| In present study, growth traits, meat contents and muscle histological characteristics of Pekin Ducks and Cherry Valley Ducks fed by different manners were investigated. Early growth and development pattern was studied. The thesis emphasizes on carcass traits, percent of amino acids, fatty acids, diameter and density of muscle fibers, length of sarcomere in two breeds ducks. Relationships among all carcass traits as well as fatty acids and amino acids variables were presented by Correlation analysis and principle components analysis.The results showed that the body weight and feed conversion efficiency of Pekin Ducks were lower by 10% and 4-7%, respectively, while weight of abdominal fat was higher by 20-30% than those of Cherry Valley Ducks fed by same manner. Male Pekin Ducks exhibited 10% body weight and 2% feed conversion efficiency higher than female. Male Cherry Valley Ducks exhibited 7% body weight higher and 4.2% lower feed conversion efficiency than female. Growth model Bertalanflfy, Gompertz and logistic were all fit for body weight's measurement. Force-feeding had a great effect on ducks' growth, force-fed group in a same breed showed 14~17% higher final BW and 2-5% lower feed conversion efficiency than group fed adlibitum.Cherry valley Ducks' carcass weight, breast muscle weight, leg muscle weight were larger than Pekin Ducks significantly (P<0.01). Pekin Ducks had higher percent of abdominal fat, skin and subcutaneous fat than Cherry Valley Ducks. There was no significant difference on percentage of breast muscle and leg muscle between two breeds. Force-fed group's carcass weight, weight of skin and subcutaneous fat and abdominal fat were also significantly larger than group fed ad libitum (P<0.01) in the same breed.Analysis of meat components showed that the ash content of Pekin Ducks' breast muscles was significantly higher than Cherry Valley Ducks' fed by same manner (PO.01). The percentage of crude protein (CP), extract ester, ash, total fatty acids, and total amino acids of force-fed group were slightly higher than the group fed ad libitum in the same breed. In terms of CP%, EE%, Pekin Ducks were slightly higher than Cherry Valley Ducks, the difference of percentage of CP% between two breeds fed ad libitum was significantly (P<0.05). The percent of fatty acid C14:l, C24:1+C22:6 of Pekins were all higher than Cherry Valley Ducks' fed with same manner (P<0.05). Percentage of total fatty acids, stearic acid (C18:0), oleic acid (C18:l), sub-oleic acid (C18:2) and flax acid (C18:3) of force-fed Cherry Valley Ducks, percent of stearic acid (C18:0) in force-fed Pekin Ducks were higher than the groups fed ad libitum significantly (PO.05). There was no significant difference in percentage of total amino acids between two the breeds.Through the study of muscle histological characteristic of experimental ducks, we found no significant differences in items of muscle fibers' diameter, density, and sarcomere between different breeds, sexes and different fed model. In one duck's body, the diameter of thigh muscle fibers were far bigger than breast muscle fibers', its sarcomere was also longer than the latter, but not significant (P>0.05). Variables correlation analysis and principle components analysis showed that the carcass weight, oleic acid, sub-oleic acid and flax acid, methionine, cystine were the most traits.The experiment confirmed that the Pekin Ducks' capability of body fat accumulation wasbetter than Cherry Valley Ducks, some content of alive fatty acids are also higher than the latter. But Cherry Valley Ducks' capability of growth and feed conversion were better than Pekin Ducks. So Pekins have some advantage on producing some particular products which requiring more subcutaneous fat like "Peking roast Ducks", and there are more advantages for Cherry Valley Ducks as a general meat bird.
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