| With the rapid development of poultry industry, decline of meat quality and energy waste is being more and more serious. How to improve meat quality through the regulation of fat deposition is becoming a hotspot research in recent years. Energy is the foundation of feed nutrition and metabolism of all life. For broiler breeders diet energy could affect egg qualities, and then may influence embryo development, early growth and fat metabolism in offspring. The study was carried out to investigate the effects of maternal dietary energy levels on growth performance, serum indices, fat deposition and carcass composition of offspring. The study commenced at the beginning of the laying period to the late laying period. All these researches would provide theoretical and practical basis to improve broiler carcass composition and fat deposition.A single factor design was adopted, a total of270females Arbor Acres broiler breeders at20weeks of age were selected from the breeder stock. These female birds were divided into3treatments randomly (each treatment represented by5replicates of18birds), including2experimental treatments and one control group. The study commenced at the beginning of the laying period, defined as the age when total egg production reached5%of the flock. Treatment2was the control group, in which normal energy density diets were fed during the experiment (11.70MJ/kg of ME). In treatments1and3, the levels of energy were increased or decreased by20%, respectively. The content and the species of other nutrients are the same except the energy. Each bird was housed in individual cage with feed supply restricted and water fed ad libitum. The nutritional requirements of the female diets showed in Table1.2701-day-old male broilers were hatched during the late laying period (60-62week-old) of maternal broilers and allocated into3groups. All of their offspring were provided ad libitum of feed and water. The experiment period of offspring lasted for49days.The results showed that:(1) As compared with the control group, no difference was found in fertilization、the hatching rate and healthy chick rate (P>0.05).(2) Compared with the control group, offspring showed a lower1-d-old weight of the low energy group (P<0.05); however the28-d-old body weight、the daily gain (1-28d) and daily feed intake (1-49d) were significant higher (P<0.05).(3) On d28, the serum Triglyceride (TG)、cholesterol (CHO) and high-density lipoprotein (HDL) of offspring were higher and the serum Triiodothyronine (T3) of offspring was lower when breeders fed high energy diets with respect to control. The serum CHO、GLU、GH and IGF-1of offspring from breeders fed low energy diets were increased. In addition, on d49, there were increasing trends of serum CHO、T3and decreasing trends of serum TG in low energy group (P>0.05). Serum GLU of offspring from breeders fed low energy diets was lower as compared with the control(P<0.05).(4) On d28, with the treatments energy level down, there were increasing trends of subcutaneous fat thickness and liver fat percentage of offspring and decreasing trends of Intermuscular fat width (P>0.05). In addition, the fat content of breast and thigh muscle in offspring was increased in broilers fed high energy diets (P<0.05).(5) As compared with the control, the abdominal fat percentage in28-d-old offspring was decreased (P<0.05) and the breast muscle ratio was increased (P<0.05) in49-d-old offspring when breeders fed low energy diets.The above results showed that broiler breeders diets energy levels during the laying period have an influence on hatch performance of eggs and growth performance, carcass quality and fat deposition of offspring, and the growth performance in offspring from breeders fed low energy diets was improved. It is good to generating practices. |
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