Effect Of Nitrogen, Phosphorus And Copper From Pig Excretion On Environment And Its Nutritional Regulation

In order to investigate the effect of N,P and Cu from pig excretion on soil and plant around pig farms and to find feasible nutritional regulation ways of reducing environmental pollution.The effect of different nutritional regulation on performance and N,P and Cu excretion were studied in three experiments based on the investigation.The result as follows:1.Effect of Excretion on N,P and Cu Content in Soil and Vegetables around Intensive or Small Sized Pig Farms and its Safety EvaluationFour typical intensive pig farms around Changsha and six small-sized pig farms in Taoyuan county were chose in this study.Feed,manure,soil,and plant were sampled,and nitrogen,phosphorus and copper content were analyzed and evaluated.The result showed that(1) intensive pig farms:The copper constant rate of exceed quota in soil is 62.5%,in which 37.5%is seriously polluted.With the increasing of the distance away from the pig farm,the nitrogen,phosphorus and copper content of soil decreases.Plant samples have different content of nitrogen,phosphorus and copper in different organizations.The average copper content of root is 17.44%higher than that of stem.Cu contents of sweet potato vines in pig excretion-amended filed did not exceed the standard limitations,while the Cu contents of lettuce exceed the standard limitations by 46%.(2) Small-sized pig farms:Manure from pig farms natural stored in the open air.During the composting,N and P concentration were lowered than the fresh manure,and N,P and Cu concentration of soils around the composting were higher than that of controls,especially Cu concentration.N,P and Cu concentration of soils from 5 and 50 meters were higher than that of controls(100 meters).The Cu constant rate of exceed quota in soils from growing pig farms is 100%(12/12),and 83.3%(10/12) of sow piggery.If manure form animal and poultry all applied on farmland,the N load quantity of farmland in Yaoyuan county is 180.3 kg/hm~2,is equal to applying 11.4 t pig manure/hm~2.2.Effect of Different Crude Protein and Fiber Level on Performance and N Excretion of Finishing PigsThe effect of different crude protein and crude fiber levels on performance and nitrogen excretion of fattening pigs fed amino acid balanced diet were studied in a 2(crude fiber:4%, 6%)×3(crude protein:15.5%,14%and 12.5%) factorial arrangement.36 fattening pigs weighted 65.77±1.08 kg were chose.The result showed that:(1) ADG,ADFI and G/F were not affected by dietary crude protein or crude fiber level.Pigs fed diet 6(12.5%crude protein and 6%crude fiber) had the lowest cost(5.59RMB/kg body weight gain).(2) Urinary N (P＜0.05),fecal N(P＞0.05) and total N(P＜0.05) excretion were reduced as dietary crude protein decreased.For each percentage unit reduction in dietary crude protein,urinary N, fecal N and total N excretion were reduced by 3.58%,1.56%and 2.53%respectively.(3) Urinary N(P＜0.05),fecal N(P＜0.01) and total N(P＜0.01) excretion were reduced as dietary crude fiber increased from 4%to 6%.3.Effect of Different Dietary Type with or without Phytase on Performance and Fecal N, P Concentration of Growing PigsThirty-six crossbred pigs(Duroc×Landrace×Yorkshire) with an average initial weight of 43.9±0.43kg were randomly allotted to four treatments either wheat-soybean meal diet or brown rice-soybean meal diet with or without additional phytase.The result showed that:(1) Growth performance:The ADG was not differ among treatments(P＞0.05).Pigs fed wheat-soybean meal diet without additional phytase has higher ADFI than others and has lower feed:gain ratio than pigs fed wheat-soybean meal diet with additional phytase and brown rice-soybean meal diet with phytase(P＜0.05).(2) Within the same diet type,pigs fed diet with additional phytase had higher P apparent digestibility and lower fecal P concentration than that of without additional phytase(P＜0.05).(3) N apparent digestibility and fecal N concentration:No treatments effect on N apparent digestibility was detected in this experiment.Pigs fed wheat-soybean meal diet with additional phytase has lower fecal N concentration than others(P＜0.05),and there are no difference of fecal N concentration between other treatments.4.Effect of Dietary Copper Source and Level on Performance and Fecal N,P Concentration of Growing PigsThe effect of addition of 10,150 or 250 ppm Cu(either as CuSO4.5H2O or Copper-methionine,Cu-Met) on performance and fecal Cu,N concentration of growing pigs was evaluated.36 crossbred pigs(Landrace×Yorkshire) with an average initial weight of 17.17±2.34 kg were randomly allotted to 6 treatments either with 10,150 or 250ppm Cu as CuSO4.5H2O or 10,150 or 250ppm Cu as Cu-Met.The result showed that(1) Growth performance:There are no Cu sources or levels effect on ADFI,ADG and F/G;regardless Cu levels,Cu-Met had the trend of increasing ADG.(2) Fecal Cu concentration:Fecal Cu concentration significantly increased as diet Cu concentration increased,regardless of Cu sources.Within the CuSO4 treatment,fecal Cu concentration of pigs fed 150 and 250ppm Cu were 455%and 768%(P＜0.01) high as controls(10ppm) respectively,whereas within the Cu-Met treatment,fecal Cu concentration of pigs fed 150 and 250ppm Cu were 244%and 400%(P＜0.01) high as controls(10ppm) respectively.(3) Fecal N concentration:There are no Cu sources or levels effect on fecal N concentration,but pigs fed 150ppm Cu had the highest fecal N concentration in either Cu sources.In a word,N,P and Cu from pig manure accumulated in soils and plants around pig farms and caused soil and plant Cu concentration exceed the standard limitations.Different ways of nutritional regulation reduced N,P and Cu excretion,and performance were not affected.