Abstract

Simple Summary Sulphur-containing amino acids (methionine and cystine) are essential for the growth and feather development of geese. However, it is not known whether geese need different amounts of these amino acids as they grow from 4 to 9 weeks of age. We fed 288 male Jiangnan white goslings either low or high levels of sulphur amino acids during their first four weeks (1–28 days) and then again during the following five weeks (29–63 days). We measured their body weight, meat quality, nutrient digestibility, blood metabolites and, in a subset of birds, gene expression in feather follicles. The results showed that the amount of sulphur amino acids given in the first four weeks determined the final body weight at 63 days, while the amount given in the later period did not affect weight. However, a higher level of sulphur amino acids in the later period greatly improved meat juiciness by reducing cooking loss by 15%. A combination of low early and high late levels caused metabolic problems (high blood uric acid and LDL cholesterol), so such abrupt changes should be avoided. Analysis of feather follicle genes revealed that high late sulphur amino acids reduced the activity of a gene that breaks down methionine (MAT1) and increased genes that stimulate cell growth (GHRHR) in our experimental design, explaining better feather development. The best overall strategy is to give 0.87% sulphur amino acids from 1 to 28 days, followed by 0.74% from 29 to 63 days.