Supplementation of reduced protein diets with

Abstract

Context. The impact of necrotic enteritis (NE) on acute-phase proteins, interleukins, blood mineral profiles, and gene expression have not been well documented. Aims. This study aimed to determine the effects of L-arginine (Arg) or L-citrulline (Cit) supplementation on serum immunological parameters, serum mineral composition and gene expression in broilers fed reduced-protein diets (RP) during subclinical NE challenge. Methods. Ross 308 cockerels (n = 720) were randomly assigned to six experimental treatments, with eight replicates of 15 birds per pen. The treatments were standard protein without and with NE challenge (SP−, SP+); reduced protein (2% points lower crude protein) without and with NE challenge (RP−, RP+), RP plus added Arg (103% of Ross 308 requirement) with NE challenge (RPA+) and RPC+ where supplemental Arg in RPA+ was replaced with Cit. A 2 × 2 factorial arrangement was employed for the first four treatments. Additionally, treatments SP+, RP+, RPA+, and RPC+ were analysed by one-way ANOVA. Key results. The NE × protein interactions indicated that serum calcium concentration decreased in birds fed the RP diets only when challenged with NE (P < 0.05). The NE × protein interactions showed that the NE challenge downregulated the mRNA expression of jejunal y+ L amino acid transporter-2, and mucin 2 only in birds fed the RP diets (P < 0.05). Feeding the RP decreased expression of catenin alpha 1, but increased expression of claudin 5 and tight junction protein genes compared with the SP (P < 0.05). Birds in the RPC+ treatment had increased gene expression of tight junction protein and claudin 5 compared with the SP+ treatment (P < 0.05). Conclusions. Dietary protein level and infection with NE both have an impact on immune response and expression of genes involved in immunity and nutrient digestibility. In part replacement of Arg with Cit in the RPC diet may have beneficial effects on gene expression in NE-challenged birds. Implications. Feeding RP diets may alleviate a decline in growth during subclinical NE by increasing gene expression of tight junction proteins compared with the SP diets.

Elucidating the Varying Impact of Necrotic Enteritis Using Performance and Health Indicators in Broiler Infection Models

“…Other studies have similarly shown variability in tight junction gene expression responses across different studies and NE-challenge models. For example, Dao et al (38) reported that an Eimeria challenge at 9 days of age followed by C. perfringens challenge at 14 days of age did not alter the expression of CLDN-1 in the jejunum of broilers at 16 days of age, but did reduce expression of CLDN-5 by 21% vs. unchallenged control birds, whereas Yuan et al (39) reported that occludin and CLDN1, but not CLDN2 or ZO-1, showed reduced expression (by 53% and 32%, respectively), in ileal samples taken at 28 days of age following a NE challenge (that comprised inoculation of 2.0 3 10 8 CFU of C. perfringens per day during 15–22 days of age). These changes were accompanied by a 12% reduction in average daily gain (ADG) and a 19-point increase in FCR during 22–28 days of age, confirming the link between effects on tight junction protein expression and impaired gross performance, as was also observed in the present study.…”

Beyond protein synthesis: the emerging role of arginine in poultry nutrition and host-microbe interactions

“…Additionally, the inhibition of mitochondrial respiration can decrease the transmembrane potential, leading to the release of cytochrome-c, which interacts with the cytoplasmic apoptosis activating factor-1 (Apaf-1) and procaspase-9 initiating the apoptotic cascade (Potoka et al, 2002). Previous research findings indicate an upregulation of NOS gene expression, increased gut permeability, and decreased expression of tight junction proteins and nutrient transporters during necrotic enteritis (Dao et al, 2022d). However, NO can play a significant role in the resolution of enteritis as well.…”

Effect of arginine supplementation on the growth performance, intestinal health, and immune responses of broilers during necrotic enteritis challenge

“…Hence, it is hypothesized that arginine supplementation will improve the immune response, gut barrier integrity, and growth performance of the birds during NE in broilers. Though there are previous studies on the effects of arginine supplementation in broilers during NE, these studies were conducted using reduced protein diets, which are not yet a standard practice in the commercial broiler industry ( Hilliar et al, 2020 ; Dao et al, 2022a ; Dao et al, 2022b ; Dao et al, 2022c ). The objective of this study was to assess the impact of arginine supplementation on the growth performance, intestinal pathology, and immune response of the birds during the NE challenge, using a diet prepared to meet or exceed the Cobb-500 nutrient requirements.…”