Effects of plant-derived isoquinoline alkaloids on growth performance and intestinal function of broiler chickens under heat stress.

Broiler chickens reared under heat stress (HS) conditions have decreased growth performance and show metabolic and immunologic alterations. This study aimed to evaluate the effect of supplementation with a standardized blend of plant-derived isoquinoline alkaloids (IQ) on the growth performance, protein catabolism, intestinal barrier function, and inflammatory status of HS-treated chickens. Three hundred sixty 0-day-old Ross 308 male broiler chickens were randomly distributed into 2 treatment groups: control diet (no additives) or diet supplemented with 100 ppm IQ. At day 14, the chicks in each diet group were further divided into 2 groups, each of which was reared under thermoneutral (TN) (22.4°C) or constant HS (33.0°C) conditions until day 42. Each group consisted of 6 replicates with 15 birds per replicate, and chickens were provided ad libitum access to water and feed. During days 15-21, the body weight gain (BWG) and feed intake (FI) were significantly lower in the HS treatment group than in the TN group, and feed conversion ratio was higher (P < 0.05); these factors were not alleviated by IQ supplementation. During days 22-42, the final BW, BWG, and FI of the HS birds were better among those administered IQ than those that were not (P < 0.05). HS treatment increased plasma lipid peroxide, corticosterone, and uric acid concentrations as well as serum fluorescein isothiocyanate-dextran, a marker of intestinal barrier function, and decreased plasma total protein content (P < 0.05). These changes were not observed in the IQ group, suggesting that IQ supplementation improved oxidative damage, protein catabolism, and intestinal barrier function of chickens under HS. Isoquinoline alkaloid supplementation inhibited the expression of intestinal inflammatory factors, IL-6, tumor necrosis factor-like factor 1A, and inducible nitric oxide synthase under HS treatment (P < 0.05). These results suggest that IQ supplementation can improve the growth performance of broiler chickens under HS conditions, which may be associated with amelioration of oxidative damage, protein catabolism, intestinal barrier function, and inflammation.

The role of supplemental glycine in establishing a subclinical necrotic enteritis challenge model in broiler chickens.

Subclinical necrotic enteritis (NE) is an economically important disease in the broiler industry. With the move towards removal of antibiotics from feeds, solutions to control subclinical NE are desperately being sought. Dietary glycine has been shown to promote proliferation of Clostridium perfringens (Cp) and may thus be useful to include in a NE challenge model. A study was conducted to evaluate the effect of increased dietary glycine levels on subclinical NE. A 2 × 2 × 2 factorial arrangement of treatments was carried out using day-old male Ross 308 chicks (n = 624) allocated to 48 floor pens with 8 treatments of 6 replicates with 11 birds per treatment. Factors were: Cp challenge (C- or C+), Eimeria spp. challenge (E- or E+), and dietary glycine in the grower diet (0 or 10 g/kg). Birds had higher FCR when challenged with Eimeria (P < 0.01) or Cp (P < 0.05) on d 24 or Cp on d 35 but FCR was lower when fed glycine on d 24 (P < 0.01). Supplementation of glycine reduced feed intake on d 24 and increased weight gain on d 35 (P < 0.05). A Cp × Eimeria × glycine interaction (P < 0.05) showed a higher jejunal lesion scores in birds challenged with a combination of Cp and glycine compared with those with Eimeria and glycine or the unchallenged birds. Lesion score interactions between Cp and glycine (P < 0.05) in the ileum and Cp and Eimeria in the duodenum (P < 0.05) and ileum (P < 0.05) illustrated higher lesion scores in birds challenged with Cp without Eimeria or glycine compared to those not challenged with Cp. This study suggests that using glycine can partially replace Eimeria in a subclinical NE challenge model in promoting the intestinal lesions but not impairing chicken performance.

Effects of yeast cell wall on growth performance, immune responses and intestinal short chain fatty acid concentrations of broilers in an experimental necrotic enteritis model.

Subclinical necrotic enteritis (NE) causes devastating economic losses in the broiler chicken industry, especially in birds raised free of in-feed antibiotics. Prebiotics are potential alternatives to in-feed antibiotics. Yeast cell wall extract (YCW) derived from Saccharomyces cerevisiae is a prebiotic with known immune modulating effects. This study examined the effects of YCW and antibiotics (AB) during subclinical NE on broiler growth performance, intestinal lesions, humoral immune response and gut microflora metabolites. The study employed a 2 × 3 factorial arrangement of treatments. Factors were: NE challenge (yes or no) and feed additive (control, AB, or YCW). Each treatment was replicated in 8 floor pens with 15 birds per pen. Challenged birds had higher feed conversion ratio (FCR) than unchallenged birds on d 35 (P < 0.05). Dietary inclusion of AB decreased FCR regardless of challenge (P < 0.05) on d 24 and 35. Inclusion of YCW reduced serum interleukin-1 (IL-1) concentration in NE challenged birds (P < 0.01) and increased immunoglobulin (Ig) G (P < 0.05) and Ig M (P < 0.05) levels compared to other dietary treatments regardless of challenge. Yeast cell wall extract increased formic acid concentration in cecal contents during challenge and increased butyric acid concentration in unchallenged birds on d 16. This study indicates YCW suppressed inflammatory response, promoted generation of immunoglobulin and increased short chain fatty acid production suggesting potential benefits to bird health.

Nagelschmidtite bioceramics with osteostimulation properties: material chemistry activating osteogenic genes and WNT signalling pathway of human bone marrow stromal cells.

Bioactive materials with osteostimulation properties are of great importance to promote osteogenic differentiation of human bone marrow stromal cells (hBMSCs) for potential bone regeneration. We have recently synthesized nagelschmidtite (NAGEL, Ca7Si2P2O16) ceramic powders which showed excellent apatite-mineralization ability. The aim of this study was to investigate the interaction of hBMSCs with NAGEL bioceramic bulks and their ionic extracts, and to explore the osteostimulation properties of NAGEL bioceramics and the possible molecular mechanism. The cell attachment, proliferation, bone-related gene expression (ALP, OPN and OCN) and WNT signalling pathways (WNT3a, FZD6, AXIN2 and CTNNB) of hBMSCs cultured on NAGEL bioceramic disks were systematically studied. We further investigated the biological effects of ionic products from NAGEL powders on cell proliferation and osteogenic differentiation of hBMSCs by culturing cells with NAGEL extracts. Furthermore, the effect of NAGEL bioceramics on the osteogenic differentiation in hBMSCs was also investigated with the addition of cardamonin, a WNT inhibitor. The results showed that NAGEL bioceramic disks supported the attachment and proliferation of hBMSCs, and significantly enhanced the bone-related gene expression and WNT signalling pathway of hBMSCs, compared to conventional beta-tricalcium phosphate (ß-TCP) bioceramic disks and blank controls. The ionic products from NAGEL powders also significantly promoted the proliferation, bone and WNT-related gene expression of hBMSCs. It was also identified that NAGEL bioceramics could bypass the action of the WNT inhibitor (10 µM) to stimulate the selected osteogenic genes in hBMSCs. Our results suggest that NAGEL bioceramics possess excellent in vitro osteostimulation properties. The possible mechanism for the osteostimulation may be directly related to the released Si, Ca and P-containing ionic products from NAGEL bioceramics which activate bone-related gene expression and WNT signalling pathway of hBMSCs. The present study suggests that NAGEL bioceramics are a potential bone regeneration material with significant osteostimulation capacity.