The enrichment of egg with folate is a viable option for supplying the general population of a food product rich in natural folates. However, attempts to increase the concentration of folate in egg beyond the achieved level of enrichment had been unsuccessful because egg folate reached a maximum plateau when folic acid (FA) was increased in the diet. Thus, experiments were conducted to determine the factors regulating the deposition of dietary FA into the eggs. In the first study, the effect of feeding equimolar intake of FA and 5-methyltetrahydrofolate (5-methylTHF), the biologically active form of folate; on egg folate concentrations, indices of folate status, and activities of folate-dependent enzymes was evaluated. Folic acid and 5-methylTHF demonstrated equivalent effects in enhancing the egg folate concentrations and improving the indices of folate status in the laying hen. The activities of folate-dependent enzymes were similar between the two forms of folate except for hepatic dihydrofolate reductase (DHFR) activity which increased in FA-fed birds compared to 5-methylTHF-fed birds. However, this demonstrated the ability of the laying hen to metabolically convert FA into its biologically active forms. Therefore, the influence of intestinal FA absorption in the regulation of FA deposition in the egg was subsequently evaluated. Using the in vitro everted intestinal sac technique, FA was absorbed in all regions of the intestine. Absorption was maximum at acidic pH 6.0, and increased in the duodenum and jejunum compared to the ileum and cecum. The rate of FA absorption in the jejunum diminished at higher FA concentrations. Therefore, further study was conducted to determine the regulation of FA absorption when levels of FA in the laying hen diet are increased. Supplementation of increased FA levels resulted to a down-regulation of FA absorption in the duodenum, but not in the jejunum of the laying hen. This down-regulation was not associated to a decreased mRNA gene expression of the duodenal folate transporters. Overall, decreased intestinal rate of FA absorption possibly associated to a post-transcriptional or translational regulation of specific folate transporters in the intestine of the laying hen may contribute to the saturation in the egg folate concentration.

We investigated the effects of dietary folic acid and age, on immunological parameters in laying hens challenged with LPS. 48 Shaver White hens at different ages were fed 2 wheat-soybean based diets with 0 or 4 mg supplemental FA per kg of diet for 8 wk. 6 hens from each dietary treatment were injected with 8 mg/kg body weight of LPS or saline and observed for 4 h. A few diet X challenge interaction were observed in young hens, whereas FA and LPS independently influenced a number of parameters. In older hens, there were very few diet X challenge interactions as well as effects of FA, whereas LPS affected several parameters. In conclusion, dietary FA influenced some immune responses in younger hens, but no such effects were observed in older hens. FA may modulate immune responses in laying hens under acute LPS challenge which could be tissue and age dependent.

Tyrimo metu mėginiai buvo imami iš 4 skirtingo amžiaus, 10 savaičių (n=10), 20 savaičių (n=10), 40 savaičių (n=10) ir 60 savaičių (n=10),veislinių vištų kategorijų. Ištyrus 10 sav. amžiaus vištų gaišenas ryškių patomorfologinių pokyčių nenustatyta. Atlikus 20 savaičių amžiaus vištų patomorfologinį tyrimą buvo nustatytos tokios patologijos: ūminė pneumonija, oro maišų uždegimas, enteritas. 40 proc. tirtų paukščių buvo diagnozuotas pododermatitas. Bendra suma 20 savaičių amžiaus paukščių grupėje lygi 5. Mikrobiologinio tyrimo metu iš 20 savaičių amžiaus vištų buvo nustatyta patogeninė E.coli. Atlikus 40 savaičių amžiaus išbrokotų vištų gaišenų patomorfologinį tyrimą, buvo nustatytos tos pačios vidaus organų patologijos kaip ir 20 savaičių amžiaus vištoms, tačiau mikrobiologinio tyrimo metu iš 40 savaičių amžiaus vištų pažeistų audinių buvo nustatytos patogeninės E.coli, Staphylococcus aureus ir Klebsiella genties bakterijos. Bei ženkliai padidėjo vištų sergančių pododermatitu, net 70 proc. Bendra suma 40 savaičių amžiaus paukščių grupėje lygi 11 balų. Atlikus 60 savaičių amžiaus vištų patomorfologinį tyrimą, 70 proc. tirtų paukščių buvo nustatyti kojų pirštų artritai ir pododermatitas. Bendra suma 60 savaičių amžiaus paukščių grupėje lygi 14 balų. Remiantis šiais tyrimų duomenimis galima teigti, kad veislinėms vištoms pododermatito atvejų daugėja didėjant paukščių amžiui. Sunkiausi pažeidimai (daugiausiai pododermatito balų) nustatomi 60 savaičių amžiaus vištoms... [toliau žr. visą tekstą] / The study samples were taken from 4 different age categories of hens 10 weeks (n = 10), 20 weeks (n = 10), 40 weeks (n = 10) and 60 weeks (n = 10). It were examined some hen carrions of the age of 10 weeks and it were not found any clear pathomorphological changes. It were examined some hens of the age of 20 weeks as well and it were foud out following deseases: acute pneumonia, inflammation of the air sacs, enteritis. Pododermatitis was diagnosed in 40 percent of examined hens. The total amount of the group of 20 week-old hens is equal to 5. Microbiological study of 20 week-old hens showed pathogenic E.coli. After the pathomorphological study, which was done to 40 week-old hen carrions, it was found out the same pathology of internal organs as in 20 week-old hens, but microbiological study of 40 week-old hens‘ damaged tissues identifyed pathogenic E. coli, Staphylococcus aureus and bacteria of the genus Klebsiella. What is more, it increased the amount of hens that suffer from pododermatitis, even 70 per cent. The total amount of 40 week-old hens in the group was equal to 11 points. After the pathomorphological study of 60 week-old hens 70 per cent of birds were diagnosed the toes arthritis and pododermatitis. The total amount of the group of 60 week-old hens was 14 points. Based on these studies it can be said that pedigree hens suffer more and more often from pododermatitis when they get older. The most serious damages (most pododermatitis points) are identifyed to 60... [to full text]

Sällan har ett litet ord på tre bokstäver skapat så stor debatt som hen gjort det senaste året. Begreppet är inte nytt, men har fått en nytändning i och med lanseringen av barnboken Kivi och monsterhund (Lundqvist 2012) som använder ordet flitigt. Forskning om begreppets betydelse ur genussynpunkt är föga utredd och det är svårt som blivande lärare att veta hur man ska ställa sig till det. Detta är en undersökning av sju aktiva lärares inställningar till genusarbete och det könsneutrala pronomenet hen i förskola och förskoleklass. Undersökningen är en kvalitativ studie, där intervju använts som metod och respondenternas svar sammanställts för att synliggöra gemensamma tendenser. De tendenser som går att skönja i de intervjuade lärarnas svar är att genus och jämställdhet ses som självklara ämnen att arbeta med, om än på olika sätt. Konkret hur detta görs är dock svårare att få svar på. Inställningen till hen däremot är främst negativ hos samtliga intervjuade lärare. Några av dem börjar dock reflektera över ordets användbarhet och konstaterar att okunskap är en stor anledning till den negativa inställningen. I lärarnas utsagor framkommer att begreppet hen upprör gamla rotade normer angående kön, eftersom det främsta argumentet är att "vi är pojkar och flickor", ett tillstånd som inte går att ändra. Detta tillsammans med medias ironisering av hen kan anses vara två bidragande orsaker till att begreppet inte etablerats i det svenska språket och inte heller antagits som ett användbart begrepp i förskoleverksamhet i vår omnejd.

Epithelial ovarian cancer is the most lethal gynecologic malignancy, with a 5-year survival rate of less than 40%. This is due in part to a lack of early detection markers and lack of specific symptoms during early disease. The laying hen is the only accessible animal model which develops epithelial ovarian cancer spontaneously, with features closely resembling the human disease. It has been estimated that approximately 30% of all cancers can be prevented with diet, exercise, and maintenance of an optimal weight, and the chronic low-grade inflammation that accompanies obesity is implicated as a causal factor in the development of cancer. Flaxseed, a rich plant source of anti-inflammatory omega-3 fatty acids and lignans which act as phytoestrogens and antioxidants, exhibits chemosuppressive effects against the development and progression of ovarian cancer. We have shown that a diet of 10% flaxseed reduces the incidence and severity of ovarian cancer when fed to laying hens over 4 years, due in part to the ability of flaxseed to suppress the production of proinflammatory PGE2 in the ovary by decreasing expression of COX enzymes. To investigate other potential specific mechanisms by which flaxseed acts to suppress ovarian cancer, we examined expression and activity of pathways known to be involved in the etiology and progression of human epithelial ovarian cancer in ovarian cancer in the laying hen, and determined whether flaxseed affected these pathways during cancer development. We investigated the effect of flaxseed and its individual components upon oxidative stress in the normal ovary and in ovarian cancer by analyzing expression of target genes of the NRF2 transcription factor. The NRF2 pathway is a "master switch" that regulates expression of ROS-responsive detoxification genes. Results revealed that expression of four genes was significantly downregulated in then ovaries of hens on the defatted flaxmeal (DFM) and whole flaxseed (WF) diets compared to hens on diets that are high in pro-inflammatory omega-6 fatty acids, suggesting that flaxseed decreases oxidative stress in the ovary. Conversely, one target gene was upregulated in ovarian cancer compared to normal ovaries, and this observation was not affected by flaxseed. Additionally, nuclear accumulation Nrf2 protein was not observed in tumor cells, suggesting that flaxseed does not exert chemosuppressive effects by modulating NRF2 signaling in ovarian cancer. To further investigate pathways potentially regulated by flaxseed, we performed a microarray with 44k features and found that a set of genes involved in branching morphogenesis was upregulated in ovarian cancer and significantly decreased by flaxseed, including E-cadherin and miR-200, suggesting that flaxseed impedes the activity of an aberrantly activated developmental program that controls gland formation during ovarian cancer progression. Lack of nuclear accumulation of ZEB1 protein in tumor cells suggests that this decrease in expression is likely not due to EMT. Finally, due to its known roles in controlling developmental programs such as EMT as well as regulating cell growth and proliferation, we performed a set of experiments to examine activity of the TGF-beta pathway. PCR array analysis revealed that SMAD target genes, ligands, receptors, and co-regulatory proteins were upregulated in ovarian tumors from hens on both diet groups, suggesting TGF-beta signaling is enhanced in ovarian cancer. However, expression of SMAD6 and SMAD7 was upregulated in tumors from hens on the flaxseed diet but not control diet, with SMAD7 protein being expressed in both epithelial tumor cells and intratumoral stromal cells. Additionally, immunohistochemical staining for pSMAD2/3 was decreased in epithelial tumor cells and absent from intratumoral stromal cells in tumors from hens on the flaxseed diet compared to tumors from hens on the control diet, and these data together suggest that flaxseed may inhibit pro-oncogenic TGF-beta signaling in ovarian cancer. Finally, flaxseed prevents the downregulation of expression of p15 and the upregulation of CCNA and CCNE in ovarian tumors, suggesting that flaxseed may slow cell cycle progression. Data from these studies provides preliminary evidence that flaxseed exerts pleiotropic effects upon gene expression to negatively regulate pathways driving the progression of ovarian cancer, including aberrant TGF-beta signaling and glandular development. These studies provide groundwork for in vitro studies to test the specific effects of flaxseed upon proteins involved in TGF-beta signaling and upon the expansion of tumor epithelia.

Ovarian cancer is a deadly gynecological disease that ranks fifth in all cancer-related deaths inwomen. The disease is often detected at an advanced stage and lack of sensitive predictive biomarkerscontribute to its poor prognosis, which is also responsible for the current five-year survival rate of only47%. Our laboratory has previously shown that a whole flaxseed supplemented diet decreases the onsetand severity of ovarian cancer in the laying hen, the only known animal model of spontaneous ovariancancer. Flaxseed is rich in omega-3 fatty acids (OM3FA), mostly α-Linoleic acid (ALA), which getsconverted to Docosahexaenoic acid (DHA) by the action of delta-6 desaturase enzyme. We have also shownthat the flaxseed diet in hens induces CYP1A1 expression in the liver while suppressing both CYP1B1 andCYP3A4 expressions. The upregulation of CYP1A1 parallels the increase in 2-hydroxyestradiol and the 2-methoxyestradiol (2MeOE2) level in the serum of the chickens. Flaxseed diet induces apoptosis to ovariantumors and not in the normal ovarian tissues. The current work explores the pro-apoptotic actions of oneof the biologically derived compounds of flaxseed diet, 2MeOE2, and describes one of its novel molecularactions. Our results indicate that 2MeOE2 -mediated pro-apoptotic actions are partly dependent on thecatalytic activation of protein kinase C delta (PKCd), which is responsible for key apoptotic histonemodifications and p38 MAPK (MAPK14) phosphorylation. Phosphorylated MAPK14, in turn, results inmore caspase-3 cleavage which activates more PKCd, therefore amplifying the apoptotic signal.The other part of this work explains one of the key anti-cancer actions of a flaxseed diet. Flaxseedreduces the number of endothelial cells and increases pericytes to endothelial cell ratio in ovarian tumorscompared to control diet-fed birds, indicating a reduction in tumor angiogenesis and an improvement inblood vessel maturation. Flaxseed decreases a-smooth muscle actin expression in ovarian tumors, whichmarks a decrease in cancer-associated fibroblasts (CAFs) in the tumor stroma. Flaxseed also reduces fibrosisin ovarian tumors. Flax -mediated reduction of ovarian fibrosis parallels an increased infiltration ofimmune cells in the preneoplastic ovaries and ovarian tumors. Therefore, this work describes how the flaxdiet differentially targets the ovarian tumor cells and the tumor stroma in preventing the incidence andseverity of ovarian cancer. Dietary supplementation with flaxseed can, therefore, be a healthy lifestylechoice as well as a potential adjuvant therapy for immunotherapy-based treatment modalities.

Commercial laying hens are heavily selected for increased egg production, but little selection has occurred for resistance to extreme temperatures. The objective of the experiment was to determine the effects of a daily cyclic heat stress (HS) on performance, body temperature, egg quality, nitrogen corrected apparent metabolizable energy, and blood chemistry in laying hens at acute and chronic time points. In total, 407 pure line laying hen pullets (18 wk) were sourced from Hy-Line International and housed individually for the duration of the experiment. Feed intake, egg production, and body weights were significantly decreased while egg weight and feed efficiency increased due to HS exposure. All egg quality parameters except yolk weight were decreased by HS exposure, including Haugh unit, eggshell and albumen weights. Egg yolk weights were increased over the first 2 wk of HS before falling. Blood chemistry was affected by HS resulting in respiratory alkalosis likely caused by increased respiration and evaporative cooling. There was a decrease in the PCO2, an increase in pH and a reduction in iCa in the blood within 4 to 6 hours of HS when compared to pre-HS levels. The data indicate that the hens were negatively affected by HS and the response was different for acute and chronic time points. At the acute time point the changes to the hen's physiology were caused by altered blood chemistry, but after chronic exposure, the low feed intake seemed to influence the responses. / Master of Science

As productive performance is improved by breed selection, amino acid requirements may change to support this higher performance in poultry. The first objective of this dissertation was to update the valine and tryptophan requirement of small-framed laying hens and the lysine requirement of young broilers using empirical dose-response methods. The tryptophan requirement was estimated as 155.8 mg/d for egg mass, 153.2 mg/d for egg production and 140.4 mg/d for feed conversion ratio using a linear broken line model. For valine, the requirement was highest for egg mass, 597.3 mg/d, followed by egg production, 591.9 mg/d and feed conversion ratio (FCR), 500.5 mg/d. The lysine requirement of young chicks was estimated by conducting four short term experiments from 1 to 3, 3 to 5, 5 to 8 and 8 to 11 days of age, respectively. The lysine requirement from 1 to 3, 3 to 5 and 5 to 8 days of age were not able to be estimated as no dose response was observed on growth performance most likely due to an overestimation of the lysine requirement. Digestible lysine requirement from 8 to 11 days of age was 1.057%, 1.050% and 1.016% based on body weight gain, FCR and pectoralis major weight using a linear broken line model, respectively. In addition to determining amino acid requirements, research was conducted to develop a new bacterial protein meal for use in laying hens diets. The data suggested that diets containing 7.5% of the bacterial protein meal was able to at least maintain egg production in laying hens, but 15% bacterial protein meal resulted in reduced performance. The second objective of this dissertation was to investigate the effects of various concentrations of dietary vitamin D3 on pullet and laying hen performance, eggshell quality and bone health in laying hens. Pullets/hens were randomly assigned to five dietary treatments containing vitamin D3 from 1,681 to 68,348 IU/kg diet from day of hatch until 68 weeks of age. These data suggested that dietary vitamin D3 fed at 68,348 IU/kg resulted in reduced egg production, but vitamin D from 8,348 to 35,014 IU/kg diet maintained egg production, increased egg vitamin D content in a dose dependent manner, and generally increased both eggshell quality and pullet and hen bone mineral status. / Ph. D.

No description available.

Light-emitting diode (LED) is an improved light delivery technology that provides better energy efficiency, longer lifespan, and the ability to select a specific wavelength of light. We evaluated the effect of blue and red-LED on performance, behavior, egg quality, hormonal concentration, and prevalence of Avian pathogenic E. coli (APEC) like E. coli in pullets and laying hens raised in cageree housing system. Results showed that birds raised in blue-LED during the pullet phase had higher body weight and earlier onset of early lay. Red-LED increased the yolk percentage, illustrating that red-LED can stimulate reproduction. Red-LED also decreased the relative spleen percentage, which is an indication of decreased immunity. Overall egg production was not affected by the light treatment. Irrespective of the light treatment, a higher prevalence of APEC like E. coli was found in colonies isolated from the trachea suggesting a possible route of transmission in cageree housing system.