Effect of in ovo lactoferrin injection in Fayoumi chicken eggs on immune response and some physiological parameters in posthatch chicks

The effects of in ovo lactoferrin (Lf) injection on some physiological parameters and immune response of posthatch chicks were investigated. Live embryonated Fayoumi chicken eggs (n = 600) were randomly allocated into four groups. The first group as a control was noninjected eggs, the second group was only injected with 0.1 mL of NaCl 0.75% solution, and the third and fourth groups were injected with 50 and 100 µL Lf dissolved in 0.1 mL saline solution respectively. The eggs were injected on Day 15 of incubation in the amnion. The results illustrated that the hatchability of eggs in two Lf groups was significantly higher than in the control, NaCl groups. The residual yolk in chicks injected with Lf (100 µL/egg) was significantly lower than the control group (p < 0.05). In ovo Lf injection improved lipid profile, liver function, antioxidant indices, blood haematology, serum immunoglobulins and jejunum histomorphometry compared to the control group (p < 0.05). In ovo injection of Lf decreased significantly (p < 0.001) of pathogenic bacteria in residual yolk such as Salmonella, Shigella and Coliform compared to the control group. In conclusion, in ovo Lf injection can improve the hatchability, lipid profile, immune response and antioxidant indices and decline pathogens in the residual yolk, thus boosting the health status of newly hatched Fayoumi chicks.

Analysis of Differentially Expressed Genes in Necrotic Enteritis-infected Fayoumi Chickens using RNA Sequencing

We identified and evaluated differentially expressed genes (DEGs) by RNA-Sequencing (RNA-Seq) in the intestinal mucosa of two Fayoumi chicken lines, M5.1 and M15.2, that are affected by necrotic enteritis (NE); these chicken lines share the same genetic background but have different major histocompatibility complexes. RNA-Seq generated over 49 and 40 million reads for lines M5.1 and M15.2, respectively. The alignment of these sequences with the Gallus gallus genome database revealed the expression of more than 14,500 genes in two lines, among which 581, 1270, and 1140 DEGs were detected when lines M15.2 and M5.1 were compared with the control and compared between each other. The analysis of all DEGs using the gene ontology database revealed annotations for 111 biological processes, 32 cellular components, and 17 molecular functions, and KEEG pathway mapping indicated that the DEGs were primarily involved in immunity, responses to various stimuli, and signal transduction. In addition, we analyzed 183 innate immune genes that were differentially expressed in NE-induced chicken lines, including 46 CD molecular genes, 89 immune-related genes, and 13 β-defensin genes with 3 lineage-specific duplications. Taken together, the transcriptional profiles showed that line M5.1 was more resistant to NE than line M15.2 and that differential gene expression patterns were associated with host genetic differences in resistance to NE. qRT-PCR and RNA-Seq analyses showed that all the genes examined had similar responses to NE (correlation coefficient R=0.84 to 0.88, p<0.01) in both lines. To the best of our knowledge, this is the first study that describes NE-induced DEGs using RNA-seq in two lines with different levels of susceptibility to NE. These results will lead to increased insights on NE disease resistance mechanisms and the role of host genes in the control of the host immune response.