Effects Of Vary Dietary Energy Levels On Productive, Reproductive Performance And Maternal Effect Of Jining Bairi Chicken

Consequently to the reduction of growing follicles and the increase in atresia follicles,the breeder's performance as well as the energy requirement decrease during the late laying period. The changing maternal energy intake impairs growth performance due to excessive fat,but also influences the productive and reproductive performance, growth control and metabolism of the offspring. Several experiments were conducted to study the effects of dietary energy levels on the productive and reproductive performance and on the maternal effect as well as to establish factorial models of energy requirement and confirm them through the trials. Subsequently, the dietary energy levels parameter was investigated by assessing performance, egg quality, serum biochemical parameters, reproductive performance and gene expression. As a result of these studies, we expected to provide theoretical and practical basis of Jining Bairi chicken's feeding standard.A total of 525 60-week-old healthy Jining Bairi chickens with the similar weights and performance were randomly allocated to 5 treatments of 5 replicates with 21 chickens each. A single factor design was used to study the impact of dietary energy based on 5 distinct energy levels(2600kcal/kg, 2650kcal/kg, 2700kcal/kg, 2750kcal/kg, 2800kcal/kg) on Jining Bairi chickens. The experiment was divided into 2 parts, the acclimation period and the formal experiment. The acclimation period lasted for 7 days while the experiment lasted for 56 days.The results showed :(1) Dietary energy levels significantly affected the feed and metabolic energy intakes of Jining Bairi chickens(P < 0.05) as well as significantly altered the chickens body weight during the late laying period(P < 0.05). Dietary energy levels significantly impaired performance such as the egg production and the feed conversion ratio(P < 0.05).(2) Dietary energy levels significantly affected the yolk color of Jining Bairi chickens during the late laying period(P < 0.05). In this way, lower energy levels negatively altered the yolk color.(3) Dietary energy levels significantly affected the serum triglyceride(TG) and uric acid(UC) concentrations of Jining Bairi chickens during the late laying period.(4) Dietary energy levels significantly influenced the number of qualified eggs of Jining Bairi chickens during the late laying period(P < 0.05).(5) Dietary energy levels had significant effects on the birth and liver weights of the offspring during the late laying period(P < 0.05)(6) Dietary energy levels significantly affected the high density lipoprotein(HDL), low density lipoprotein(LDL), the total serum protein(TA), albumin(ALB), uric acid(UA) and urea(UREA) of the newborn chicks(P < 0.05).(7) Dietary energy concentrations had significant effects on FAS and PPAR? expression levels in the liver of the offspring during the late laying period(P < 0.05) and showed a trend for the LPL expression although it could not be considered as significant.Conclusion: Dietary energy levels can significantly decrease the feed intake, body weight and feed conversion ratio(P<0.05) while enhancing egg production and yolk color. This parameter can also promote the birth and liver weights of the offspring and impact fat metabolism.(1) The factorial model of energy requirement considering the metabolic energy intake(MEI) as the dependent variable(Y) and the average daily gain(ADG), average daily egg mass(ADEM) and body weight(BW) as independent variables(X) is expressed as follows:MEI=14.443ADG+2.5685ADEM+134.830BW0.75(2) The factorial model of energy requirement considering the metabolic energy intake(MEI) as the dependent variable(Y) and the average daily gain(ADG), average daily qualified egg mass(ADQEM) and body weight(BW) as independent variables(X) is expressed as follows: MEI=16.007ADG+2.699ADQEM+134.073W0.75(3) Take performance as evaluation criterion, the appropriate energy requirement is2800 kcal/kg. Take reproductive performance as evaluation criterion, the appropriate energy requirement is 2779 kcal/kg.(4) The regulation of maternal dietary energy can programmed control the processes of energy and fat metabolism in offspring.