ABSTRACT
1. A dose-response experiment was conducted with male Korean native ducklings (KND) to evaluate the total sulphur amino acid (TSAA) requirement from hatch to 21 d of age. 2. A completely randomised design with 7 dietary TSAA concentrations (0.62%, 0.65%, 0.68%, 0.71%, 0.74%, 0.77% and 0.80%) were used with 6 replications per treatment. 3. Body weight (BW) and feed intake were measured weekly to calculate average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR). One duckling per pen (n = 6) was killed by cervical dislocation to weigh empty body and drumsticks at the conclusion of experiment. 4. BW was improved significantly with increasing TSAA content, in a non-linear manner. A significant decrease of FCR was shown with increasing TSAA contents. TSAA requirement was determined by taking a mean value after fitting the data to both a linear-plateau and a quadratic-plateau model. Estimated TSAA requirements were 0.70%, 0.70%, 0.66% and 0.70% for the maximum BW, ADG and ADFI and for the minimum FCR, respectively. Increasing TSAA content improved quantity of full body weight (FBW), empty body weight (EBW) and drumstick weight (DSW), but there was no effect on proportion of DSW in relation to EBW and proportion of EBW to FBW. 5. In conclusion, the growth of male KND during 1 to 21 d of age was improved with increasing TSAA content, suggesting optimal TSAA requirements estimated by two analysis models.
Subject(s)
Amino Acids, Sulfur/metabolism , Ducks/physiology , Energy Metabolism , Nutritional Requirements , Weight Gain , Animal Feed/analysis , Animals , Diet/veterinary , Dose-Response Relationship, Drug , Ducks/genetics , Ducks/growth & development , Male , Random AllocationABSTRACT
A study was conducted to determine the apparent metabolizable energy (AME) requirement of Korean native ducklings for hatch to 21 d of age. A total of 336 one-day-old male Korean native ducklings were used in a completely randomized design having 8 dietary treatments to provide a range of AME content from 2,600 to 3,300 kcal/kg (i.e., 100 kcal/kg disparity). Eight experimental diets containing varying levels of AME were formulated to meet the NRC (1994) nutrient specifications. Ducklings were randomly allocated to 48 pens (6 replicates per treatment and 7 ducklings per pen) and were offered their respective diets on an ad libitum basis for the period of study. Body weight and feed intake were measured weekly to calculate feed conversion ratio, energy intake, and protein intake. Two ducklings per pen (n = 6) were euthanized via cervical dislocation to weigh empty body and drumsticks at the conclusion of the experiment. Data were fitted to both linear-plateau and quadratic-plateau models for estimation of the AME requirements for Korean native ducklings for hatch to 21 d of age. The estimated AME requirements were 2,953, 3,007, and 2,950 kcal AME/kg diet for maximum daily gain, daily feed intake, and for minimum feed conversion ratio, respectively.