Supplementation of Microbial Phytase with Safflower Meal in Rainbow Trout (Oncorhynchus mykiss): The Effects on Growth, Digestibility, Environmental, and Serum Biological Parameters

Table 1

Nutritional and chemical proximate composition of experiment feeds.

Ingredients	Control	SFM10	SFM20	SFM10 ± P1000	SFM20 ± P2000
Formulation (g kg^−1 as fed)
Fish meal	435	435	445	435	445
Soybean meal	295	270	240	270	240
Wheat meal	135	120	110	120	110
Fish oil	100	100	100	100	100
Safflower meal	—	30	60	30	60
Wheat gluten	20	30	30	30	30
Vitamin-mineral mix	5	5	5	5	5
Antioxidant	10	10	10	10	10
Phytase	—	—	—	1000 IU/kg	2000 IU/kg
Composition
Dry matter	91.57 ± 0.6^a	91.46 ± 0.83^a	91.64 ± 0.62^a	91.33 ± 0.75^a	91.78 ± 0.43^a
Crude protein	44.39 ± 0.32^a	44.35 ± 0.21^a	44.10 ± 0.56^a	44.33 ± 0.13^a	44.13 ± 0.42^a
Crude lipid	12.96 ± 0.03^a	12.55 ± 0.4^a	13.42 ± 0.28^a	12.48 ± 0.36^a	13.50 ± 0.27^a
Crude ash	10.29 ± 0.24^a	10.28 ± 0.23^a	10.32 ± 0.28^a	10.22 ± 0.21^a	10.38 ± 0.28^a
NFE^1	32.36	32.41	32.16	32.97	31.99
Gross energy (kJkg^−1)^2	23.10	22.82	23.08	22.87	23.06

Each value refers to mean ± standard deviation. Values expressed in different exponents in the same column are statistically different from each other . ¹Nitrogen-free extracts (NFE) = matter − (crude lipid + crude ash + crude protein). ²Energy calculated according to 23.6 kJ g⁻¹ protein, 39.5 kJ g⁻¹ lipid, and 17.0 kJ g⁻¹ NFE.