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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.
41

Sexual Dimorphism in a Joint-Nesting Plural Breeder, the Smooth-Billed Ani (Crotophaga ani) / Sexual Dimorphism in Smooth-Billed Anis / Sexual Selection in a Joint-Nesting Plural Breeder, the Smooth-Billed Ani (Crotophaga ani)

Barclay, Megan 09 1900 (has links)
Sexual selection has been investigated in many different systems but information is lacking in joint-nesting species. Both sexual dimorphism and possible signals of quality were explored in this study for a joint-nesting plural breeder, the smooth-billed ani (Crotophaga ani). Sexual dimorphism can be examined for a species in an attempt to reveal particular traits that might be under sexual selection and the strength of sexual selection on them. In mate choice decisions, sexually selected traits may be used by the choosy individual to assess the quality of potential mates. These honest traits need to reveal the condition and genetic quality of the individual accurately. For example, it has been proposed that plumage colour reveals condition, and more specifically parasite resistance in birds. This study explores sexual size dimorphism and dichromatism in smooth-billed anis, as well as the ability of their feather colour to reveal body condition (measured as residuals from a regression of mass versus body size), body size, and parasite numbers. Additionally, because anis are group living birds, this study investigated whether group size had an effect on parasite numbers. Anis from a population in southwestern Puerto Rico were measured for size, their feathers were collected and analyzed using a spectrometer, and ectoparasites were collected by dustruffling. For all size traits measured, males were significantly larger than females. Males also had more exaggerated bill depths (relative to body size) than females. There were no differences between the sexes for all colour morphometries, except tail saturation; females had more saturated tails than males. While no decisive conclusions can be drawn as to why the dimorphic traits are different between males and females, sexual selection may have played a role. The relationship between log10 average lice numbers per group and group size was positive, but not significant. In male smooth-billed anis, plumage colour was not related to lice or mite numbers, or body size and body condition. Plumage colour was also not related to body condition and size in females. Additionally, ectoparasites did not have an effect on male body condition. Plumage may not only be an inaccurate signal of parasite resistance or body size and body condition in the smooth-billed ani, but ectoparasites may not even have a negative effect on their host. The inability to find significant results may have been affected by other factors, such as feather wear and the age of individuals. These results warrant a more detailed look into the social behaviour of the group-living smooth-billed ani. / Thesis / Master of Science (MSc)
42

Heat transfer and fluid flow aspects of fuel-coolant interactions.

Corradini, M. L January 1979 (has links)
Thesis. 1979. Ph.D. cn--Massachusetts Institute of Technology. Dept. of Nuclear Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / Ph.D.cn
43

Physiological stress and behavioural differences in broiler breeder hens subjected to daily and 5:2 feed restriction regimens

Johansson, Alexandra January 2016 (has links)
Feed restriction in the parental stock of meat producing chickens, broiler breeders, is essential in order to decrease the high growth rate that they are genetically selected for. The feed restriction does however lead to chronic hunger and stress. Stress can be measured by counting H/L ratios and the method of manually counting H/L ratios was evaluated. The method was not a good way to ensure reliable individual H/L ratios but still gives an H/L ratio indication on a group level and was therefore still used in the study. Two different feeding regimens were investigated in the study: 5:2 skip-a-day (SKIP) with two fasting days and daily feed restriction (CTRL), with chickens sampled at 9 and 12 weeks of age. There was no significant difference in body mass between the treatments at either age. SKIP chickens had significantly higher H/L ratios compared to CTRL at 12 weeks of age (P=0.020), but both treatments had H/L ratios above the reported limit of stress (0.5). The SKIP group on a feeding day significantly increased plasma glucose levels during the day (10.3 to 11.5 mmol/L, P=0.020) and had significantly higher liver mass and liver glycogen levels compared to the CTRL (P≤0.001). The SKIP group were also less fearful on fasting days and significantly less active than the CTRL (P≤0.050), regardless of age or daily feed differences. The conclusion was that both treatments were stressed but skip-a-day chickens were habituated to their regimen and did not experience worse welfare than daily fed broiler breeders.
44

The effect of channeling on the dryout of heated particulate beds immersed in a liquid pool

Reed, Alfred Walters January 1982 (has links)
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Alfred Walters Reed. / Ph.D.
45

From pup to predator : ontogeny of foraging behaviour in grey seal (Halichoerus grypus) pups

Carter, Matt January 2018 (has links)
For young animals, surviving the first year of nutritional independence requires rapid development of effective foraging behaviour before the onset of terminal starvation. Grey seal (Halichoerus grypus) pups are abandoned on the natal colony after a brief (15-21 days) suckling period and must learn to dive and forage without parental instruction. Regional and sex-specific differences in diet and foraging behaviour have been described for adults and juveniles, but the early-life behaviour of pups during the critical first months at sea remains poorly understood. This thesis investigates sources of intrinsic and extrinsic variation in the development of foraging behaviour and resource selection in grey seal pups. The studies presented here feature tracking and dive data collected from 52 recently-weaned pups, tagged at six different breeding colonies in two geographically-distinct regions of the United Kingdom (UK). Original aspects of this thesis include: (Chapter I) a comprehensive review of analytical methods for inferring foraging behaviour from tracking and dive data in pinnipeds; (Chapter II) description and comparison of regional and sex differences in movements and diving characteristics of recently-weaned pups during their first trips at sea; (Chapter III) implementation of a novel generalized hidden Markov modelling (HMM) technique to investigate the development of foraging movement patterns whilst accounting for sources of intrinsic (age, sex) and extrinsic (regional) variation; and (Chapter IV) the first analysis of grey seal pup foraging habitat preference, incorporating behavioural inferences from HMMs and investigating changes in preference through time.
46

Qualidade da carne de matriz pesada em final de ciclo de produção e tecnicas de agregação de valor /

Komiyama, Claudia Marie, 1978- January 2009 (has links)
Orientador: Ariel Antonio Mendes / Banca: Roberto de Oliveira Roça / Banca: Marcia Regina Boaro Martins / Banca: Hirasilva Borba / Banca: Rodrigo Garófallo Garcia / Resumo: O objetivo do trabalho foi avaliar as características de qualidades da carne de matrizes pesadas de descarte. Foram realizados três ensaios para se avaliar a qualidade da carne em final de ciclo produtivo. Todas as aves pertenciam a linhagem comercial Ross, procedentes de Uberlândia (MG) e Campo Verde (MT) com idade e peso médio de 479 dias e 3.971g, respectivamente. No Ensaio 1 foram coletados 120 peitos de matrizes em 6 coletas diferentes e avaliados os seguintes parâmetro: pH, cor, valor R, perda por gotejamento, capacidade de retenção de água e absorção de água, capacidade de emulsificação, perdas por cocção e força de cisalhamento. No Ensaio 2 foi realizado o teste sensorial da carne de peito de matrizes comparado a frangos de corte, sendo coletado 20 peitos de matrizes de descarte e 20 peitos de frangos de corte em abatedouro comercial. No Ensaio 3, foram avaliados a composição química, o teor de colesterol e o perfil de ácidos graxos da carne de matrizes pesadas de descarte. A carne de peito de matrizes apresentou valores médios do parâmetro valor de L* de 50,11. Para a capacidade de retenção, perda de peso por cozimento e força de cisalhamento, os valores médios foram 76,67, 17,92% e 4,94kgf/cm2 respectivamente. Na análise sensorial, a carne de matriz apresentou baixa intensidade de maciez (6,9), menor suculência (3,4) e mais elástica, borrachenta e difícil deglutição. A carne de matrizes apresentou percentagem de gordura, proteína, matéria seca, umidade, cinzas e colesterol de 1,39%, 24,26%, 27,71%, 72,29%, 1,42% e 72,59mg/100g, respectivamente. A carne de matrizes pesadas de descarte apresentou boas características de qualidade tecnológicas que possibilitam sua utilização como matéria-prima para a elaboração de industrializados. Além disso, apresentou composição química semelhante a da carne de frangos de corte, não possuindo altos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This present aimed to evaluate the meat quality characterists of spent breeder hens. There were realized three trials to evaluate meat trait of spent breeder hens. All birds were Ross stain, from Uberlândia city (MG) and Campo Verde city (MT) with age and weigth average of 479 days and 3.971g, respectively. In trial 1, there were evaluated: pH, color, R value, drip loss, water holding capacity, water absorption capacity, emulsifying capacity, cooking loss and shear force. In trial 2, it was realized the sensory test using breast meat of breeder hens compared to broiler chicken, collecting 20 spent breeder hen breast and 20 broiler chicken breast cropped in commercial processing plant. In trial 3, there were evaluate the chemistry composition, cholesterol value and fatty acid profile of spent breeder hens meat. Breeder hens meat presented L* value means of 50.11. To water retention capacity, cooking loss and shear force, means values were 76.67, 17.92% e 4.94kgf/cm2, respectively. In sensory test, breeder hens meat presented low intensity tenderness (6.9), lower juiciness (3.4) and elasticier, rubber and difficult to swallow. Breeder hens meat presented percent of fatty, protein, dry material, humidity, material mineral and cholesterol of 1.39%, 24.26%, 27.71%, 72.29%, 1.42% e 72.59mg/100g, respectively. Broiler hen meat presented good technology quality characteristics that it can be possible to use as meat for industry elaborated. Besides, this meat present chemistry composition equal of the meat of broiler chicken, do not hold high value of fat and cholesterol, hence these meat can be consider a meat with healthy characteristics. / Doutor
47

Exigência de cobre para matrizes de frango de corte / Copper requirements of broiler breeder hens

Berwanger, Eveline January 2018 (has links)
Esta tese foi conduzida com o objetivo de avaliar a exigência do micromineral cobre para matrizes de frangos de corte. Cento e vinte reprodutoras de frangos de corte Cobb 500, com 20 semanas de idade, foram distribuídas aleatoriamente em gaiolas individuais. Depois de alimenta-las por 4 semanas com a dieta deficiente em cobre, as galinhas receberam dietas com níveis graduados de suplementação de cobre (0,0; 3,5; 7,0; 10,5; 14, and 17,5 ppm), utilizando sulfato de cobre (CuSO4 5H2O), totalizando níveis de 2,67; 5,82; 9,38; 12,92; 16,83; 20,19 ppm de cobre analisado na dieta por 20 semanas. As estimativas da exigência de cobre foram feitas utilizando os modelos: exponencial assimptótico (EA), broken line com quadrática (BLQ), e quadrática polinomial (QP). Os requerimentos de cobre obtidos para a produção de ovos (%) e produção total de ovos incubáveis por galinha foram 6,2, 7,3, 12,9 ppm e 8,1, 9,0 e 13,4 ppm, respectivamente usando os modelos EA, BLQ e QP. O modelo QP foi o único que se ajustou para o número total de ovos por galinha, fornecendo 13,1 ppm de cobre como requerimento. A hemoglobina, hematócrito e concentração de cobre no soro das galinhas tiveram os requerimentos estimados em 13,9, 11,3, 18,5 ppm, e 14,6, 13,0, 19,0 ppm, e16,2, 14,6 e 14,2 ppm, respectivamente para os modelos EA, BLQ e QP. O modelo QP foi o único que se ajustou para o número total de ovos por galinha, fornecendo 13,1 ppm de cobre como requerimento. A hemoglobina, hematócrito e concentração de cobre no soro das galinhas tiveram os requerimentos estimados em 13,9, 11,3, 18,5 ppm, e 14,6, 13,0, 19,0 ppm, e16,2, 14,6 e 14,2 ppm, respectivamente para os modelos EA, BLQ e QP. A hemoglobina dos pintos recém-eclodidos não foi afetada pelos níveis de cobre da dieta, enquanto os requerimentos para o hematócrito, peso corporal e comprimento foram de 10,2, 12,3, 13,3 ppm usando os modelos EA, BLQ e QP, e 6,8, 7,1 ppm e 12,9, 13,9 ppm utilizando os modelos EA, BLQ e QP, respectivamente. A máxima resposta para peso do ovo, conteúdo de cobre na gema, espessura da membrana da casca do ovo foram obtidas usando 14,9, 12,7, 15,1 ppm, 15,0, 16,3, 15,7 ppm, e 7,3 7,8, 14,0 ppm de cobre, respectivamente para os modelos EA, BLQ e QP. As porcentagens de gema e albúmen foram ajustadas apenas pelo modelo QP e obtiveram requerimentos estimados em 11 ppm e 11,3 ppm, respectivamente, enquanto a espessura da camada mamilar da casca do ovo foi maximizada com 10,6, 10,1 e 14,4 ppm de cobre usando os modelos EA, BLQ e QP, respectivamente. A média de todos os requerimentos de cobre estimados no presente estudo foi 12,5 ppm. / This thesis was conducted with the objective of evaluating the Cu requirement of broiler breeder hens. One hundred and twenty Cobb 500 hens, 20 weeks of age were randomly allocated into individual cages with the objective of estimating Cu requirements. After being fed a Cu deficient diet for 4 wks, hens were fed diets graded increments of supplemental Cu (0.0; 3.5; 7.0; 10.5; 14, and 17.5 ppm) from Cu sulfate (CuSO4 5H2O), totalizing 2.67; 5.82; 9.38; 12.92; 16.83; 20.19 ppm analyzed Cu in feeds for 20 wks. Estimations of Cu requirements were done using exponential asymptotic (EA), broken line quadratic (BLQ), and quadratic polynomial (QP) models. Cu requirements obtained for hen day egg production and total settable eggs per hen were 6.2, 7.3, 12.9 ppm and 8.1, 9.0 and 13.4 ppm, respectively using EA, BLQ and QP models. The QP model was the only one having a fit for total eggs per hen with 13.1 ppm Cu as requirement. Hemoglobin, hematocrit and serum Cu from hens had requirements estimated as 13.9, 11.3, 18.5 ppm and 14.6, 13.0, 19.0 ppm and 16.2, 14.6, 14.2 ppm, respectively for EA, BLQ and QP models. Hatching chick hemoglobin was not affected by dietary Cu whereas requirements estimated for hatching chick hematocrit, body weight and length were 10.2, 12.3, 13.3 ppm using EA, BLQ and QP models, and 6.8, 7.1 ppm and 12.9, 13.9 ppm Cu using EA and BLQ models, respectively. Maximum responses for egg weight, yolk Cu content, and eggshell membrane thickness were 14.9, 12.7, 15.1 ppm, 15.0, 16.3, 15.7 ppm and 7.3, 7.8, 14.0 ppm Cu, respectively for EA, BLQ and QP models. Yolk and albumen percentage were only adjusted with the QP model and had requirements estimated at 11.0 ppm and 11.3 ppm, respectively, whereas eggshell mammillary layer was maximized with 10.6, 10.1 and 14.4 ppm Cu using EA, BLQ and QP models, respectively. The average of all Cu requirement estimates obtained in the present study was 12.5 ppm Cu.
48

Luteinizing Hormone an Progesterone Respnse to GnRH Administration at Insemination in Repeat-Breeder Holstein Cows

Callan, Robert Joseph 01 May 1988 (has links)
Several studies suggest that the administration of GnRH near the time of insemination improves pregnancy rates in cattle. It has also been reported that there is greater improvement in repeat-breeder animals than at first service. The mechanism for this observation has not been established. Twenty-eight lactating Holstein cows that returned to estrus after one or more inseminations from the usu caine Dairy were used in the study. Anilrals were rarxiomly divide:i into tW'O treatment groups, intrarmJscular administration of 100 ug GnRH or saline oontrol at the tirre of insemination. Blood samples were collected at o, 1, 1.5, 2, 2.5, 3 and 4 hours post-insemination for LH determination and on days 0 through 7, 10, 16 and 22 for progesterone determination. Pregnancy status was detennined by rectal palpation 40 to 47 days post insemination. serum IR concentrations reached peak concentrations (9.33 ± 5.5 ng/ml) by one hour following GnRH administration. This was significantly different from saline controls (p Serum progesterone levels increased as expected. from day o to day 16 in all animals. Animals treated with GnRH that became pregnant tended to have the highest progesterone levels beginning from day 4. Animals treated with GnRH that were non-pregnant at 40 to 47 days tended to have the lowest progesterone levels from days 4 through 10 but were high on day 16. Pregnant animals had higher progesterone levels than non-pregnant animals from days 4 to 16. These differences approached significance (0.25 > p < 0.10). These results support the contention that GnRH administration affects progesterone levels rut do not conclusively establish increased early progesterone levels as the mechanism for improved pregnancy rates. Other hormonal andl functional factors may be involved.
49

Effect of double interspiking on fertility, behavior, and blood parameters in broiler breeder males reared under heat stress conditions

Chung, Karianne Mei-Ying 01 August 2010 (has links)
Broiler breeders experience a natural decline in fertility levels as a flock ages. A male management practice such as double interspiking could be applied to counteract this decline. Our objective was to investigate the effects of double interspiking on flock fertility, testosterone concentrations, stress responses, and behavioral responses of broiler breeders in heat stressed environments. Two hundred and eighty-eight broiler breeder pullets and thirty-six broiler breeder roosters (Ross 708) were assigned to three groups at 21 weeks of age (WOA). All three groups were housed in slatted floor pens in which room temperature cycled from 23.8 to 30 C to mimic heat stressed environments. Double interspiking was carried out between two pens at 42 and 52 WOA. Beginning at 32 WOA, eggs were set every two weeks, candled at day 12, and percent fertility calculated. Concentrations of the hormones testosterone and corticosterone (CS) were measured by radioimmunoassays at specific time points in the experiment. Lymphocytes and heterophils were counted in order to calculate heterophil:lymphocyte (H:L) ratios. Behavior was monitored with Panasonic video cameras which recorded video footage using the Noldus MPEG Recorder from 1900 hr to 2100 hr at specific time points. Recordings were analyzed, and frequency of specific behavioral responses of individual (preening, feather ruffling, wing flapping), male-to-male (fighting, pecking, retreating), and male-to-female (attempted and completed mating) behaviors were assessed. The introduction of unfamiliar roosters resulted in a fertility increase (P<0.01) between control and spiked birds after the first interspike and a sustainment of fertility levels after the second interspike. Testosterone concentrations declined (P<0.0001) from 1.95ng/mL to 0.11ng/mL as the birds aged. Corticosterone concentrations differed among bird groups and was elevated (P=.0333) for both groups that were interspiked. H:L ratios were also different among bird groups with all birds housed in the interspiked rooms showing higher ratios. Double interspiking increased the occurrence of male-to-male interactions, but there were no significant differences in male-to-female or individual behaviors. Regardless of treatment, there was a decrease in male-to-female behaviors as the birds aged. Double interspiking does show promise as a tool to increase fertility levels in a broiler breeder flock.
50

Effect of double interspiking on fertility, behavior, and blood parameters in broiler breeder males reared under heat stress conditions

Chung, Karianne Mei-Ying 01 August 2010 (has links)
Broiler breeders experience a natural decline in fertility levels as a flock ages. A male management practice such as double interspiking could be applied to counteract this decline. Our objective was to investigate the effects of double interspiking on flock fertility, testosterone concentrations, stress responses, and behavioral responses of broiler breeders in heat stressed environments. Two hundred and eighty-eight broiler breeder pullets and thirty-six broiler breeder roosters (Ross 708) were assigned to three groups at 21 weeks of age (WOA). All three groups were housed in slatted floor pens in which room temperature cycled from 23.8 to 30 C to mimic heat stressed environments. Double interspiking was carried out between two pens at 42 and 52 WOA. Beginning at 32 WOA, eggs were set every two weeks, candled at day 12, and percent fertility calculated. Concentrations of the hormones testosterone and corticosterone (CS) were measured by radioimmunoassays at specific time points in the experiment. Lymphocytes and heterophils were counted in order to calculate heterophil:lymphocyte (H:L) ratios. Behavior was monitored with Panasonic video cameras which recorded video footage using the Noldus MPEG Recorder from 1900 hr to 2100 hr at specific time points. Recordings were analyzed, and frequency of specific behavioral responses of individual (preening, feather ruffling, wing flapping), male-to-male (fighting, pecking, retreating), and male-to-female (attempted and completed mating) behaviors were assessed. The introduction of unfamiliar roosters resulted in a fertility increase (P<0.01) between control and spiked birds after the first interspike and a sustainment of fertility levels after the second interspike. Testosterone concentrations declined (P<0.0001) from 1.95ng/mL to 0.11ng/mL as the birds aged. Corticosterone concentrations differed among bird groups and was elevated (P=.0333) for both groups that were interspiked. H:L ratios were also different among bird groups with all birds housed in the interspiked rooms showing higher ratios. Double interspiking increased the occurrence of male-to-male interactions, but there were no significant differences in male-to-female or individual behaviors. Regardless of treatment, there was a decrease in male-to-female behaviors as the birds aged. Double interspiking does show promise as a tool to increase fertility levels in a broiler breeder flock.

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