Impact of dietary fat types on expression levels of dopamine and serotonin transporters in the ileum of broiler chickens

Abstract

Various types of dietary fats undergo distinct fermentation processes by gut microbes, potentially leading to the production of neurotransmitters that can influence the gut. Serotonin and dopamine are recognized neurotransmitters with positive effects on gut function. A broiler chicken trial was conducted to evaluate the influence of dietary fat types on protein expression of 2 neurotransmitter transporters, dopamine (DAT) and serotonin (5-HTT). A total of 560 day-old (Ross 708) male broiler chicks were randomly assigned to 7 dietary treatments. The experimental treatments included a basal diet of corn-soybean meal (SBM), supplemented with 3% of various fats: poultry fat (CON), olive oil (OLIV), fish oil (FISH), canola oil (CANO), lard (LARD), coconut oil (COCO), or flaxseed oil (FLAX). Bodyweight (BW) and feed conversion ratio (FCR) were recorded. Ileal tissues were aseptically collected to determine the expression levels of DAT and 5-HTT through western blot analysis. In addition, plasma samples were analyzed for reactive oxygen metabolites (d-ROM) tests on d 55. Results showed that dietary fat type inclusion did not have any detrimental effect on growth performance parameters. The expression levels of DAT were higher (P < 0.05) in FLAX treatments compared to CON treatments on d 20 and d 55, respectively. Similarly, with 5-HTT levels, FLAX, CANO, and LARD treatments were higher (P < 0.05) than CON treatments on d 20 and d 55. However, higher levels of oxidative stress (d-ROM values) were recorded in COCO (32.75 Carr U), CANO (29 Carr U), and CON treatments (25.5 Carr U) compared to FLAX (18.5 Carr U; P < 0.05) treatment. These findings suggest that incorporating dietary flaxseed oil at a 3% level in the diet has significant potential to elevate the expression levels of intestinal DAT and 5-HTT without inducing oxidative stress.

Keywords: broiler chicken; dietary fat type; dopamine; ileum; serotonin.

Figure 1

Effect of dietary fat types on the expression levels of ileal DAT at 20 d (A), 41 d (B), and 55 d (C). The data are expressed as means ±SEM, with n = 5 per treatment. ^{a, b, c}means with a different superscript are significantly different (P < 0.05).

Figure 2

Effect of dietary fat type on the expression levels of ileal 5-HTT at 20 d (A), 41 d (B), and 55 d(C). The data are expressed as means ±SEM, with n = 5 per treatment. ^{a, b, c}means with a different superscript are significantly different (P < 0.05).

Figure 3

Effect of dietary fat type on plasma oxidative status. The data are expressed as means ±SEM, with n = 5 per treatment. ^{a, b, c}means with a different superscript are significantly different (P < 0.05).