Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains viii, 71 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 61-70).

Während der Kalbung kommt es neben physischen Belastungen auch zu weit reichenden Veränderungen auf hämatologischer und klinischchemischer Ebene. Durch verschiedene Prozesse kommt es zusätzlich zur Entstehung von oxidativem Stress. Zusammen hat dies einen entscheidenden Einfluss auf das Wohlbefinden, die Gesundheit und die Leistung der Kühe im postpartalen Zeitraum. Ziel der vorliegenden Untersuchung war es, die antioxidative Kapazität und den Stoffwechsel von Färsen im geburtsnahen Zeitraum unter Berücksichtigung des Geburtsverlaufes und des Gesundheitsstatus post partum zu analysieren.

The objective of this study was to evaluate the variability of growth curves of dairy heifers and estimate genetic parameters. 15066 records taken from birth until 26 months (808 days) on 2754 heifers of Quebec were considered. The pedigree file comprised 10123 animals. The Mixed procedure of SAS with ordinary polynomials was used for simple phenotypic analyses, fitting fixed linear, quadratic and cubic regressions of body weight (in kilograms) on age (in months) as well as random intercept, and random linear and quadratic regressions for each animal. The Wombat program (Meyer, 2007), with Legendre polynomials was used to estimate the genetic parameters by fitting fixed herd-year-season of birth and quartic regression of body weight on age in days, as well as random regressions for quadratic additive genetic and cubic permanent environmental effects. Heritability estimates of body weight ranged from 0.22 at around 70 days to 0.45 at around 210 days. Heritabilities of body weight at birth and 808 days were 0.35 and 0.32, respectively. The additive genetic correlations between body weights at different ages ranged from -0.37 to 1.00. In general, the genetic correlations were higher than the permanent environmental and phenotypic correlations.

Dairy heifers were submitted to high or moderate plane of nutrition before and during first gestation. High plane of nutrition did not increase milk production but negatively affected reproduction and health. In addition, high plane of nutrition decreased growth hormone (GH) concentration and increased prolactin concentration during gestation. There was no effect of previous plane of nutrition on peripartum concentrations of hormones. Milk production was positively correlated with GH concentrations, but was negatively correlated to concentrations of insulin-like growth factor-1(IGF-1) concentrations postpartum. / The effect of GH administration on mammary vasculature and on paracrine secretion of growth factors was investigated in lactating and non-lactating dairy cows. The injection of GH induced a linear increase of IGF-1 concentration in blood and mammary primary lymph, but did not affect concentrations of prostaglandin E$ sb2$ (PGE$ sb2$) concentrations. However, the rate of IGF-1 increase was slower in lymph than in blood, suggesting that blood is the source of most lymph IGF-I. Therefore, GH did not seem to affect paracrine secretion of IGF-1 and PGE$ sb2$ by the bovine mammary gland. Growth hormone administration induced a gradual increase in mammary blood flow in lactating cows while it remained constant in non-lactating animals. Changes in lymphatic, but not blood, concentrations of a stable metabolite of the vasodilatator prostacyclin I$ sb2$ parallelled the changes in blood flow. This indicates that local secretion of this vasodilatator may be responsible for the effect of GH on mammary blood flow. / Mitogenic activity of mammary primary lymph samples taken at different physiological stages was evaluated on mammary epithelial and mammary fibroblast cell lines. The results indicate that the mitogenic activity of lymph in epithelial cells was not related to physiological stage but to PGE$ sb2$ concentration. In fibroblasts, mitogenic activity of lymph was not related to physiological stage or to the content in any of the growth factors assayed.

Thesis (Ph.D.) -- Mississippi State University. Department of Animal and Dairy Sciences. / Title from title screen. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 1994. / Typescript (photocopy). Includes bibliographical references (leaves 40-46). Also available on the World Wide Web.

CNPq / O trabalho foi desenvolvido para avaliar os efeitos das diferentes densidades de semeadura de ervilhaca (Vicia sativa L.) consorciada com aveia preta (Avena strigosa Schieb) mais azevém (Lolium multiflorum) na composição estrutural e bromatológica das pastagens, na densidade e dinâmica populacional de perfilhos, e no desempenho de novilhos de corte. O experimento foi realizado na Universidade Tecnológica Federal do Paraná em Dois Vizinhos. Foi utilizada uma área de 8,3 ha, divididos em 11 piquetes de 0,75 ha. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro tratamentos: pastagem de aveia + azevém, pastagem de aveia + azevém + 15 kg de ervilhaca ha, pastagem de aveia + azevém + 30 kg de ervilhaca ha e pastagem de aveia + azevém + 45 kg de ervilhaca ha, com 76 dias de avaliação. Foram avaliados as variáveis de produção da pastagem, densidade e dinâmica populacional de perfilhos valor nutritivo e desempenho produtivo dos novilhos. O método de pastejo utilizado foi o de lotação contínua e taxa de lotação variável para manter oferta de forragem de 15%. Não houve influência (P>0,05) dos tratamentos sobre os parâmetros produtivos da pastagem. Os ganhos de pesos médios diários (GMD) apresentados durante o experimento foram crescentes para os respectivos tratamentos, 0; 15; 30; 45 kg/ha de ervilhaca. A carga animal e os ganhos de peso por área foram semelhantes dentro dos tratamentos e dos períodos, obtendo médias de 877,48 kg/ha, 0,765 kg/dia, respectivamente. Para as análises químicas houve aumento em proteína apenas para a ervilhaca com o aumento nas maiores densidades da leguminosa. / The study was conducted to evaluate the effects of different seeding rates of vetch (Vicia sativa L.) mixed with oat (Avena strigosa Schieb) plus annual ryegrass (Lolium multiflorum) in the structural and chemical composition of pasture, density and population dynamics of, and performance of beef steers. The experiment was conducted at the Federal Technologic University of Paraná in Dois Vizinhos. An area of 8.3 ha, divided into 11 paddocks of 0.75 ha. The experimental design was completely randomized blocks with four treatments: oat + ryegrass, oat + ryegrass + 15 kg/ha vetch, oat + ryegrass + 30 kg/ha vetch and oat + ryegrass + vetch 45 kg/ha, with 76 days of evaluation. Pasture production, density and population dynamics of tillers bromatological quality and productive performance of heifers were evaluated. The grazing method was continuous stocking to keep herbage allowance of 15%. There was no effect (P>0.05) among treatments for pasture production parameters. The higher vetch proportion the higher the average daily weight gain (ADG) obtained. The stocking rate and gains weight per area were similar within treatments and periods, averaging 877.48 kg/ha. Chemical analyzes there was an increase in protein only for vetches with increasing density.

O presente estudo procurou avaliar as características de carcaça,qualidade e o perfil lipídico da carne atrelado à espessura de gordurasubcutânea das carcaças (EGS), utilizando o peso de abate como covariável. Os dados obtidos oram analisados por teste estatístico de analise de variância e a nível de 10% de significância, e posteriormente feita a análise de regressão para as variáveis que apresentaram diferença significativa. A qualidade da carcaça e da carne é influenciada pela espessura de gordura subcutânea interferindo no peso de carcaça quente e fria, e consequentemente nos seus rendimentos. O peso de carcaça quente (PCQ) é a principal forma de remuneração ao produtor pelos frigoríficos, aplicando-se valores de 6 mm de gordura subcutânea, em um animal com peso de abate de 450 kg na equação (PCQ=-23,77+0,60*PA+1,99*EG+0,32*EG²), encontra-se o valor de 269,69 kg de peso de carcaça quente, para peso de carcaça fria (PCF) utilizando os mesmos valores na equação (PCF=-11,86+0,56*PA+1,64*EG), o animal apresentara em média 249,98 kg de PCF. Ocorreram diferenças significativas para as porções teciduais do animal, com decréscimo da fração osso e aumento das frações músculo e gordura, conforme se aumentou a espessura de gordura subcutânea na carcaça. Para a qualidade organoléptica da carne,não ocorreram respostas significativas ao grau da espessura de gordura subcutânea. Nas análises do perfil lipídico, os ácidos graxos saturados (AGS)não sofrem alteração com o aumento da espessura de gordura na carcaça, ao contrário dos ácidos graxos insaturados (AGI), que aumentaram de forma quadrática até o ponto de 5,8 mm de espessura de gordura. Para os poliinsaturados ocorreu diferença significativa linear decrescente, para os monoinsaturados apresentaram foi encontrado efeito quadrático (AGM=14,27+0,037*PA+4,22*EG-0,31*EG²). Dentre os principais ácidos graxos encontrados na carne bovina, o C14:0 não demonstrou diferença significativa, bem como o ácido graxo C18:0. Já o C16:0 demonstrou diferença significativa (P= 0,0095) apresentando 6,6 mm EGS como ponto de máximo. O Isômero C18:1ω9c, importante precursor na síntese do CLA, obteve comportamento quadrático atingindo valor máximo de 6 mm EGS. O CLA obteve resposta quadrática, a sua concentração aumenta até 6,9 mm de espessura de gordura, após essa espessura de gordura seus valores começam a decair. A relação entre os ácidos graxos ω6:ω3 não apresentam diferença significativa. O ω3 obteve resposta quadrática, aumentando sua deposição até 6,3 mm de espessura de gordura, após esse valor começa decair interferindo na boa relação entre ω6:ω3. A espessura de gordura subcutânea de 6,0 mm influência positivamente o peso e rendimento de caraça quente e fria, na quantidade de osso, músculo e gordura presentes na carcaça e nos ácidos graxos benéficos a saúde humana. / This study was develop to evaluate the carcass characteristics,quality and lipid profile linked to subcutaneous fat thickness (SFT) using the slaughter weight as a co-variable. The data were analyzed by statistical test for analysis of variance with a 10% level of significance, and subsequently made the regression analysis for the variables that showed significant differences. The carcass and meat quality was influenced by the subcutaneous fat thickness interfering in the hot and cold carcass weight, and consequently on their yields. The hot carcass weight (HCW) was the principal form of remuneration to farmers for slaughterhouses, applying values of 6 mm of subcutaneous fat thickness in an animal that was slaughter with weight of 450 kg in equation (HCW = 23,77+0,60*SW+1,99*FT+0,32*FT²), shows the value of 269.69 kg of hot carcass weight and cold carcass weight (CCW) using the same values in equation (CCW =-11,86+0,56*SW+1,64*FT), the animal had presented averaged 249.98 kg of CCW. There were significant differences for the portions of the animal tissue with decreased bone fraction and increased muscle and fat fractions, as increased the subcutaneous fat thickness in the carcass. For the organoleptic quality of meat, there were no significant responses for the different subcutaneous fat thickness level. In the analyzes of the lipid profile, the saturated fatty acids (SFA) do not change with increasing thickness of carcass fat, unlike the unsaturated fatty acid (UFA), which increased quadratically to the point of 5.8 mm fat thickness. The IFA were divided into monounsaturated (MUFA) and polyunsaturated fats, polyunsaturated occurred for linear significant difference decreasing. Monounsaturated responded quadratically (AGM = 14,27+0,037*SW+4,22*FT-0,31*FT²). Among the major fatty acids found in beef cattle, C14: 0 showed no significant difference as well as the fatty acid C18: 0. Have the C16: 0 present a significant difference (P = 0.0095) showing 6.6 mm SFT as the maximum point. The isomer C18: 1ω9c important in the synthesis of CLA obtained quadratic comportment present a maximum value of 6 mm SFT. The CLA obtained quadratic response, its concentration increases up to 6.9 mm subcutaneous fat thickness, after this fat thickness the CLA values begin to decline. The ratio between the fatty acids ω6:ω3 did not show different significance. The 3 obtained quadratic response, increase your deposition up to 6.3 mm of fat thickness, this value starts declining after interfering in good relationship between ω6: ω3. The fat thickness of 6.0 mm has positively influence in the weight and yield of hot and cold carcass, the amount of bone, muscle and fat present in the animal carcass and influences the beneficial fatty acids for human health.

The main goal of this master?s thesis is to assess heifer fattening conducted in two grazing cycles in the mountain region of Southern Bohemia. The observation was carried out in two cycles in the years 2008/2009 and 2010/2011. A total of 99 heifers was observed, all of them crossbreeds of Aberdeen Angus or Simmental cattle. In the first grazing cycle, the heifers were raised on pasture together with the mothers and stabled for the winter season. The heifers were slaughtered after the end of the second grazing cycle in the next year. Live weight of the heifers was recorded at the end of the first grazing cycle, at the end of the winter season and again at the end of the second grazing cycle. The weight of the dressed carcass and results of the SEUROP carcass classification were further recorded. The average daily gain was calculated for each period from the live weight. The data set was sorted by the month of birth and by the SEUROP class score. Data analysis was conducted using Microsoft Excel. In order to evaluate the results, basic statistical parameters were calculated for each of the selected variables and the cogency of the differences between the groups was tested with the two-tailed t-test at the corresponding level of significance. The average weight of the heifers at the end of the first grazing cycle was 281,2 kg, average weight at the end of the winter season was 366,1 kg and the average weight at the end of the second grazing cycle was 511,6. The average age of the heifers at the end of the first grazing cycle was 221,5 days and they were slaughtered at the average age of 568,9 days. The average daily gain was 1,16 kg during the first grazing cycle, 0,53 kg during the winter season and 0,81 kg during the second grazing cycle. The lifetime average daily gain was 0.85 kg. Net gain averaged 0,45 kg per heifer. The average weight of the dressed carcass was 253,8 kg. 2,1 % of the heifers gained SEUROP class ?U?; 54,5 % class ?R? and 43,4 % class ?O?. The heifers showed considerable variability, especially in the weight at the end of the second grazing cycle (sx = 42,4 kg). Data analysis revealed correlations of r2=0,62 between weaning weight and slaughter weight and r2=0,69 between weaning weight and JUT weight.

Made available in DSpace on 2014-06-11T19:33:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-10Bitstream added on 2014-06-13T20:45:12Z : No. of bitstreams: 1 vieira_br_dr_jabo.pdf: 745384 bytes, checksum: dc2143964d7559ca196e2a2ff2d18c49 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivou-se avaliar a estrutura do dossel, o comportamento ingestivo, o consumo de forragem e o desempenho animal de novilhas, da raça Nelore, suplementadas em pastagens de Brachiaria brizantha cv. Marandu sob lotação contínua com taxa de lotação variável, durante o período das águas. Foram avaliados três alturas do dossel (15, 25 e 35 cm) e três suplementos (sal mineral, suplemento energético, e suplemento energético-protéico) em um esquema fatorial 3x3 totalizando nove tratamentos. Com exceção do sal mineral, que foi fornecido ad libitum, os suplementos foram fornecidos a 0,3% do PC/dia. O delineamento experimental foi inteiramente casualizado com duas repetições de piquete. As avaliações ocorreram entre os meses de janeiro e maio de 2009. Na época seca foi avaliado o impacto dos manejos da época de águas em dois sistemas de terminação (pasto ou confinamento) sobre o ganho de peso, o tempo de terminação e as características de carcaça dos animais. A maior altura do dossel determinou maior massa e oferta de forragem do pasto, superior consumo e menor tempo de pastejo dos animais. Entretanto, os suplementos não influenciaram essas características. O uso de suplementos energético e energéticoprotéico aumentou o desempenho animal, não havendo diferença entre os suplementos para nenhuma das vaiáveis estudadas, com exceção da concentração de amônia ruminal, que foi influenciada pelo suplemento energético-protéico em alguns horários do dia. O uso da suplementação energético-protéica, assim como as maiores alturas do pasto reduziram o tempo de terminação dos animais no período de seca, indiferente do sistema utilizado, mas não interferiu nos ganhos de peso e no consumo de matéria seca dentro de cada sistema. A terminação em confinamento aumentou a deposição de gordura nas carcaças / The objective was evaluate the canopy structure, the ingestive behavior, the forage intake and the performance of Nellore heifers supplemented in Brachiaria brizantha cv. Marandu pasture under continuous stocking and variable stoking rate during the rainy season. The treatments consisted of three canopy heights (15, 25 and 35 cm) associated with three types of supplements (a mineral, an energy supplement and a protein/energy supplement) on a factorial 3x3, totalizing 9 treatments. The mineral salt was provided ad libitum while the other supplements were provided at 0.3% of body weight/day. Experimental design was completely randomized with two paddocks replications. The evaluations were realized between January and May of 2009. In the following dry season were evaluated the impact of the previous treatment on finish systems (pasture or feedlot) on the performance, days to slaughtered and carcass quality. It was observed that the sward height affect forage mass, forage allowance, all the pasture structural features, animal intake and grazing time. However, the supplements did not affect these variables. The use of energy or protein supplement increased animal performance, without differences between the supplements for any variable evaluated, other than ruminal ammonia concentration, witch were affected by the protein supplement. The use of energy/protein supplement, as well as higher pasture height were positively related to time to slaughtered on the dry season, independent on the finish system, but did not affect the daily gain nor feed intake. The feedlot finish increased the fat deposition on the carcass