Mononuclear leukocyte fatty acid composition and inflammatory phenotype in periparturient and lactating sows

Circulating Non-Esterified Fatty Acids as Biomarkers for Fat Content and Composition in Pigs

Simple Summary

Circulating non-esterified fatty acids (NEFA) may be valuable as biomarkers for intramuscular fat content and fatty acid composition, as well as for other meat quality traits, in finishing heavy Duroc pigs. However, circulating NEFA composition may be affected by other factors such as age, fasting duration, and genetic variants related with adipogenesis and fatty acid metabolism pathways (e.g., SCD and LEPR). This study revealed that the circulating NEFA composition, especially the oleic acid content, reflects the metabolic status of an animal at a given time but has limited value as biomarker of intramuscular fat content and fatty acid composition.

Abstract

Circulating non-esterified fatty acids (NEFA) can reflect the composition of dietary fat or adipose tissues depending on the fasting conditions. Therefore, circulating NEFA may be valuable as biomarkers for meat quality traits, such as intramuscular fat content and fatty acid composition in finishing pigs. Genetic variants that regulate lipid metabolism can also modulate the circulating NEFA. We conducted an experiment with 150 heavy Duroc pigs to evaluate fluctuations in the circulating NEFA composition due to age, fasting duration and two genetic polymorphisms, one in the leptin receptor (LEPR; rs709596309) and one in the stearoyl-CoA desaturase (SCD; rs80912566) gene. Circulating NEFA were more saturated and less monounsaturated than the subcutaneous and intramuscular adipose tissues. Absolute circulating NEFA content was more influenced by fasting duration than age. The SCD polymorphism did not impact NEFA content or composition. The LEPR polymorphism affected the content but not the fatty acid composition. Circulating oleic acid NEFA content after a short fasting was positively correlated with intramuscular fat content and, after a long fasting, with intramuscular oleic acid content. We conclude that circulating NEFA reflect environmental and genetic metabolic changes but are of limited value as biomarkers for intramuscular fat content and fatty acid composition.

Astaxanthin inhibits cytokines production and inflammatory gene expression by suppressing IκB kinase-dependent nuclear factor κB activation in pre and postpartum Murrah buffaloes during different seasons

AIM

We examined regulatory function of astaxanthin on mRNA expression of nuclear factor κB (NF-κB) p65, interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and interferon gamma (IFN-γ) in peripheral blood mononuclear cells in pre and postpartum Murrah buffaloes during summer (temperature-humidity index [THI]=86; relative humidity [RH]=24) and winter (THI=58.74; RH=73) seasons.

MATERIALS AND METHODS

A total of 32 Murrah buffaloes apparently healthy and in their one to four parity were selected from National Dairy Research Institute herd and equally distributed randomly into four groups (control and supplemented groups of buffaloes during summer and winter season, respectively). All groups were fed according to the nutrient requirement of buffaloes (ICAR, 2013). The treatment group was supplemented with astaxanthin at 0.25 mg/kg body weight/animal/day during the period 30 days before expected date of calving and up to 30 days postpartum.

RESULTS

There was downregulation of NF-κB p65 gene in all the groups. NF-κB p65 mRNA expression was lower (p<0.05) in treatment than control group from prepartum to postpartum during summer, while mRNA expression was low only on day 21 after calving during winter season. The mRNA expression of IL-6, TNF-α, and IFN-γ was lower (p<0.05) in treatment than a control group of buffaloes during summer and winter seasons. The mRNA expression of NFkB p65, IL-6, TNF-α, and IFN-γ was higher (p<0.05) in summer than in winter seasons.

CONCLUSION

The xanthophyll carotenoid astaxanthin a reddish-colored C-40 compound is a powerful broad-ranging antioxidant that naturally occurs in a wide variety of living organisms, such as microalgae, fungi, crustaceans, and complex plants. Astaxanthin blocked nuclear translocation of NF-κB p65 subunit and IκBα degradation, which correlated with its inhibitory effect on IκB kinase (IKK) activity. These results suggest that astaxanthin, probably due to its antioxidant activity, inhibits the production of inflammatory mediators by blocking NF-κB activation and as a consequent suppression of IKK activity and IκB-degradation.

Differences in the Oxylipid Profiles of Bovine Milk and Plasma at Different Stages of Lactation

Mastitis is caused by a bacterial infection of the mammary gland, which reduces both milk quality and quantity produced for human consumption. The incidence and severity of bovine mastitis are greatest during the periparturient period that results from dysfunctional inflammatory responses and causes damage to milk synthesizing tissues. Oxylipids are potent fatty acid-derived mediators that control the onset and resolution of the inflammatory response. The purpose of this study was to investigate how oxylipid profiles change in bovine milk at different stages of the lactation cycle. Results showed significantly lower concentrations of both milk polyunsaturated fatty acid content and total oxylipid biosynthesis during early lactation when compared to mid- or late-lactation. The only oxylipid that was higher during early lactation was 20-hydroxyeicosatetraenoic acid (HETE), which is often associated with inflammatory-based diseases. Milk oxylipid profiles during the different stages of lactation differed from plasma profiles. As such, plasma fatty acid and oxylipid concentrations are not a proxy for local changes in the mammary gland during the lactation cycle.