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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Phospholipase A��� mRNA expression in testes from roosters (Gallus domesticus) characterized by high or low sperm mobility phenotype

Eguchi, Yuko. 22 September 2000 (has links)
Previous research has shown that sperm mobility is a primary determinant of fertility in fowl. Sperm mobility denotes the net movement of a sperm population, and males can be characterized by phenotype. Sperm acylcarnitine content differs between low and high sperm mobility phenotypes. The release of acyl groups from phospholipids within sperm depends on the action of the enzyme phospholipase. Inhibition of phospholipase A��� (PLA���) activity eliminates sperm motility, thereby rendering sperm immobile. This research was performed to test whether cPLA��� was expressed differentially in roosters characterized by low or high sperm mobility phenotype. cPLA��� expression in the two phenotypes was compared using reverse transcription - polymerase chain reactions. The cDNA amplified was a 352 nucleotide fragment encoding the Ca����� binding domain of cPLA���. Two sequential experiments were performed using full- and half-sib roosters. In the first experiment (n=3 full�� sibs per phenotype), cPLA��� expression was greatest in testes from the high phenotype relative to ��-actin or 18S rRNA (P < 0.05 and P < 0.0057, respectively). The average cPLA��� : ��-actin ratios for high and low sperm mobility phenotypes were 0.63 �� 0.260 (mean �� SEM) and 0.32 �� 0.123, respectively. The cPLA��� : 18S rRNA average ratios were 0.74 �� 0.158 and 0.38 �� 0.135 for high and low sperm mobility phenotypes, respectively. In the second experiment (n=6 half-sibs per phenotype), the high mobility phenotype also showed greater (P < 0.023) expression of cPLA��� relative to the 18S rRNA control with averages of 0.74 �� 0.141 and 0.49 �� 0.104 for high and low sperm mobility phenotypes, respectively. Moreover, sequence analysis of the nucleotide fragment showed no difference between phenotypes. cPLA��� expression clearly differed between sperm mobility phenotypes. It was concluded that a difference in the regulation of cPLA��� mRNA expression contributes to variation between lines of roosters generated by selection for sperm mobility. / Graduation date: 2001
12

Thyroid hormone activation by intestinal tissue of high and low weight-selected chickens /

Suvarna, Shayela, January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 41-47). Also available via the Internet.
13

Energy efficiency and nutrient partitioning in the modern broiler chicken

Aitchison, Mia January 2014 (has links)
No description available.
14

Effects of moderate ascarid infections upon the resistance of chickens to bacterial toxin

Folse, Dean Sydney January 2011 (has links)
Typescript, etc. / Digitized by Kansas State University Libraries
15

A survey on isozyme genetics of the domestic chicken (Gallus domesticus)

衛善敏, Wai, Sen-mun. January 2000 (has links)
published_or_final_version / Zoology / Master / Master of Philosophy
16

Protection and stimulation of intestinal innate immunity using mannan oligosaccharides

Brady, Jessica 10 December 2010 (has links)
Necrotic enteritis (NE) caused by Clostridium perfringens is a re-emerging disease of economic importance in areas of the world where antibiotic growth promoters have been banned. Various alternatives to antibiotic growth promoters are being tested including prebiotics known as mannan oligosaccharides (MOS) which have been shown to mitigate the effects of NE and potentially boost the immune system, though the mechanism is not completely understood. The objective of this study is to test the effectiveness of MOS on balance of microbial populations, gut morphology and immune system ability; specifically: C. perfringens genetic populations, villi architecture and TLR2 and TLR4 activity. This study focuses on organic broiler chickens fed MOS at 0, 2, 4, 6 and 8g/kg feed and challenged with an inoculation of C. perfringens isolated from an outbreak on a local organic farm. Toxinotype and 16S phylogenetic analysis of C. perfringens were reviewed as well as feed efficiency, gut morphology and gene expression of Toll Like Receptors 2 and TLR4 using qRT-PCR. All field isolates were found to be Type A C. perfringens, as were most experimental isolates except for two isolates taken pre-innoculation, which were more likely attributed to contamination of the experiment room by cattle which were housed there previously. No association between pathogenecity and toxin genes cpb2 or netB could be established during this study. 16S analysis found all C. perfringens isolates to be highly related, though there seemed to be a change in populations post inoculation which did match the field isolate used for inoculation. Gut morphology readings including villi height, width and area, crypt depth and lymphocyte and goblet cell concentrations showed some significant effect though it was not in a common area of the intestine and was often due to the interaction between treatments and time. These results also failed to reproduce effects found by other authors. TLR2 and 4 were not found to be significantly different between treatments, though certain trends were noted. The lack of significant treatment effects as well as the low reproducibility of these outcomes leads to the conclusion that, though MOS may contribute to gut health and maturity based on these and conclusions found by other authors, its effect is hinging on other factors such as management and nutrition.
17

Protection and stimulation of intestinal innate immunity using mannan oligosaccharides

Brady, Jessica 10 December 2010 (has links)
Necrotic enteritis (NE) caused by Clostridium perfringens is a re-emerging disease of economic importance in areas of the world where antibiotic growth promoters have been banned. Various alternatives to antibiotic growth promoters are being tested including prebiotics known as mannan oligosaccharides (MOS) which have been shown to mitigate the effects of NE and potentially boost the immune system, though the mechanism is not completely understood. The objective of this study is to test the effectiveness of MOS on balance of microbial populations, gut morphology and immune system ability; specifically: C. perfringens genetic populations, villi architecture and TLR2 and TLR4 activity. This study focuses on organic broiler chickens fed MOS at 0, 2, 4, 6 and 8g/kg feed and challenged with an inoculation of C. perfringens isolated from an outbreak on a local organic farm. Toxinotype and 16S phylogenetic analysis of C. perfringens were reviewed as well as feed efficiency, gut morphology and gene expression of Toll Like Receptors 2 and TLR4 using qRT-PCR. All field isolates were found to be Type A C. perfringens, as were most experimental isolates except for two isolates taken pre-innoculation, which were more likely attributed to contamination of the experiment room by cattle which were housed there previously. No association between pathogenecity and toxin genes cpb2 or netB could be established during this study. 16S analysis found all C. perfringens isolates to be highly related, though there seemed to be a change in populations post inoculation which did match the field isolate used for inoculation. Gut morphology readings including villi height, width and area, crypt depth and lymphocyte and goblet cell concentrations showed some significant effect though it was not in a common area of the intestine and was often due to the interaction between treatments and time. These results also failed to reproduce effects found by other authors. TLR2 and 4 were not found to be significantly different between treatments, though certain trends were noted. The lack of significant treatment effects as well as the low reproducibility of these outcomes leads to the conclusion that, though MOS may contribute to gut health and maturity based on these and conclusions found by other authors, its effect is hinging on other factors such as management and nutrition.
18

Epidemiology and control of the poultry red mite, Dermanyssus gallinae /

Nordenfors, Helena, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.
19

Laying hens in loose housing systems : clinical, ethological and epidemiological aspects /

Gunnarsson, Stefan, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.
20

Feather pecking in laying hens : social and developmental factors /

Bilčík, Boris. January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

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