Table 2.

Characteristics of included studies^a.

Refernces	Country	Genetic background	PUFA source	Duration	Concentration	Basal diet	Energy differenceb	Nc	Sex	Growth stage	Growth performance parametersd	Outcomese
O'Quinn et al. (10)	American	PIC L326 or 327 boars × C22 sows	CLA 60	37.6–106.4 kg	50%	Corn-soybean	NA	24	Barrows	Growing-finishing pigs	ADG, ADFI, G:F ratio	Drip loss, meat color
Wiegand et al. (11)	American	NA	Conjugated linoleic acid	40–106 kg	0.75%	Corn-soybean	→	20	Barrows	Growing-finishing pigs	ADG, ADFI, G:F ratio	IMF, meat color
Joo et al. (12)	Korea	Landrace × Large White × Duroc	Conjugated linoleic acid	4 weeks	1%, 2.5%, 5%	NA	NA	20	Gilts	Finishing pigs	NA	IMF, drip loss, meat color, pH 24 h
Tischendorf et al. (13)	Germany	Pietrain × (Landrace × Large White)	Conjugated linoleic acid	8 weeks	2%	Barley-soybean	→	40	20 female and 20 male- castrated	Growing-finishing pigs	ADG, ADFI, G:F ratio	IMF, drip loss, meat color, pH 45 min, pH 24 h
Corino et al. (14)	Italy	Large White	Conjugated linoleic acid	97–172 kg	0.25%, 0.5%	Corn-soybean	→	36	18 barrows and 18 gilts	Finishing pigs	NA	meat color, pH 45 min, pH 24 h
Dugan et al. (15)	Canada	NA	Conjugated linoleic acid	35–115 kg	0.25%, 0.5%	Barley-soybean	→	108	NA	Growing-finishing pigs	NA	IMF, drip loss, meat color, pH 24 h
Sun et al. (16)	China	Duroc × Landrace × Large White	Conjugated linoleic acid	3, 6 weeks	2%, 4%	Corn-soybean	→	54	Crossbred barrows	Finishing pigs	ADG, ADFI, G:F ratio	IMF, drip loss
Luo et al. (17)	China	Landrace × NewDamLine	Linseed	30, 60, 90 days	10%	Corn-soybean	→	24	Barrows	Growing-finishing pigs	NA	IMF, drip loss, pH 45 min
Dannenberger et al. (18)	Germany	Landrace	High, reduced protein diet with linseed oil	60~100 kg to 120 kg	4.5%	Barley-soybean	↑	24	Male-castrated	Finishing pigs	ADG, ADFI, G:F ratio	IMF, drip loss, meat color, pH 45 min, pH 24 h
Huang et al. (19)	China	Rongchang pigs	Conjugated linoleic acid	30–60 kg, 60–90 kg	0.5%, 1%, 1.5%, 2%	Corn-soybean	→	160	NA	Growing-finishing pigs	NA	IMF, meat color, pH 45 min, pH 24 h
Deng et al. (20)	China	NA	Flaxseed	72 days	5%, 10%	Corn-soybean	→	72	NA	Growing-finishing pigs	ADG, ADFI, G:F ratio	IMF, drip loss, meat color, pH 45 min, pH 24 h
Nevrkla and Vaclavkova (21)	Czech Republic	(Large White × Landrace) × (Duroc × Pietrain)	Linseed	57 days	7%	Barley-soybean	↑	40	Gilts	Finishing pigs	NA	IMF, drip loss, pH 45 min, pH 24 h
Trombetta et al. (22)	Brazil	50% Large White ×50% Landrace	Linseed oil	90 days	3%	Corn-soybean	NA	22	10 castrated males and 12 females	Finishing pigs	ADG	IMF, drip loss, meat color, pH 24 h
Chang Hyun et al. (23)	Korea	Landrace × Yorkshire × Duroc	Linseed (n-6: n-3 PUFA ratio)	NA	1.5% (4:1), 3% (2:1)	Corn-soybean	→	108	NA	Finishing pigs	ADG, ADFI, G:F ratio	Drip loss, meat color, pH 45 min, pH 24 h

^aNA, not available.

^b↑, higher energy density in treatment group; →, similar energy density in treatment and control groups; ↓, lower energy density in treatment group.

^cNumber of pigs included in studies.

^dADG, average daily gain; ADFI, average daily feed intake; G: F ratio, gain: feed ratio.

^eIMF, intramuscular fat; pH 45 min, pH value measured at 45 min postmortem; pH 24 h, pH value measured at 24-h postmortem.