A Study On Energy Requirements Of Guizhou Yellow Chickens Aged 0-6 Weeks

The study take Guizhou yellow chicken as the experimental object to explore the energy requirements of Guizhou yellow chicken during 0-6 weeks,aiming to provide theoretical basis and data reference for the scientific breeding of Guizhou yellow chicken and formulating its breeding standards,and to provide Guizhou yellow chicken production practice provide guidance.Experiment one:The effect of energy level on growth performance and apparent nutrient metabolizabilities of Guizhou yellow chicken during 0-6 weeks.A total of 400 healthy 1-day-old Guizhou yellow chicken chicks were selected in a one-way completely randomized trial design and randomly divided into 4 groups with 5 replicates of 20 chicks each.The energy levels of each group were 10.03MJ/kg,11.71 MJ/kg,12.54 MJ/kg and 13.16 MJ/kg,respectively,the trial period was6 weeks.The body weight and feed intake of Guizhou yellow chicken from 0-6 weeks were measured,and the average weekly daily weight gain,average daily feed intake and feed-to-weight ratio were calculated.The metabolic test was carried out using the4 mol/L hydrochloric acid non-ash method to determine the apparent metabolic rate of nutrients and to explore the effects of different energy levels of diets on the growth performance and apparent metabolizabilities of nutrients of Guizhou yellow chicken during 0-6 weeks,and to determine the appropriate energy level.Results:（1）Dietary energy level had significant effects（P<0.05）on body weight,average daily weight gain,average daily feed intake and feed-to-weight gain ratio of Guizhou yellow chicken during 0-6 weeks.As a judge index,recommend 0-6 weeks of Guizhou yellow chicken appropriate energy level is 11.71 MJ/kg.（2）Dietary energy level had a significant effect on the apparent metabolizabilities of nutrients in Guizhou yellow chicken during 0-6 weeks（P<0.05）,and appropriate increase in dietary energy level could improve the apparent metabolizabilities of each nutrient and thus improve feed utilization.As a judge index,recommend 0-6 weeks of Guizhou yellow chicken appropriate energy level is 12.54 MJ/kg.Experiment two:The effect of energy level on nutrient deposition in Guizhou yellow chicken during 0-6 weeks and the study of energy requirement.Using the comparative slaughter method,three healthy Guizhou yellow chicken near the average body weight at the age of 1 day were selected for cervical dislocation lethality as the control group at the beginning of the test,and one healthy Guizhou yellow chicken of male and female near the average body weight was selected in each replicate at the end of the test,10 chickens in each test group,and 40 chickens were lethally killed in total.The energy,protein and fat contents of the chickens were measured,and the energy,protein and fat deposition rates of the chickens were calculated and used to determine the appropriate energy levels.The energy requirement model Y=a X+b was established using regression analysis with energy intake as Y and energy deposition as X to determine the energy requirement.Results:（1）Dietary energy level had a significant effect（P<0.05）on the intake and deposition rate of three major nutrients:energy,fat,and protein in Guizhou yellow chicken during 0-6 weeks.The appropriate dietary energy level would increase the deposition rate of the three nutrients,as a judge index,recommend 0-6 weeks of Guizhou yellow chicken appropriate energy level is 12.54 MJ/kg.（2）The predicted model of energy requirement of Guizhou yellow chicken during 0-6 weeks established by regression analysis was AME_G=377.70+1.6069NE_G（R²=0.7591）,and the maintenance metabolic energy requirement per kg of metabolic body weight was 377.70 KJ/W^0.75,and its net energy conversion rate of weight gain metabolic energy was 62.23%.Considering feed utilization,feeding cost and economic benefits,the recommended energy level of Guizhou yellow chicken ration during 0-6 weeks is12.54 MJ/kg.