Frequently asked questions (FAQs)

1. What is a typical, suitable proximate analysis for the diet for Atlantic salmon?

Proximate composition	Life stage/size class
(% dry feed basis)	Fry	Fingerling	Juvenile	Grower	Marine grower	Broodstock
Crude protein, % min	50	45-50	45	42-45	40-45	45
Crude lipid, % min	16-18	20	20	20-24	24-30	24
Carbohydrate, % max	10	10	12	12	12	12
Crude fibre, % max	2	3	3	3	3	3
Digestible energy, min kJ/g	19	19	19	20	20	19
Protein to energy ratio, mg/kJ	23–24	22–23	21–22	20–21	17–18	18
Phosphorous, % min	0.07	0.07	0.06	0.06	0.06	0.06

2. What is a typical feed formulation for Atlantic salmon diets?

Ingredient composition (%)	Life stages
	Fry	Fingerling	Grower	Marine grower	Broodstock
Fishmeal, herring	60.05	40.01	32.04	28.08	35.07
Corn gluten meal	0	10	10	8	0
Poultry byproduct meal	0	10	10	10	8
Fish soluble protein concentrate	5	0	0	0	0
Krill meal	2	0	0	0	2
Poultry feather meal	0	5	3	6	5
Soybean meal, dehulled	0	5	12	12	10
Brewer’s yeast	4	0	0	0	4
Blood meal	2	0	3	0	0
Ground wheat	14.01	13.01	8.02	7.04	14.01
Fish oil	10.04	14.08	19.04	25.08	19.02
Vitamin premix	1	1	1	1	1
Mineral premix	1	1	1	1	1

Ingredient composition (%)	Life stages
Ingredient composition (%)	Fry	Fingerling	Grower	Marine grower	Broodstock
Fishmeal, herring	60.5	40.1	32.4	28.8	35.7
Corn gluten meal	0.0	10.0	10.0	8.0	0.0
Poultry byproduct meal	0.0	10.0	10.0	10.0	8.0
Fish soluble protein concentrate	5.0	0.0	0.0	0.0	0.0
Krill meal	2.0	0.0	0.0	0.0	2.0
Poultry feather meal	0.0	5.0	3.0	6.0	5.0
Soybean meal, dehulled	0.0	5.0	12.0	12.0	10.0
Brewer’s yeast	4.0	0.0	0.0	0.0	4.0
Blood meal	2.0	0.0	3.0	0.0	0.0
Ground wheat	14.1	13.1	8.2	7.4	14.1
Fish oil	10.4	14.8	19.4	25.8	19.2
Vitamin premix	1.0	1.0	1.0	1.0	1.0
Mineral premix	1.0	1.0	1.0	1.0	1.0

3. What protein and key amino acid levels should be considered in Atlantic salmon diets?

Dietary protein requirement of Atlantic salmon varies at different stages of its life and they require 10 essential amino acids like any other fish species for normal growth.

Nutrients	Life stage/size class
Nutrients	Fry	Fingerling	Juvenile	Grower	Marine grower	Broodstock
Crude protein, % min	50	45–50	45	42–45	40–45	45
Amino acids (% minimum of dietary protein)
Arginine	2.0	2.0	2.0	1.6	1.6	1.6
Histidine	0.7	0.7	0.7	0.8	0.7	0.7
Isoleucine	0.8	0.8	0.8	0.8	0.8	0.8
Leucine	1.4	1.4	1.4	1.4	1.4	1.4
Lysine	2.0	1.8	1.8	1.8	1.8	1.8
Methionine	1.1	1.0	1.0	1.0	1.0	1.0
Phenylalanine	1.2	1.2	1.2	1.2	1.2	1.2
Threonine	0.8	0.8	0.8	0.8	0.8	0.8
Tryptophan	0.2	0.2	0.2	0.2	0.2	0.2
Valine	1.3	1.3	1.3	1.3	1.3	1.3

4. What protein sources can be used in Atlantic salmon feeds?

Several protein supplements such as high-quality fishmeal, plant protein products (soybean meal, corn gluten meal, canola meal and pea meal), animal by-product meal (poultry by product meal, meat meal, blood meal, and hydrolyzed feather meal) and crustacean meal (krill, shrimp, crab) are used in salmon feed formulation depending upon economics and availability.

Ingredients	Protein content %
Fishmeal, Norse-LT94	77.5
Fishmeal, anchovy	66.5
Fishmeal, herring	72.3
Meat meal	55.6
Poultry by product meal	59.7
Blood meal	89.2
Corn gluten meal	60.7
Soybean meal, dehulled	50.0
Soybean protein concentrate	65.5
Canola meal	38.0
Wheat gluten meal	81.0
Brewer's yeast, dehydrated	42.6

5. Some commonly used animal and plant oil sources and their fatty acid profiles (%)

Fatty acid	Anchovy	Herring	Capelin	Menhaden	Redfish	Poultry fat	Canola	Soybean
20:5n-3*	17.0	8.4	4.6	11.0	8.0
22:6n-3**	8.8	4.9	3.0	9.1	8.9
Σ n-6	1.3	1.4	1.8	1.5	1.2	19.6	20.2	51.0
Σ n-3	31.2	17.8	12.2	25.1	19.1	1.0	12.0	6.8

6. What is the most appropriate feeding schedule for Atlantic salmon at different stages of the life cycle?

The most appropriate time to start feeding small-size particles in the form of granules or crumbles is when the yolk reserve is completely absorbed. At this stage, they are switched to starter feeds and fed frequently by automatic feeders or belt type clockwork feeders throughout daylight hours.
The frequency of feeding is dependent on the water temperature and body size. Generally, feeding is reduced from 8–12 times or more daily to 3–4 times a day for fingerlings and parr. Modern demands feeders and feeding schedules developed by feed manufacturers based on fish size, water temperature and energy content of feed provide appropriate directions to achieve maximum growth and feed utilization under diverse environmental and culture conditions, as shown in the table below:

BW (g)	4 °C		8 °C	12 °C		16 °C	18 °C
Freshwater
<0.3		Ad libitum
0.3–0.8		2.0	3.0		4.0	4.5	4.5
0.8 - 5.0		1.8	2.7		3.5	3.9	3.9
5.0–10.0		1.6	2.1		3.1	3.4	3.4
10.0–25.0		1.4	2.0		2.7	3.1	3.0
25.0–40.0		1.0	1.6		2.2	2.7	2.6
40.0–60.0		1.0	1.3		2.0	2.6	2.5
Seawater
80–200		1.5	1.9		2.2	2.8
200–300		1.3	1.9		2.3	2.6
300–500		1.2	1.7		2.0	2.3
500–775		1.0	1.4		1.7	2.0
775–1 000		0.8	1.0		1.5	1.8
1 000–1 250		0.7	1.0		1.3	1.5
1 250–1 500		0.6	0.9		1.2	1.4
1 500–2 000		0.5	0.7		1.1	1.2
2 000–3 000		0.5	0.7		0.9	1.1
3 000 +		0.5	0.6		0.9	1.0