Novel MHC BLB2 gene polymorphism and its association with IgY concentration and Newcastle disease antibody titer in IPB-D2 chickens.

This study aimed to identify the polymorphism of the B Locus Beta 2 (BLB2) gene and its association with immunoglobulin Y (IgY) concentration and Newcastle disease (ND) antibody titer; we analyzed BLB2 gene expression in different categories of ND antibody titers in IPB-D2 chickens. The total sample used was 100 IPB-D2 chickens. Blood samples were collected at 21 weeks old for an ELISA (enzyme-linked immunoassay) test, an HI (hemagglutination inhibition) test, and genotyping. The method for BLB2 polymorphism was Sanger sequencing. Analysis of BLB2 gene expression was performed using the cecal tonsil tissue of IPB-D2 chickens. Polymorphism data were analyzed using SNPstats and DNAsp (DNA Sequence Polymorphism) software. The association of the single-nucleotide polymorphisms (SNPs) with IgY concentration and ND antibody titer was analyzed using SAS software (version 9.2). The genotype mean values were compared by means of a T test. The relative mRNA expression analysis was performed using a quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that 13 SNPs were found in exon 2 and exon 3 in the BLB2 gene. As many as 4 out of the 13 SNPs were associated with IgY concentration. As many as 9 out the 13 SNPs may have changed amino acids. The ΔCt value showed that the expression of the BLB2 gene in IPB-D2 chickens with high ND antibody titers is higher than IPB-D2 chickens with low ND antibody titers. In conclusion, the AA genotype of g.458 T > A was associated with high IgY concentrations, and the BLB2 gene presented with a high expression in IPB-D2 chickens with high ND antibody titers.

Flow cytometric evaluation of CD4+ and CD8+ T-cell in IPB-D2 chickens with different Newcastle disease antibody titers level.

Background and Aim: IPB-D2 chickens are selected from IPB-D1 due to their disease-resistance characteristics. One-way to evaluate the strength of a chicken's immune system is by examining the number of circulating T lymphocytes. This assessment can be conducted using a modern analytic method called flow cytometry which relies on monoclonal antibodies to detect the relative proportions of each cell and measure the quality and quantity of biological and physical features of cells, including specific membrane or intracellular glycoprotein markers. Therefore, this study aimed to evaluate the population of lymphocytes, cluster of differentiation (CD)4+ and CD8+ in IPB-D2 chickens. Materials and Methods: Flow cytometry was used to evaluate the population of lymphocytes, CD4+, and CD8+ in IPB-D2 chickens. The data obtained in this study were analyzed by Minitab, and the mean values were compared using a t-test. Results: The lymphocytes, CD4+, and CD8+ populations of IPB-D2 chicken with high Newcastle disease (ND) antibody titers were 65.04%, 10.53%, and 5.47%. Meanwhile, this breed, with low ND antibody titers had lymphocytes CD4+ and CD8+ population of 57.19%, 8.40%, and 4.11 %. The comparison of CD4+ and CD8+ populations in chickens with high and low ND antibody titers was 1.92 and 2.04, respectively. Conclusion: IPB-D2 chickens with high ND antibody titers exhibited increased lymphocyte, CD4+, and CD8+ cell populations in comparison to those with low ND antibody titers. However, the high ND antibody titer group had a lower CD4+/CD8+ ratio.

Performance, Egg Quality, and Immunity of Laying Hens due to Natural Carotenoid Supplementation: A Meta-Analysis.

This study aimed to investigate the effectiveness of carotenoid supplementation on the performance, egg quality, and immunity of laying hens using a meta-analysis approach. The database was searched using Google Scholar and Scopus, from 2012 to 2022. The literature was published in English. 47 Articles were selected for meta-analysis. Analyses were performed using the Open Meta-analyst for Ecology and Evolution (OpenMEE) software. The heterogeneity and data validation against publication bias were analyzed using JASP 0.16.2 software. Overall, the results showed that carotenoid supplementation improved feed intake by 0.32 g/day/hen [95% confidence interval (CI)=0.02 to 0.61], final body weight by 0.33 g/hen (95% CI=0.05 to 0.60), egg production by 0.38% (95% CI=0.14 to 0.63), egg weight by 0.29 g (95% CI=0.09 to 0.5), yolk colour by 2.11 (95% CI=1.71 to 2.51), Haugh unit (HU) by 0.26 (95% CI=0.11 to 0.42), yolk carotenoids by 1.17 µg/kg (95% CI=0.59 to 1.75), immunoglobulin A (IgA) by 0.74 mg/L (95% CI=0.18 to 1.29), and lower yolk cholesterol by -0.38 mg/g (95% CI=-0.59 to -0.16). Feed conversion ratio (FCR), eggshell thickness, and white blood cells were unaffected by the application of carotenoids. The heterogeneity analysis showed variability in all studies (<0.05). In conclusion, carotenoid supplementation can elevate productivity, enhance egg quality, and improve immunity. However, based on Kendall's test, there was a publication bias in several parameters, namely FCR, egg weight, HU, yolk carotenoids, and IgA.

Polymorphism of prolactin (PRL) gene exon 5 and its association with egg production in IPB-D1 chickens.

The prolactin (PRL) gene regulates the egg production and incubation in laying chickens. Local chickens' reproductive systems will disrupt as a result of the incubation period activity, and they will lay fewer eggs. This study aimed to determine the prolactin gene polymorphism in IPB-D1 hens and its relationship to egg production. The polymorphism of the exon 5 prolactin gene was examined on 112 samples of the IPB-D1 chicken DNA collection from the Division of Animal Genetics and Breeding, Faculty of Animal Sciences, IPB University. By performing the phenol-chloroform method, the genomic DNA was obtained. A polymerase chain reaction (PCR) product with a size of 557 bp was produced as a result of the DNA amplification. Three single-nucleotide sequences were discovered. Three single-nucleotide polymorphisms (SNPs), g.7835A  >  G, g.7886A  >  T, and g.8052T  >  C, were found in exon 5 of the PRL gene. Each mutation was polymorphic and in Hardy-Weinberg equilibrium. The point mutation g.8052T  >  C significantly impacted the egg production of IPB-D1 chickens, according to the SNP association analysis on egg production, and may serve as a marker to enhance the selection for the features of egg production in IPB-D1 chickens.