PROTEINS
Corn fermented protein tested successfully in rainbow trout Dr. Steve R. Craig, Louis Rens, Green Plains
A 12-week feeding trial with Green Plains’ corn fermented protein (CFP) has aligned with previous research in showing the ingredient is suitable for certain fish diets. This most recent study was conducted with rainbow trout at the Optimal Aquafeed AquaLab in Shenandoah, Iowa, in the United States. Findings show that CFP60 (60% crude protein, as fed) inclusion rates ranging from 12-21% of the total diet are suitable for commercial diet formulations for rainbow trout and have significantly lower coloration impacts than corn gluten meal, even at much higher inclusion rates.
Methodology Rainbow trout (Oncorhynchus mykiss) were obtained from the same cohort of eggs (Steelhead strain, Riverence Brood, Rochester, U.S.), hatched in the AquaLab hatchery and reared using standard hatchery protocols. After reaching an average weight of 200 grams, 30 fish were weighed and placed into each of the 21 individual experimental tanks (630 fish total), as part of a recirculating aquaculture system equipped with a moving bed biological filter, mechanical filtration, UV sterilization, temperature control and pure oxygen
Table 1. Composition of the evaluated diets for rainbow trout during the 12-week feeding trial. See text for details.
Ingredient
No Corn
12CFP
15CFP
18CFP
21CFP
8CGM
Commercial
Wheat flour
27.10
29.75
28.95
27.95
27.05
31.40
Poultry byproduct meal
18.00
18.00
18.00
18.00
18.00
18.00
Fishmeal
12.00
12.00
12.00
12.00
12.00
12.00
C
Soybean meal
13.00
----
----
----
----
----
L O
CFP60
----
12.00
15.00
18.00
21.00
----
Corn gluten meal
----
----
----
----
----
8.00
S
Fish oil
12.00
12.00
12.00
12.00
12.00
12.00
E
Feather meal
7.50
6.50
5.20
3.70
2.00
7.25
D
Blood meal
4.50
3.50
2.50
2.00
1.50
5.00
Vitamin premix
1.25
1.25
1.25
1.25
1.25
1.25
F
Mineral premix
0.75
0.75
0.75
0.75
0.75
0.75
O
Choline chloride
0.60
0.60
0.60
0.60
0.60
0.60
R
Lysine
1.75
2.10
2.10
2.10
2.20
2.10
M
Methionine
0.50
0.50
0.50
0.50
0.45
0.40
U
Threonine
0.30
0.30
0.40
0.40
0.45
0.50
L
Stay-C
0.25
0.25
0.25
0.25
0.25
0.25
A
Taurine
0.50
0.50
0.50
0.50
0.50
0.50
No Corn
12CFP
15CFP
18CFP
21CFP
8CGM
Analyzed composition
Commercial
Crude protein
43.3
42.8
43.5
42.8
42.5
41.8
45.8
Crude lipid
14.0
15.4
15.2
14.4
13.0
14.1
13.4
Crude fiber
4.0
4.8
4.7
6.0
5.4
3.9
3.2
Ash
6.9
5.9
6.1
6.0
6.3
6.4
8.0
Aquafeed: Advances in Processing & Formulation Vol 15 Issue 4 2023
51