Made available in DSpace on 2014-10-09T12:55:09Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:55Z (GMT). No. of bitstreams: 0 / Queratinócitos são um veículo bastante atrativo para a transferência gênica ex vivo e liberação sistêmica uma vez que as proteínas secretadas por estas células podem atingir a circulação via um mecanismo similar ao processo natural. Um eficiente vetor retroviral (LXSN) contendo o gene do hormônio de crescimento de camundongo (mGH) foi utilizado para transduzir queratinócitos humanos primários. Os queratinócitos transduzidos apresentaram um nível de secreção in vitro alto e estável atingindo até 11 g mGH/106 células/dia. Os epitélios formados por estes queratinócitos geneticamente modificados apresentaram, porém, uma queda na taxa de secreção > 80 % quando foram retirados da placa de cultura utilizando um procedimento clássico. A substituição desta metodologia clássica por uma cultura organotípica resolveu completamente este problema. Camundongos anões imunodeficientes (lit/scid) implantados com estes enxertos organotípicos foram acompanhados durante 4 meses, e apresentaram um aumento de peso significativo (P<0,05) nos primeiros 40 dias. Níveis circulatórios de mGH atingiram um pico de 21 ng/mL 1 h após o implante, mas estes níveis rapidamente atingiram níveis basais (~2 ng/mL). Os queratinócitos humanos primários apresentaram portanto altos níveis de expressão in vitro e os maiores níveis circulatórios, porém por um breve período de tempo, reportados até o momento para GH neste tipo de células. Em conjunto com resultados que mostraram uma recuperação considerável da eficiência de secreção de mGH em cultura por enxertos organotípicos retirados dos animais, foram discutidos os fatores que ainda impedem a utilização clínica deste modelo promissor de terapia gênica cutânea. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Foram utilizadas 24 ovelhas da raça Santa Inês para coleta de tecido adiposo, sendo 16 lactantes e 8 secas. Oito ovelhas lactantes foram tratadas in vivo com bST (160 mg, em duas doses em intervalo de 14 dias) iniciando a injeção subcutânea de hormônio no 13 o dia de lactação, sendo que os animais restantes receberam somente vitamina E. Outros 8 animais encontravam-se em período seco, para que fosse verificada também a diferença das taxas lipolíticas em diferentes estados fisiológicos. Foi verificada a hipótese de que ocorra uma atuação da ST através de mudança na resposta do sistema antilipolítico da proteína Gi ligada a receptores da adenosina. O tratamento com ST exógena aumentou o ganho de peso das ovelhas lactantes (P<0,05) e também o peso dos cordeiros oriundos do grupo tratado ao final do período experimental, no entanto, não foi verificado aumento na produção de leite. As concentrações de AGNE diminuíram no decorrer da lactação para os dois grupos de ovelhas lactantes, chegando no 36 º dia de lactação a concentrações similares ao do grupo de ovelhas secas. A concentração de IGF-I sérico das ovelhas aumentou após tratamento com bST, sendo 8 dias após a segunda dose do hormônio (36 dias de lactação) superior à concentração observada para ovelhas secas. A lactação não teve influência na lipólise basal entre os diferentes estados fisiológicos. Houve um aumento significativo (P<0,01) da taxa lipolítica do tecido adiposo quando estimulada por b adrenérgico (ISO) para animais em quaisquer dos estados fisiológicos. Todavia, a taxa estimulada por ISO foi significativamente (P<0,01) mais elevada no tecido das ovelhas tratadas com bST. Na presença de ADA, ocorreu um aumento da taxa em relação à basal, mas não ultrapassou àquela estimulada por isoproterenol. O estímulo lipolítico pela eliminação de adenosina no meio através da ADA apresentou-se significativamente (P<0,01) mais elevado para ovelhas lactantes, sendo este efeito amenizado pelo tratamento com bST. O uso do análogo da adenosina PIA quando colocado no meio de cultura do tecido que foi tratado in vivo com bST teve seu efeito diminuído. Os resultados indicam um aumento da taxa lipolítica em resposta a agonista b-adrenérgico no tecido adiposo do omento de ovelhas lactantes tratadas com bST in vivo, bem como confirmam a hipótese de diminuição da ação inibitória da adenosina na cascata lipolítica naquele tecido. / Bovine somatotropin (bST) treatment in vivo alters adipose tissue metabolism by enhancing lipolytic response to adrenergic agonists. We examined the impact of bST and lactation on basal and stimulated lipolytic rates with isoproterenol (ISO; 10 -5 nM), adenosine deaminase (ADA; 0.75 U/mL), ISO plus ADA in short-term (2h) incubations of ovine adipose tissue. The anti-lipolytic effect of phenylisopropyladenosine (PIA; non-hydrolyzable adenosine analog) was evaluated at various concentrations (0.5, 1.5, 3, 100 nM). Sixteen lactating Santa Ines ewes were randomly assigned to two groups. They received two s.c. injections, with a 14 day interval, starting at d 13 postpartum with either bST (160 mg) or Vitamin E (control). Eight similar nonlactating ewes received vitamin E. Omental adipose tissue biopsies were taken on d 8 after the second bST or vitamin injection. The performance of weight and milk production were taken. The serum IGF-I was analyzed. The lipolytic rate was determined by NEFA release in serum and media as mEq of oleic acid.2h -1 g -1 tissue. Basal lipolytic rates did not change with lactation or with bST treatment in vivo (P>0,05). ISO stimulated lipolytic rate increased compared to basal and was higher for the adipose tissue from lactating ewes treated with bST (P<0,01).The lipolytic rate for adipose incubated with ADA was higher than basal for lactating ewes, with the greater response for the control. The ADA treated tissue from lactating ewes receiving bST showed intermediate lipolytic rates. Maximum lipolytic rate with ISO+ADA was also higher for lactating ewes treated with bST (P<0.01), and there was no difference between lactating and nonlactating ewes. The PIA effects were evaluated by the inhibition of ISO+ADA lipolysis, and adipose tissue from lactating ewes treated with bST showed a reduced response to PIA. The results demonstrate that in vivo somatotropin treatment increases maximal lipolytic rates stimulated by adrenergic agonist and decreases the antilipolytic effect of PIA in omental adipose tissue in ewes.

<p>The first four months of a dairy calf’s life provide the foundation for future production and health. Therefore, it is critical that calves are managed to optimize both health and growth, to maximize their potential. Calf morbidity, which leads to less productive animals and is an economic impact on producers, continue to be areas of opportunity in the dairy industry. In addition, the animal agricultural community is working to reduce the use of antibiotics, due to a growing concern regarding antibiotic resistant bacteria. This provides researchers with the challenge of identifying strategies to reduce calf morbidity and mortality, while also decreasing reliance on antibiotics. The objective of this dissertation was to evaluate nutritional strategies supplemented to calves as well as maternal factors that impact colostrum. The studies focused on strategies to improve the innate and adaptive immune responses and growth of the calf, ultimately reducing reliance on antibiotics. Chapters 2 and 3 discuss feeding dairy calves <i>Saccharomyces cerevisiae</i> fermentation products in milk replacer and solid feeds until 4 months of age. This study concluded that feeding <i>Saccharomyces cerevisiae</i> fermentation products to calves improves average daily gain and feed efficiency post-weaning and reduces antibiotic treatment incidence for respiratory disease. It also increases the evenness of the fecal microbiome and the acute innate immune response, as determined by increased TNF-α, glucose, and respiration rate during a lipopolysaccharide challenge. Chapter 4 evaluated the effects of feeding dairy calves medium chain fatty acids (C8:0 and C10:0) in milk replacer until 60 days of age. Feeding C8:0 and C10:0 to calves reduced plasma NEFA concentrations around weaning, suggesting the mobilization of less adipose tissue to meet the energy demands of the calf. This trial also determined that vaccinating calves at 3 weeks of age with ovalbumin combined with an aluminum hydroxide adjuvant, is an effective way to evaluate their adaptive immune responses. </p> <p>Supplementing calves directly is not the only way to impact calf growth and health, maternal factors also impact calf nutrition through colostrum consumption. Last, chapter 5 explored maternal factors that influence the lipidome of colostrum and therefore the lipid intake of the newborn calf. This study concluded that the metabolic status of the cow affects circulating lipids and the lipid content of colostrum. Also, the lipidome of colostrum is distinct from the circulating lipidome of the calf, which is similar to the circulating lipidome of the cow, except for phosphatidylglycerol, where it appears that colostrum serves as the source for the phosphatidylglycerol present in the circulation of the calf. There are many different nutritional strategies that can impact the health and productivity of calves. Calves can be directly supplemented with nutraceuticals like <i>Saccharomyces cerevisiae</i> fermentation products or medium chain fatty acids, or calf nutrition can be influenced by the maternal factors through the consumption of colostrum. </p>

<p>  </p> <p>In modern society, continuous light exposure and obesity are increasingly prevalent, especially in women of childbearing age. Circadian, metabolic, and reproductive systems have a complex, inter-regulated relationship. Thus, the disruption of one system likely impedes another. Excessive adiposity and circadian disruption alter normal behavior and physiology and disrupt the endocrine milieu. The overall goal of the studies described in this thesis was to develop and test a model system that could tease apart the influence of prepregnancy obesity and circadian disruption, as well as study the combined effects on female reproductive competence. </p> <p>The first study focuses on the prepregnancy period and aims to determine the effect of high fat diet feeding on diurnal eating pattern, body weight over the four-week period, the body composition at the end of the four-week period, hair corticosterone levels, and circadian fecal corticosterone patterns on female ICR mice. Five-week-old female ICR mice were randomly assigned to control (CON; 10% fat) or high fat (HF; 60%) diets and fed for four weeks to achieve adequate adiposity. During this four-week time period, mice had routine light exposure of 12h light and 12h dark. Feed was weighed at 0600 and 1745 Monday-Friday to determine diurnal feed intake. The mice were weighed on a weekly basis. After four weeks on respective diets, mice were anesthetized with isoflurane to measure crown-rump length to calculate BMI and hair was shaved for corticosterone extraction. Once mice recovered from anesthesia, body composition was measured with EchoMRI. After 1 week on diets, HF mice consumed more (P<0.05) during the day than CON mice, which is typically when mice are inactive. After two weeks on diets, HF mice weighed more (P<0.05) than CON, as well as had higher BMI and percent body fat (P<0.05) than CON after four weeks on diets. After four weeks on diets, HF mice had high hair corticosterone (P<0.05). Sampling feces over a 48h period at the end of the four weeks demonstrated that HF mice had elevated basal corticosterone, attenuated circadian rhythms, and a shift in corticosterone amplitude. The prepregnancy period demonstrated that high fat diets alone alter circadian eating pattern and corticosterone rhythms.</p> <p>The remainder of the study continued the dietary treatments assigned during the prepregnancy period, as well as implemented light conditions to create a 2Χ3 factorial study design. There were three light conditions: 12h light and 12h dark (LD), 24h dim light (L5), or 24h bright light (L100). Mice were moved into experimental light conditions after the observation of a vaginal plug or after 5 days with males. This portion of the study aimed to determine the effect of diet (CON or HF) and light exposure (LD, L5, or L100) on gestation length, number of pups born, milk composition, litter weight on postnatal day 12, as well as dam feed intake, hair corticosterone levels, and plasma prolactin. Continuous light exposure increased gestation length, with L5 (19.1 d ± 0.23) and L100 (18.9 d ± 0.21) having longer gestation lengths (P<0.05) than LD (18.1 d ± 0.25). Diet affected the number of pups born (P<0.05), with HF dams having fewer pups (9.99 ± 0.4) than CON (11.4 ± 0.4). Despite no difference in birth weight of standardized litters (n=8 pus/litter), litters of HF dams weighed more than CON by day 4 postnatal. The greater litter weight of HF dams continued until the end of the study on day 12 of lactation (P<0.05). Light had a tendency to increase litter weight (P=0.07). Diet, light, and stage of reproduction influenced dam feed intake (P<0.05). L100 dams had higher plasma prolactin, as well as final dam and mammary wet weights (P<0.05). Constant light exposure decreased ATP content in the mammary gland (P<0.05) and decreased milk lactose concentration (P<0.05). Pearson’s correlation analysis showed a positive relationship between mammary weight, fat pad weight, BMI, kcal of feed intake, and gestation length (P<0.05). In CON mice, hair corticosterone was negatively correlated with litter weight on lactation day 12. Liver weight was positively correlated with d 12 litter weight in HF mice. Together, these studies demonstrate that feeding high fat diets and continuous light alter maternal behavior and physiology, which may impact offspring health and development, however continuous light may not be the best approach to studying circadian disruption. Elevated maternal plasma prolactin and increased dam weight suggests a long day photoperiod was likely induced, thus potentially mitigating the circadian disruptive effects from constant light. Other model systems should be considered, such as using a chronic jet lag model that changes the light exposure every 3 d. </p>

<p dir="ltr">Boars in the swine industry are one of the select animals subject to limit feeding. Limit feeding boars occurs once boars are selected to enter the boar stud. Before selection boars are <i>ad libitum</i> fed like a nursery or grow finishing pig. Research involving boar nutrition and the impact it has on growth, development, and semen characteristics are limited compared to the rest of the swine industry. The objective of these studies conducted at Purdue University were to determine how varying nutritional feeding strategies impact semen quality and quantity as well as growth and development of artificial insemination boars.</p><p dir="ltr">Feeding fiber is a commonly used strategy in gestating sow nutrition to mitigate some of the negative side effects of limit feeding animals. A variety of fiber sources are available to the swine industry, however most of the common sources used are wheat bran, alfalfa meal, sugar beet pulp, and soybean hulls. Soyhulls are one of the more easily accessible sources of fiber in Indiana and the Midwest U.S. due to large amounts of soybean production and processing which will continue to grow with bi-energy demands. Boars fed the fiber diet (14.3% soyhulls) had increased bodyweight and body condition changes over the twelve-week period. Additionally, fiber inclusion in the diet had no impact on semen characteristics but semen was impacted by the age and breed of the boar. Salivary cortisol levels were reduced in boars fed fiber as well as some changes in behavior were observed.</p><p dir="ltr">The addition of fiber had impacts on growth and development but no impacts on semen. Since boars are limit-fed for so long from selection after the grow-finish period until they are culled this drew up the question if feeding boars different levels after selection (1.8 kg/d or 2.7 kg/d) impacted trainability, first time semen collection characteristics, growth and development of young boars. No differences were observed for feeding level impacting trainability with 92% of all boars regardless of treatment being successfully trained. Semen volume was increased in boars fed 2.72 kg/d by approximately 50% but no other semen characteristics were impacted. Boars fed 2.72 kg/d also had increased bodyweight and body condition score measures.</p><p dir="ltr">The boars subject to the training study unknowingly arrived at the farm naturally infected with porcine circovirus three (PCV3). Research has been conducted on the ability of viruses (PRRSv, PEDv) to be detected and transmitted through semen. Porcine circovirus three is a relatively new variant of circovirus so the opportunity to evaluate the question of if this virus was able to be detected in seminal plasma and the impacts it has on semen characteristics was presented. Serum and semen samples were collected for polymerase chain reaction analysis of detection of PCV3 conducted at Purdue Animal Disease Diagnostic Laboratory. Porcine circovirus three was able to be detected in the serum of positive boars however no positive detection occurred for seminal plasma samples. Morphological abnormalities such as distal midpiece reflex, distal droplets, and head and tail differed between infected and non-infected boars. Young boars sero-positive for PCV3 had decreased total sperm, total normal sperm motility, and head and tail abnormalities but had decreased distal midpiece reflex abnormalities when compared to PCV3 negative young boars. Young boars were also able to maintain the virus for 98+ days, while some old boars were able to clear the virus withing 14 weeks of becoming positive.</p><p dir="ltr">The next chapter evaluated maintenance energy equation listed in the swine NRC 2012 and if it was still accurate for sexually active boars and if weight management through the use of this equation impacted boar performance. Boars were subject to three treatments (150%, 100%, 80%) of maintenance energy for the first nine-week period and 150% and 80% diets were switched for second nine-week period while 100% stayed the same the entire time in a cross-over design. Semen, bodyweight, and body condition parameters were analyzed throughout the two nine-week periods. Boars fed 80% of maintenance had the largest reduction in semen parameters compared to 150% and 100% maintenance fed boars. Additionally, switching 80% feed intake boars to 150% maintenance feed intake, boars were able to recover some of the negative impacts, however they were not able to fully recover in the second nine-week period. Boars fed 100% and 80% maintenance energy lost weight regardless of age. The loss of body weight of the 100% maintenance fed boars indicates the swine NRC 2012 equation is underestimating the modern AI boar maintenance needs. Old boars were able to handle changes in weight and body condition better than young boars as there was reduced variation in serum metabolites analyzed with old boars compared to young boars.</p><p dir="ltr">The last chapter of this thesis focused on a big data project from commercial sow farms. The objective of this study was to determine if breeding gilts at first signs of estrus or after has an impact on sow performance and economic value to parity three. A regression model was developed from on farm data to determine the difference in total born piglets to parity 3 between gilts bred on their first estrus or after. Gilts bred on their first estrus had six fewer total piglets to parity three compared to gilts who were bred after the first estrus. Also, gilts bred after their first estrus had a larger percentage of sows being profitable compared to gilts bred on first estrus. This model data was compared to actual data for comparison between the two. The model with the limited variables inputted and compared to the actual data was fairly accurate with economic profitability and with more refinement the accuracy can be increased.</p><p dir="ltr">Overall, nutrition of the boar needs to be an area of interest in the swine industry to continue improving efficiency of production. Feeding fiber to boars has minimal impact on semen characteristics but can be used to reduce stress in boars that are limit-fed for weight and body condition management. Limit feeding boars beginning at selection reduces growth and development and had negative impacts on first time semen collection volume. Porcine circovirus 3 was not found in the seminal plasma of naturally infected boars when serum analysis was positive. Boars fed below maintenance levels listed in the swine NRC 2012 have negative impacts on semen, bodyweight, and body condition parameters. Once diets were changed boars were able to recover from the feed restriction but not meet baseline measures prior to feed restriction. Young boars are more sensitive to feeding changes than old boars, this could be due to the young animal still growing while the older animal is closer to mature size. Big data projects can aid producers in making production changes decisions to estimate the economic impact it can have to an individual farm or the entire production system.</p>

O objetivo dessa pesquisa foi o de avaliar o efeito de massa de forragem no resíduo sobre as características morfológicas, produção das pastagens, desempenho e produtividade animal. O experimento foi desenvolvido no período de 30 de outubro de 1999 até 03 de janeiro de 2001 em um sistema rotacionado de pastagens irrigadas de Panicum maximum Jacq. cv. Tanzânia estabelecidas na Escola Superior de Agricultura "Luiz de Queiroz" em Piracicaba/SP. O delineamento experimental foi o de blocos (4) completos ao acaso com três disponibilidades de forragem no resíduo (1000, 2500 e 4000 kg/ha de matéria seca verde (MSV)). A semeadura foi realizada em 17 de março de 1999 e a adubação de correção do solo tinha o objetivo de atingir os seguintes valores: 80% de saturação por bases; 30 mg/cm3 de fósforo e 5% de potássio na CTC. Os piquetes foram adubados com 334 kg/ha/pastejo de 24-04-24. Os animais utilizados foram machos castrados da raça nelore com cerca de 10 meses de idade. Foram conduzidos quatro pré experimentos sendo três deles para deteminar a melhor relação dimensão: formato da unidade amostral e a quantidade de amostras para avaliar a massa de forragem. O quarto pré experimento teve como objetivo avaliar a relação entre profundidade de pastejo e altura das planta antes do pastejo. A avaliação da massa de forragem em piquetes estabelecidos com plantas que formam touceiras deve ser realizada através de quatro amostras de 1 m2 (1m x 1m). A profundidade de pastejo foi relacionada linearmente com a altura das plantas independente da intensidade de pastejo e do dia de ocupação do pasto. A intensidade de pastejo não teve efeito sobre o angulo de inclinação dos perfilhos mais externos da touceira, sobre o formato das touceiras e sobre a distribuição da densidade de forragem no perfil da pastagem indicando que o capim Tanzânia tem pouca plasticidade em relação a essas características. Entretanto a proporção de haste, de folhas, de material morto, da altura, da relação folha/haste foram características morfológicas afetadas pelos tratamentos e épocas do ano. A taxa de cobertura do solo diminuiu durante período experimental independente do tratamento enquanto que o tamanho das touceiras esteve associado a mecanismos rápidos de adaptação da planta a mudanças no meio ambiente causadas pelas diferentes disponibilidades de forragem. O desempenho animal esteve mais relacionado com a oferta e disponibilidade de forragem do que com a relação folha/haste e a densidade de forragem. Apesar da produtividade animal não ser alterada pelos tratamentos, o manejo mais adequado seria o de manter a disponibilidade de forragem no resíduo superior a 2915 kg MSV/ha assim como as ofertas de forragem maiores do que 14,9 kg MSV/100 kg PV ou 6,1 kg de folhas/100 kg PV afim de melhorar o desempenho dos animais e reduzir a idade de abate em 150 dias quando comparado com o tratamento que teve como massa de forragem no resíduo 1266 kg MSV/ha. / This research was to evaluate effect of the post-grazing pasture mass on morphological characteristics, herbage production and animal performance and productivity from irrigated and rotationally grazed system with Panicum maximum Jacq. cv. Tanzânia. The experimental period was October 30/1999 to January 03/2001 and established at Escola Superior de Agricultura "Luiz de Queiroz", Piracicaba/SP. A complete randomized block design with three postgrazing residues (1.000, 2.500 e 4.000 kg/ha of green dry matter - GDM) and four replicates was used. The grass seeding was performed on March 17/1999 and soil was limed and fertilized to 80% base saturation, phosphorus (resin) level of 30 mg/cm3 and 5% potassium in the cation exchange capacity. In each grazing cycle paddocks were fertilized with 24-04-24 (334 kg/ha). Nellore steers with approximately 10 months of age were used. Four pre-experiments were conducted, the first three to determine the best dimesion:format ratio of the sampling unit and the most appropriate number of samplings in evaluating herbage mass. The fourth pre-experiment aimed to evaluate the relationship between grazing depth (progressive sward defoliation during the grazing period) and plant height before grazing. Herbage mass evaluation in tussock-forming pastures should be performed taking four 1 m2 samples (1m x 1m). Grazing depth was linearly correlated to plant height, irrespective of grazing intensity and days on the grazing period. Grazing intensity had no effect on the slope of the angle between soil and tillers on the border of the tussock, neither on tussock shape nor on forage bulk density across the sward profile, indicating Tanzania grass has limited plasticity for these characteristics. However, stem, leaf and dead material proportion in herbage samples, as well as leaf/stem ratio and plant height were affected by treatments (post-grazing residues) and season of the year. The ground area covered by grass tussocks decreased during the experimental period, irrespective of the treatment. The tussock size was associated with fast adaptation mechanisms of the plants in response to changes in environment resulting from different post-grazing herbage masses. Animal performance was better related to herbage allowance and post-grazing residues than with leaf/stem ratio or forage bulk density. Treatments did not altered animal productivity. In spite of this, it would be more adequate to allow post-grazing pasture mass to be higher than 2.915 kg GDM/ha and herbage allowance to be higher than 14,9 kg GDM/100 kg live weight (LW) or 6,1 kg of leaves/100 kg LW. This grazing management would improve animal performance and anticipate slaughter age in 150 days when compared to the treatment with post-grazing pasture mass of 1.266 kg GDM/ha.

Experimento I: Foram utilizadas 60 borregas da raça Santa Inês com o objetivo de avaliar os efeitos de três taxas de crescimento até os 7 meses de idade. Os tratamentos foram delineados visando obter alta taxa de crescimento (ATC), moderada taxa de crescimento (MTC) e baixa taxa de crescimento (BTC). Foram avaliados o consumo de matéria seca, o ganho de peso corporal e as concentrações séricas de progesterona para a detecção da idade à puberdade. Foram verificados efeitos lineares (p<0,01) para o peso corporal e metabólico, sendo os maiores valores encontrados para os animais do tratamento ATC. Efeito linear (p<0,01) foi verificado para o ganho médio diário (GMD) sendo de 0,182; 0,156 e 0,136 kg/dia para os tratamentos ATC, MTC e BTC respectivamente. Borregas pertencentes ao tratamento ATC apresentaram maior conversão alimentar sendo os valores para o tratamento ATC de 6,1; MTC de 7,1 e BTC de 9,2 kg MS/ kg de ganho de peso. Verificou-se diferença (p<0,01) quanto a porcentagem de animais que atingiram a puberdade sendo o tratamento MTC com o maior número de borregas púberes até os 7 meses de idade (60%), seguida dos tratamentos ATC (45%) e BTC (15%)com peso médio de 39,3 kg de peso corporal, sendo 70% do peso adulto. Experimento II: As borregas utilizadas no experimento 1 com 37 Kg de PC entraram em estação de monta e após o parto receberam uma única dieta, sendo blocadas de acordo com o peso e dias de lactação. Observou-se efeito quadrático (p<0,01) na produção de leite em 3h (137,9; 150,1 e 104,4 g), efeito quadrático (p<0,05) para LCG (167,2; 178,9 e 129,4) e efeito quadrático (p<0,03) LCGP (216,5; 140,5 e 162,7). Os teores de gordura (9,8; 8,9 e 8,3%) e de proteína (4,2; 4,2 e 4,6 apresentaram efeitos lineares sendo (p=0,01) para gordura e (p<0,01) para proteína. Experimento III: Os objetivos deste experimento foram avaliar o efeito da inclusão de bagaço de cana-de-açúcar in natura (BIN) sobre o consumo e a digestibilidade aparente dos nutrientes, balanço de nitrogênio e os parâmetros ruminais de cordeiros Santa Inês. Quatro cordeiros providos de cânula ruminal com peso corporal (PC) médio inicial de 30kg foram alojados individualmente em gaiolas para ensaios de metabolismo. O tratamento controle positivo (CONT) consistia de uma ração de alto concentrado contendo de 10% de feno de coastcross (Cynodon sp.) na MS, sendo os demais tratamentos níveis crescentes de BIN em 10, 20 e 30% da MS, constituindo os tratamentos 10BC, 20BC e 30BC. As rações experimentais foram isonitrogenadas (13,75±0,25% PB). Não verificou-se efeito de tratamento (p>0,05) sobre o consumo de MS, MO, e PB em kg/dia e g/kg de PC 0,75; apenas sobre consumo de FDN com efeito linear (p< 0,01). O balanço de nitrogênio, assim como a concentração de acetato, propionato, butirato, concentração total de AGCC, amônia no fluido ruminal e a de digestibilidade aparente da MS, MO, PB e FDN não foram afetados pelos tratamentos. / Trial I: Sixty Santa Ines ewe lambs were used to evaluate the effects of three growing rates until 7 months of age. Treatments were defined to achieve high (HGR), moderate (MGR) and low (LGR) growing rates. The dry matter intake and average daily gain (ADG) were evaluated, well as serum levels of progesterone in order to detect the age of puberty. Linear effects (P<0.01) to body weight (BW) with values being 59.5, 61.4, and 58.0 to HGR, MGR and LGR, respectively. Linear effects (P<0.01) was also observed for average daily gain with values being 0.182, 0.156, and 0.136 kg/day, for HGR, MGR and LGR, respectively. The feed:gain ratio showed a linear effects (p<0.02) according to raw sugarcane bagasse inclusion in diet with values being 6.1, 7.1 (M) and 9.2 kgDM/kg BW for HGR, MGR and LGR, respectively. Linear effects (p<0.01) was observed for the percentage of animals of ewe lambs the reached puberty at 7 months of age, showing highest values for MGR (60%), followed by HGR (45%) and LGR (15%) treatment. Trial II: The same ewe lambs of Experiment 1 were bred at 37 kg of BW and after lambing they received a unique diet. The ewe lambs were blocked according to body weight and days in milking. According to the energy density increase in the diet, quadratic effects (p<0.01) was observed on milk production recorded in a 3-hour interval (137.9; 150.1 and 104.4 g), fat corrected milk (167.2, 178.9 and 129.4 g) and fat and protein corrected milk (216.5, 140.5, 162.7g). Fat (9.77, 8.92 and 8.35%) and protein (4.2, 4.2, and 4.6%) showed linear effects (P=0.01) for fat and (P<0.01) for protein. Trial III: The aim of this study was to evaluate the inclusion of raw sugarcane bagasse (RSB) on dry matter intake and apparent digestibility of nutrients, nitrogen balance and ruminal parameters of Santa Ines ram lambs. Four ruminally fistulated ram lambs averaging 30 kg of BW were placed in metabolism crates. The control treatment (CONT) consisted of a high concentrate diet with 10% of coastcross (Cynodon sp.) hay in the dietary DM and the others treatments consisted of 10, 20 and, 30% of RBS in the dietary DM. The diets were formulated to provide similar concentration of crude protein (13.75±0.25%). No effects were observed for DMI, OM, and CP in kg/day and g/kg of BW0.75. Linear effects (p<0.02) was observed for NDF intake according RBS inclusion. Variables, as well as total SCFA, acetate, propionate, and butyrate concentrations. Ruminal ammonia and apparent nutrient digestibility also did not differ among treatments.

Queratinócitos são um veículo bastante atrativo para a transferência gênica ex vivo e liberação sistêmica uma vez que as proteínas secretadas por estas células podem atingir a circulação via um mecanismo similar ao processo natural. Um eficiente vetor retroviral (LXSN) contendo o gene do hormônio de crescimento de camundongo (mGH) foi utilizado para transduzir queratinócitos humanos primários. Os queratinócitos transduzidos apresentaram um nível de secreção in vitro alto e estável atingindo até 11 g mGH/106 células/dia. Os epitélios formados por estes queratinócitos geneticamente modificados apresentaram, porém, uma queda na taxa de secreção > 80 % quando foram retirados da placa de cultura utilizando um procedimento clássico. A substituição desta metodologia clássica por uma cultura organotípica resolveu completamente este problema. Camundongos anões imunodeficientes (lit/scid) implantados com estes enxertos organotípicos foram acompanhados durante 4 meses, e apresentaram um aumento de peso significativo (P<0,05) nos primeiros 40 dias. Níveis circulatórios de mGH atingiram um pico de 21 ng/mL 1 h após o implante, mas estes níveis rapidamente atingiram níveis basais (~2 ng/mL). Os queratinócitos humanos primários apresentaram portanto altos níveis de expressão in vitro e os maiores níveis circulatórios, porém por um breve período de tempo, reportados até o momento para GH neste tipo de células. Em conjunto com resultados que mostraram uma recuperação considerável da eficiência de secreção de mGH em cultura por enxertos organotípicos retirados dos animais, foram discutidos os fatores que ainda impedem a utilização clínica deste modelo promissor de terapia gênica cutânea. / Keratinocytes are a very attractive vehicle for ex vivo gene transfer and systemic delivery, since proteins secreted by these cells may reach the circulation via a mechanism which mimics the natural process. An efficient retroviral vector (LXSN) encoding the mouse growth hormone gene (mGH) was used to transduce primary human keratinocytes. Organotypic raft cultures were prepared with these genetically modified keratinocytes and were grafted onto immunodeficient dwarf mice (lit/scid). Transduced keratinocytes presented a high and stable in vitro secretion level of up to 11 g mGH/106cells/day. Conventional epidermal sheets made with these genetically modified keratinocytes, however, showed a drop in secretion rates of > 80% simply due to detachment of the epithelium from its substratum. Substitution of conventional grafting methodologies with organotypic raft cultures completely overcame this problem. The stable long-term grafting of such cultures onto immunodeficient dwarf (lit/scid) mice could be followed for more than 4 months, and a significant weight increase (P<0.05) over the control group was observed in the first 40 days. Circulating mGH levels revealed a peak of 21 ng/mL just 1h after grafting, but unfortunately these levels rapidly fell to baseline values (~ 2 ng/mL). mGH-secreting primary human keratinocytes presented the highest in vitro expression and peak circulatory levels reported to date for a form of GH with this type of cells. Together with data showing that excised implants can recover in culture a remarkable fraction of their original in vitro mGH secretion efficiency, the factors that might still hamper the success of this promising model of cutaneous gene therapy are discussed. SUMÁRIO

Foram estudados dados provenientes do experimento de seleção estabelecido na Estação Experimental de Zootecnia de Sertãozinho (IZ - SP), com o objetivo de avaliar a resposta direta no peso ao sobreano de machos e fêmeas e as respostas correlacionadas no tamanho e caracteres reprodutivos das matrizes. O experimento iniciou em 1978, com três rebanhos da raça Nelore, seleção (NeS), tradicional (NeT) e controle (NeC), sendo os dois primeiros selecionados para maior peso ao sobreano e o terceiro para a média deste peso. O NeT diferencia-se de NeS por ter recebido, eventualmente, touros de outros rebanhos, inclusive comerciais. Registros de dias ao parto foram analisados separadamente nas novilhas, vacas e vacas e novilhas sem incluir e incluindo as fêmeas não paridas. Nenhuma diferença significativa (P<0,05) foi detectada entre os desempenhos das fêmeas dos rebanhos selecionados (NeS e NeT) e as do controle (NeC). As herdabilidades variaram de 0,02 a 0,16, sendo as mais altas obtidas em arquivos nos quais foram incluídos os registros das fêmeas não paridas. Os registros repetidos de dias ao parto de vacas e novilhas incluindo as fêmeas não paridas foram também analisados por modelo de regressão aleatória com polinômios ortogonais (Legendre) da idade na monta (em anos) como a covariável independente, para avaliar este caracter longitudinalmente durante a vida produtiva das fêmeas. As herdabilidades estimadas aumentaram de 0,08 a 0,28 da 1 a à 6 a monta. A seleção para peso não alterou o valor genético médio das vacas de NeS e NeT, entretanto os valores genéticos das vacas do NeC mostraram tendência de queda no decorrer dos anos, além de longitudinalmente, com o avanço da idade. Registros de peso ao sobreano dos animais nascidos de 1978 a 1998, e da altura na garupa ao sobreano das fêmeas nascidas a partir de 1985 foram analisados por modelo animal para obter a tendência genética de 1981 a 1996. Médias de peso, altura e escore de condição corporal na entrada da monta, dias ao parto e sucesso ao parto das matrizes nascidas nos últimos 4 anos foram contrastadas entre os selecionados e o NeC, em análise de quadrados mínimos. As tendências genéticas médias obtidas em 16 anos foram 1,7±0,2; 2,3±0,2 e -0,1±0,1 kg/ano nos machos e 1,9±0,2; 2,4±0,2 e -0,1±0,1 kg/ano nas fêmeas para peso, e 0,25±0,03; 0,24±0,04 e -0,04±0,03 cm nas fêmeas para altura ao sobreano, respectivamente em NeS, NeT e NeC. Novilhas e vacas de NeS e NeT foram 19% e 15% mais pesadas e 4% mais altas na entrada da monta, em relação às do NeC. Não foram detectadas diferenças significativas (P<0,05) no desempenho reprodutivo das matrizes selecionadas em relação ao NeC. Os resultados indicaram que a seleção para peso corporal promoveu respostas altas e consistentes nos pesos e alturas ao sobreano e em idades mais tardias, sem comprometer o desempenho reprodutivo das matrizes. / Data from a selection experiment, carried out AT Experimental Station of Sertãozinho, State of São Paulo, Brazil, were analyzed in order to evaluate the direct response of yearling weight and the correlated responses of the size and reproduction traits of cows. The experiment started in 1978, with three lines of Nelore cattle, selection (NeS), traditional (NeT), both selected for greater yearling weight, and control (NeC), selected for mean yearling weight. The NeT line is different from the NeS one because sires from another herds were eventually introduced into the NeT line. Records of days to calving were analyzed separately for heifers, cows and cows and heifers with and without non-calver females. There were no significant differences (P<0.05) between the performance of females from the selection lines (NeS and NeT) and those from the control line (NeC). The heritabilities were between 0.02 and 0.06, and the higher estimates were from data sets including non-calver females. The repeated records of days to calving of cows and heifers with non-calvers, were too analyzed using a random regression model, with orthogonal polynomials (Legendre) of age in the breeding season (in years) as the independent covariable, to order to evaluate this trait longitudinally during the herd life of the females. The estimates of heritability increased from 0.08 to 0.28, from first up to 6 th breeding season. The selection for weight did not alter the average breeding value of cows from NeS and NeT, although the average genetic breeding values of cows declined throughout the years, and too longitudinally, with advancing age. Yearling weight of the animals born from 1978 to 1998, and the yearling hip height of females born from 1985 to 1998, were evaluated using an animal model, in order to obtain the genetic trends for the years 1981 to 1996. The averages for weight, height and body condition score at the start of the breeding season, days to calving and calving success of cows born in the last 4 years, were contrasted between the selected (NeS and NeT) and control lines. The genetic trends obtained after 16 years were 1.7±0.2; 2.3±0.2 and -0.1±0.1 kg/year for males and 1.9±0.2; 2.4±0.2 e -0.1±0.1 kg/year for females with respect to weight, and 0.25±0.03; 0.24±0.04 and -0.04±0.03 cm for females with respect to yearling height for the NeS, NeT and NeC lines, respectively. Heifers and cows from NeS and NeT were 19% and 15% heavier and 4% taller at the start of the breeding season than those from NeC. Significant differences (P<0.05) were not detected with respect to the reproductive performance between selected (NeS and NeT) and control females. The results indicated that the selection according to body weight gave high and consistent responses for weight and height both at the yearling and later ages, without compromised the reproductive performance of the cows.

Foram analisadas informações provenientes de um experimento de avaliação de sistemas cruzamento entre raças bovinas de corte, executado na Embrapa Pecuária Sudeste, com o objetivo de avaliar o efeito dos polimorfismos genéticos da kappa-caseína-HinfI (CSN3): AA e AB, do hormônio do crescimento-AluI (GH): LL e LV e da b-lactoglobulina-HaeIII (LGB): AA, AB e BB sobre a curva de crescimento de bovinos de três grupos genéticos, ½Nelore+½Canchim (NC), ½Nelore+½Aberdeen-Angus (NA) e ½Nelore+½Simental (NS), nascidos nos anos de 1998 e 1999. Os pesos foram medidos ao nascimento, ao desmame e mensalmente dos 8 aos 19 meses de idade. As análises foram realizadas por meio de duas abordagens. Na primeira, as estimativas dos parâmetros A (valor assintótico), k (taxa de maturação) e m (ponto de inflexão) obtidas do modelo Logístico, ajustado para descrever o crescimento de cada animal, foram analisados usando um modelo linear, que incluiu além do efeito do genótipo, o qual foi formado pela concatenação dos polimorfismos genéticos de CSN3, GH e LGB (G1=AALLAA, G2=AALLAB, G3=AALLBB, G4=AALVAB, G5=AALVBB, G6=ABLLAA, G7=ABLLAB, G8=ABLLBB, G9=ABLVAA, G10=ABLVAB e G11=ABLVBB), o ano de nascimento, o sexo e o manejo alimentar. Para os animais do grupo genético NC, os genótipos influenciaram significativamente as estimativas dos parâmetros A e k da curva de crescimento. O genótipo G3 apresentou valor inferior de A e superior de k em relação aos genótipos G7 e G8. Na segunda abordagem, os dados foram analisados por modelos não lineares, incluindo no modelo, os efeitos fixos de grupo contemporâneo e de genótipo dos genes CSN3 GH e LGB, com o objetivo de verificar a influência destes genes sobre a curva de crescimento destes animais e estimar os parâmetros da função Logística, simultaneamente. Os resultados deste estudo sugerem que a função Logística utilizada para descrever o crescimento dos grupos genéticos NC, NA e NS, foi influenciada pelos genótipos dos genes CSN3, GH e LGB. As maiores diferenças entre os genótipos dos genes CSN3, GH e LGB foram encontradas a partir dos 12-13 meses de idade. O genótipo AA para CSN3 apresentou maior taxa de maturação (k) que o genótipo AB nos grupos genéticos NC, NA e NS. Quanto ao valor assintótico (A), diferença entre AA e AB, foi pequena nos grupos genéticos NC e NS. Para o polimorfismo do GH no grupo genético NA, a curva que descreve o crescimento dos animais do genótipo LL mostrou-se mais desejável, do ponto de vista de produção de bovinos de corte. Entretanto, ocorreu uma inversão desta tendência no grupo genético NS. O mesmo ocorreu para o LGB, em que os genótipos AA e AB apresentaram estimativas do parâmetro k superiores em relação ao genótipo BB no grupo genético NA, enquanto o genótipo AB apresentou estimativa de k inferior em relação ao genótipo BB, no grupo genético NS. Evidências de que os polimorfismos dos genes CSN3, GH e LGB estejam ligado a QTL influenciando a curva de crescimento de bovinos, indicam que no futuro os genótipos destes genes podem ser usados em programas de seleção assistida por marcadores. / Data from a crossbreeding experiment, carried out at Embrapa Southeast Cattle Research Center, State of São Paulo, Brazil, were analyzed in order to evaluate the effects of kappa-casein-HinfI (CSN3): AA and AB, growth hormone-AluI (GH): LL and LV, and b-lactoglobulin-HaeIII (LGB): AA, AB and BB, polymorphism on the growth curve of three beef cattle crosses, ½Nellore + ½Canchim (NC), ½Nellore + ½Aberdeen Angus (NA) and ½Nellore + ½Simmental (NS). Animals were born in the years 1998 and 1999. Weight measurements were collected at birth, weaning (7 months of age) and monthly from 8 to 19 months of age. The effect these genetic polymorphisms were analyzed by two approaches. In the first one, the parameters A (asymptotic value), k (maturing rate) and m (inflection point) estimated by Logistic model for each animal, were analyzed by least squares, fitting a linear model which included the fixed effects of the genotype, which was identified by combination of polymorphic RFLP’s of the genes CSN3, GH e LGB (G1=AALLAA, G2=AALLAB, G3=AALLBB, G4=AALVAB, G5=AALVBB, G6=ABLLAA, G7=ABLLAB, G8=ABLLBB, G9=ABLVAA, G10=ABLVAB e G11=ABLVBB), year of birth, sex and feed management. For the NC genetic groups, was detected significant effect of genotypes groups for A and k parameters estimates. The genotypes G3 presented inferior value of A and superior of k in relation to G7 and G8. In the second approach, it was fitted a Logistic non linear model which included the fixed effects of the contemporary group and genotype of the genes CSN3, GH and LGB, to examine the effect of these markers on growth curve parameters and to obtain the parameters estimates of the Logistic function, simultaneously. The growth curve used to explain the growth of the NC, NA and NS genetic groups, was influenced by genotypes of the CSN3, GH e LGB markers The major differences started at 12-13 months of age. The value of the maturing rate (k) of the AA genotype for CSN3 was superior in relation to AB genotype in the NC, NA and NS genetic groups. However, there was observed small difference in estimate of the asymptotic value (A) for the AA and AB genotypes in NC and NS genetic groups. For the GH polymorphism in NA genetic group the growth curve of the LL genotype showed more desirable to production of the beef cattle. The same was observed for the LGB, there were superior values of the parameter k of the AA and AB genotypes in relation to the BB for the NA genetic group, however there was inferior value of the parameter k of the AB genotype in relation to the BB, for the NS genetic group. Evidences that CSN3, GH and LGB polymorphism are linked to QTL influencing growth curve in beef cattle, indicates these genotypes may be a useful marker in future maker-assisted selection programs.