| Different nutrition dietary levels of broiler breeders can regulate the nutritional composition of egg, and then affect the development of embryo and performance of offspring. Lipid metabolism is a very important physiological activitie. Studies on broiler’s lipid metabolism after leaving the shell and the theory of lipid deposition in eggs have been understood thoroughly, whereas lipid metabolism during embryo period was poor understanding. The objective of this study was to investigate effects of broiler breeder diet with lower energy density on embryonic lipid deposition during the later laying period in broiler breeders. The systematical investigation of maternal energy intake on lipid deposition in different levels was commenced on egg composition, growth performance, serum lipid, tissue lipid deposition in embryos during embryonic period in broiler breeders. This research was intended to regulate maternal dietary energy intake in order to affect the embryonic lipid deposition and reduce the lipid deposition of chicken. Meanwhile, it can also provide scientific theoretical basis and technical support to improve the meat quality by controlling maternal energy levels.A single factor design was adopted, and360broiler breeders (20weeks of age) with similar weight were randomly allocated into three groups (6replicates per group and20birds each replicate). The experiment was conducted when laying rate reached5%. The birds in the control group were fed a corn-soybean meal based diet, and those in trial groups were fed the diets with80%,70%energy levels of the basal diet, respectively. During the experiment period, feed intake in each group was restricted with a same level. The nutrient levels were all the same except for energy level in groups. After artificial insemination at60weeks old, hatching eggs in each group were collected and hatched in accord with the group of the breeders during the later laying period. Yolk samples serum samples were allocated at12,13,14,15,16,17,18,19,20and21embryonic day. Breast muscle, thigh muscle and liver samples were allocated at13,14,15,16,17,18,19,20and21embryonic day.The results were showed as follows:(1) Results of indexes on the development of embryo showed as follow. As compared with the control group, egg weight of broiler breeders before the hatching period in70%and80%energy group was significantly decreased (P<0.05); egg weight at12and13embryonic days, embryo weight at15and20embryonic days in70%energy group were significantly decreased (P<0.05); breast muscle weight, thigh muscle weight and liver weight at both13and21embryonic days, thigh muscle weight at17embryonic day in80%energy group were significantly improved (P<0.05). (2) Results of indexes on egg composition related to lipid metabolism exhibited as follow. As compared with the control group, crude fat of yolk at16,17,18,19,20and21embryonic days, gross energy of yolk at15,16,17,18,19,20and21embryonic days in70%and80%energy group were significantly decreased (P<0.05); the total cholesterol of yolk at each embryonic day in70%energy group was significantly decreased (P<0.05).(3)Results of indexes on serum composition related to lipid metabolism showed as follow. As compared with the control group, content of serum CHO at13,14,15,16,17,18,19,20and21embryonic days in80%energy group were significantly improved (P<0.05); content of serum GLU at each embryonic day and LDL at each embryonic day except for12embryonic day were significantly improved while content of serum TG at each embryonic day were significantly decreased in70%and80%energy groups (P<0.05); content of serum HDL at12,13,14,15,16,17,18and19embryonic days in70%energy group was significantly improved (P<0.05); content of serum LDH at12,13,14,15,16,17and21embryonic days in70%and80%energy groups were significantly improved (P<0.05).(4) Results of indexes on tissue composition related to lipid metabolism showed as follow. As compared with the control group, content of total cholesterol in breast muscle at13,14embryonic days and liver at15,16,17,18,19,20embryonic days in70%and80%energy groups were significantly decreased (p<0.05); content of total cholesterol in breast muscle at19,21embryonic days and thigh muscle at20embryonic day in80%energy group were significantly improved (P<0.05); content of total cholesterol in breast muscle at16embryonic day and thigh muscle at16,17embryonic day in70%energy group were significantly decreased (P<0.05); content of total cholesterol in liver and crude fat of breast muscle at21embryonic day in80%energy group were significantly improved (P<0.05).The above results showed that effects of maternal dietary energy restriction on embryo were significant. Compared with other groups, broiler breeders which fed a80%energy diet improved the levels of serum GLU, LDL, CHO, and contents of cholesterol, crude fat and the weight of breast muscle and thigh muscle, while reduced crude fat and gross energy of yolk in the embryonic period. The results demonstrate that maternal dietary energy restriction directly affects lipid metabolism on embryo during the later laying period. The maternal effect occurs and becomes manifest after the day12of embryonic development. |
