Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains vi, 83 p. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains xi, 77 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (MMedVet (Altil))--University of Pretoria, 2001. / Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1964. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 63-69.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains v, 46 p. : col. ill. Includes abstract. Includes bibliographical references.

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.

The objective of this study was to investigate the effects of cage density and excess vitamin D₃ on the incidence and severity of leg abnormalities in broiler chickens. In addition, sequential morphometric and radiographic characteristics of leg bone development were described in normal and abnormal broilers in an attempt to develop a pattern recognition for leg abnormalities in poultry. Twisted leg, characterized by a progressive medial (varus) or lateral (valgus) deviation of the distal tibiae was the predominant leg abnormality observed. Lateral deviations were more common than medial deviations (92% and 8%, repectively) and it occurred equally on the right and left leg. The incidence of twisted leg was considerably higher in cages than on litter (21% vs 4%, respectively). High density and excess dietary vitamin D₃ resulted in a significant increase in the incidence of twisted leg. Differences in incidence could not be explained through differences in body weight or feed consumption. However, broilers fed the excess vitamin D₃ consumed more but gained less body weight, suggesting a metabolic stress may have been involved. High density appeared to increase the severity of the disorders, while excess vitamin D₃ had no effect on severity. Morphometric and radiographic comparisons of tibiae from normal broilers and those with twisted leg suggested that the development of twisted leg may be related to a structural abnormality in the distal tibiae; namely shallow distal condyle grooves. Changes in tibiae morphology associated with the progression of the disorder appeared as functional adaptations to the deformation rather than the primary cause of the bone deviations themselves. Sequential radiography of tibae from clinically normal broilers revealed a high incidence of tibial dyschondro-plasia in the proximal metaphyses at 3, 4 and 5 weeks (60%, 20% and 20%, respectively). It was concluded that tibial dyschondroplasia may be more common than it is realized. / Land and Food Systems, Faculty of / Graduate

The effects of various aging, thawing and storage methods on the tenderness of frozen broiler Pectoralis major muscle were studied. Initial experiments were carried out to establish standard methods of freezing, cooking and tenderness evaluation to be used in subsequent experiments. The effects of varying the aging, thawing and storage techniques were then investigated using the established methods. Whole carcasses were frozen in a liquid nitrogen blast freezer after cooling in ice water for periods of 1 to 10 hours after slaughter, stored for 1 week at -31°C and thawed for varying lengths of time. The P. major muscles were removed and cooked in boiling water between metal plates. Tenderness evaluations were carried out using the Allo-Kramer shear press. The length of thawing time was shown to greatly influence the degree of toughness of the cooked muscles. When a thawing period of 4 hours in water at 25°C was used, a decrease in toughness took place in carcasses frozen between 1 and 2 hours post-mortem. This was followed by an increase to maximum toughness in birds frozen between 4 and 8 hours post-mortem. Maximum tenderness occurred in birds frozen 10 hours after death. Thawing birds in air at 4°C for 24 and 4 8 hours decreased the level of toughness attained after freezing 4 to 8 hours post-mortem. It did not significantly alter the degree of tenderness reached after 10 hours. Similarly, the decrease in toughness in birds frozen between 1 and 2 hours post-mortem, remained significant. Longer storage (3 months) at -23°C followed by rapid thawing eliminated both the decline in toughness of carcasses frozen between 1 and 2 hours post-mortem and the maximum toughness level attained by carcasses frozen 4 to 8 hours after death. An attempt was made to explain the decrease in toughness in carcasses frozen between 1 and 2 hours postmortem in terms of the aging temperature and medium used prior to freezing. No difference in the pattern was observed, however, when other pre-freezing aging techniques were used. Increases in the sarcomere lengths of muscle frozen at 2 hours post-mortem were observed, corresponding to the increase in tenderness occurring in carcasses frozen at this time. Isometric tension measurements, however, did not correlate well with these observations. Taste panel members were unable to discern differences in the tenderness of muscle frozen between 1 and 3 hours post-mortem although excellent correlations were obtained between Allo-Kramer shear press values and sarcomere length measurements. The results of these experiments therefore show that the ultimate tenderness of broiler muscle can be greatly influenced by the interaction of pre-freezing aging time, length of storage and thawing techniques used prior to cooking. / Land and Food Systems, Faculty of / Graduate

Memoria para optar al Título Profesional de Médico Veterinario / El objetivo de este estudio fue determinar el efecto de la inclusión de orujos de uva secos en la dieta de pollos broiler sobre variables productivas, características de la canal y capacidad antioxidante de la carne. Se caracterizaron orujos blancos (OB) y rosados (OR) secos por análisis químico proximal (AQP), polifenoles (PT), taninos totales (TT) y capacidad antioxidante por 2,2-Difenil-1-Picrilhidrazilo (DPPH). Luego 120 pollos broiler se distribuyeron a tres grupos de alimentación: control, C (0% OR y OB); grupo OB (20% OB) y grupo OR (20% OR). Se cuantificaron variables productivas: peso vivo (PV), consumo de alimento (CA), ganancia diaria de peso (GDP) y eficiencia de conversión alimentaria (ECA). La carne de pechuga y trutro se caracterizó por AQP, DPPH y color (ANOVA p<0,05). El uso de OB y OR no tuvo un efecto significativo sobre las variables productivas, a excepción de la ECA que fue mayor para el grupo OR. El contenido de extracto etéreo de la carne de pechuga de los grupos OB (1,5%) y OR (2,6%) fue mayor que el C (0,9%), sin embargo, la carne de trutro no mostró diferencias al AQP. No se observaron diferencias de color en la carne. La capacidad antioxidante de la carne de pechuga y trutro del grupo OB (16,7±0,5 y 16,4±0,5 µmoles ET/g, respectivamente) fue superior a los otros grupos (≈13 µmoles ET/g). La inclusión de OB no afecta las variables productivas de los pollos y aumenta la capacidad antioxidante de la carne. / The aim of this study was to determine the effects of the inclusion of dried grape pomace in diets of broiler chickens over productive parameters, carcass characteristics and antioxidant capacity of the meat. The white grape pomace (WGP) and pink grape pomace (PGP) were characterized by proximate analysis (PA), total polyphenols (TP), total tannins (TT) and antioxidant capacity by 2.2-Diphenyl-1-Picrylhydrazyl (DPPH). Then 120 broiler chicks were distributed to three feeding groups: control, C (0% WGP and PGP); WGP group (20% WGP) and PGP group (20% PGP). Productive parameters were quantified, such as: live weight (LW), weight gain (WG), feed intake (FI) and feed conversion efficiency (FCE). The breast and thigh meats were characterized by PA, DPPH, and color (ANOVA p<0.05). The use of WGP and PGP did not have a significant effect over the productive parameters, unlike the FCE that was greater for the PGP group. The crude lipid in the breast meat of the WGP (1.5%) and PGP (2.6%) groups was greater than C (0.9%), however, the thigh meat did not show differences in the PA. No color differences were observed in the meat. The antioxidant capacity of the breast and thigh meat of the WGP group (16.7±0.5 and 16.4±0.5 µmoles ET/g, respectively) was greater than the other groups (≈13 µmoles ET/g). The inclusion of WGP does not affect the productive parameters of the chickens and increases the antioxidant capacity of the meat.

The purpose of this study was to evaluate the Lys and Thr responses of TP-16 male broilers. Experiment 1 (14-28 d of age) showed no significant live performance effects. In Experiment 2, Lys and Thr (P=0.021) interacted to affect 28 to 42 d body weight gain and (P=0.004) feed intake. Lys main effects improved body weight gain (P=0.002), and feed conversion (P=0.009). Thr fed at the 0.68% level improved body weight gain and feed conversion. Mortality did not differ among treatments and averaged 0.09% across all treatments. The study indicated the sensitivity of the Thr:Lys ratio when broilers are fed diets containing marginal Lys. Although Thr X Lys interactions occurred in this study, the Lys levels in the test diets may have been too high for determining a ratio to an amino acid in a factorial study. Interaction results indicate that the Thr:Lys ratio in broilers from 28 to 42 days of age is between 0.57 to 0.68.