Research On Metabolic Pattern And Requirement Of Protein And Growth Pattern Of Luxi Game Chickens

A series of experiments were conducted to study the effects of dietary crude proteinlevels on production performance, nutrients utilization, slaughter performance, internal organsgrowth, body composition and protein deposition of Luxi Game Chickens. Factorial modelshad been established by means of rearing, metabolism and comparative slaughter experiments,and concluded protein requirement of Luxi Game Chickens. Growth model had beenestablished by analyzing data of rearing and metabolism experiments.A single factor design was used to a24week experiment to study the effects of dietarycrude protein levels on production performance of Luxi Game Chickens. A total of600one-day-old Luxi Game Chickens （sex-mixed） were randomly divided into five experimentaltreatments with six replicates of twenty birds each. The feeding period was divided into fourperiods:0to6weeks,7to12weeks,13to18weeks and19to24weeks. Each period ownfive dietary crude protein levels. Crude protein levels （%） of each stage were15.29,16.33,17.30,18.29,19.30;14.00,15.00,16.04,17.00,18.00;13.00,14.00,15.00,16.00,17.00;11.66,12.65,13.65,14.66,15.66, respectively.Results showed that average daily feed intake was not significantly affected by dietarycrude protein levels （P>0.05）. From0to6,7to12,13to18weeks, body weight and averagedaily gain increased and feed to gain decreased as dietary crude protein increased （P <0.05）,however, the production performance appeared to provide lower when the crude proteinbeyond a certain level. Production performance was not significantly affected by dietary crudeprotein levels from19to24weeks （P>0.05）.A single factor design was used to study the effects of dietary crude protein levels onnutrients utilization of Luxi Game Chickens. Seventy-two Luxi Game Chickens werechosen and randomly assigned to six experimental groups with12birds each. Different crudeprotein diets were fed from group1to5. The total fecal collection method was used to studythe effects of dietary crude protein levels on nutrients utilization in4period metabolicexperiments with ten day each started at21d,63d,105d and147d of age, respectively.Endogenous losses were obtained from control groups fasted24h to clear the alimentarycanal, then excreta collected exactly for24h.The results showed as follows: From21to31d, the metabolic rate of dry matter, organicmatter and crude protein increased as dietary crude protein increased and group18.29%appeared to provide the highest （P <0.05）. From63to73d, the metabolic rate of organic matter and crude protein increased as dietary crude protein increased and group17.00%appeared to provide the highest （P <0.05）. From105to115d, the metabolic rate of crudeprotein increased as dietary crude protein increased and group16.00%appeared to providethe highest （P <0.05）. However, the metabolic rate decreased when the crude protein beyonda certain level. The metabolic rate of gross energy was not significantly affected by dietarycrude protein levels during all stages （P>0.05）.A series of comparative slaughter experiments were conducted to study the effects ofdietary crude protein levels on slaughter performance, internal organs growth andprotein deposition of Luxi Game Chickens. A total of8one-day-old Luxi Game Chickens（sex-mixed） were chosen to measure body composition at the beginning of rearing experiment.At the end of6,12,18and24weeks, a total of60Luxi Game Chickens were chosen tobutcher with12birds of each experimental treatments. Half of them were used to measureslaughter performance, internal organs growth, others were used to measure bodycomposition.Study on requirement of crude protein. Result showed that slaughter performance wasnot significantly affected by dietary crude protein levels at the end of6,12and24weeks （P>0.05）. Dressing percentage and leg muscle rate were not significantly affected by dietarycrude protein levels at the end of18weeks （P>0.05）. Part-empty thoracic cavity rate, emptythoracic cavity rate and breast muscle rate increased as crude protein increased and group16.00%appeared to provide the highest （P <0.05）. Internal organs and body compositionwere not significantly affected by dietary crude protein levels during all the stages （P>0.05）.Both crude protein intake and deposition increased as dietary crude protein increased duringall the stages （P <0.05）. Deposition rate of crude protein decreased as dietary crude proteinlevel increased from0to6weeks, group19.30%appeared to provided the highest and group17.30%was the lowest （P <0.05）. From7to12,13to18,19to24weeks, deposition rate ofcrude protein were not significantly affected by dietary crude protein levels （P>0.05）.Study on requirement of crude protein of Luxi Game Chickens. Crude protein intake（CPI） and average daily gain （BGW） were regarded as dependent variable （Y） andindependent variable （X） respectively, then linear regression were made, the result as follows:From0to6weeks: CPR=1.17W^0.75+370.87BGW （R²=0.7470）From7to12weeks: CPR=1.20W^0.75+578.97BGW （R²=0.8697）From13to18weeks: CPR=1.30W^0.75+776.70BGW （R²=0.8865）From19to24weeks: CPR=1.30W^0.75+795.57BGW （R²=0.5899）In the regression equation above, CPR means crude protein requirement （g/d）; W^0.75 means metabolic weight （kg）; BGW means average daily gain （g）.Daily crude protein requirement of each stage were3.12g,9.05g,13.91g and15.71g,respectively, according to the regression equation above. Dietary crude protein levels of eachstage were18.55%,17.39%,16.55%,15.05%combined to the average daily feed intake ofeach stage, respectively.Research the growth pattern of production performance, internal organs. Averagedaily feed intake （ADFI）, body weight （BW）, average daily gain （ADG） were regarded asdependent variable （Y） and weeks of age （t） was regarded as independent variable（X）; internalorgans weight were regarded as dependent variable, body weight was regarded as independentvariable, then regression equation were made, the result as follows:ADFI=-0.0811×t²+6.8703×t–1.4476（R²=0.9883，P <0.001）;BW=2587.90/(1+20.81×e^-0.20t)（R²=0.9916，P=0.002）;ADG=-0.0380×t²+1.4258×t+3.8002（R²=0.9839，P <0.001）;Internal organs and weight were linear increased as body weight increased （P <0.05）.