Effect Of Different Ammoniating Conditions On Energy Metabolism,Nitrogen Deposition And Methane Emission Of Sheep

This experiment selects ammoniated corn straw as the experimental material,aiming at a comparative study of the apparent digestibility,energy metabolism,nitrogen deposition efficiency and methane emissions of trophozoites by direct and alternative methods.Optimize the rate of replacement of corn straw and further develop feed resources;and using this alternative ratio,continue to study the effects of different pressure treatment conditions on the performance of ammoniated straw on the performance of sheep and energy metabolism indicators and selecting optimal ammoniated straw treatment conditions.Experiment 1: Comparison of direct and alternative methods for determining the effect of ammoniated straw on energy metabolism in mutton sheepThe experiment selected 20 hybrid rams with a body weight of 25 kg or so and with good body condition,German mutton merino and Northeast Fine-wool sheep,and were randomly divided into 5 groups according to the single-factor design,namely,the direct method group of the fully ammoniated corn straw.Replacement method for replacing basal diets with different proportions of ammoniated straw: fed basal diets,fed diets with 20%,40% and 60% replacement rates.The in vivo method was used to measure animal digestive metabolism and breath heat measurement.After the pre-feeding for 15 days,the formal test was started for 45 days.The test results showed that the apparent digestibility of dry matter(DM),crude protein(CP),and organic matter(OM)in the diets of the substitution method decreased significantly with the increase of the substitution ratio,but both were significantly higher than those of the direct method.Ammoniated corn straw group(P<0.01).The digestive energy(DE)and metabolic energy(ME)values of the alternative groups were also significantly higher than those of the direct method(P<0.01).By comparing the digestive energy and metabolizable energy in the alternative group,the digestive energy and metabolizable energy values were: basal diet> 20% Substitution> 40% Substitution> 60% Substitution.In the determination of nitrogen deposition efficiency,the contents of digestible nitrogen and sedimentary nitrogen in the total ammoniated straw group were significantly lower than those in the basal diet group and the replacement group(P<0.01).As the substitution ratio increased,digestible nitrogen and sedimentation were observed.Nitrogen content,nitrogen digestibility,and nitrogen deposition rate were significantly reduced(P<0.01).In the 5 groups of diets,methane emissions in the total ammoniated straw group was significantly higher than those in the replacement group(P<0.01),and the ratio of methane energy to metabolizable energy was significantly higher than that in the replacement group(P<0.01);The proportion of methane emissions increased significantly(P<0.05),and the proportion of methane energy and metabolic energy increased gradually.It is concluded that when using the direct method and alternative method to evaluate the energy value of ammoniated corn straw,the most suitable replacement ratio was 20%.Experiment 2: Effect of different pressure treated ammoniated straw feed on energy metabolism and nitrogen deposition efficiency of mutton sheepFourteen hybrid rams of 4 months of age and about 25 kg of German mutton merino and Northeast fine-wool sheep were randomly selected and divided into 4 groups according to the single factor design: untreated corn straw,the aminated straw diet containing 3 ammonia aerated treatments at 0.10,0.20,and 0.30 MPa for 3 hours.The proportions of the diets in the treatment groups were the same ones,and they were all based on the optimal feed ratio obtained from the first trial: 20% substitution.The in vivo method was used to measure animal digestive metabolism and breath heat measurement.After the pre-feeding for 15 days,the formal test was started for 45 days.The results showed that the apparent digestibility of DM and OM in the control group was significantly lower than that in the ammoniated group(P<0.05).The apparent digestibility of NDF and ADF in the ammoniated group was significantly lower than that in the control group(P<0.05).The value of GE,DE,ME and the ratio ME and DE were gradually increased with the increase of pressure,with significant differences among groups(P<0.01).For the apparent digestibility and energy value of ammoniated straw,the apparent digestibility of DM,OM and CP in the control group was significantly lower than that in the ammoniated group(P<0.05).The apparent digestibility of DM,OM and CP in the ammoniated group was 0.30 MPa group> 0.20 MPa group> 0.10 MPa group,and there was a significant difference between groups.The DE and ME in the ammoniated straw group were significantly higher than those in the control group.In the ammoniated group,the value of DE,ME of 0.30 MPa group were highest.After ingestion of an equivalent amount of feed,the nitrogen intake,digestible nitrogen content,deposition nitrogen content,nitrogen digestibility,and nitrogen utilization rate in the ammoniated group were significantly higher than those in the control group(P<0.05).The fecal nitrogen and urine nitrogen were significantly lower than the ammoniated group.The digestible nitrogen,nitrogen deposition,nitrogen digestibility,and nitrogen deposition rate all increased with pressure,with significant differences among groups(P<0.01).In the comparison of the effects of different amination conditions on energy metabolism,nitrogen deposition efficiency and methane emissions of mutton sheep,the most suitable pressure value was 0.30 MPa.