Dietary conjugated linoleic acid (CLA) has comparable effects to ractopamine on the growth performance, meat quality and fatty acid profiles of loin muscles of finishing pigs under commercial husbandry

Figures & data

Table 1. Diet composition on a dry basis, finishing pigs (kg ton⁻¹).

	Treatments^g
	RAC	CLA 0.5%	CLA 1.0%
Ingredients
	Wheat 12% crude protein	835.750	836.700	836.700
Soybean meal 47% crude protein	124.000	124.000	124.000
Mixed fatty acids	20.000
Soybean oil	0.000	14.300	9.300
CLA-Lutalin™^a	0.000	5.000	10.000
Mic. End LP^b	20.000	20.000	20.000
Ractopamine Hydrochloride^c	0.250	0.000	0.000
Analysis calculated
Metabolizable energy (MCal/kg)	3341	3341	3341
Protein (%)	16.580	16.580	16.580
Fat (%)	3.660	3.660	3.660
Lysine (%)	0.947	0.947	0.947
Fibre (%)	2.336	2.336	2.336
Total phosphorus (%)	0.442	0.442	0.442
Calcium (%)	0.474	0.474	0.474
Analysis
Protein (%)	15.040	15.060	14.840
Ether fat (%)	3.090	3.450	3.880
Fatty acid composition (mg^−1/100 mg total FA)
SFA^d	22.980	17.580	18.190
C14:0	1.140	0.070	0.190
C16:0	16.510	13.980	13.740
C18:0	4.390	3.520	4.060
MUFA^e	32.190	24.090	26.410
C18:1, c9	28.560	24.090	25.850
PUFA^f	44.830	58.330	55.400
C18:2, n-6	1.590	1.280	1.230
C18:2, n-6	39.210	48.140	44.030
C18:3, n-3	3.510	5.090	4.300
Conjugated linoleic acid	0.000	2.960	5.830

^a Lutalin™ BASF, composed of 30% cis-9, trans-11 isomer and 30% trans-10, cis-12 isomer.

^b Premix of minerals and vitamins.

^c Racmina2% ®, 2 g ractopamine hydrochloride in 100 g c.b.p PISA, Agropecuaria, México.

^d SFA: Saturated fatty acids.

^e Monounsaturated fatty acids.

^f Polyunsaturated fatty acids.

^g Treatments: RAC, animals receiving a diet with ractopamine (control group); CLA 0.5%, animals supplemented with 0.5% of conjugated linoleic acid; CLA 1%, animals supplemented with 1% of conjugated linoleic acid.

Table 2. Productive performance of gilts and barrows supplemented with CLA for 30 d.

	Gilts			Barrows				p Value^e
Treatments^d	RAC	CLA 0.5%	CLA 1%	RAC	CLA 0.5%	CLA 1%	SEM^f	Sex	Treat	Sex × Treat
Variable^g
IBW, kg	73.300	71.400	71.700	78.400	72.500	77.600	1.100	.170	.370	−
FBW, kg	101.200^a	104.300bc	102.600^a	106.400^c	105.100^bc	106.300^c	0.920	<.001	.602	.049
ADG, kg	0.899^a	1.005^b	0.949^ab	1.070^c	1.030^bc	1.070^c	0.030	<.001	.590	.040
Feed intake, kg	2.500^a	2.460^a	2.600^b	2.500^a	2.450^a	2.610^b	0.200	.605	<.001	.931
Feed conversión, kg	2.750	2.390	2.690	2.430	2.360	2.490	0.080	.093	.085	.328

^abc Means with different superscripts within the row are different (p < .05).

^d Treatments: RAC, animals receiving a diet with ractopamine (control group); CLA 0.5%, animals supplemented with 0.5% of conjugated linoleic acid; CLA 1%, animals supplemented with 1% of conjugated linoleic acid.

^e Probability values: Sex (Sex), treatment (Treat), and interaction (Sex × Treat) effects.

^f SEM: Standard error of the mean.

^g Variables, IBW: initial body weight; FBW: final body weight; ADG: average daily gain.

Table 3. Meat quality of longissimus thoracis (LT) muscle from pigs supplemented with RAC and CLA for 30 d.

	Treatments^c
Variable	RAC	CLA 0.5	CLA 1%	SEM^d	p value
pH	5.950	5.760	5.770	0.120	.340
Lightness (L*)	55.370	51.570	55.670	1.820	.190
Redness (a*)	9.230	7.760	8.960	0.670	.130
Yellowness (b*)	8.780	7.640	9.460	0.780	.100
Hue angle^e	43.970	44.010	46.600	2.850	.740
Cooking loss %	13.890	18.150	17.040	2.290	.620
WBSF, kg^f	7.180	7.070	6.270	0.570	.560
TBARS value^g	0.288	0.324	0.208	0.150	.470
MetMb^h	47.330	50.860	48.450	3.010	.800

^ab Means with different superscripts within a row are different (p ≤ .05).

^c Treatments: RAC: animals receiving a diet with ractopamine (control group); CLA 0.5%, animals supplemented with 0.5% of conjugated linoleic acid; CLA 1%, animals supplemented with 1% of conjugated linoleic acid.

^d Standard error of mean.

^e Hue = tan⁻¹ (b*/a*)×57.29.

^f WBSF: Warner Bratzler shear force.

^g TBARS: Thiobarbituric acid reactive substances.

^h MetMb: Metmyoglobin.

Table 4. Effect of dietary CLA on colour parameters of pork meat during 15 d of storage at 4 °C.

		Treatments^c
Colour value	Days	RAC	CLA 0.5%	CLA 1%	SEM^d
Lightness, L*	1	55.37	51.57	55.67	1.05
	5	53.36	52.51	54.26	1.22
	10	54.71	55.07	57.01	1.36
	15	53.96	54.27	55.94	1.24
Redness, a*	1	9.22	7.75	8.96	0.63
	5	6.73	5.49	7.15	0.67
	10	5.68	5.34	5.41	0.54
	15	3.77	3.82	4.54	0.66
Yellowness, b*	1	8.72	7.63	9.46	0.78
	5	7.90	7.47	8.84	0.73
	10	7.21	7.26	7.64	0.69
	15	6.62	6.44	7.71	0.78
Hue Angle	1	43.97	44.0	46.60	2.85
	5	49.34	53.45	50.57	2.56
	10	51.53	53.90	54.59	2.86
	15	60.81	59.28	59.69	2.84

^ab Means with different superscripts within a row are different (p ≤ .05).

^c Treatments: RAC: animals receiving diet with ractopamine (control group); CLA 0.5%, animals supplemented with 0.5% of conjugated linoleic acid; CLA 1%, animals supplemented with 1% of conjugated linoleic acid.

^d Standard error of mean.

Table 5. Effect of dietary CLA on lipid oxidation (TBARS) and metmyoglobin (MetMb) of pork meat during 15 d of storage at 4 °C.

		Treatments^c
Variable	Days	RAC	CLA 0.5%	CLA 1%	SEM^d
TBARS^e, mg/kg	1	0.28	0.32	0.20	0.15
	5	0.30	0.38	0.38	0.13
	10	0.40	0.50	0.61	0.14
	15	1.45^b	1.46^b	0.94^a	0.13
MetMB, %	1	47.33	50.85	48.84	3.01
	5	61.03	60.82	58.45	2.77
	10	68.14	63.28	66.62	3.15
	15	56.41	61.49	64.95	3.02

^ab Means with different superscripts within a row are different (p ≤ .05).

^c Treatments: RAC: animals receiving diet with ractopamine (control group); CLA 0.5%, animals supplemented with 0.5% of conjugated linoleic acid; CLA 1%, animals supplemented with 1% of conjugated linoleic acid.

^d Standard error of the mean.

^e Thiobarbituric acid-reactive substances, mg malondialdehyde/kg tissue.

Table 6. Intramuscular fat (g⁻¹/100 g tissue), fatty acid profile (% of total fatty acid methyl esters) and CLA content (mg⁻¹/100 g tissue) of longissimus thoracis (LT) muscle from pigs supplemented with CLA.

	Treatments^d
Fatty acids	RAC	CLA 0.5%	CLA 1%	SEM^e	p value
SFA^f
C14:0	1.480	1.410	1.500	0.130	.900
C16:0	25.360^a	25.640^a	27.820^b	0.360	.001
C17:0	0.380	0.320	0.800	0.330	.550
C18:0	10.600	12.560	13.190	0.820	.090
C20:0	0.120	0.170	0.120	0.020	.290
C21:0	0.130	0.190	0.320	0.060	.100
C22:0	0.100	0.100	0.080	0.020	.660
C23:0	1.590^a	1.620^a	0.690^b	0.160	.001
MUFA^g
C16:1	3.790	3.350	3.920	0.380	.560
C17:1 c10	0.450	0.410	0.280	0.040	.070
C18:1	45.470^a	43.120^ab	42.620^b	0.670	.020
C20:1c11	0.220	0.440	0.390	0.090	.200
C22:1 n-9	0.250^b	0.180^ab	0.080^a	0.030	.020
PUFA^h
C18:2 n-6	8.000^ab	8.340^a	6.060^b	0.640	.040
C18:2 n-6	0.080	0.010	0.350	0.110	.250
C18:2 c9, t11, CLA	0.031^a	0.146^b	0.211^c	0.011	<.001
C18:2 t10, c12, CLA	0.012^a	0.051^b	0.092^c	0.007	<.001
C18:3 n-3	0.770	0.400	0.320	0.110	.220
C20:2 c11, 14	0.280	0.270	0.190	0.120	.400
C20:3 n-6	0.800	0.120	0.100	0.020	.180
C20:5 n-3	0.130^ab	0.140^a	0.060^b	0.010	.001
C22:6 n-3	0.090^ab	0.190^a	0.060^b	0.020	.001

^abc Means with different superscripts within row are different (p ≤ .05).

^d Treatments: RAC: animals receiving diet with ractopamine (control group); CLA 0.5%, animals supplemented with 0.5% of conjugated linoleic acid; CLA 1%, animals supplemented with 1% of conjugated linoleic acid.

^e Standard error of mean.

^f Saturated fatty acids.

^g Monounsaturated fatty acids.

^h Polyunsatured fatty acids.

Table 7. Partial sums of fatty acids and nutritional value of the intramuscular fat of the longissimus thoracis muscle per treatment.

		Treatments^d
	RAC	CLA 0.5%	CLA 1%	SEM^e	p value
Partial sums
Σ SFA	40.000^a	42.720^ab	45.330^b	0.760	.001
Σ MUFA	50.270^b	47.610^a	47.370^a	0.840	.040
Σ PUFA	9.610^b	9.610^b	7.250^a	0.700	.010
Σ n-3	1.000^b	0.740^ab	0.450^a	0.100	.001
Σ n-6	8.300	8.580	6.590	0.660	.090
Ratios
MUFA/SFA	1.270^b	1.110^ab	1.040^a	0.040	.006
PUFA/SFA	0.240^b	0.220^ab	0.160^a	0.010	.010
n-6/n-3	9.430^a	12.810^b	16.470^c	1.730	.030

^abc Means with different superscript within a row are different (p ≤ .05).

^d Treatments: RAC: Animals receiving diet with ractopamine (control group); CLA 0.5%, animals supplemented with 0.5% of conjugated linoleic acid; CLA 1%, animals supplemented with 1% of conjugated linoleic acid.

^e Standard error of mean.