In situ hybridization of ovalbumin mRNA in the chick oviduct reveals target cell specificity for estrogen and progesterone

The effectiveness of Bio-plus2B®, Techno Mos® and their mixture on the rate of egg production, egg characteristics, retention of nutrients and blood metabolites through the early period of production

BACKGROUND

The trend of using probiotic, prebiotic and their mixture as alternative feed additives which works as growth promoters in poultry diets to increase the productive performance and the immunity of the flock still have an importance consideration. So that the aim of this study is to estimate the impact of Bio-plus2B® (probiotic), Techno Mos® (prebiotic) or their mixture (synbiotic) on egg production, egg and shell quality, some blood metabolites and retention of nutrients between 28 and 40 weeks of age. The hens (ISA brown laying) were allocated randomly in 40 cages; 10 cages/treatment with two hens each. The treatments were the control (T1), T2 (Probiotic: 1 g Bio-plus2B® (Bacillus licheniformis plus Bacillus subtilis)/kg feed), T3 (Prebiotic: 1 g Techno Mos® (Mannanoligosaccarides (MOS) and 1,3 B-glucan) /kg feed) and T4 (Synbiotic: 1 g Bio-plus2B® plus 1 g Techno Mos®/ kg feed).

RESULTS

Hen-day egg production% and mass were significantly increased (P < 0.05) with T2 and T4 treatments. The experimental treatments recorded an increase in albumen index, Haugh unit (P < 0.01), shell thickness (P < 0.05), the retention of crude protein (CP), crude fiber (CF) and ether extract (EE) (P < 0.05), plasma globulin, albumin and total protein (P < 0.001) versus to the untreated group, while egg weight was not affected. Synbiotic treatment showed a significant (P < 0.001) increase in shell calcium content. T3 and T4 treatments were significantly decreased plasma cholesterol (P < 0.001) and low density lipoprotein (LDL) (P < 0.05). Alanine transaminase (ALT) was significantly (P < 0.001) decreased and estradiol hormone was increased (P < 0.001) in the experimental groups versus to the control.

CONCLUSIONS

It concluded that adding probiotic and/or prebiotic in the early age laying hens diets had beneficial effects for productivity with improving the egg shell thickness.

Effect of estradiol-17β on follicle-stimulating hormone secretion and egg-laying performance of Japanese quail

The aim of this study was to measure the effect of estradiol-17β (E2) injection on follicle-stimulating hormone (FSH) secretion and egg-laying performance of Japanese quail. Female Japanese quail were housed in cages and fed ad libitum. After a 7-day adaptation period, the birds were randomly assigned to three groups, that is, one control group and two test groups. The birds were weighed, before every injection. The control group was subcutaneously injected with 0.2 ml sesame oil-ethanol mixture, whereas test groups were injected, twice in a week, with 0.2 ml sesame oil-ethanol mixture containing 0.1 or 0.2 mg E2 along the study. One day after the first injection, egg number, egg weight, eggshell strength and food conception were daily recorded. On the last day of the experiment, the birds were injected and 3 h later seven birds from each group were randomly selected for bleeding. Blood samples (2 ml/bird) were collected from the jugular vein for the measurements of serum concentrations of E2, FSH, calcium (Ca) and phosphorus (P). E2 injection did not cause any significant changes in serum FSH concentrations, daily egg laid/bird, food conception/bird, serum concentrations of the Ca and the P. Egg weight was significantly increased in the 0.1 mg E2-injected group as compared with the control and 0.2 mg E2-injected groups. Eggshell strength in the 0.2 mg E2-injected group was significantly high as compared with the control, whereas the difference between the 0.1 mg E2- and 0.2 mg E2-injected groups was not statistically important. These results show that serum FSH concentration was not increased even when slightly suppressed by subcutaneous injection of 0.1 or 0.2 mg E2. Different doses of E2 have different functions. The increase in BWs in the 0.1 mg E2-injected group was a result of the dose effect, which probably increased growth hormone secretion from the pituitary or IGF-1 synthesis from the liver or both. The dose, 0.2 mg E2, was ineffective in increasing the BW, but it significantly increased eggshell strength probably via the increase in Ca and P utilizations.

Virulence characteristics of Escherichia coli isolates obtained from broiler breeders with salpingitis

Thirty isolates of Escherichia coli from broiler breeders with salpingitis were studied. Using the slide agglutination test, the isolates were found to belong to serogroups O1, O2, O5, O36, O45, O53 and O78. Pathogenicity for day-old chicks was determined by air sac inoculation and isolates were categorized as having high, intermediate or low virulence. Growth on iron starvation medium was observed together with aerobactin production. Based on the results of in vitro adherence tests, attachment to oviduct epithelium from old birds was found to be superior to that observed using corresponding material from young birds. DNA hybridization testing for type 1, P, and S fimbriae revealed predominant expression of type 1, correlating with mannose-sensitive hemagglutination using guinea-pig erythrocytes. In this study, P and S fimbriae were not considered to be important adherence factors. Study findings would suggest that, as far as salpingitis is concerned, type 1 fimbriae can play an important role in E. coli infection in breeders. An interesting result to emerge from the study was the observation that E. coli isolates were completely resistant to serum from young breeders, whereas they were completely sensitive using serum from older breeders. Based on serogroups involved, pathogenicity for day-old chicks and virulence indicators, the salpingitis isolates were similar to those from cases of chronic respiratory disease.

Messenger RNA encoding an estrogen-dependent oviduct secretory protein in the sheep is localized in the apical tips and basal compartments of fimbria and ampulla epithelial cells implying translation at unique cytoplasmic foci

Data from our laboratory have shown that an estrogen (E2)-dependent M(r) 90,000-92,000 protein and its mRNA are synthesized and expressed in abundant amounts at estrus from the fimbria and ampulla, not isthmus, oviduct of the sheep. Immunocytochemical studies have shown that the M(r) 90,000-92,000 protein is contained in apical secretory granules of oviduct epithelial cells. The objective of this study was to determine whether the mRNA for the E2-dependent oviduct protein was localized and compartmentalized in similar manner. Fimbria, ampulla, and isthmus oviducts obtained from estrous ewes were flash frozen in liquid nitrogen, cryosectioned, fixed in 4% paraformaldehyde, hybridized with digoxigenin (DIG)-labeled oviduct-specific riboprobes, incubated in anti-DIG antibodies conjugated with alkaline phosphatase, and developed in color substrate. Oviduct protein-specific transcripts were localized to basal perinuclear compartments and, surprisingly, at sites distant from the nucleus in the apical cytoplasm of epithelial cells in the fimbria and ampulla. No specific reaction product was observed in the underlying mucosa or smooth muscle layers. Oviduct protein mRNA was contained predominantly in the apical cytoplasm of epithelial cells at the free margins of mucosal folds and in the basal regions of cells located at the crypts of longitudinal folds. No reaction product was present when sections of the fimbria and ampulla oviduct of estrous ewes were incubated in sense riboprobe to the oviduct protein. In addition, when sections of the isthmus oviduct obtained from estrous ewes or fimbira and ampulla oviducts from long-term ovariectomized ewes were hybridized with antisense riboprobes no specific reaction product was detected. Electron microscopy of oviduct protein mRNA containing areas revealed the presence of secretory granules, rough endoplasmic reticulum (RER) and Golgi in the apical cytoplasm, and RER in the basal regions of epithelial cells. These data show that the mRNA encoding an E2-dependent oviduct-specific protein is distributed in epithelial cells at perinuclear foci and at sites distant from the nucleus, which are also the sites of protein localization and protein synthesizing organelles, implying translation at unique cytoplasmic foci.