Effect of genotype on performance, vitamin and carotenoid deposition, oxidative stability, fatty acid profile and sensory characteristics in cockerels housed on litter and in mobile boxes on pasture

Figures & data

Table 1. Composition of chicken diets.

Ingredient, g/kg	Starter	Grower–finisher
Wheat	451.5	576.3
Maize	150.0	80.0
Soybean meal	310.5	268.5
Fish meal	10.0	–
Monocalcium phosphate	8.8	6.3
Limestone	14.4	11.2
Sodium chloride	2.8	2.5
Soybean oil	34.1	10.0
Animal fat	–	29.3
Sodium sulphate	1.1	1.2
Amino acid premix	8.0	7.7
Vitamin–mineral premix	8.8	7.0

Table 2. Analysed nutrient content of the diets and freeze-dried pasture.

Nutrient	Starter	Grower–finisher	Freeze-dried pasture herbage
Dry matter, g/kg	904.3	903.4	948.4
Crude protein, g/kg	216.1	197.0	159.6
Fat, g/kg	54.5	57.7	22.8
AME, by calculation MJ/kg	12.6	12.9	5.12
SFA, mg/100 g	1913	1941	375
MUFA, mg/100 g	2579	2616	281
PUFA, mg/100 g	5225	5673	1132
n6/n3	7.8	8.3	0.6
α-Tocopherol, mg/kg	43.2	41.9	63.5
γ-Tocopherol, mg/kg	31.5	29.0	13.2
Retinol, mg/kg	1.75	1.53	–
Zeaxanthin, mg/kg	0.59	0.62	83.2
Lutein, mg/kg	0.95	0.97	99.7

AME: apparent metabolisable energy; SFA: saturated fatty acids (caproic, caprylic, capric, lauric, tridecylic, myristic, pentadecylic, palmitic, margaric, stearic, arachidic, heneicosylic, behenic, tricosylic); MUFA: monounsaturated fatty acids (myristoleic, palmitoleic, oleic, vaccenic, 11-eicosenoic, erucic, nervonic); PUFA: polyunsaturated fatty acids (linoleic, γ-linolenic, α-linolenic, eicosadienoic, dihomo-linolenic, arachidonic, eicosatrienoic, eicosapentaenoic, docosapentaenoic, docosahexaenoic).

Table 3. Effect of housing system and genotype on performance characteristics.

	Litter			Mobile box			SEM	p Value
Housing (H) Genotype (G)	ISA Dual	Hubbard JA757	Ross 308	ISA Dual	Hubbard JA757	Ross 308		Housing	Genotype	H × G
Body weight, day 0, g	37.0	41.0	40.2	37.3	41.4	39.4	0.16	–	<.001	–
Body weight, day 14, g	187	327	460	191	324	449	5.3	–	<.001	–
Body weight, day 35, g	689^e	1457^c	2276^a	713^e	1332^d	2024^b	29.1	<.001	<.001	<.001
Body weight, day 42, g	898^c	2277^a	–	941^c	2093^b	–	27.9	<.001	<.001	<.001
Body weight, day 81, g	2286	–	–	2181	–	–	16.4	.001	–	–
F:G, g/g	2.15^b	1.62^d	1.36^f	2.26^a	1.70^c	1.51^e	0.021	<.001	<.001	<.001
Feed intake, g/day/bird	59.5	83.9	84.9	58.2	82.8	85.0	0.92	.325	<.001	.412
Mortality, %	1.3	5.2	2.6	6.5	2.6	3.9	0.04	.316	.221	.752
Average pasture herbage intake, g DM/day/bird				4.05^a	3.63^b	3.50^c	0.031	–	.001	–

SEM: standard error of the mean; F:G: feed:gain; DM: dry matter.

Means followed by different letters (^a–f) differ significantly.

Table 4. Effect of housing system and genotype on carcase characteristics.

Housing (H)	Litter			Mobile box			SEM	p Value
Genotype (G)	ISA Dual	Hubbard JA757	Ross 308	ISA Dual	Hubbard JA757	Ross 308		Housing	Genotype	H × G
Dressing percentage, %	72.4	75.3	75.0	70.2	72.9	73.4	0.30	<.001	<.001	.640
Breast yield, %	13.2^d	19.9^c	25.0^b	12.4^d	20.1^c	27.7^a	0.85	.174	<.001	.026
Leg yield, %	30.7	28.1	28.6	31.5	29.7	28.1	0.27	.136	<.001	.128
Breast muscle
Thickness, mm	17.7	25.0	31.5	16.5	23.6	32.0	0.94	.387	<.001	.523
Length, mm	172	167	159	163	157	155	1.7	.022	.041	.795

SEM: standard error of the mean.

Means followed by different letters (^a–d) differ significantly.

Table 5. Effect of housing system and genotype on nutrient, carotenoid and vitamin contents and oxidative stability of fat in breast muscle.

Housing (H)	Litter			Mobile box			SEM	p Value
Genotype (G)	ISA Dual	Hubbard JA757	Ross 308	ISA Dual	Hubbard JA757	Ross 308		Housing	Genotype	H × G
Dry matter, g/kg	265^a	258^b	253^c	260^ab	264^a	260^ab	0.9	.084	.005	.006
Fat, g/kg DM	23.2^c	28.9^c	67.3^a	24.3^c	26.0^c	43.9^b	2.6	.007	<.001	.001
Protein, g/kg DM	889	884	839	888	882	856	3.3	.455	<.001	.083
Ash, g/kg DM	42.0	45.1	45.2	40.8	42.7	45.0	0.34	.032	<.001	.246
Lutein, mg/kg	0.101^c	0.094^c	0.109^c	0.147^a	0.134^b	0.137^b	0.0046	<.001	.001	.043
Zeaxanthin, mg/kg	0.061	0.063	0.067	0.100	0.091	0.096	0.0035	<.001	.001	.642
α-Tocopherol, mg/kg	4.91^e	5.26^e	5.45^d	6.21^b	6.01^c	6.47^a	0.195	.002	<.001	.024
γ-Tocopherol, mg/kg	0.813	0.864	1.065	1.108	0.976	1.233	0.0493	.746	<.001	.747
Retinol, mg/kg	0.044	0.040	0.050	0.054	0.052	0.056	0.0023	.010	.015	.327
MDA, day 0, mg/kg	0.334	0.329	0.364	0.292	0.249	0.278	0.0090	<.001	.197	.440
MDA, day 5, mg/kg	0.551^a	0.449^b	0.383^bc	0.315^c	0.340^c	0.393^bc	0.0162	<.001	.260	.001

SEM: standard error of the mean; DM: dry matter; MDA: malondialdehyde.

Means with different superscripts (^a–c) differ significantly.

Table 6. Effect of housing system and genotype on composition and indices of fatty acids and cholesterol content in breast muscle.

Housing (H)	Litter			Mobile box			SEM	p Value
Genotype (G)	ISA Dual	Hubbard JA757	Ross 308	ISA Dual	Hubbard JA757	Ross 308		Housing	Genotype	H × G
SFA, %	36.1^c	38.8^b	40.7^a	35.8^c	36.2^c	38.0^b	6.6	<.001	<.001	<.001
MUFA, %	22.0^e	23.4^a	23.1^b	22.9^c	22.2^e	22.5^d	8.96	<.001	<.001	<.001
PUFA, %	41.9^a	37.8^c	36.2^d	41.3^a	41.6^a	39.5^b	11.3	<.001	<.001	<.001
n6/n3	6.92^c	7.16^b	7.55^a	6.12^d	6.86^c	7.23^b	0.120	.011	<.001	.045
AI	0.403^c	0.428^b	0.460^a	0.369^d	0.379^d	0.392^c	0.0077	<.001	<.001	<.001
TI	0.789^c	0.834^b	0.911^a	0.738^e	0.752^d	0.791^c	0.0145	.301	<.001	<.001
h/H	2.39^b	2.06^c	1.75^e	2.61^a	2.46^b	1.92^d	0.055	.001	<.001	<.001
Cholesterol, mg/kg	507^ab	362^c	564^a	495^b	461^b	508^ab	12.1	.506	<.001	.002

SEM: standard error of the mean; SFA: saturated fatty acids; MUFA: monounsaturated fatty acids; PUFA: polyunsaturated fatty acids; AI: atherogenic index; TI: thrombogenic index; h/H: hypocholesterolaemic/hypercholesterolaemic fatty acid ratio.

Means with different superscripts (^a–e) differ significantly.

Table 7. Effect of housing system and genotype on sensory analysis of breast muscle.

Housing (H)	Litter			Mobile box			SEM	p Value
Genotype (G)	ISA Dual	Hubbard JA757	Ross 308	ISA Dual	Hubbard JA757	Ross 308		Housing	Genotype	H × G
Odour	5.46	5.45	4.81	5.39	5.26	4.80	0.094	.013	.625	.928
Tenderness	4.46^d	5.80^c	7.66^a	4.65^d	4.91^d	7.05^b	0.096	<.001	.005	.015
Juiciness	4.40	4.86	6.18	4.32	4.50	6.18	0.086	<.001	.032	.606
Flavour	5.51	5.75	5.75	5.64	5.41	5.43	0.089	.998	.314	.481
Total acceptability	5.10	5.38	6.03	5.29	5.23	5.76	0.084	.001	.650	.513

Means with different superscripts (^a–d) differ significantly; SEM: standard error of the mean.

Data availability statement

The original data of the paper are available upon request from the corresponding author.