The effect of fish oil, lycopene and organic selenium as feed additives on rabbit meat quality

Figures & data

Table 1. Division of experimental groups^a due to the way of feeding, chemical composition the basal diet (BD), highly selenized yeast (SeY), sunflower oil (SO) and odourless fish oil (OR).

Control group		Experimental groups
Control	Group FO	Group FOLyc	Group FOSe	Group FOLycSe
BD	BD	BD	BD	BD
4% SO	4% FO	4% FO	4% FO	4% FO
–	–	15 ppm Lyc^b	–	15 ppm Lyc^b
–	–	–	0.25 ppm Se as SeY	0.25 ppm Se as SeY
Ingredients (g/kg BD)		The basal diet (BD)
Post-extraction soya middings		100
Wheat bran		186
Barley middings		250
Dried alfalfa		230
PreLak milk replacer		20
NaCl		4
Feed phosphate		10
Vitamins and mineral premix^b		10
Composition of highly selenized yeast (SeY)
Total Se, mg Se/g dry mass SeY		1.8
Identified Se species, % of total Se		88.3
Se-methionine, % of total Se		83.0
Se-cysteine, % of total Se		5.0
Sodium selenite, % of total Se		0.3
		Sunflower oil (SO):
The energy content: 37.0 MJ kg^−1 The iodine value: 119–135 g/100 g SO The acid value: 1.3 mg KOH/g SO		The fatty acid composition (%): C12:0 ∼0.05, C14:0 ∼1.9, C16:0 5.4, C16:1 0.3, C17:0 0.2, C17:1 ∼0.03, C18:0 2.7, cis9C18:1 (c9C18:1) 39.1, c9c12C18:2 48.3, c9c12c15C18:3 0.3, C20:0 0.25, C20:1 0.14, C22:0 0.9, C22:1 0.15, C22:2 ∼0.05, C24:0 0.25 and C24:1 ∼0.27.
		Odourless fish oil (FO):
The energy content: 36.8 MJ kg^−1 The iodine value: 50–65 g/100 g FO The acid value: 20 mg KOH/g FO		The fatty acid composition (%): C12:0 0.01, C14:0 1.23, c9 C14:1 0.02, C15:0 0.047, C16:0 5.69, c7C16:1 0.03, c9C16:1 0.04, ΣC16:2 1.55, C17:0 0.04, c9C17:1 0.02, C18:0 0.9452, c6C18:1 0.02, c7C18:1 0.08, c9C18:1 29.06, c12C18:1 1.58, c14C18:1 0.02, c9c12C18:2 11.45, c9c12c15C18:3 2.10, c11C20:1 2.42, c7c9c12c15C18:4 0.04, c11c14C20:2 0.24, c8c11c14C20:3 0.03, c5c8c11c14C20:4 0.03, c8c11c14c17C20:4 0.06, C22:0 0.014, c13C22:1 1.11, c11C22:1 0.17, c5c8c11c14c17C20:5 0.69, c13c16C22:2 0.01, c7c10c13c16C22:4 0.11, c15C24:1 0.04, c7c10c13c16c19C22:5 0.20 and c7c10c13c16c19C22:6 2.67.

^a Experiments were carried out on 50 New Zealand White rabbits (25 males (♂) and 25 females (♀)) with an average initial body weight of 0.858 ± 0.087 kg at 35 days of age.

^b Lycopene.

^c 1 kg of vitamins and mineral premix (provided by LNB Sp. z.o.o. Kiszowo, Poland) comprised: vitamins A as E672-retinol (10,00,000 IU), D₃ as E671-cholecalciferol (1,50,000 IU), E as Dl-α- tocopherol (2 727 mg), K₃ as menadione (52 mg), B₁ (50 mg), B₂ (400 mg), B₃ (2000mg), B₅ (786 mg), B₆ as pyridoxine hydrochloride (50 mg), B₁₂ (1500 mcg), biotin (10,000 mcg), choline chloride (12,500 mg), folic acid (57 mg), trace elements (Fe – 5000 mg, Mn – 7500 mg, Cu – 750 mg, Zn – 5000 mg, I – 100 mg, Co – 100 mg, Se – 20 mg); vitamin-mineral premix carrier: calcium carbonate containing 22.2% Ca. The BD without vitamins and mineral premix contains 0.05 ppm Se.

Table 2. Comparison of average feed intake, feed conversion ratio (FCR), body weight gain (BWG) of rabbits and longissimus thoracis muscle mass of the studied groups of rabbits (♀ = 5; ♂ = 5; Σ(♀ and ♂) = 10) at 90 days of life (i.e. after 55 days of experiments on rabbits).

		Control group	Experimental groups				SEM	P
		Control	FO	FOLyc	FOSe	FOLycSe
Average feed intake by the rabbit per day [g/day]	♀	70.1 a	90.8 b	92.8 b	78.7 ab	85.4 ab	4.16	0.05
	♂	74.1 a	75.8 a	91.7 b	74.2 a	84.5 ab	3.49	0.05
	Σ(♀ and ♂)	72.1 a	83.3 ab	92.2 b	76.4 a	84.9 ab	3.50	0.05
FCR (feed intake [kg] per kg of BWG of rabbits) FCR	♀	2.77 a	3.31 b	3.46 b	3.77 b	3.35 b	0.16	0.05
	♂	2.98 a	2.85 a	3.27 b	3.38 b	3.05 ab	0.10	0.05
	Σ(♀ and ♂)	2.88 a	3.08 ab	3.37 b	3.58 b	3.20 ab	0.12	0.05
	♀	1.378 b	1.534 b	1.501 b	1.166 a	1.423 b	0.06	0.05
Average BWG, [kg]^a	♂	1.356 ab	1.490 b	1.569 b	1.226	1.549 b	0.06	0.05
	Σ(♀ and ♂)	1.367 ab	1.512 b	1.535 b	a1.196 a	1.486 b	0.06	0.05
Average longissimus thoracis	♀	119.6	138.2	127.0	125.0	119.8	3.39	NS
muscle mass [g]	♂	127.0	141.5	136.3	127.2	140.3	3.12	NS
	Σ(♀ and ♂)	123.3	139.9	131.7	126.1	130.1	2.83	NS

^a The average body mass gain = (BW_{90 days} – BW_{35 days}); BW_{35 days} – the body weight of rabbits at 35 d of age; BW_{90 days} – the body weight of rabbits at 90 days of age; NS – non-significant.

Table 3. The concentration sums (mg/g) of saturated fatty acids (ΣSFAs)^a, atherogenic^b (A^SFA) and thrombogenic^c (T^SFA) saturated fatty acids, monounsaturated fatty acids (ΣMUFAs)^d, polyunsaturated fatty acids (ΣPUFAs)^e, all assayed fatty acids (ΣFAs), Σn-3PUFAs (Σn-3), Σn-6PUFAs (Σn-6) and the ratio of Σn-6 to Σn-3 (Σn-6/Σn-3) in the longissimus thoracis muscle of rabbits.

Group	A^SFA	TSFA	ΣSFAs	ΣFAs	ΣMUFAs	ΣPUFAs	Σn-3	Σn-6	Σn-6/Σn-3
Control	5.55b	6.72b	6.96b	27.19a	3.49b	16.70 a	3.48a	12.31a	3.54b
FO	6.73b	8.95b	9.15bc	31.88b	3.63b	19.13 b	5.24ab	13.86a	2.64a
FOLyc	3.10a	3.93a	4.04ab	26.39a	1.87a	20.51 b	6.29ab	13.99a	2.22a
FOSe	2.09a	2.15a	2.53a	25.67a	1.63a	21.52 b	7.49b	13.58a	1.82a
FOLycSe	2.03a	4.96ab	6.01b	26.99a	1.47a	19.53 b	5.51ab	13.88a	2.52a
SEM	0.95	1.17	1.14	1.09	0.47	0.81	0.66	0.31	0.28
P	0.05	0.05	0.05	0.05	0.05	0.05	0.05	0.05	0.05

Note: Mean values in columns having the different superscripts are significantly different at a, b P < 0.05.

^a The sum of C8:0, C10:0, C12:0, C14:0, C16:0, C18:0, C20:0, C22:0 and C24:0.

^b A^SFA: C12:0 + C14:0 + C16:0.

^c T^SFA: C14:0 + C16:0 + C18:0.

^d The sum of c7C14:1, c9C14:1, c7C15:1, c9C16:1, c10C16:1, c9C17:1, c10C17:1, c6C18:1, c9C18:1, t11C18:1, c12C18:1, c11C20:1 and c13C22:1.

^e The sum of c9c12C18:2, c9t11CLA, t10c12CLA, c6c9c12C18:3, c9c12c15C18:3, c6c9c12c15C18:4, c11c14C20:2, c8c11c14C20:3, c11c14c17C20:3, c5c8c11c14C20:4, c8c11c14c17C20:4, c5c8c11c14c17C20:5, c7c10c13c16C22:4, c7c10c13c16c19C22:5, c4c7c10c13c16c19 C22:6 and c13c16C22:2.

Figure 1. Average concentration of malondialdehyde (MDA) in meat samples [mg/kg product] in the test groups (n = 10). a, b – means marked with different letters differ significantly at P < 0.05.

Figure 2. Comparison of sensory quality of odour notes of rabbit meat in the experimental groups (n = 50).

Table 4. Values of correlation coefficients (r) between the analyzed variables (n = 50).

Attribute	meat o.	sharp.o	fat o.	sour o	rancid o	other o.	overall quality
meat o.	1	−0.53*	−0.47	0.34	−0.62	−0.65	0.82
sharp.o		1	0.12	0.27	0.45	0.59	−0.75
fat o.			1	0	0.45	0.17	−0.39
sour o				1	0.37	0.28	−0.27
rancid o					1	0.56	−0.75
other o.						1	−0.74
overall quality							1

Note: o- odour.

*Correlation coefficients marked in bold are significant at the level of significance P < 0.05.