The relationship between dietary methionine and growth, digestion, absorption, and antioxidant status in intestinal and hepatopancreatic tissues of sub-adult grass carp (Ctenopharyngodon idella)

Table 2 Initial body weight (IBW), percentage weight gain (PWG), food intake (FI), feed efficiency (FE), and protein efficiency ratio (PER) of sub-adult grass carp fed diets with graded levels of methionine for 8 wk¹

Met, g/kg diet	2.21	4.24	6.22	8.25	10.24	12.26
IBW, g/fish	450.6 ± 0.89	452 ± 1.58	451.4 ± 0.55	450.8 ± 0.84	451 ± 1.00	452 ± 1.00
PWG, %	47.53 ± 4.23^a	117.87 ± 3.43^b	161.10 ± 8.58^d	142.60 ± 10.09^c	121.17 ± 8.30^b	116.28 ± 5.69^b
FI, g/fish	522.3 ± 4.6^a	952.5 ± 1.4^c	1249.8 ± 27.8^f	1164.9 ± 6.9^e	996.7 ± 4.0^d	905.8 ± 1.2^b
FE, %	46.04 ± 3.82^a	62.84 ± 1.93^b	65.38 ± 3.48^b	61.99 ± 4.33^b	61.60 ± 4.40^b	65.18 ± 3.24^b
PER	1.46 ± 0.12^a	2.00 ± 0.06^b	2.08 ± 0.11^b	1.97 ± 0.14^b	1.96 ± 0.14^b	2.07 ± 0.10^b
Regressions
Y_PWG = −2.805X² + 45.358X – 30.628				R ² = 0.860		P = 0.052
Y_FI = −19.734X² + 313.563X – 38.287				R ² = 0.909		P = 0.013

^a-fMeans in the same row with different superscript letters differ significantly (P < 0.05)
¹Values are mean ± SD (n = 5). Survival among all dietary treatments was 100%

ISSN: 2049-1891