The effects of dietary essential fatty acid ratios and linoleic acid level in grow–finish pigs

Abstract

The objective of this study was to investigate the effects of dietary linoleic acid level and the ratio of linoleic acid:linolenic acid (LA:ALA) on the growth performance, expression of genes associated with lipid metabolism and inflammatory status of grow-finish pigs. A total of 300 growing pigs (BW = 41.1 ±6.3 kg) were randomly assigned to either a high (30 g/kg; HLA) or low (15 g/kg; LLA) dietary linoleic acid level with a high (23:1; HR), moderate (13:1; MR) or low (4:1; LR) dietary LA:ALA in a 2 × 3 factorial design. Diets were fed across three 28-day phases and were balanced for dietary metabolizable energy. Pigs were housed 5 pigs per pen in single-sex pens. Blood samples were collected on d 0, 21, 42, and 84, and synovial fluid was collected from the hock joint on d 0 and 84 for inflammatory marker analysis. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with initial body weight as a covariate, pen as the experimental unit, and LA level, LA:ALA, sex, phases, and their interactions as fixed effects. Compared to HLA, LLA pigs tended to have increased BW at d 56 and d 84 (P = 0.088). There was no effect of LA × LA:ALA for growth performance. For the overall d 0 – 84 growth period, pigs fed HR had increased ADG compared to MR, with pigs receiving LR performing intermediate of MR and HR. Gilts receiving HR diets had increased d 84 BW compared to gilts receiving the low and moderate LA:ALA (P = 0.006), which was a result of improved overall d 0 – 84 ADG compared to gilts receiving the MR diets (P = 0.023). Barrows fed LR had improved BW on d 56 compared to MR and HR and higher final BW compared to HR, with MR performing intermediately (P = 0.006). This was a result of greater d 0 – 84 ADG (P = 0.023). Overall, C-reactive protein (CRP), tumor necrosis factor-α(TNFα), and interleukin-6 (IL-6) were reduced in the plasma of pigs over time (P ≤ 0.037). Across all treatments, CRP and TNFαwere reduced in the hock and carpus synovial fluid on d 84 vs. d 0 (P ≤ 0.049). In conclusion, LA:ALA ratios utilized in this study can be fed at varying linoleic acid levels without impacting growth or inflammation. Additionally, LA:ALA ratios can differentially impact the growth of gilts and barrows.

Effects of Dietary Eucommia ulmoides Leaf Extract Supplementation on Growth Performance, Meat Quality, Antioxidant Capacity, and Lipid Metabolism of Finishing Pigs

“…C18:1cis-9 and C20:1 are considered to help reduce the level of LDL (“bad” cholesterol) [ 73 ], and the increase in its content has a positive effect on the cardiovascular health of consumers [ 74 ]. Linoleic acid (LA; 18:2n-6) and α-linoleic acid (ALA; 18:3n-3) must be obtained from the diet [ 75 ]. They are precursors of n-6 and n-3 PUFA, which can be converted into fatty acids such as C18:2n-6, C18:3n-6, C20:3n-6, and C20:4n-6 in the body.…”