Call number: LD2668 .T4 1957 B46 / Master of Science

Call number: LD2668 .T4 1958 R63

Call number: LD2668 .T4 1962 J65

In broiler operations, various health problems develop during the final two weeks of the growing period, resulting in increased mortality and condemnation losses. At this stage, sickly birds were found to be systemically infected by various bacteria regardless of varied clinical signs. The main objective of the present study was to determine the prevalence and nature of systemic bacterial infections in unthrifty commercial broiler chickens and to establish a reproducible infection model in the laboratory. Thirty-one unthrifty 6-week-old broilers were obtained from three farms, and bacterial isolations were conducted on blood, liver, and hock joint. Bacteria were isolated from 87, 90, and 71% of the blood, liver and hock joint samples, respectively. Mean bacterial counts (log������ CFU/ml or g) of the blood and liver were 2.15 and 2.93, respectively. Among 132 bacterial isolates, major species were; Staphylococcus (60%), Corynebacterium (18%), Escherichia coli (5%), and Stomatococcus (4%). Among 79 Staphylococcus isolates, 77 were coagulase-negative. Major species of staphylococci were; S. lentus (19%), S. simulans (18%), S. cohnii (13%), S. gallinarum (10%) and S. captis (7%). In addition, 6 species of gram-positive and 5 species of gram-negative organisms were isolated. Apparently systemic infections were not caused by predominant pathogenic bacterial species, and adequately described as mixed infections. However, there were some significant relationships between isolated bacterial species and sampling sites, suggesting that certain organisms were abundant in the environment of a particular poultry house. These results indicate that systemic infections in market age broilers are caused by mixed bacterial species and suggest that they are caused by suppressed host antibacterial systems rather than pathogenic factors of microorganisms. Antibiotic susceptibility results showed 100% susceptibility of staphylococcal isolates (n=69) against vancomycin and enrofloxacin. Of these coagulase negative staphylococci showed 19% and 73% resistance against methicillin and penicillin G, respectively. There was also heterogeneity in antibiogram profiles within species of coagulase-negative staphylococci. Pathogenicity of representative field isolates from the above described study was tested in 5-day-old embryonated eggs and in 3- week-old broiler chicks. Consistent lethality was demonstrated with S. aureus in embryos. Staphylococcus intermedius or S. lentus demonstrated some pathogenicity, while S. gallinarum or Corynebacterium were non-pathogenic in embryos. In 3-week-old broilers, however, only S. aureus caused septicemia and death; other bacterial species mentioned above caused neither clinical signs of acute or chronic staphylococcosis nor mortality. / Graduation date: 1998

Seven experiments were carried out to investigate the involvement of carbohydrate and lipid metabolism on the incidence of Sudden Death Syndrome (SDS) in broiler chickens. Hepatic arachidonate level decreased after 1 h postmortem. The decreased level of hepatic arachidonate previously observed in SDS birds was, therefore, associated with the post-mortem aging. Broiler chickens fed diets high in glucose monohydrate (cerelose) were more susceptible to SDS mortality than broilers fed diets high in corn starch or corn-soy. Feeding broilers a high cerelose diet increased the levels of plasma calcium, total protein, triacylglycerol, and uric acid compared to broilers fed corn starch diet. Broilers fed cerelose diet also showed the higher incidence of leg abnormality than broilers fed corn starch or corn-soy diets. Daily intraperitoneal injection with 0.25 ml of L(+) lactic acid solution (100 mg lactic acid/ml) to broilers over a 7-d period failed to reproduce the SDS incidence, whereas intravenous injection of 40% lactic acid solution (200 mg lactic acid/kg body weight) resulted in 100% incidence of SDS-type mortality. No SDS-type mortality was observed with the intravenous injection of 40% sodium lactate solution (200 mg sodium lactate/kg body weight). Disturbance of physiological acid-base balance might be a factor in the SDS-type mortality. Suboptimal thiamin level in broilers fed cerelose diets was observed. Thiamin supplementation to cerelose diet improved the thiamin status of the broilers. Mortality due to SDS was decreased when thiamin hydrochloride was supplemented to cerelose diet at the level of 0.6 and 2.8 mg thiamin hydrochloride/kg diet, respectively. Thiamin supplementation, however, did not change the liver pyruvate dehydrogenase activity and the proportion of pyruvate dehydrogenase in the active form. Disturbance of acid-base balance was postulated to be associated with the incidence of SDS. Other genetic, nutritional, and environmental factors are likely to modify the incidence by affecting the acid-base status of the chicken. / Graduation date: 1993

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Two immunologically distinct strains of poultry coccidium Eimeria maxima, Guelph (GS) and M6 strains, were investigated. Paired in vivo experiments demonstrated that GS and M6 have prepatent periods of approximately 120 h followed by peak oocyst shedding at 144 150 h post inoculation. Fecundity of E. maxima M6 (12.8×103±1.95 oocysts shed/oocyst inoculated) was approximately twice that of GS (6.9×103±3.33) when inoculated with 1×103 infective oocysts per bird. Numerous sequential observations of synchronized populations of oocysts sporulating at 26°C showed no difference in the sporulation kinetics of the two strains; in both strains, sporogony was divided into five morphologically distinguishable stages whose abundance peaked at the following times during sporulation: unsporulated oocysts at 0 h; sporoblast anlagen at 18 h; sporoblasts without sporocyst walls at 22 h; and sporocysts without mature sporozoites at 38 h. Total RNA was isolated from four stages of sporogonic development (18 h, 22 h and 38 h of sporulation, and excysting sporozoites). These RNA samples were quantitatively pooled from each strain separately prior to selection of poly A mRNA that was then fragmented, end-labeled and pyrosequenced using an Illumina HiSeq 2000 sequencer. The resulting transcriptome sequences (~48.8×109bp total reads) were paired and de novo assembled. Ten thousands transcripts (5,000 from each strain) were searched against GenBank using blastx. A total of 2,067 transcripts of GS and 1,610 transcripts of M6 were assigned to putative biological function; ~60% of functionally annotated transcripts mapped to metabolic or cellular processes. GPI anchored surface antigens (SAgs) identified in GS (18 SAgs) and M6 (18 SAgs) belonged to four major multi copy gene families and 2 single copy loci. Relative expression of SAgs expressed by both strains was generally similar; however, 3 GPI-anchored SAgs were uniquely expressed by each of GS and M6. One multigene locus demonstrated strain-specific SAg expression that may explain the lack of cross immunity between these strains. This represents the first transcriptome data of sporulation of E. maxima and first comparison of immunologically distinct strains of any Eimeria sp. These data should aid in the search for antigenic targets that could be included in future subunit vaccines against these important agricultural parasites. / Research Funding: Natural Sciences and Engineering Research Council of Canada (NSERC) and the Ontario Ministry of Agriculture and Food (OMAF); Funding of Studies: Iraqi Ministry of Higher Education and Scientific Research (MOHESR) for PhD scholarship support; American Society of Parasitologists for a Marc Dresden Travel Award to attend the 2012 ASP Annual Meeting.

This investigation was concerned with determining the relationships of Culicoides to poultry in Virginie while studying their role as potential vectors of infectious synovitis. In addition, a survey of Culicoides in Virginia was made to study their distribution, bionomics and life histories. The insects were trapped in the field, collected as larvae, and reared in the laboratory. Using light traps in chicken coops at Ferrum, Virginia in 1959, it was found that the following species of Culicoides were present; arboricola, crepuscularis, debilipalpis, guttipennis, haematopotus, obsoletus (most abundant), ousairani, stellifer, travisi, variipennis, venustus, and villosipennis. During the same summer, traps at Poplar Camp took many of the above species plus biguttatus and the piliferus group. That same year a single specimen of C. paraensis was taken while biting the author. Light trapping in 1960 was done at Blacksburg about three nights a week for six months. Other trapping was done at Elkton, Newport and Saltville. At Blacksburg and Elkton traps were operated both in the woods and in poultry houses. The 1960 trapping activities revealed the following species were present: arboricola, baueri, biguttatus, crepuscularis, chiopterus, debilipalpis, guttipennis, haematopotus, obsoletus, ousairani, piliferus group, snowi, spinosus, stellifer, travisi, variipennis, venustus, and villosipennis. All but chiopterus, debilipalpis, snowi, and spinosus have been taken in poultry houses. In 1960 crepuscularis was the most abundant species taken in poultry houses and travisi was the most numerous species in the woods. It was found that more Culicoides were taken in poultry houses located near a woods than in ones farther from a woods. Trapping revealed that Culicoides were most abundant at Blacksburg in June, with May being the next most favorable month. The following species were found every month: haematopotus, obsoletus, stellifer, and variipennis. All specimens were preserved in 70 per cent ethyl alcohol and latex mounted in phenol-balsam on microscope slides. Apparently the weather had little influence on the trapping results. During 1959 and 1960 larvae were collected in a number of situations, but mostly from rot hole: in trees and soft mud. Tree-hole collections produced specimens of C. arboricola, guttipennis, and namis. Mud and muddy water produced C. variipennis. The latter were extremely abundant in saline mud at Saltville, there being found as many as 2000 larvae per 500 cc. of mud. These were used in the infectious synovitis transmission experiments. The larvae were reared in pans and crocks containing their original substrate. After emergence they were held in cages fashioned from round ice cream cartons, and kept in an incubator at 75° F. and approximately 40 per cent relative humidity. Under these conditions the adults lived an average of 27.7 days after emergence with the longest time being 96 days. The adults emerged in largest numbers four to eight days after collection. In 1959 attempts were made to transmit infectious synovitis to healthy chickens by injecting them with macerated, engorge. Culicoides which had been live-trapped in poultry houses containing chickens infected with the disease. These attempts were unsuccessful. In 1960 specimens of C. variipennis were induced to feed upon chickens injected with the agent of infectious synovitis. These were later macerated at varying intervals and injected into healthy chickens. No transmission was demonstrated. It was found that the insects fed most readily on the heads of chickens when the insects were two to four days old. / Ph. D.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.