Salmonella Typhimurium (ST) is a foodborne pathogen that adversely affects the health of both animals and humans. Since poultry is a common source and carrier of the disease, controlling ST infection in chickens will have a protective impact on human health. In the current study, Beijing-You (BY) and Cobb chicks (5-day-old specific-pathogen-free) were orally challenged by 2.4 × 10¹² CFU ST, spleen transcriptome was conducted 1 day post-infection (DPI) to identify gene markers and pathways related to the immune system. A total of 775 significant differentially expressed genes (DEGs) in comparisons between BY and Cobb were identified, including 498 upregulated and 277 downregulated genes (fold change ≥2.0, p < 0.05). Several immune response pathways against Salmonella were enriched, including natural killer-cell-mediated-cytotoxicity, cytokine–cytokine receptor interaction, antigen processing and presentation, phagosomes, and intestinal immune network for IgA production, for both BY and Cobb chickens. The BY chicks showed a robust response for clearance of bacterial load, immune response, and robust activation of phagosomes, resulting in ST resistance. These results confirmed that BY breed more resistance to ST challenge and will provide a better understanding of BY and Cobb chickens’ susceptibility and resistance to ST infection at the early stages of host immune response, which could expand the known intricacies of molecular mechanisms in chicken immunological responses against ST. Pathways induced by Salmonella infection may provide a novel approach to developing preventive and curative strategies for ST, and increase inherent resistance in animals through genetic selection.

This study aimed to investigate the possibility of producing broiler meat rich in long-chain n-3 polyunsaturated fatty acids especially eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3) with preventing lipid oxidation of the produced meat by supplementing the diets with linseed oil or fish oil along with vitamin E (Vit. E) or sweet chestnut tannins (SCT) as antioxidants. A total of 144 1-day-old Cobb broiler chicks were divided into six treatments with three replicates, eight chicks each. The treatments were basal diets containing 2 g linseed oil/100 g (T1), 2 g linseed oil/100 g + 200 mg Vit. E/kg (T2) and 2 g linseed oil/100 g + 2 g SCT/kg (T3), 2 g fish oil/100 g (T4), 2 g fish oil/100 g + 200 mg Vit. E/kg (T5), and 2 g fish oil/100 g + 2 g SCT/kg (T6) for 5 weeks. Fatty acid composition, thiobarbituric acid (TBA), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were determined. Dietary 2 g fish oil/100 g elevated (P ≤ 0.001) long-chain omega-3 polyunsaturated fatty acids in broiler meat mainly EPA and DHA. At the same time, dietary fish oil resulted in a significant decrease (P ≤ 0.001) in α-linolenic acid in broiler meat (6%). However, total omega-3 fatty acids in meat were higher (P ≤ 0.001) with dietary fish oil than with dietary linseed oil. The ratio of n-6:n-3 PUFA was decreased (P ≤ 0.001) in the meat of broilers fed diets containing 2 g fish oil/100 g compared with broilers fed diets containing 2 g linseed oil/100 g. The two sources of antioxidant decreased (P ≤ 0.05) TBA value and increased (P ≤ 0.05) the DPPH radical scavenging activity in broiler meat compared to the diet without antioxidant. No significant differences observed between chicks fed 2 g SCT/kg or 200 mg Vit. E/kg on TBA and DPPH radical scavenging activity. It is concluded that inclusion of 2 g fish oil/100 g in broiler diets elevated levels of long-chain omega-3 PUFA mainly EPA and DHA, but decreased n-6:n-3 ratio. Moreover, the addition of 2 g SCT/kg diet or 200 mg Vit. E/kg diet as antioxidant sources inhibited lipid oxidation and enhanced antioxidant activity value in broiler meat, and each of them had the same effect.

The effects that maternal dietary methionine have on progeny have been reported on broilers. However, the paternal effects are not known, so the current study was conducted to explore the influences of paternal dietary methionine (Met) have on progeny carcass traits, meat quality, and related gene expressions. A total of 192 hens and 24 roosters from Ross parent stock at 36 weeks of age were selected. From week 37 to 46, the roosters were allocated to two groups with three replicates of 4 cocks each, (control, 0.28% Met), and methionine group (MET group, 0.28% Met + 0.1% coated Met). The results revealed that, although the heavier live body weight in progeny at day 49 of control group compared to MET group (p < 0.05), the relative eviscerated yield and relative thigh muscle yield were higher in MET group (p < 0.05); but the relative abdominal fat was lower (p < 0.05). In thigh and breast muscles, a positive response of pH_{24 h} value, shear force (g) and drip loss (%) were observed in MET group (p < 0.05). The lightness (L) and redness (a) were increased (p < 0.05) in breast muscles of MET group, while only the redness (a*_{24 h}) and yellowness (b*_{24 h}) were increased (p < 0.05) in thigh muscles of MET group. The gender has a significant (p < 0.05) effect on carcass traits and muscle redness (a*), where these traits improved in males, and no interaction between treatments and gender were observed for these results. The expression levels of PRKAG2 and PRDX4 supported the changes in muscle pH, with these up-regulated in thigh and breast muscles of MET group, the PPP1R3A gene supported the changes in pH value being down-regulated (p < 0.01) in these same muscles. The BCO1 gene expression was consistent with the changes in meat color and was up-regulated (p < 0.01) in thigh muscles of MET group, consistent with the changes in b* color values. Finally, it was concluded that the supplementation of 0.1% Met to rooster diets could improve carcass characteristics and meat quality of progeny.

Quantification of leukocyte profiles is among the simplest measures of animal immune function. However, the relationship between H/L ratio and innate immunity and the measure’s utility as an index for heterophil function remains to be analyzed. Variants associated with H/L ratio were fine-mapped based on the resequencing of 249 chickens of different generations and an F2 segregating population generated by crossing selection and control lines. H/L ratio in the selection line was associated with a selective sweep of mutations in protein tyrosine phosphatase, receptor type J (PTPRJ), which affects proliferation and differentiation of heterophils through its downstream regulatory genes. The SNP downstream of PTPRJ (rs736799474) have a universal effect on H/L, with CC homozygotes exhibiting improved heterophil function because of downregulated PTPRJ expression. In short, we systematically elucidated the genetic basis of the change in heterophil function resulting from H/L selection by identifying the regulatory gene (PTPRJ) and causative SNP.

Toll-like receptors (TLRs) are involved in the sensing of pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharide (LPS), flagellin, unmethylated double-stranded DNA (CpG), single-stranded RNA (ssRNA) and lipoproteins. Myeloid differentiation primary response protein 88 (MyD88) is a canonical adaptor for the Toll-like receptor family which has crucial roles in host defense against infection by microbial pathogens. The dysregulation of MyD88 may also induce autoimmune diseases. Here, we demonstrate that the deubiquitinase USP7 interacts with MyD88 in chicken, with knockdown or overexpression of USP7 leading to the regulation of MyD88 protein in a positive manner. Consequently, USP7 positively regulates the expression of proinflammatory factors upon LPS challenge. Furthermore, we observed USP7-deficient mice to be more susceptible to infection by Salmonella typhimurium. Collectively, our findings demonstrate MyD88 as a bona fide substrate of USP7 and uncover a mechanism by which USP7 regulates innate immune signaling.

The aim of this study is to evaluate the beneficial effects of coconut essential oil on growth performance, carcass criteria, antioxidant status, and immune response of broiler chicks. A total of 192 un-sexed 7-days broiler chicks were divided into six treatment sets with four copies of 8 chicks per set. The groups were as follows: (1) basal diet (without additive), (2) basal diet plus 0.5 ml coconut essential oil/kg, (3) basal diet plus 1 ml coconut essential oil/kg, (4) basal diet plus 1.5 ml coconut essential oil/kg, (5) basal diet plus 2 ml coconut essential oil/kg and (6) basal diet plus 2.5 ml coconut essential oil/kg. The results showed that the most prevalent compound in coconut oil is 6-Octadecenoic acid (oleic acid) representing 46.44% followed 2(3H)-Furanone, dihydro-5-pentyl- (CAS) (11.36%), Hexadecanoic acid (CAS) (4.71%), and vanillin (2.53%). Dietary 1 and 1.5 ml of coconut oil improved significantly the body weight and gain of broiler chickens. Dietary supplementation of 1 ml of coconut oil improved significantly liver function compared to control and other treatment groups. The supplementation with 1 ml coconut oil significantly reduced TG and VLDL compared to control and other treatment groups, while no significant differences in TC, HDL, and LDL due to dietary coconut oil. The present findings showed that dietary coconut oil with 1 and 1.5 ml/kg feed improved significantly antioxidants status through increased antioxidant enzymes like SOD and GSH while decreasing significantly MDA levels compared to control and other treatment groups. Therefore, it was concluded that the diets of broiler chickens could be fortified with coconut oil with 1 or 1.5 ml to improve the growth, feed utilization, and antioxidant status of broiler chickens.