data obtained by using other breeds of ducks (that is, Muscovy and "mule" ducks) have been used to fill several voids in the requirement data of Table 5-1, especially with respect to amino acids and minerals. Published research reviewed in Appendix Table A-6 on lysine and total sulfur amino acid (TSAA) requirements indicates that values listed in the previous edition of this report were too high (Jeroch and Hennig, 1965; Dean, 1967; Gazo et al., 1970; Leclercq and de Carville, 1977a,b; Adams et al., 1983; Elkin et al. 1986). Adjustments were made accordingly. In addition, a tentative methionine requirement for starting ducks (0.40 percent) is given on the basis of data reported by Elkin et al. (1986). Noteworthy is information published recently by Elkin et al. (1988) showing that the relative value of the D-methionine isomer was 78 percent of that of the L-isomer. Consequently, in instances where supplemental methionine is needed in duck diets, adjustments may be needed in supplemental levels of the DL-methionine sources used.

Only single papers have been published documenting the requirements of starting ducks for arginine, tryptophan, leucine, isoleucine, and valine (Chen and Shen, 1979; Wu et al., 1984; Yu and Shen, 1984). The values for these nutrients listed in Table 5-1 must therefore be viewed as tentative. The same is true of the requirement values for breeding ducks because relevant information is scarce (Cvetanov et al., 1969).

Research to determine the mineral and vitamin requirements of ducks has focused primarily on the starting

period (0 to 2 or 3 weeks of age). In most instances, data on these nutrients are meager, and, with the exception of some research on dietary selenium and niacin requirements, only one report has appeared in the literature since 1980. Leclercq et al. (1990) reported that the calcium requirements of Muscovy ducks were 0.46 and 0.42 percent for age periods of 3 to 8 and 8 to 12 weeks, respectively. No information has been published recently on the calcium requirements for modern-day Pekin ducks.

Body weight and feed consumption data for ducks from time of hatching to 8 weeks of age are given in Table 5-2.

Front Matter (R1-R16)

Overview (1-2)

1. Components of Poultry Diets (3-18)

2. Nutrient Requirements of Chickens (19-34)

3. Nutrient Requirements of Turkeys (35-39)

4. Nutrient Requirements of Geese (40-41)

5. Nutrient Requirements of Ducks (42-43)

6. Nutrient Requirements of Ring-Necked Pheasants, Japanese Quail, and Bobwhite Quail (44-45)

7. Signs of Nutritional Deficiencies in Chickens and Turkeys (46-57)

8. Toxicity of Certain Inorganic Elements (58-60)

9. Composition of Feedstuffs Used in Poultry Diets (61-79)

10. Standard Reference Diets for Chicks (80-82)

Appendix A: Documentation of Nutrient Requirements (83-112)

Appendix B: Estimating the Energy Value of Feed Ingredients (113-113)

Appendix C: Conversion Factors (114-114)

References (115-142)

Authors (143-144)

Index (145-157)