Study On The Energy Requirement Of Cage-feeding Jin-ding Laying Ducks From Five To Sixteen Weeks

Three experiments were conducted to study the requirement of cage-feeding Jin-ding ducks from five to sixteen weeks. The experiment was conducted in three periods, which was 5 to 12, 13 to 16, 19 to 28 weeks.In experiment 1, 252 (4 weeks of age) un-ding ducks of commercial strain were assigned to six groups randomly, with three replicated per group. Each group was fed with the metabolizable energy(ME) content of 10.88, 11.09, 11.3, 11.51,11.72 or 11.93 Mu/kg diets contained 16.75% CP respectively. Four basal ducks were slaughtered at the beginning of the test period. The body weight and feed-intake were estimated bi-weekly. The slaughter test was carried at age of 8, 10 or 12 weeks. Metabolic test was carried at age of 12 weeks. The results showed that effect of ME content of diets on the growth performance was significant (pO.05). The feed-intake of group 4 was significant higher than group 3, group 5 or group 6 (p<0.05), however there was no significant difference among group 3, group 5 or group 6. The feed conversion ratio (FCR) of group2 was higher than group 3(pO.OS). The best growth performance was group3, the ME content of diets was 11.30 MJ/kg.Effect of ME content on retention of energy and protein was significant (pO.O5). The best retention of protein was groupl. The metabolic test results showed that effect of ME content on the availability of Nitrogen, Ca or P was significant (p0.05).The retention of energy of group 6 was higher than all others groups. The suitable energy level of diets was 11 .09 to 11.30 Mi/kg. The metabolic test results showed: the retention of N was significant affected by energy content (p0.05).the regression equation between MEn (y) and AME(x) was as followed : y~l .253x-4.305 (r?0.9884),the regression equation between AME(y) and TME(x) was as followed: y0.6656x+3.357 (r=0.9715).The mean of excreted endogenous energy was 27.31 KJ per kg body size.Over the experiment periods, the metabolizable energy intake (ME1) and retention of energy for body gain (RE3) per unit metabolic body size were estimated. The regression of ME1 on RE3 indicted that ME mean of maintenance requirement for Jin-ding ducks was 0.5948MJ per kg W0 ~ efficiency of ME1 conversion to REG was 64.33%. The formula to calculate the ME (Y) requirement for un-ding ducks was as followed:5-12weeks Y=0.5948W075+0.0174AW13-16 weeks Y=0.5948W075+0.014/~WIn experiment 3, one replicated was kept to determine the effect of energy level of growing periods on the early layer performance. All ducks were fed the same laying diets from 19 to 28 weeks. Th...