Table 3.
Effect of methionine restriction in rainbow trout on weight (g), feed intake (% body weight/d), feed efficiency, hepatosomatic index (HIS) and 16 h postprandial plasma methionine level.
| CTL | MD | |||
|---|---|---|---|---|
| Mean | SEM | Mean | SEM | |
| Initial body weight(g) | 63.97 | 1.53 | 61.14 | 1.26 |
| Final body weight (g) | 137.33a | 3.77 | 99.97b | 3.49 |
| Daily growth index (%/d) | 3.63a | 0.29 | 2.13b | 0.11 |
| Feed intake (%body weight/d) | 1.86 | 0.02 | 1.93 | 0.09 |
| Feed efficiency | 1.19a | 0.07 | 0.75b | 0.01 |
| HSI | 0.94a | 0.02 | 1.75b | 0.01 |
| Plasma methionine level (mg/ml) | 2.31a | 0.65 | 0.06b | 0.01 |
CTL, control diet; MD, methionine deficient diet. Daily growth index = 100 × (mean final body mass1/3 – mean initial body mass1/3)/day. Feed intake = 100 × the total amount of ingested feed (kg) divided by the mean biomass over the experimental period ((initial biomass + final biomass)/2), expressed as kg wet mass) and the number of days. Feed efficiency = Gain in total biomass [(final biomass – initial biomass) (kg wet mass)] divided by the amount of ingested dry matter (kg DM). HSI = (liver weight/total body weight) × 100. a,bMean values with unlike superscript letters were significantly different among the two dietary groups (P < 0.05; t-test).