Brewer’s yeast as a diet supplement in carp aquaculture: impact on production coefficients and haematological and biochemical plasma parameters

Figures & data

Table 1. Analytical composition of the feed mixture used in this study.

Component	Content
Moisture, %	11.53
Crude protein, %	17.94
Crude fibre, %	5.36
Crude oils and fats, %	3.91
Crude ash, %	7.41
Lysin, %	0.73
Methionine, %	0.29
Calcium, %	1.71
Phosphorus, %	0.60
Sodium, %	0.02
Butylhydroxyanisol, mg	1.25
Butylhydroxytoluene, mg	5.48
Vitamin D3, IU	1500.00
Vitamin A, IU	8100.00
Sulphate ferrous monohydrate, mg	100.26
Iodine calcium, mg	1.02
Sulphate cupric pentahydrate, mg	4.95
Manganese dioxide, mg	20.10
Zinc dioxide, mg	86.64
Selenium, mg	0.41

Table 2. Mean water quality parameter values for each test treatment over the course of the experiment.

	Group
Parameter	C	B-2.5	B-5	B-10
Water temperature, ^oC	23.90 ± 0.03	24.00 ± 0.03	24.20 ± 0.09	24.00 0.04
Dissolved oxygen content, mg.L^−1	7.50 ± 0.01	7.50 ± 0.01	7.50 ± 0.02	7.60 ± 0.04
Oxygen saturation, %	91.40 ± 0.13	93.00 ± 0.14	91.70 ± 0.15	94.80 ± 0.15
pH	± 7.80	± 7.80	± 7.80	± 7.80
N-NH4^+, mg.L^−1	0.10 ± 0.02	0.10 ± 0.02	0.10 ± 0.02	0.10 ± 0.02
N-NO2^−, mg.L^−1)	0.10 ± 0.02	0.10 ± 0.03	0.10 ± 0.03	0.10 ± 0.01
Cl^−, mg.L^−1	114.20 ± 0.04	114.20 ± 0.02	114.20 ± 0.04	114.20 ± 0.01

Notes: Water temperature, dissolved oxygen content, oxygen saturation and pH were measured once a day. Every second day, ammonium nitrogen (N-NH₄⁺), nitrogen dioxide (N-NO_2-) and chloride (Cl-) were determined.

Table 3. Length-weight and condition indices of common carp used in this study (mean ± SD, n = 12).

	Group
Parameter	C	B-2.5	B-5	B-10
Total length, mm	207.08 ± 11.91^a	207.92 ± 10.95^a	213.31 ± 9.88^b	212.43 ± 20.20^b
Body weight, g	128.96 ± 28.40^a	128.71 ± 23.11^a	135.88 ± 20.36^a	135.89 ± 49.60^a
Fulton’s condition factor	2.89 ± 0.21^a	2.83 ± 0.23^a	2.79 ± 0.18^a	2.73 ± 0.18^b
Clark’s condition factor	2.54 ± 0.21^a	2.51 ± 0.19^a	2.46 ± 0.17^a	2.42 ± 0.15^b
Hepatosomatic index, %	1.71 ± 0.34	1.75 ± 0.45	1.74 ± 0.39	1.78 ± 0.77
Viscerosomatic index, %	11.96 ± 2.26	11.44 ± 1.71	11.67 ± 2.00	11.12 ± 1.59
Splenosomatic index, %	0.15 ± 0.03	0.14 ± 0.03	0.16 ± 0.09	0.16 ± 0.04
Gonadosomatic index, %	3.62 ± 2.97	2.33 ± 1.83	3.57 ± 2.92	2.78 ± 1.90
Widebackedness index, %	17.77 ± 0.80^a	17.48 ± 0.61^a	17.31 ± 0.65^a	17.14 ± 0.84^b
Highbackedness index, %	2.95 ± 0.13	2.98 ± 0.14	3.02 ± 0.15	3.02 ± 0.15

Notes: Significant differences (p < .05; one-way ANOVA with Tukey post-hoc tests) indicated by different superscript letters. Note that the same superscript letter (^a) across all experimental diets indicates that, while there was a significant effect in the treatment overall, we were unable to distinguish between diets.

Table 4. Production parameters for the common carp used in this study (mean ± SD, n = 3).

	Group
Parameter	C	B-2.5	B-5	B-10
Feed conversion ratio (FCR)	2.45 ± 0.07	2.40 ± 0.03	2.31 ± 0.08	2.34 ± 0.04
Specific growth rate (SGR), %.d^−1	1.10 ± 0.03	1.11 ± 0.03	1.17 ± 0.04	1.14 ± 0.01
FCR/SGR	2.23 ± 0.13	2.17 ± 0.08	1.97 ± 0.13	2.05 ± 0.04
Weight gain, %	114.24 ± 4.88	115.25 ± 4.40	124.36 ± 5.95	117.32 ± 3.75
Protein efficiency ratio	1.89 ± 0.05	1.91 ± 0.02	1.97 ± 0.07	1.95 ± 0.03
Lipid retained, %	229.00 ± 4.17	222.88 ± 29.88	213.07 ± 47.94	182.32 ± 38.11
Apparent net protein utilisation, %	31.48 ± 3.74	32.68 ± 3.77	36.73 ± 5.45	37.03 ± 1.52
Fat in muscle, %	4.23 ± 0.75	4.16 ± 0.58	4.68 ± 0.91	4.49 ± 1.11
Ash in muscle, %	1.20 ± 0.10	1.22 ± 0.06	1.26 ± 0.08	1.34 ± 0.15
Nitrogenous matter in fat, %	18.67 ± 1.20	18.68 ± 0.87	19.60 ± 1.34	19.04 ± 0.88
Fat in liver, %	15.11 ± 1.49	16.27 ± 0.28	14.58 ± 0.57	12.26 ± 3.14
Fat in viscera, % (except liver)	12.49 ± 1.18	12.38 ± 1.72	11.85 ± 3.45	10.83 ± 2.38

Note: No statistically significant difference was demonstrated in the parameters.

Table 5. Haematological parameters for the common carp used in this study (mean ± SD, n = 12).

	Group
Parameter	C	B-2.5	B-5	B-10
Haematocrit, g.L^−1	0.34 ± 0.02	0.35 ± 0.03	0.35 ± 0.03	0.35 ± 0.03
Haemoglobin, g.L^−1	101.63 ± 7.41	101.00 ± 7.68	106.62 ± 7.93	105.57 ± 11.45
MCHC, g.L^−1	0.30 ± 0.02	0.29 ± 0.02	0.30 ± 0.02	0.30 ± 0.03
Number of erythrocytes, T.L^−1	1.58 ± 0.17^a,b	1.51 ± 0.18^a	1.98 ± 0.34^b,c	1.52 ± 0.27^a
Number of leukocytes, G.L^−1	44.81 ± 12.64	41.90 ± 12.54	38.48 ± 9.90	38.00 ± 9.33
MCV, fl	220.41 ± 24.25	233.68 ± 35.65	182.87 ± 39.87	234.62 ± 42.98
MCH, pg	65.17 ± 9.15	67.66 ± 9.57	55.43 ± 11.37	71.10 ± 13.16

Notes: MCHC: mean corpuscular haemoglobin concentration; MCV: mean corpuscular volume; MCH: mean corpuscular haemoglobin. Significant differences (p < .05; one-way ANOVA with Tukey post-hoc tests) indicated by different superscript letters. No statistically significant difference was demonstrated in the parameters.

Table 6. Biochemical parameters for the common carp used in this study (mean ± SD, n = 7).

	Group
Parameter	C	B-2.5	B-5	B-10
ALB, g.L^−1	7.39 ± 1.63	6.84 ± 1.59	7.77 ± 1.28	6.23 ± 1.64
ALP, µkat.L^−1	1.20 ± 0.42	1.51 ± 0.43	1.30 ± 0.48	1.47 ± 0.56
ALT, µkat.L^−1	0.14 ± 0.05	0.13 ± 0.02	0.15 ± 0.03	0.15 ± 0.05
AST, µkat.L^−1	2.29 ± 0.72	2.49 ± 0.81	2.27 ± 0.74	2.23 ± 1.02
Ca, mmol.L^−1	2.46 ± 0.21	2.33 ± 0.17	2.48 ± 0.23	2.52 ± 0.27
CHOL, mmol.L^−1	3.91 ± 0.60	3.94 ± 0.54	3.82 ± 0.96	4.24 ± 0.66
CREA, µmol.L^−1	13.33 ± 10.30	12.41 ± 3.80	11.52 ± 4.18	9.93 ± 3.59
GLUC, mmol.L^−1	4.53 ± 0.69	3.60 ± 0.60	4.73 ± 0.80	4.01 ± 1.12
LDH, µkat.L^−1	15.04 ± 15.01	12.01 ± 8.75	12.67 ± 12.17	17.51 ± 19.86
Mg, mmol.L^−1	1.06 ± 0.14	1.00 ± 0.12	1.08 ± 0.10	1.14 ± 0.14
PI, mmol.L^−1	1.81 ± 0.38	1.80 ± 0.32	2.07 ± 0.32	2.26 ± 0.53
TP, g.L^−1	29.93 ± 2.12	28.30 ± 2.15	29.08 ± 2.64	27.90 ± 2.51
TAG, mmol.L^−1	4.53 ± 1.23	3.91 ± 1.06	3.92 ± 0.82	4.57 ± 1.92
UREA, mmol.L^−1	2.26 ± 0.50	2.19 ± 0.43	2.07 ± 0.37	2.05 ± 0.49

Note: ALB: albumin; ALP: alkaline phosphatase; ALT: alanine aminotransferase; AST: aspartate aminotransferase; Ca: calcium; CHOL: cholesterol; CREA: creatine; GLUC: glucose; LDH: lactate dehydrogenase; Mg: magnesium; PI: inorganic phosphorus; TP: total protein; TAG: triacylglycerol; UREA: urea. No statistically significant difference was demonstrated in the parameters.

Data availability statement

The data that support the findings of this study are available from the corresponding author, [LV], upon reasonable request.