Studies On Gosling Yolk Sac Nutrition And The Optimum Levels Of Energy And Protein For 0～3 Week-Old Gosling

An experiment was conducted with gosling to compare yolk sac absorption and utilization with fasting and feeding, and the effect of different levels of diet nutrition (CP: 21%; ME:12.18,11.34,10.50MJ/kg) on yolk utilization. In order to further determine the requirement of energy and protein for 0~3 week-old goslings, the goslings were fed with 9 diets in a 3 X 3 factorial arrangement of treatments involving three ME levels (ME:12.18,11.34,10.50MJ/kg) and three CP levels (CP:21,19,17%). The results indicated that:l.At hatch the gosling had a yolk sac, the average weight of which was 9.37g,which was 10.22% of its hatch weight. The percents of crude moisture (CM), crude fat (CF) and crude protein (CP) of the yolk were 41.96%, 22.51% and 28.70% respectively at hatch. With the hours old increasing, the percent of CM of yolk went up continually while the percent of CP and CF dropped continually. During the period of 11~59 hours old, energy, CP, CF, Met and Lys declined at rates of 6.723~7.210Kcal, 0.86~0.92g, 1.07- 1.19g, 47.22~49.03mg and 65.51~95.71mg per 24 hours.2. During the period of 11~59 hours in fasted goslings absorption and utilization of yolk nutrient was approximately 75%, while in fed goslings was 80%. After the 83 hours, the yolk sac weight and air-dry material were higher in feed-deprived goslings than in fed goslings significantly (P<0.01), which suggested that fed' gosling utilized yolk nutrient more rapidly than fasted gosling (P<0.01). Energy had a little influence on the absorption and utilization of yolk, low energy had a tendency to accelerate absorbing and utilizing the yolk nutrient, but not significantly (P>0.05).3.Energy and protein had significant influence on the growth of gosling (P<0.01),and the interaction of which also affected the growth of gosling significantly (P<0.05).The relationship of those factors in the growth of gosling were: energy> protein>interaction. The results of the experiment indicated that the average body weight of gosling and daily gain were higher significantly in low energy treatment than in high energy treatment (P<0.01), and under a certain level of energy, body weight and daily gain went up with the increasing of the level of protein and feed conversion ratio was improved. Binomial regression equations were established between indicators of body weight and daily gain and the factors of energy and protein, and the optimum levels of ME and CP were found out: ME11.01~11.38MJ/kg,CP19.65-~21.16%, CP/ME17.85-18.59g/MJ.4.The concentration of T3 showed a significant positive correlation with body weight and daily gain in 3-week-old goslings (P<0.01), but there was no correlation between the concentration of T4 and body weight or daily gain. Under a certain level of energy the ratio of T31 T4 declined with the level of protein dropping. The relationship between the activity of Amy, AKP and body weight or daily gain were positive significant (P<0.01). The body weight and daily gain showed a significant negative correlation with the activity of GOT (P<0.01) and a significant positive correlation with the activity of GPT (P<0.05).