Effects of Polyunsaturated Fatty Acids Supplementation on The Meat Quality of Pigs: A Meta-Analysis

Abstract

Background: Polyunsaturated fatty acids (PUFAs) supplementation has been widely discussed as a strategy for improving meat quality in pig production but the effects are inconsistent. This meta-analysis was performed to comprehensively evaluate its effects on the meat quality including intramuscular fat (IMF) content, drip loss, meat color, pH 45min and pH 24h of pigs.Methods: We searched the PubMed and Web of Science databases (articles published from Jan 1st, 2000, and Oct 16th, 2020) and compared PUFAs-supplemented diets with control diets. We identified 1670 studies, of which 14 (with data for 752 pigs) were included in our meta-analysis. We used a random-effects model and a fixed-effects model to calculate the weighted mean differences (WMDs) and 95% confidence intervals (CIs). We used sensitivity and subgroup analysis to ensure the pooled estimates are robust. The subgroup analysis was classified as treatment (conjugated linoleic acid (CLA) or linseed), concentration (high or low concentration) and initial stage (growing and finishing pigs).Results: Our analysis found that PUFAs supplementation increased the IMF content (WMD= 0.467%, 95% CI: 0.312 to 0.621, P<0.001), decreased the meat color L* (WMD= -0.636, 95% CI: -1.225 to -0.047, P=0.034) and pH 24h (WMD= -0.021,95% CI: -0.032 to -0.009, P<0.001). CLA supplementation improved IMF content (WMD= 0.542%, 95% CI: 0.343 to 0.741, P<0.001) and reduced meat color b* (WMD= -0.194, 95% CI: -0.344 to -0.044, P=0.011). Linseed supplementation increased IMF content (WMD= 0.307%, 95% CI: 0.047 to 0.566, P=0.021), decreased meat color L*(WMD= -1.740, 95% CI: -3.267 to -0.213, P=0.026) and pH 24h (WMD= -0.034, 95% CI: -0.049 to -0.018, P<0.001). We discovered an increase on IMF content in both high and low concentration PUFAs supplementation (WMD= 0.461%, 95% CI: -0.344 to -0.044, P<0.001; WMD= 0.456%, 95% CI: 0.276 to 0.635, P<0.001). Besides, we also found the effects of PUFAs supplementation on meat color L* and pH 24h are concentration- and stage-dependent.Conclusions: PUFAs supplementation can improve meat quality of pigs which mainly emerge in greatly increasing IMF content.

CLA improves the lipo-nutritional quality of pork and regulates the gut microbiota in Heigai pigs

“…16 Previous studies and our meta-analysis have found that CLA could decrease the backfat thickness and regulate the meat quality in the lean breeds of pigs and Rongchang pigs. 6,17 In our study, we found that adding 1% CLA can decrease the backfat thickness by almost 14.6%, which is in agreement with previous studies. Researchers discovered that CLA regulated fat deposition by affecting adipocyte proliferation and differentiation 18 and inducing adipocyte apoptosis.…”

“…19 Our results showed neither pH 45 min below 5.5 nor pH 24 h above 6.4 in pigs, and there was no significant effect on growth performance parameters including ADG, ADFI, and the F : G ratio in pigs. Combined with our meta-analysis and previous studies, 6,20 CLA could decrease the backfat thickness and increase the IMF content in pork. These findings indicate that CLA may serve as a body fat regulator to regulate fat deposition and meat quality in pigs regardless of breed.…”

“…Based on our meta-analysis, which showed that the effective concentration for improving the meat quality was 0.25-5% and considering the cost of the feed, we chose 1% CLA addition. 6 A total of 56 Heigai finishing pigs (body weight: 85.58 ± 10.39 kg) were randomly divided into 2 treatment groups and fed with 2 types of diets (1% soyabean oil and 1% CLA, cis-9 and trans-11 (c9, t11) : trans-10 and cis-12 (t10, c12) = 1 : 1, 80%). The composition and nutritional levels of the diet are shown in Table S1.…”

“…Our meta-analysis and recent studies have found that CLA could influence the meat quality, especially the IMF content, in lean breeds of pigs and Rongchang pigs. 6,7 However, the effects of CLA on regulating the lipo-nutritional quality of pork remain unclear.…”

The chemistry of flavor formation in meat and meat products in response to different thermal and non‐thermal processing techniques: An overview

“…Polyunsaturated fatty acids (PUFA) supplementation has been shown to have beneficial effects on improving the meat quality of pigs. This is most apparent in increasing intramuscular fat (IMF) content in finishing pigs, regardless of breed (Wang et al, 2021).…”