs lie down to rest for a long time, so the abnormal behaviors such as biting the hoof、ears、tails、fence、soffit reduce obviously. But the abnormal behaviors still exist, and this shows the tunnelventilation need to be improved.Conclusion: Through designing tunnel ventilation mode for the Henan Province’s climate inwinter and compared with the traditional ventilation modes, we can see that the tunnel ventilationmode is better than traditional ventilation modes such as natural and mechanical ventilation. It canmeet the requirements of thermal insulation and ventilation at the same time, and is good foranimal welfare production and rapid growth of pigs, it will to be a new type of ventilationcultivation mode worthing to promote in large farms.