Table 2.
Total amino acid composition of skim milk powder, sweet whey, ideal whey, and acid whey, determined by high-performance cation exchange.
| TAA g/kg Total Protein | Skim Milk Powder | Sweet Whey Powder | Ideal Whey Powder | Acid Whey Powder | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GRS | CLV | TMR | GRS | CLV | TMR | GRS | CLV | TMR | GRS | CLV | TMR | |
| Cysteic acid | 11.2 | 11.8 | 10.6 | 29.4 | 29.0 | 28.9 | 34.1 | 31.4 | 32.9 | 34.6 | 32.9 | 34.0 |
| Taurine | 9.52 | 8.97 | 9.78 | 32.4 | 36.2 | 35.7 | 38.3 | 50.8 | 35.5 | 35.7 | 41.7 | 41.4 |
| Methionine Sulfone | 33.3 | 34.3 | 34.6 | 21.0 | 21.3 | 20.0 | 23.8 | 21.0 | 21.2 | 20.0 | 20.4 | 20.3 |
| Asparagine | 73.3 | 73.9 | 74.1 | 97.0 | 96.4 | 94.0 | 99.8 | 93.7 | 96.9 | 101 | 98.1 | 98.6 |
| Threonine | 41.1 | 41.0 | 41.2 | 62.0 | 60.4 | 57.5 | 41.5 | 37.7 | 40.1 | 41.4 | 40.2 | 39.2 |
| Serine | 50.1 | 49.9 | 49.9 | 41.2 | 39.7 | 37.8 | 35.4 | 31.0 | 33.8 | 34.6 | 33.1 | 32.1 |
| Glutamine | 190 | 193 | 189 | 159 | 155 | 142 | 155 | 138 | 143 | 159 | 153 | 139 |
| Glycine | 16.3 | 16.7 | 15.6 | 20.2 b | 18.9 b | 15.8 a | 20.6 | 20.0 | 18.2 | 19.6 b | 18.6 a,b | 16.4 a |
| Alanine | 28.4 | 28.0 | 27.9 | 39.6 | 41.2 | 36.9 | 38.6 | 32.0 | 31.4 | 38.0 | 35.6 | 34.8 |
| Cysteine | 7.13 | 8.14 | 7.88 | 20.7 | 24.4 | 21.5 | 25.7 a,b | 34.6 b | 21.6 a | 22.2 a,b | 30.4 b | 15.4 a |
| Valine | 55.3 | 57.8 | 56.2 | 54.6 | 52.9 | 52.0 | 51.8 | 46.6 | 43.3 | 51.3 b | 48.9 a,b | 36.7 a |
| Isoleucine | 43.7 | 45.6 | 44.5 | 53.8 | 51.5 | 48.4 | 44.1 | 38.1 | 40.9 | 46.6 | 44.0 | 42.7 |
| Leucine | 93.5 | 95.5 | 94.7 | 88.1 | 88.4 | 82.1 | 98.5 | 91.5 | 92.5 | 103 | 100 | 93.7 |
| Tyrosine | 30.2 | 34.1 | 32.7 | 8.92 | 9.63 | 12.0 | 13.7 | 12.5 | 13.2 | 8.87 | 10.5 | 8.77 |
| Phenylalanine | 42.4 | 42.2 | 40.8 | 24.3 | 22.8 | 23.2 | 31.1 b | 24.5 a | 28.4 a,b | 30.0 | 30.0 | 26.9 |
| Histidine | 35.7 | 35.4 | 35.7 | 25.3 | 28.2 | 25.6 | 33.6 | 35.7 | 31.7 | 40.2 | 41.2 | 35.7 |
| Lysine | 72.6 | 73.1 | 73.7 | 75.7 | 74.5 | 70.8 | 77.8 | 68.4 | 71.5 | 82.0 | 77.8 | 74.7 |
| Arginine | 31.4 | 32.0 | 31.5 | 19.8 | 19.5 | 20.0 | 24.1 | 23.3 | 24.9 | 25.3 | 24.2 | 23.0 |
| Proline | 84.2 | 86.1 | 88.7 | 44.0 | 48.0 | 35.0 | 27.2 | 24.2 | 32.9 | 30.3 | 25.1 | 21.9 |
GRS—cows fed perennial ryegrass only. CLV—cows fed perennial ryegrass/20% white clover sward. TMR—cows fed indoor total mixed ration ad-libitum. a,b indicates values within a row for each ingredient not sharing a common superscript letter differed significantly (p < 0.05).