Thesis (Ph. D.)--University of Wisconsin--Madison, 1974. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 254-271).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1942. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 51-54.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 76).

Thesis (M.S.)--University of Wisconsin--Madison, 1940. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 20-21).

Thesis (M.S.)--Ohio State University. / Includes bibliographical references (leaves 20-27). Available online via OhioLINK's ETD Center.

Thesis (Ph. D.)--University of Chicago, 1922. / Letterpress descriptive of opposite plate on verso of each plate. "Author's abstract of this paper issued by the [Wistar institute] Bibliographic service, March 14." Stamped on t.p.: Private edition, distributed by the University of Chicago libraries, Chicago, Illinois. "Reprinted from the Journal of experimental zoölogy, vol. 33, no. 1, May, 1921." "Literature cited": p. 40-41. Also available on the Internet.

The aim of the study was to evaluate the effect of ozone (O3) on mature body weight (MBW), feed conversion rate (FCR), mortality rate (MR) and ammonia (NH3) production of broiler chickens (referred to as “broilers” in this thesis) under controlled conditions. Ozone was used for the purifying of air and water in order to eliminate harmful microorganisms. Two trials were conducted over a twelve week production period. In experiment 1, day old broiler chicks were randomly allocated to a control (n=130) and treatment (n=130) group. The treatment groups were exposed to ozone continuously for the entire period of the trial. Both air and water were ozonated on a 24 hours daily basis, while the control group was reared under normal commercial conditions. In experiment 2: day old broiler chicks were randomly allocated to a control (n=123) and a treatment (n=123) group. The treatment group was exposed to ozone for 3 hours per day for the entire period of the trial. Both air and water were ozonated, where the air was treated for 3 hours/day and the water for 1 hour/day during the entire production period. The control group was reared under normal commercial conditions. The results indicate that broilers exposed to continuous O3 (0.1 ppm) conditions had significantly higher (P< 0.001) mortality rates than the control group. The treatment group had a mortality rate of 55.38% compared to the 5.38% for the control group. No significant difference (P= 0. 2468) for MBW was found between the broilers that were reared in the O3 environment compared to the control iii group. Although the control group were on average 200g heavier at the end of the trial. No significant difference (p = 0. 6143) was recorded in FCR between the O3 and control groups. However the FCR of the broilers treated with O3 was lower by 100g than that of the control group. The O3 significantly (P< 0. 0001) reduced the NH3 in the treatment group. When the trial was repeated with limited exposure to an O3 environment there was no significant difference in MBW (P = 0. 0979), FCR (P = 0. 8913) and MR (P = 0. 1108) between the treatment and control groups. However, ammonia levels were lower in the treatment group compared to the control group. When the data was further analyzed comparing the two trials, the results indicated that there was no significant difference (P = 0. 4112) in the MBW for the broilers reared under normal conditions (control group) from experiment 1 and experiment 2, while a significant difference (P = 0. 0002) was recorded between the broilers reared under continuous O3 and regulated O3 conditions from experiment 1 and experiment 2 respectively. When the FCR data was analyzed using the Gompertz equation a significant difference (P = 0.0403) in the FCR of broilers reared in the control group between experiment 1 and experiment 2 was recorded (Table 8). No significant difference (P = 0.3226) in the FCR of broilers raised under O3 conditions of continuous and regulated O3 production were reported between experiment 1 and experiment 2. A highly significant difference (P = 0. 0001) in the MR of broilers reared under ozone conditions was recorded between experiment 1 and experiment 2. In experiment 1, the MR was 55.38% while in experiment 2 the MR was only 8.78%. A significant difference (P = 0.0355) was also recorded in the MR of broilers that iv were raised in the control groups between experiment 1 and experiment 2. The MR for broilers in the control group was 5.38% in experiment 1 and for experiment 2 it was 9.74%. The mortality rate of broilers raised in the control groups conditions increased by approximately 4% points or 81% between experiment 1 and experiment 2. The level (0.1 ppm) of ozone production had a limited effect on the MBW and FCR of broilers, however it is evident that ozone is toxic to broilers when they are exposed to a continuous ozonated environment. Ozone was however effective in controlling ammonia levels.

Characterization of village chicken phealth and management practices in the Amatola Basin of the Eastern Cape Province, South Africa By Njongenhle M. B. NYONI The majority of rural households in South Africa own village chickens which contribute significantly to their livelihoods. However, limited research has been conducted to characterize, understand and develop village chicken production in South Africa. This hinders the designing and implementation of village chicken-based developmental programmes that will benefit farmers in rural areas. Thus, it is imperative to initiate studies to describe village chicken production. This study was conducted to characterize village chicken production in Amatola Basin of the Eastern Cape Province of South Africa. Baseline information was gathered using a questionnaire survey of 81 identified from 7 out of 13 villages using snowball sampling technique. Consequently, 20 households were selected to participate in a monitoring study (from July 2010 to June 2011) through purposive sampling. Most (60%) chicken flocks were owned by women and mainly raised to meet household food requirements. Some (28.4%) farmers occasionally sold cocks and hens to neighbours, at an average price of R50 (USD7.55) per bird, as a way of culling their flocks and generating income. However, village chickens were mainly kept for food security rather than for their terminal benefit of cash. Although, all chicken flocks were produced under the scavenging feeding system, most (96%) flocks were provided with supplementary feed and drinking water. A majority (93.8%) of households also provided some form of shelter for their chickens. The mean cock to hen to chick ratio was 1:5:15. On average, iii each household owned 17 (±2 S.E.M.) chickens, and hens had 3.3 clutches per annum. Chicks hatched and chickens received as gifts represented the flock entries, while exits included mortality, consumption, sales and gifts or donations, in that order. Generally, both exits and entries were more pronounced in the summer season than in other seasons. Most (81.5%) farmers experienced chicken losses due to predation and health related problems. Parasitism ranked high amongst the village chicken health challenges. During monitoring, the endoprasites identified included nematodes, cestodes and protozoa. Coccidia were the most prevalent endoparasites. The chickens were also infested with a variety of ectoparasites namely: mites, lice, fleas and ticks. The sticktight flea Echidnophaga gallinacean was the most prevalent species. Although ectoparasite infestations were most pronounced in summer, almost all chickens harbored one or more of these parasites throughout the study period. The prevalence and intensity of parasite infestations were significantly (P<0.05) higher in the summer season compared to the other seasons. This was followed by the autumn, spring and winter seasons, respectively. The majority (77.5%) of farmers resorted to alternative remedies, mostly medicinal plants, for treating diseases and controlling parasites. Medicinal plants were used because they were locally available, cheap and perceived to be effective. Therefore, village chicken production in the rural Eastern Cape Province is characterised by several challenges which counter the significant role chickens play in the livelihood of rural households.