生长期能量采食水平对生长蛋鸡的影响

试验用 43 2只伊莎褐商品蛋鸡 ,研究了三个不同能量采食水平日粮对生长、性成熟的影响。试验得出在 7～ 9,10～ 12 ,13～ 15 ,16～ 18周内 ,高能量采食水平组鸡比中、低能量采食水平组鸡的日增重高 2 .5 2 %、5 .43 %(P <0 0 5 ) ,3 .3 3 %、16.5 9%(P <0 .0 1) ,8.1%、12 .9%(P <0 .0 1) ,2 3 .6%、45 .1%(P <0 .0 1) ,各期日增重差异显著 ;饲料转化效率在 7～ 9周高能采食水平组比中、低能量采食水平组高 4.5 %、6.0 %(P <0 .0 5 ) ,在 10～ 12周高能组比中、低能组高5 79%、10 .93 %(P <0 .0 1) ,在 16～ 18周高、低能组比中能组鸡高 2 3 .4%、3 9.2 %(P <0 .0 1)。全期体重随能量采食水平增加而增加。高、中能量采食水平组鸡达 5 %产蛋率日龄比低能组分别提前 14和 12 .4d(P <0 .0 5 ) ,高、中能组鸡达5 0 %产蛋率的时间比低能组早 6.2d、5 .8d(P <0 .0 1)。表明生长期能量采食水平高的鸡 ,日增重多 ,体重增加的快、;体重大的鸡 ,开产早 。

Effects of Dietary Soy Isoflavones on Feed Intake,Growth Performance and Digestibility in Juvenile Japanese Flounder(Paralichthys olivaceus)

An 8-week feeding trial was conducted to investigate the effects of dietary soy isoflavones on feeding intake,growth performance,and digestion of juvenile Japanese flounder(Paralichthys olivaceus).Four isonitrogenous(49% crude protein) and isoenergetic(20.1 MJ kg-1) diets were formulated to contain four graded levels of soy isoflavones,namely,0,1,4 and 8 g soy isoflavones in 1 kg of diet.Each diet was randomly fed to triplicate tanks of fish(Initial average weight:2.58 g ± 0.01 g),and each tank was stocked with 35 fish.No significant difference was observed among diets with levels of 0,1 and 4 g kg-1 soy isoflavones in feed intake,weight gain,feed efficiency ratio(FER),proximate composition of fish whole body and apparent digestibility coefficients(ADC) of nutrients and energy(P>0.05).However,high dietary soy isoflavones level(8 g kg-1) significantly depressed weight gain,FER,whole-body crude lipid content of fish and ADC of nutrients(P<0.05).These results indicate that high level of dietary soy isoflavones(above 4 g kg-1) significantly depresses growth responses and FER of Japanese flounder.However,as the content of soy isoflavones in soybean meal is around 1 to 3 g kg-1,the adverse effects might be neglected when soybean products are used as a fish feed ingredient.