| Experimentâ… Test to study the impact of methane,carbon dioxide,ammonia & hydrogen sulfidewith different types of forage in young cows cowshed air in cold season. Selected one cowshed with 100 young cows (of which 71 Holstein, Brown Swiss cattle 29), followed by feeding forage to concentrate ratio of group A (23:77 corn silage and alfalfa hay), group B (10:90 corn silage), group C (10:90 alfalfa hay), group D (60:40 alfalfa hay) of the diet, analyze concentration of CH4,CO2,NH3,H2S in cowshed. Results showed that:with the proportion of dietary concentrate increased, CH4 concentrations decreased, the average concentration of each group were 73.58,115.83,93.60 and 50.18 mg/m3, significant differences among the groups (P<0.05), where group A & B, group B & D, group C & D were highly significant different (P<0.01);there was no significant difference between the groups (P>0.05); average concentrations of CO2 each group was 3696,4061,5847 and 3162 mg/m3, group C with group A & D were significant different (P<0.05); average concentration of NH3 were 2.63,2.62,5.38 and 4.09 mg/m3, except group A & B was no significant difference (P>0.05), the other groups were significantly different (P<0.05); average concentration of H2S in each group was 0.0481,0.0396,0.0352 and 0.0402 mg/m3. It was significant correlation between concentration of four kinds of gas at the same layer and total concentration of the cowshed. Test showed that high-concentrate diets reduce the concentration of CH4 and CO2; diets protein level increased, then the concentration of NH3 increased.Experimentâ…¡Test to compare methane,carbon dioxide,ammonia & hydrogen sulfidewith between high-yield and middle-yield dairy cows in the cowshed in cold season.Selected a high-yield and a middle-yield cowshed, analyzed concentration of CH4,CO2,NH3 and H2S in cowshed. Results showed that: high-yield dairy cows in the cowshed of each gas concentration increased by 2.69%,66.95%,32.65%and 3.58% with middle-yield dairy cows. Each high-yield dairy cow emissions CH4 296.15g per day, intake 1NND energy emissions CH4 5.97g, production lkg standard milk emissions CH4 11.43g, intake lkg of dry matter emissions CH4 12.18g. Each middle-yield dairy cow emissions CH4 210.54g per day, energy intake 1NND emissions CH4 6.27g, production lkg standard milk emissions CH4 12.08g, intake lkg of dry matter emissions CH4 12.54g. Test showed that concentrations of CH4, NH3, H2S and CO2 will increase by feed intake. Intake 1NND energy, high-yield dairy cow emissions CH4 lower 4.72% than middle-yield dairy cow, production lkg standard milk emissions CH4 lower 5.42% than middle-yield dairy cow, intake 1kg of dry matter emissions CH4 lower 2.81% than middle-yield dairy cow.Experimentâ…¢Test to study the effects of different types of forage diets on young Holstein cows' dung water content, total nitrogen (TN), ammonia nitrogen (AN) concentration from fecal and urine and emission of NH3, H2S from fecal. Selected 71 young Holstein cows for the trial, followed by feeding forage to concentrate ratio of group A (23:77 corn silage and alfalfa hay), group B (10:90 corn silage), group C (10:90 alfalfa hay), group D (60:40 alfalfa hay) of the diet, fecal water content, urine total nitrogen (TN) ammonia nitrogen (TN) concentrations and fecal emission of NH3 and H2S gas. The results showed that: Group B of fecal water content was significantly higher than Group D (P<0.05); NH3 emission of group C was significantly higher than group A & B (P<0.05), group D was significantly higher than group B (P<0.05); H2S emission of group D was significantly higher than group B (P<0.05); TN content of feces of group C & D was significantly higher than the group A & B (P<0.01); TN content in urine of group D was significantly higher than the other three groups (P<0.01); group C and group D in the fecal concentration of AN significantly different (P<0.05); concentration of group C of AN in the urine of most significantly higher than group D (P<0.01), group D was significantly higher than group A & B (P<0.01). Test showed that water content in fresh diet with huge differences, lead water content in fecal a little different. As the level of dietary crude protein increased, emission of NH3, H2S from fecal, fecal and urine in the concentration of TN and AN will increase.Experimentâ…£Test to compare the high-yield and middle-yield Holstein dairy cows in feces water content, the total nitrogen (TN), ammonia nitrogen (AN) concentration in feces and urine, NH3 and H2S emission content in feces. Selected a high-yield and a middle-yield cowshed, determination the feces water content, the total nitrogen (TN), ammonia nitrogen (AN) concentration and NH3, H2S emission content in feces. The results showed that:high-yield Holstein dairy cows in the fecal water content was lower 0.32% than the middle-yield Holstein dairy cows, NH3 and H2S emission content in feces was higher 2.83% and 3.09% than the middle-yield Holstein dairy cows, TN concentration in fresh feces and urine was higher 4.04% and 12.53% than the middle-yield Holstein dairy cows, AN concentration in fresh feces and urine was higher 3.48% and 22.72% than the middle-yield Holstein dairy cows. Test showed that the ratio of crude protein intake and demand increase, the nitrogen and sulfur content in feces and urine will increase. Protein, which more than demand will almost all be excreted through urine, the rate of increase urine nitrogen is greater than the rate of increase fecal nitrogen. Reduce the fecal nitrogen is not an effective way to reduce nitrogen pollution.
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