Q.  Wang, H.F.  Li, Y.L.  Dai, K.W.  Chen, B.L.  Li, Z.Y.  Wang, J.  Zhang, 
    Effect of Dietary Crude Protein and Energy on Gaoyou Ducklings Growth Performance and Carcass Trait,
    Journal of Animal and Veterinary Advances,
    Volume 9,Issue 4,
    2010,
    Pages 826-830,
    ISSN 1680-5593,
    javaa.2010.826.830,
    (https://makhillpublications.co/view-article.php?doi=javaa.2010.826.830)
    Abstract: The study was undertaken to assess dietary CP and ME concentrations for optimum growth performance and carcass characteristics of Gaoyou ducklings. In a 3x3 factorial arrangement, three hundred and sixty zero-day-old  Gaoyou ducklings were  randomly  assigned  to experimental diets with 11.70, 11.90 and 12.12 MJ of ME kg<SUP>-1</SUP> of diet; each contained 18.0, 19.0 and 20.0% CP, respectively, from 0-28 days of age. Each dietary treatment had 4 replicates. Body weight and feed consumptions were  measured at every weekend, from 0-28 days of age and carcass characteristics were evaluated at 28 days of age. The result showed that ducklings on a diet with 11.70 and 11.90 MJ of ME kg<SUP>-1</SUP> at 0-28 days of age exhibited greater BW gain than this diet with 12.12 MJ of ME kg<SUP>-1</SUP> (p&lt;0.01), though BW gain was not different among 11.70 and 11.90 MJ of ME kg<SUP>-1</SUP> of diet. Mean BW gain of birds fed 18.0, 19.0 and 20.0% CP diets was significantly different (p&lt;0.001). Feed intake was influenced by dietary ME levels (p&lt;0.000) also. Feed intake of birds fed 18.0% CP diets was higher than those of birds on 19.0 and 20.0% CP diets (p&lt;0.01). Feed conversion ratios of birds fed on 11.70 and 11.90 MJ of ME kg<SUP>-1</SUP> of diet were better than those fed on 12.12 MJ of ME kg<SUP>-1</SUP> (p&lt;0.001). Feed conversion ratios of birds fed on 18.0% CP diets were better than those fed on 19.0 and 20.0% CP diets. In the study, there were significant interactions between dietary CP and ME on growth performance. There was a direct relationship between dietary ME levels and eviscerated carcass percentage (p&lt;0.014), abdominal fat percentage (p&lt;0.000) and breast weight (p&lt;0.037). But the half-eviscerated carcass percentage, eviscerated carcass percentage, breast and leg meat percentage were not influenced by dietary CP concentration. Thus, diets with 11.70 MJ of ME kg<SUP>-1</SUP> and 18.0% CP were used more efficiently from 0-28 days of age by Gaoyou ducklings.
    Keywords: Gaoyou ducklings;crude protein;metabolizable energy;growth performance;carcass traits;China