Determine The True Calcium Digestibility Of Different Calcium Source And Study On True Digestible Calcium Requirement For Hunan Yellow Broiler

Three trials were conducted in this study.On the basis of determine true calcium digestibility,the true digestible calcium requirement of 0-21days old and 28-56 days old Hunan Yellow Broilers has been studied.Our objective was to provide an experimental support for calcium in animal nutrition and for designing diet formulas of Hunan Yellow Broilers.Experiment 1.The objectives of this experiment was to determine true calcium (Ca) digestibility and the endogenous Ca output for male broilers,using the regression analysis technique and difference level techniques.Thirty-two male broilers were allotted four groups randomly,fed four diets each group according to a 4×4 Latin Square design.Four diets containing four levels of total Ca(0.62%,0.71 %,0.82%and 0.92%).Results showed that:There were significant linear relationship between fecal Ca outputs and dietary inputs of Ca when both expressed as g/kg dry matter intake,endogenous Ca output in feces were no significant differences (P＞0.05) with different experiment diet which determined by REG and difference levels technique,implicated that the two methods were valid for estimating endogenous Ca outputs in male broilers.The endogenous Ca output was 2.12g/kg DMI.Under tested total Ca levels.Using the regression analysis technique the true Ca digestibility value of limestone,light calcium carbonate,Bone meal and dicalcium phosphate in male broilers were 63.52%,64.52%,68.29%and 70.15%,when using difference level techniques the true Ca digestibility value were 62.81%,64.28%, 70.64%and 71.40%respectively.Experiment 2.The objection of this experiment was to study the true digestible calcium requirement of 0-21day old Hunan Yellow Broilers.Five hundred 1-day-old female Hunan Yellow Broilers were randomly allotted into 5 treatments of 5 replicate pens with 20 birds each.Broilers were fed five graded levels of true digestible calcium.The graded levels of true digestible calcium were 0.35%,0.45%,0.55%, 0.65%and 0.75%.The results indicated that,the feed intakes and the weight gains were affected by the true digestible calcium level.In this experiment,using optimum growth performance,tibia ash content and tibia breaking tenacity as criteria for evaluating the true digestible calcium requirement for 0-21days old Hunan Yellow Broiler,they were 0.41%,0.60%,0.62%and 0.61%respectively.Experiment 3.The experiment was conducted to study the true digestible calcium requirement of 28-56days old Hunan Yellow Broiler.Four hundred 28 day old female Hunan Yellow Broiler were randomly allotted into 5 treatments,5 replicate pens of 16 birds each per treatment.Broilers were fed five graded level of true digestible calcium.The graded levels of true digestible calcium were 0.28%,0.38%, 0.48%,0.58%and 0.68%.The results indicated that,the feed intakes and the weight gains were significant affected by the true digestible calcium level.In this experiment, using optimum growth performance,tibia ash content and tibia breaking tenacity as croteria for evaluating the true digestible calcium requirement for 28-56days old Hunan Yellow Broilers,they were 0.22%,0.54%,0.41%and0.45%respectively.In conclusion,Using the regression analysis technique the true Ca digestibility value of limestone,light calcium carbonate,Bone meal and dicalcium phosphate in male broilers were 63.52%,64.52%,68.29%and 70.15%,when using difference level techniques the true Ca digestibility value were 62.81%,64.28%,70.64%and 71.40% respectively,the true digestible calcium requirement recommendation in diet formulas for 0-21 days old and 28-56days old Hunan Yellow Broilers was 0.41%-0.62%and 0.41%-0.54%respectively.