Effect of reducing the ratio of omega-6-to-omega-3 fatty acids in diets of low protein quality on nursery pig growth performance and immune response

Abstract

A total of 240 newly weaned pigs (5.25 ± 0.15 kg BW) were used to determine the dietary omega-6-to-omega-3 (ω-6:ω-3) fatty acid ratio that optimized growth performance and immune responses when fed corn and soybean meal (SBM)-based diets with low protein quality. Pigs were randomly assigned to 1 of 5 dietary treatments (n = 6 pens per treatment; day 0 of study): [1] positive control (High; included animal proteins and 5% corn oil), [2] negative control (Low0; corn- and SBM-based and 5% corn oil), or 1 of 3 Low diets with increasing supplementation of fish oil to replace corn oil: [3] 1.25% (Low1.25), [4] 2.5% (Low2.5), [5] 5% (Low5) to achieve 5:1, 3:1, and 1:1 ω-6:ω-3 ratios, respectively. Pigs were fed dietary treatments in 2 phases for 7 and 14 d, respectively, followed by a common phase III diet for 21 d. On day 6 and 20, 12 pigs per treatment were immune sensitized with 0.5 mg ovalbumin (OVA) and 0.5 mg Quil A adjuvant in 1 mL saline. The dermal hypersensitivity response (DHR) was evaluated on day 40 in these same pigs, using intradermal injection of OVA; changes in skin-fold thickness were measured. On day 21, 4 pigs per pen were immune challenged with LPS (30 µg Escherichia coli LPS per kg BW) or saline (n = 12); rectal temperature was monitored over 3 h. During phase I only, ADG, ADFI, and G:F were greater for pigs fed the High diet vs. those fed the Low diet (P < 0.05), and increased with increasing fish oil supplementation up to 2.5% (Low2.5), but decreased for pigs fed the Low5 diet (quadratic; P < 0.05, P = 0.086, and P < 0.05 for ADG, ADFI, and G:F, respectively). On day 21, LPS increased rectal temperature (vs. saline at 1-, 2-, and 3-h post-challenge; P < 0.001); fish oil supplementation reduced rectal temperature 2-h post-challenge in the Low-fed pigs (linear; P < 0.05). On day 22, serum haptoglobin was greatest for pigs fed Low0 and decreased with increasing fish oil supplementation (linear; P < 0.05). Immunization with OVA induced a serum anti-OVA IgG response, which was reduced on day 34 among pigs fed Low diets with increasing fish oil supplementation (linear; P = 0.050). On day 40, and 6 h after intradermal injection of OVA, the DHR was least for pigs fed the Low2.5 diet (P< 0.05). Inclusion of 2.5% fish oil (3:1, ω-6:ω-3) optimized growth performance during the early nursery phase when pigs were most sensitive to diets with low protein quality; the ideal ω-6-to-ω-3 fatty acid ratio may differ when using immune responses as the major outcome.

RNA-seq based SNP discovery in liver transcriptome of Polish Landrace pigs

“…Our results provide novel cSNP transcriptomic data (https://www.ncbi.nlm.nih.gov/sra) of Polish Landrace breed to explain the regulatory mechanisms of the liver tissue's biological response to increased concentration of PUFAs diets [22]. Related studies showed that consumption of PUFAs and other fatty acids diets were genetically regulated the growth performance and immune system in pigs [23]. Our mapping results identified a total of 25.3 million paired-end reads (13.5 million in high PUFAs and 11.8 million low PUFAs group) in the liver transcriptome of Polish Landrace pig, in comparison to 50.5 million paired-end reads (18 million in high PUFAs and 32.5 million low PUFAs group) in gluteus medius muscle transcriptome of Polish Landrace pig [24].…”

Effects of dietary supplementation with graded levels of omega-3 fatty acids on growth performance, nutrients digestibility, blood profile, faecal microbial in weaning pigs

“…temperature after LPS challenge (Huber et al 2018). Although inflammatory cytokines were not measured in the current study, it is likely that the blunted acute-phase and body temperature responses observed for pigs that received diets supplemented with fish oil was due to reduced inflammatory cytokine production.…”

“…Divergence results are that Huber et al (2018) indicated that moderated the release of the acute-phase protein haptoglobin by increasing the level of n-3FA. There is some inconsistency in the findings associated with n-3FA supplementation.…”

“…Our experiment demonstrated that coated n-3FA had little effect on the increasing concentration of serum IgG and had no effect on serum haptoglobin. A study by Huber et al (2018) demonstrated that anti-OVA IgG tended to be reduced with increasing fish oil supplementation. After LPS challenge, the n-3FA supplementation independently reduced the numbers of white blood cells, serum concentrations of cortisol and the TNF-α (Upadhaya et al 2015).…”

RNA-seq based SNP discovery in gluteus medius muscle of Polish Landrace pigs

“…ncbi.nlm.nih.gov/sra) of Polish Landrace breed to explain the regulatory mechanisms of the muscle tissue's biological response to increased concentration of omega-6 and omega-3 fatty acids (PUFAs) diets [22]. Recent studies have reported that consumption of PUFAs and other fatty acids diets were genetically regulated the growth performance and immune system in pigs [23]. In our study, the mapping results identified a total of 50.5 million paired-end reads (18 million in high PUFAs and 32.5 million low PUFAs group) in gluteus medius muscle transcriptome of Polish Landrace pig and were successfully mapped to the Exon-exon and Exon- [24].…”