| Thirteenth five year plan emphasizes strengthening the harmless and resources treatment of livestock pollutant, while it puts forward into requirements of precision development of livestocks.In this case, the intelligent pig growth performance measurement system has been introduced widely in China, which in order to achieve accurate feeding of pig breeding and precise management for large-scale farming. The traditional sow raising mode in crates has been changed by the intelligent pig performance measurement system, and it also establishes a breeding system which can select good and fine rearing. However, the defect of this system is the lack assessment for the environmental risk.In this study, to explore the impact on the environment of intelligent pig growth performance measurement system in the process of large-scale farming, nitrogen and phosphorus characterization in gilts feed, manure and urine in the whole growing period were monitored using Nedap Velos intelligent pig growth performance measurement system. Modeling were built based on the transformation characteristics of nitrogen and phosphorus, which revealed the input and emissions law of nitrogen and phosphorus in the gilts feed, manure and urine, explored the migration shape and pollutant ability of pig manure under the precise feeding, and provided basic data for the environmental risk assessment of large-scale farming. This study will be used to improve the precision breeding management of the livestocks. The main findings are shown as below:（1） Nedap Velos intelligent pig growth performance measurement system was used to monitor the feed input. The amount of pig feed increased gradually when gilts age was under 70 d, however,it remained unchanged after 70 d. The growth rate was controlled at a constant speed of weight growth basically in the system of precise feeding. The cumulative total nitrogen and phosphorus inputs in the whole gilts growth stage were 4514.38 g·head-1and 876.53 g·head-1, respectively.（2） The cumulative nitrogen emission of pig manure and urine in gilts growth period were3491.61 g·head-1 and 1464.14 g·head-1, while the cumulative phosphorus emission were 314.92g·head-1 and 1605.34 mg·head-1, respectively. Compared with other research, the emission level of nitrogen and phosphorus in this study were high relatively.（3） Nitrogen emissions ratio of Manure and urine was about 2.3:1. Higher TN and ANemission were found from large pig growth stage, while NO3--N had higher emissions in the small and large pig growth stage. Phosphorus was mainly concentrated in the feces, and small pig growth stage had higher emission, while the middle stage unchanged essentially.（4） A good linear relationship was shown between the NO3--N, TN and TP emission in the pollutant and AN, ON and TP in the feed, which was significant（P < 0.001）. Emissions of nitrogen and phosphorus in manure and urine had a strong curvilinear relationship with nitrogen and phosphorus input, which was significantly（P < 0.001）. Through modeling, it could be found that it can reduce the threat to the environment without affecting the growth performance by keeping the total nitrogen inputs under 62 g·head-1·d-1 and total phosphorus inputs under 6g·head-1·d-1,（5） Considering the environmental impact and pig growth performance, Response surface model fitted well and it could be applied to precision feed for gilts breeding. It could control emissions of nitrogen and phosphorus through the value predicted by the model, adjust feed formulation, and achieve a full range of precision measurement.（6） The Growth Stage 5（GS5） showed the highest biogas and methane yield, which were526.29 mL·g-1 TS and 155.17 mL·g-1 TS, respectively, while Growth Stage 1（GS1） produced the smallest methane yield. According to the modified Gompertz model, the avrage methane production rate was predicted, which was 189.42 mL·g-1 TS·head-1·d-1. The methane potential in the whole growth stage was up to 12.71 L·g-1 TS·head-1. |
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