BACKROUND: The use of feed withdrawal method for molt induction can be caused physiological stress and negatively affected the immunological response of hens. OBJECTIVES: The aim of the present study was to survey of hormonal changes and immunological response in hens fed by alfalfa molt diet during the molt period. METHODS: In this experiment 108 Hy-line (W36) laying hens aged 74 weeks in a completely randomized design with 3 treatments and 6 replicates were used. The using treatments for 12 days molt period were included: 1- control group fed with layer ration (FF), 2- feed withdrawal group (FW), 3- group fed with 90% alfalfa and 10% layer ration (A90). Performance of birds was monitored for 12 weeks after the end of the molting period. RESULTS: Total circulating leukocyte were generally lower in FW hens group compared with the other groups during the initial stage of molt (P<0.05). On d 3 and 6 of molt, heterophil to lymphocyte ratio were incresed in molted hens and FW hens had higher levels than other groups. On d 3 of molt, plasma corticosterone was generally incresed in molted hens and FW hen higher level than A90 hens (P<0.05). Plasma T3 was significantly decreased in molted hens than nonmolted hens during the molt period (P<0.05). Plasma T4 was significantly increased in molted hens than nonmolted hens during the molt period (P<0.05). On d 6 and 9 of molt, concentrations of T4 were higher in FW hens than in the A90 hens (P<0.05). Date of reentry and days return to 50% and 80% egg production were significantly lower in A90 groups than in the FW groups (P<0.05). CONCLUSIONS: The results showed that, A90 diet can limit physiological stress and improve the performance of immunological response that accompany feed withdrawal method during an induced molt.

BACKGROUND: The use of feed withdrawal for molt induction can negatively affected the structure and microbial environment of intestine and lead to greater intestinal colonization by salmonella infection. OBJECTIVES: The aim of the present experiment was to determine the effects of alfalfa as a high fiber ingredient for molt induction on intestinal morphometric characteristics and performance of commercial laying hens. METHODS: In this experiment 108 Hy-line (W36) laying hens aged 74 weeks in a completely randomized design with 3 treatments and 6 replicates were used. Using treatments for 12 days molt period were included: 1- control group fed with layer ration (FF), 2- feed withdrawal group (FW), 3- group fed with 90% alfalfa and 10% layer ration (A90). Performance of birds was monitored for 12 weeks after the end of the molting period. RESULTS: Feed withdrawal hens had lowest villus height in all three regions of the intestine (p<0.05).The highest average of deudenal crypt depths was observed in FW hens. In all three regions of the intestine, the lowest amounts of villus index and villus surface was observed in FW hens (p<0.05). In all three regions of the intestine, the highest and lowest average of goblet cells was seen in the A90 and FW hens respectively. The highest mean of post molt egg mass was observed in FW hens (p<0.05). The best FCR was seen in the A90 group. CONCLUSIONS: The use of alfalfa-riched feed for molt induction of laying hens results in improvement of morphometric characteristic of intestine and post molt performance.

An experiment was conducted to study the effect of turmeric powder on production performance and egg quality characteristics of Rhodo White (RW) layers. Seventy two RW layers were weighed individually and distributed randomly into four turmeric powder supplemented reated experimental diets with three replicates of six layers each and the experimental diet was given for a period of 20 weeks from 26 to 45 weeks age of the birds. There was no significant difference in total egg production, hen day egg production (HDEP) and hen housed egg production (HHEP) among the treatment groups. The feed intake in all treatment groups was almost similar during 26 to 45 weeks of birds. Turmeric powder did not inÀuence the feed intake and feed efficiency in all treatment groups. A non-significant difference was observed in egg quality characteristics. The egg yolk cholesterol was significantly (P&lt;0.01) reduced by 18.59 %, 24.91 % and 33.24 % in 0.05, 0.10 and 0.15 % turmeric powder supplemented groups respectively than control. It was concluded that the inclusion of turmeric powder did not inÀuence the production performance &amp; egg quality characteristics and however the egg cholesterol level was significantly reduced at 0.15 % in RW layers

The present research was planned to realize and determine the calcification inthe kidneys of two ages (18 months and 24 months) of laying hens. There are no cleardifferences in histological appearance by using (H&amp;E) stain between to ages, butthere are higher significant differences in the height of epithelium cells and lowersignificant differences in the lumen of renal tubules in the kidneys of laying hens for(24 months) than in the (18 months). By using special dyes (Van Kossa)revelateddeposits of calcium salts and using immunohistochemistry method, theresults showed presence of calcification in form of small foci in varying sizes bearingwithin them brown to dark color calcium deposits in the glomerulus, the epitheliumlayer and basement membrane of the renal tubules and between them. In general thecalcified foci in different areas of kidneys in the 24 month age increase than in the 18months age.

This study compared a new live attenuated Salmonella Enteritidis vaccine candidate secreting Escherichia coli heat-labile enterotoxin B subunit (SE-LTB) with a commercial Salmonella Enteritidis (SE) vaccine for efficacy of protection against SE infection in laying hens. Chickens were divided into 3 groups of 20 each. Group A chickens were inoculated orally with phosphate-buffered saline and served as controls, group B chickens were inoculated orally with the vaccine candidate, and group C chickens were inoculated intramuscularly with a commercial vaccine, the primary inoculation in groups B and C being at 10 wk of age and the booster at 16 wk. Groups B and C showed significantly higher titers of plasma immunoglobulin G, intestinal secretory immunoglobulin A, and egg yolk immunoglobulin Y antibodies compared with the control group, and both vaccinated groups showed a significantly elevated cellular immune response. After virulent challenge, group B had significantly lower production of thin-shelled and/or malformed eggs and a significantly lower rate of SE contamination of eggs compared with the control group. Furthermore, the challenge strain was detected significantly less in all of the examined organs of group B compared with the control group. Group C had lower gross lesion scores only in the spleen and had lower bacterial counts only in the spleen, ceca, and ovary. These findings indicate that vaccination with the SE-LTB vaccine candidate can efficiently reduce internal egg and internal organ contamination by Salmonella and has advantages over the commercial vaccine.

Objective—To determine the effects of resveratrol (RES) on growth and immune status in chickens receiving conventional vaccinations. Animals—Two hundred forty 1-day-old layer chickens. Procedures—Chickens received conventional vaccinations throughout the study and were randomly assigned to 1 of 4 treatments in 6 replicate pens/treatment. Treatments included 1 control group (basal diet) and 3 experimental groups fed the basal diet plus 200, 400, and 800 mg of RES/kg of diet. At 40 days of age, 1 bird/pen was randomly selected to have blood and tissues collected to determine serum immunity indices; mRNA relative expression of proinflammatory cytokines in splenocytes; mRNA relative expression of nuclear transcription factor-κB, growth hormone receptor, and insulin-like growth factor-1 in hepatocytes; cell proliferation; and apoptosis. Results—Average daily gain, antibody titers against Newcastle disease virus and avian influenza viruses H5 and H9, and insulin-like growth factor-1 expression were quadratically increased with increasing RES concentration. In hepatocytes, growth hormone receptor gene mRNA relative expression was quadratically increased and nuclear transcription factor-κB gene mRNA relative expression was linearly decreased with increasing RES concentration. In splenocytes, nterleukin-1β and tumor necrosis factor-α mRNA relative expression was linearly decreased with increasing RES concentration. Resveratrol supplementation delayed cell proliferation and reduced apoptosis in immunocytes. With increasing RES concentration, proliferation index and relative weight of the thymus, ratio of CD4+ to CD8+ cells, and CD4+ cell count were quadratically increased, and IgM concentration was linearly increased. Conclusions and Clinical Relevance—Dietary resveratrol supplementation improved growth, protected immunocytes against antigen-induced apoptosis, and upregulated immune response in chickens that received conventional vaccinations.

Virulence of three Canadian poultry strains of Salmonella enteritidis, namely phagetypes (PT) 4, 8 and 13, and one Salmonella heidelberg strain was assessed in orally and intraperitoneally inoculated one-day old chickens and compared to the virulence of a human S. enteritidis PT 4 strain from the United Kingdom (UK). The two PT 4 strains were also compared in orally inoculated adult laying hens. In addition, orally inoculated Balb/c mice were used to evaluate virulence of the above strains and two strains of Salmonella typhimurium containing different plasmids. In orally inoculated one-day old chickens, the UK S. enteritidis PT 4 strain was more virulent than the Canadian PT 4 strain. The UK PT 4 strain was also more virulent and invasive in adult laying hens than the Canadian PT 4 strain. The S. enteritidis PT 8 strain and one S. typhimurium strain isolated from a chicken hatchery were the most virulent for orally inoculated Balb/c mice. This strain of S. typhimurium contained the 60 megadalton plasmid associated with virulence for Balb/c mice which was not present in the S. typhimurium strain isolated from a pig with septicemic disease.

In this study, the immune responses to and protective efficacy of a live attenuated Salmonella-delivered vaccine candidate secreting the papA, papG, iutA, and clpG antigens of Escherichia coli were evaluated against infection with avian pathogenic E. coli (APEC) in layer chickens. Primary vaccination was done at age 7 d and booster vaccination at age 5 wk. The levels of intestinal secretory immunoglobulin A specific to the 4 antigens were significantly higher in the vaccinated group than in the control group. A potent lymphocyte-proliferation response and increased levels of interferon-γ, interleukin-2, and interleukin-6 in the plasma and in culture supernatants of antigen-stimulated lymphocytes from the vaccinated group suggested significant induction of the cell-mediated immune response in this group compared with the control group. Upon challenge with a virulent APEC strain at 8 wk of age, the vaccinated group had no deaths, whereas the control group had a 15% mortality rate. In addition, the morbidity rate was significantly higher in the control group (55%) than in the vaccinated group (15%). Thus, giving primary and booster vaccination with the Salmonella-delivered APEC vaccine candidate significantly elevated both mucosal and cellular immune responses, which protected the chickens against colibacillosis.

OBJECTIVE To evaluate the effects of dietary nonphytate phosphorus (NPP) content on ileal lymphocyte subpopulations and cytokine expression in the cecal tonsils and spleen of hens that were or were not inoculated with Salmonella Typhimurium. ANIMALS 64 Salmonella-free hens. PROCEDURES Hens were fed a diet with 0.22% (control; n = 32) or 0.42% (high-P; 32) NPP for 6 weeks and then orally inoculated with S Typhimurium (5 × 107 CFUs) or PBSS. Tissues were obtained from 8 S Typhimurium–inoculated and 8 PBSS-inoculated hens from each group at 2 and 7 days postinoculation (DPI). Percentages of ileal CD4+ and CD8+ lymphocytes were determined by flow cytometry. Cytokine mRNA expression was determined by quantitative real-time PCR assays. RESULTS For S Typhimurium–inoculated hens, plasma parathyroid hormone concentration was significantly increased and 1,25-dihydroxyvitamin D3 concentration was decreased in hens fed the high-P diet, compared with values in hens fed the control diet. Salmonella Typhimurium inoculation caused an increase in the percentage of ileal CD8+ lymphocytes and the expression of interleukin (IL)-1β, IL-6, IL-8, interferon-γ, IL-12, and IL-18 in the cecal tonsils and spleen and a decrease in the expression of IL-4 and IL-10 in the cecal tonsils. Hens fed the high-P diet had significantly increased splenic expression of interferon-γ at 2 DPI and IL-1β, IL-6, IL-12, and IL-18 at 7 DPI, compared with hens fed the control diet. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested there was a T-helper 1 cytokine reaction in the cecal tonsils and spleen of S Typhimurium–inoculated hens, and dietary NPP content altered calcium regulation hormone concentrations and affected splenic cytokine expression.