Studies On Lysine Requirement And Ideal Pattern Of Amino Acids For Mule Duck

Two experiments were conducted to investigate lysine requirement and ideal pattern of amino acids for mule duck, using a dose effect method to assess growth performance, slaughter performance and blood biochemical index to study the mule duck in lysine optimal requirement. The ideal pattern of amino acids was studied by amino acid deduction method with N retention.In experiment1, a dose-response experiment was conducted to evaluate the effecets of5dietary Lys levels on the growth performance, slaughter performance, blood biochemical indexes of mule ducks, to determine the Lys requirements of mule ducks. The test was divided into two phases. In the first period, a total of2407-day-old mule ducks were randomly divided into5groups, each containing6replicate pens with8birds per pen, and these birds were raised from1to3weeks of age. During the second period, a total of18021-day-old mule ducks were randomly divided into5groups, each containing6replicate pens with6birds per pen, and these birds were raised from4to8weeks of age. In this study, corn-soybean diet was used. The dietry energy and protein were2.86Mkal/kg and18.52%in the first period, while were3.04Mkal/kg and16.55%in the second period. At1to3weeks of each treatment of dietary lysine level in0.80(basal diet),0.88,0.96,1.04and1.12%; at4to8weeks for0.60(basal diet),0.68,0.76,0.84and0.92%.The results were as follows:Growth performance of mule ducks was significantly affected by dietary Lys levels (P<0.05). In order to obtain optimum weight gain, appropriate dietary lysine was0.96%for mule ducks aged from1to3weeks,0.76%for ducks aged from4to8weeks. In order to obtain optimum feed conversion rate, dietary Lys levels at1to3weeks as appropriate in1.04%, at4to8weeks for0.76%. Different dietary Lys levels had no significant effect on daily feed intake of mule ducks in the growth stage (P>0.05). The quadratic analysis regression estimation model of mule duck dietary lysine levels is as following, based on the average daily gain of estimated value:at1to3weeks for0.993%, at4to8weeks for0.804%; based on feed gain ratio estimation value of at1to3weeks for1.023%, at4to8weeks for0.797%. According to quadratic regression, the lysine requirements of mule ducks for average daily weight gain (ADWG) and feed/gain ratio (F/G) were0.993%and1.023%for ducks from1to3weeks of age,0.804%and0.797%for4to8weeks of age.The optimum of Lys levels in diet significantly improve mule duck carcass quality and slaughter performance (P<0.05), reduced fat deposition. The pectoral muscle rate as evaluation index, dietary Lys appropriate levels at1to3weeks for0.96%-1.12%, at4to7weeks for0.76%-0.92%; with the increased Lys levels, the abdominal fat rate significantly linear declined (P<0.05), dietary Lys levels at1to3weeks for1.12%, at4to8weeks for0.92%, the abdominal fat rate minimum. Using quadratic model to estimate mule ducks dietary lysine levels, based on breast muscle ratio estimation at1to3weeks for1.054%, at4to8weeks for0.856%.Optimum dietary Lys levels significantly increased by at1to3weeks (P<0.05), at4 to8weeks of mule duck body on amino acid utilization efficiency, reducing blood uric acid levels, while increasing the blood levels of total protein and albumin. At1to3weeks of mule duck, dietary Lys levels of1.04%, uric acid level minimum, at4to8weeks of mule duck, dietary Lys levels of0.76%, the lowest level of uric acid serum and total protein of different stages mule ducks increased as dietary Lys levels increased.In experiment2. The experiment was conducted to evaluate the ideal pattern of amino acids for mule duck on N retention, using amino acid deduction method. The test is divided into two phases. In the first period,240mule ducks, divided into5groups randomly,6replicates in each group, each repeat8; In the second period,180mule ducks, divided into5groups randomly,6replicates in each group, each repeat6. Different amino acid ratio dietary were used in the each group. The requirement of amino acids in control (I) were:Lys1.05%, Met0.5%, Thr0.65%and Trp0.23%. The basal diets were deduction of20%Lys,20%Met,20%Thr and20%Trp on the basis of I group in group â…¡, â…¢, FVand V respectively and other amino acids content remains unchanged. In the later experiment period, the control (â… ) dietary amino acids requirement were:Lys0.80%, Met0.38%, Thr0.51%and Trp0.18%. The basal diets were deduction of20%Lys,20%Met,20%Thr and20%Trp on the basis of I group in group â…¡, â…¢, â…£and â…¤ respectively and other amino acid content remains unchanged, adding Ile, Val reached Taiwan native Mule Duck diets recommended level of each stage, and by adding glutamate (Glu) so that each group total protein content consistency. Through the treatment group of mule ducks of the corresponding amino acid intake and N retention on the linear relationship between the calculation of four kinds of essential amino acid ratio. The results were as follows:In the first period of mule duck, except for the-20%Trp group daily weight gain and feed intake and control group had no significant difference (P>0.05), the other groups decreased significantly (P<0.05); from the body protein content, other groups were lower than the control group and-20%Trp group, but the difference was not significant (P>0.05). Although the treatment of N retentionwas significant difference (P<0.05), but the unit weight increase in N retention was not significant difference (P>0.05), is obtained by calculating the four kinds of essential amino acids ratio:Lys:Met:Thr:Trp=100:37:67:19.In the second period of mule duck, except for the-20%Met and-20%Trp group daily weight gain and fed intake and control group had no significant difference (P>0.05), the other two groups decreased significantly (P<0.05); from the body protein content, as the group was higher than that of each of the other experimental group, but the difference was not significant (P>0.05); the treatment of N retention had significant difference (P<0.05), but the unit weight which increase in N retention was not significant difference (P>0.05), and the result is obtained by calculating the four kinds of essential amino acids ratio:Lys: Met:Thr:Trp=100:33:64:18.