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Made available in DSpace on 2015-03-26T13:54:58Z (GMT). No. of bitstreams: 1 texto completo.pdf: 847490 bytes, checksum: 96b19b5b36a4040238163990d01928e6 (MD5) Previous issue date: 2010-02-22 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The present work was developed based on two experiments. The first experiment was conducted aiming to evaluate the effects of ruminal energy-protein synchronization on feed intake, nutrients digestibility, feed conversion, animal performance, carcass yields and composition, composition of the carcass gain, percentage of commercial cuts and meat quality of feedlot heifers. In this trial, twenty crossbreed heifers (240+6kg) were used, all of them coming from the same contemporary group. At the beginning, four animals were slaughtered as reference group and the sixteen animals remaining were assigned to a completely randomized design in 2x2 factorial schemes, two levels of concentrate (40 and 80%, based on dry matter) and two levels of ruminally undegradable protein (RUP). These animals were individually fed during 112 days and slaughtered at the end of the trial. There was no interaction (P>0.05) between the level of concentrate and RUP. The dry matter intake (DMI), feed intake and nutrients digestibility were not affected (P>0.05) by RUP level. However, the animals fed higher level of RUP diets had higher (P<0.05) average daily gain (ADG) compared with the animals fed lower level of RUP diets. The level of concentrate did not affect (P>0.05) the DMI, feed conversion and ADG, but the intakes of TDN, NDFcp and EE, were superior (P<0.05) in the animals fed higher concentrate diets. The digestibilities of all nutrients, except the NDFcp, were greater (P<0.05) for the 80% concentrate diets. There was no affect (P>0.05) of RUP level on carcass yields. Similarly, the percentage of commercial cuts, the composition of the carcass and the composition of the carcass gain were not affected (P>0.05) by the level of RUP and concentrate. However, the animals fed 80% concentrate diets had a larger (P<0.05) rib eye area (REA) compared with the animals fed 40% concentrate diets. No differences (P>0.05) in Warner-Bratzler shear force, myofibrillar fragmentation index, percentage of total cooking loss, and chemical composition of the Longissimus dorsi, were found among the levels of concentrate and RUP. It can be concluded that the level of RUP did not affect the feed intake and nutrients digestibilities, but improved the feed conversion and increased the ADG. Neither level of RUP nor level of concentrate affected the carcass composition, composition of carcass gain, percentage of commercial cuts and the meat quality of the feedlot heifers. The second experiment was conducted to evaluate the beef carcass traits and meat quality of cattle differing in numbers of permanent incisors. Sixty-three Nellore bulls, non-castrated, all from the same farm and grown on pasture, were used. The animals were selected at a large commercial beef plant. Immediately after the slaughter, the numbers of incisors were recorded after a visual examination by looking directly at the teeth and the carcasses were grouped in four categories according to teeth maturity (two, four, six or eight). After 24-h chill, data of carcass weight, pH, rib eye area (REA) and 12th rib fat thickness were collected. After carcass data collection, a boneless Longissimus section between the 9th and 11th rib was removed, vacuum packaged, frozen and held at -200C. The REA and the 12th rib fat thickness increased (P<0.05) as the number of permanent incisors increased. However, no differences (P>0.05) in carcass ultimate pH were found among the four dental classes. There was no effect (P>0.05) of dental maturity on percentage of evaporative and total cooking losses, but differences in percentage of thawing and drip losses were found (P<0.05) among the four dental classes. The Longissimus intramuscular fat and water content were affected (P<0.05) by the dental maturity. However, there was no difference (P>0.05) in percentage of protein and ashes among the dental classes. With the exception of b* values, the dental maturity did not affect (P>0.05) the instrumental color of the Longissimus. The Warner-Bratzler shear force (WBSF), the myofibrillar fragmentation index (MFI) and collagen solubility were affected (P<0.05) by dental maturity, whereas the WBSF has increased while the MFI and collagen solubility decreased as the number of permanent incisors increased. An increase of WBSF was associated (P<0.01) with decreased MFI (r = -0,36) and collagen solubility (r = - 0,14). It can be concluded that the physiological maturity, based on dental classification, affects the carcass traits and meat quality of Nellore cattle. It can also be concluded that meat from non-castrated Zebu cattle up to four permanent incisors has a desirable tenderness. / O presente trabalho foi desenvolvido a partir de dois experimentos. O primeiro foi conduzido para de avaliar o efeito da adequação de energia e proteína na dieta sobre o consumo, digestibilidade dos nutrientes, conversão alimentar, desempenho, características e composição físico-química da carcaça, composição do ganho de carcaça, rendimento de cortes comerciais e características qualitativas da carne de novilhas confinadas. Nesse experimento, foram utilizadas 20 novilhas mestiças, provenientes de um mesmo grupo contemporâneo e com peso corporal médio inicial de 240 kg. Quatro animais foram abatidos no inicio do experimento para constituir o grupo referência e os 16 animais restantes foram distribuído em quatro tratamentos em delineamento experimental inteiramente casualizado, em esquema fatorial 2x2, 40 e 80 % de concentrado, e dois níveis de proteína não degradável no rúmen (PNDR). Os animais permaneceram em média 112 dias em confinamento, sendo alimentados individualmente e foram abatidos ao final do período experimental. Não foi verificada interação (P>0,05) entre o nível de concentrado na dieta e a degradabilidade da proteína. Não houve efeito da PNDR (P>0,05) sobre o consumo e digestibilidade dos nutrientes. Entretanto, PNDR influenciou (P>0,05) o ganho de peso médio diário (GMD) dos animais. O nível de concentrado na dieta não influenciou (P>0,05) o consumo de matéria seca (CMS), a conversão alimentar e o GMD dos animais. Entretanto, o consumo de nutrientes digestíveis totais (NDT), fibra em detergenteneutro corrigido para cinzas e proteína (FDNcp) e extrato etéreo (EE) dos animais alimentados com dietas contendo 80% de concentrado mostrou-se superior (P<0,05) em relação aos animais alimentados com a dieta contendo 40% de concentrado. A dieta contendo 80% de concentrado propiciou maiores coeficientes de digestibilidade (P<0,05) de todos os nutrientes, comparado-se a dieta contendo 40% de concentrado, exceto para a FDNcp. As novilhas alimentadas com os diferentes níveis de concentrado apresentaram composição físico-química da carcaça e do ganho de carcaça similar (P>0,05). O nível de concentrado na dieta influenciou (P<0,05) a área de olho de lombo (AOL), e as novilhas alimentadas com dietas contendo 80% de concentrado apresentaram maior AOL em relação às novilhas alimentadas com dietas contendo 40% de concentrado. O rendimento dos cortes comerciais e as características qualitativas da carne não foram influenciadas (P>0,05) pela quantidade de PNDR presente na dieta nem pelo nível de fornecimento de concentrado. O nível de PNDR na dieta não alterou o consumo e digestibilidade dos nutrientes; melhorou a conversão alimentar e o desempenho de novilhas confinadas; não alterou a composição físico-química da carcaça, do ganho de carcaça e as características qualitativas da carne. As novilhas alimentadas com 80% de concentrado apresentam composição físico-química da carcaça, composição do ganho de carcaça e características qualitativas da carne semelhantes às novilhas alimentadas com dietas contendo 40% de concentrado. Conclui-se o maior fornecimento de PNDR na dieta de novilhas confinadas não implica em melhorias nas principais características de carcaça e qualidade da carne. Conclui-se ainda que novilhas confinadas alimentadas níveis moderados de concentrado na dieta (40% na matéria seca total) apresentam características de carcaça e da carne semelhantes às novilhas alimentadas com altos níveis de concentrado (80% na matéria seca total). No segundo experimento objetivou-se avaliar as características de carcaça e a qualidade da carne de bovinos em diferentes estádios de maturidade fisiológica, avaliada através da contagem do número de dentes incisivos permanentes (d.i.p.) na arcada dentária. Foram utilizados 63 animais da raça Nelore, todos machos não castrados e criados a pasto. Os animais foram selecionados em frigorífico comercial previamente ao abate. As carcaças dos animais selecionados foram agrupadas em quatro categorias de acordo com o número de d.i.p presentes na arcada dentária (2, 4, 6 e 8 d.i.p.). Após o período de resfriamento, as carcaças foram pesadas e realizou-se a mensuração do pH, área de olho de lombo (AOL) e espessura de gordura subcutânea (EGS). Em seguida foram coletadas amostras do músculo Longissimus entre a 9a e a 11a costela para realização das análises de qualidade de carne. A maturidade alterou (P<0,05) o peso da carcaça fria, AOL e a espessura de gordura subcutânea (EGS) da carcaça sendo observado aumento dessas características com o aumento do número de d.i.p na arcada dentária dos animais. Entretanto, a maturidade não alterou (P>0,05) o pH final da carcaça sendo o valor médio encontrado para essa característica igual a 6,4. Em relação as perdas das carne, à exceção das perdas por descongelamento e gotejamento, não foram detectadas diferenças (P>0,05) entre os grupos de dentição. Não houve diferença (P>0,05) entre os grupos de dentição para o teor de proteína e cinzas do músculo Longissimus. Entretanto, foram verificadas diferenças (P<0,05) entre os grupos de dentição quanto ao teor de água e extrato etéreo presentes no Longissimus. Os valores de luminosidade (L*) e intensidade de vermelho (a*) da carne não diferiram (P>0,05) entre os grupos de dentição. Entretanto, verificou-se que a maturidade alterou (P<0,05) a intensidade de amarelo (b*). A força de cisalhamento (FC), o índice de fragmentação miofibrilar (IFM) e o teor de colágeno solúvel foram influenciados (P<0,05) pela maturidade sendo observado o aumento da FC e redução dos valores de IFM e colágeno solúvel com o aumento no número de d.i.p. A FC apresentou-se negativamente correlacionada (P<0,01) com o IFM (r = -0,36) e com o teor de colágeno solúvel (r = -0,14). Conclui-se que a maturidade fisiológica avaliada pela análise da arcada dentária, influencia as características de carcaça e os principais parâmetros qualitativos da carne de bovinos Nelore. Conclui-se ainda que para animais zebuínos inteiros abatidos em frigorífico comercial, a carne pode ser considerada com maciez aceitável nos animais com até 4 dentes incisivos permanentes, ou seja, animais de até 36 meses, aproximadamente.

Classical Swine Fever (CSF) is a highly contagious viral disease of swine that causes major losses to pig production. CSF virus is a member of the genus Pestivirus of the family Flaviviridae and is closely related antigenically to other Pestiviruses, Bovine Viral Diarrhoea (BVD) virus and Border Disease (BD) virus. In the Lao People’s Democratic Republic (Laos), CSF has been recognised as a disease that causes significant loss to the smallholder pig sector. However, there exists in Laos a deficiency in fully understanding the epidemiology and impact of CSF, together with limitations in being able to reliably detect CSF outbreaks in a timely manner. (For complete abstract open document)

Les disques protoplanétaires entourant les jeunes étoiles sont les embryons des systèmes planétaires. A différentes phases de leur évolution, ils peuvent subir d'importantes pertes de masse par photoévaporation : des photons énergétiques, issus de l'étoile centrale ou d'une étoile voisine, chauffe le disque qui perd en masse sous l'échappement des particules. Cependant, ce mécanisme et la physique sous-jacente n'ont que peu été contraints par les observations. Les objectifs de cette thèse sont d'étudier la photoévaporation dans le cas particulier où elle est due à des photons FUV, d'identifier les principaux paramètres physiques (densité, température) et processus (chauffage et refroidissement) impliqués, et d'estimer son impact sur l'évolution dynamique des disques. L'étude repose sur le couplage observations - modélisations des disques photoévaporés par les photons UV en provenance d'étoiles massives proches. Ces objets, appelés "proplyds", ont leur disque entouré d'une large enveloppe nourrie des flots de photoévaporation. A l'aide d'un modèle 1D d'une région de photodissociation, j'ai développé un modèle pour l'émission dans l'infrarouge lointain des proplyds. Ce modèle a été utilisé pour interpréter les observations, issues principalement de Herschel, pour quatre proplyds. Il apparait que les conditions physiques en surface de leur disque sont similaires: une densité de l'ordre de 10 6 par cm cube et une température d'environ 1000 K. Cette température est maintenue par un équilibre dynamique : si la surface se refroidit, la perte de masse diminue et l'enveloppe se réduit. L'atténuation UV produite par l'enveloppe diminue alors et le disque, recevant plus de photons UV, chauffe. La majorité du disque peut s'échapper sous forme de flots de photoévaporation avec des taux de perte de masse de quelques 10 -7 masse solaire par an ou plus, en accord avec les observations précédentes des traceurs du gaz ionisé. A la suite de ce travail, j'ai développé un modèle hydrodynamique 1D pour étudier l'évolution dynamique d'un disque en photoévaporation par un champ de rayonnement externe. [...] / Protoplanetary disks are found around young stars, and represent the embryonic stage of planetary systems. At different phases of their evolution, disks may undergo substantial mass-loss by photoevaporation: energetic photons from the central or a nearby star heat the disk, hence particles can escape the gravitational potential and the disk loses mass. However, this mechanism, and the underlying physics regulating photoevaporation, have not been well constrained by observations so far. The aims of this thesis are to study photoevaporation, in the specific case when it is driven by far-UV photons, to identify the main physical parameters (density, temperature) and processes (gas heating and cooling mechanisms) that are involved, and to estimate its impact on the disk dynamical evolution. The study relies on coupling observations and models of disks being photoevaporated by UV photons coming from neighbouring massive star(s). Those objects, also known as "proplyds", appear as disks surrounded by a large cometary shaped envelope fed by the photoevaporation flows. Using a 1D code of the photodissociation region, I developed a model for the far-IR emission of proplyds. This model was used to interpret observations, mainly obtained with the Herschel Space Observatory, of four proplyds. We found similar physical conditions at their disk surface: a density of the order of 10 6 cm and a temperature about 1000 K. We found that this temperature is maintained by a dynamical equilibrium: if the disk surface cools, its mass-loss rate declines and the surrounding envelope is reduced. Consequently, the attenuation of the UV radiation field by the envelope decreases and the disk surface, receiving more UV photons, heats up. Most of the disk is thus able to escape through photoevaporation flows leading to mass-loss rates of the order of 10 -7 solar mass per year or more, in good agreement with earlier spectroscopic observations of ionised gas tracers. Following this work, I developed a 1D hydrodynamical code to study the dynamical evolution of an externally illuminated protoplanetary disk. [...]

This thesis investigates the feasibility and performance of an inertial based positioning system for dairy cows in a barn environment. The investigated positioning method is pedestrian dead reckoning using inertial navigation with MEMS sensors. While this method is well known for human positioning applications, there has not been a lot of studies of its use on terrestrial animals. Since inertial based positioning systems are dependent on drift correction, the focus of the research is drift correction methods. Two methods, zero velocity update (ZUPT) and sparse locations, are compared with regards to positioning accuracy, energy consumption and sensor placement.  The best positioning estimates are achieved by using ZUPT corrections at a sample rate of 10 Hz, resulting in a mean position drift of 0.2145 m=m. Using a proposed equidistant sample time based sleep mode scheme, this would require a theoretical supply current of 0.21 mA. It is also seen that better position estimates are obtained for sensors that are placed low and on the front legs. The sparse locations method suffers from severe position drift between the locations, resulting in unusable positioning data. A combination of ZUPT and sparse location yields less accurate positioning than ZUPT only. / Denna masteruppsats undersöker genomförbarhet och prestanda av ett tröghetsbaserat positioneringsssystem för mjölkkor i en lada. Den undersökta metoden är död räkning för fotgängare mha. tröghetsnavigering med MEMSsensorer. Denna metod är välkänd för positionering av människor, men få studier har gjorts kring dess användbarhet för djur. Eftersom tröghetsbaserad navigering är beroende av driftkorrigering är detta fokuset för forskningen. Två olika metoder utvärderas, zero velocity update (ZUPT) och sparse locations, och en jämförelse görs med avseende på positionsnoggrannhet, energiförbrukning och sensorplacering.Bäst positionering uppnås med ZUPT-korrigeringar vid en samplingsfrekvens på 10 Hz, vilket ger ett medelvärde av positionsdrift på 0.2145 m=m. Om ett föreslaget ekvidistant samplingstidsbaserat schema för viloläge används skulle 10 Hz kräva en teoretisk matningsström på 0.21 mA. Vidare fås bättre positioneringsresultat för sensorer som är placerade lågt och på frambenen. Korrektionsmetoden med sparse locations ger en svår positionsdrift mellan platserna, vilket resulterar i oanvändbar positionsdata. En kombination av ZUPT och sparse locations ger sämre precision än om endast ZUPT används, samt ökar energiförburkningen på grund av behovet av ytterligare sensorer.

This thesis examines the trajectory and role of development within the context of transition from a command to market economy, in a northern region of the Lao PDR. It looks at how the long-term effects of development interventions have contributed to a context of regional integration where the role of foreign investment and the private sector are increasing. In particular, it examines the role of development interventions in the processes of diversification and differentiation that accompany market integration. The village of Ban Jai illustrates this process as a site where despite the failures of development projects a diversification of livelihoods have developed. The implementation of UNDP projects in Ban Jai raises questions regarding the role of international projects and suggests that rather than alleviating poverty they produce a chain of effects that contribute to the tensions that result from structural changes to the village household economy. My analysis examines the tensions produced by such shifts and how villagers negotiate their engagement with the market economy. The experience of women traders illustrates how relations of solidarity are reworked in an attempt to negotiate tensions produced through processes of market integration. As structural shifts take place with increasing economic integration, international agencies also respond in particular ways by shifting strategies. I also ask what changes shifts in strategy introduce at the local level and how this intersects with the way policies are rationalized by local officials and the UNDP. An examination of this trajectory over a period of two decades, suggests that changing strategies in development have involved a shifting role between international development organizations and the private sector. I ask what kind of context this intersection of structural shifts, policy shifts and institutional shifts produces on the ground and how such shifts are negotiated locally.

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Contexte : Environ 257 millions de personnes dans le monde sont infectées de manière chronique par le virus de l'hépatite B (VHB). La transmission mère-enfant représente la majorité des nouveaux porteurs chroniques du VHB, en particulier en Asie. Le VHB peut être transmis in utero, lors de l'accouchement ou pendant la petite enfance voire plus tard. Environ 80 à 90% des nourrissons infectés à la naissance développent une infection chronique par le VHB avec le risque élevé de développer de graves complications, notamment une fibrose du foie, une cirrhose, un carcinome hépatocellulaire jusqu’à un décès lié au foie à l’âge adulte. Nous avons évalué la proportion des enfants immunisés avec succès dans deux grands hôpitaux de Vientiane, en République démocratique populaire lao, où l’immunoglobuline HB (HBIg) n’est pas disponible. Méthodes : Nous avons étudié une cohorte prospective de femmes enceintes infectées par le VHB et de leurs enfants jusqu'à six mois après la naissance de janvier 2015 à mars 2017. Tous les nourrissons ont reçu le vaccin anti-HB à la naissance et six, 10 et 14 semaines après la naissance. Le statut d’infection par le VHB chez l’enfant a été évalué à l’âge de 6 mois. Le séquençage du gène de surface du VHB a été effectué chez des couples mère-enfant infectés. Résultats : Sur 153 mères ayant été dépistées positives pour l'antigène de surface HB (AgHBs), 60 (39%) avaient l'antigène HBe (AgHBe) positif. Les femmes enceintes ayant AgHBe-positif étaient plus jeunes que les femmes ayant d’AgHBe négatif ((âge médian 26 versus 28 ans; p = 0,02). et avaient une charge virale du VHB significativement plus élevée à l'accouchement (médiane 8,0 versus 4,0 log10 UI / mL, p <0,001). Au total, 141 nouveau-nés, dont une paire de jumeaux, sont nés pendant l'étude. Parmi les 112 nouveau-nés pour lesquels l’information concernant le délai entre la naissance et l’heure d’administration du vaccin contre le VHB était disponible, 110 (98%) ont reçu le vaccin dans les 24 heures suivant la naissance. Le délai médian entre la naissance et l'administration du vaccin était de 6 heures (EI 3 à 13), avec 95 (72%) dans les 12 heures suivant la naissance. Un nouveau-né a reçu le vaccin 26 heures après la naissance car le vaccin n'était pas disponible dans la salle d'accouchement et un autre nouveau-né a reçu le vaccin 3 jours après la naissance car, en raison d'une détresse respiratoire sévère à la naissance, le vaccin a été considéré comme contre-indiqué. Parmi les 120 enfants évalués à l'âge de 6 mois, 5 (4%) étaient positifs pour AgHBs et présentaient une charge virale détectable pour le VHB par réaction en chaîne avec une polymérase. Tous sont nés de mères ayant l’AgHBe positif et une charge virale> 8,5 log10 UI / mL. Cependant, seulement quatre enfants (3,3%, IC à 95%, 0,5% à 7,0%) avaient une souche virale étroitement apparentée à celle de leur mère. Des mutations du gène de surface du VHB (G145G/R, G145G/A, M133T, M133I) ont été détectées chez 4 des 5 enfants infectés. Le taux d'anticorps anti-HBs était supérieur à 10 UI / L chez 105 nourrissons (88%) à l'âge de 6 mois. Conclusions : La transmission de la mère à l'enfant s'est produite moins souvent que ce que nous avions prévu en absence de l'utilisation de HBIg. L’ajout d’une prophylaxie par HBIg et / ou antivirale maternelle aurait pu prévenir certaines de ces infections. L'observation du taux d'anticorps anti-HBs non satisfait chez 9% des enfants non infectés à 6 mois souligne la nécessité d'améliorer les procédures d'immunisation universelles / Background: An estimated 257 million people are chronically infected with the hepatitis B virus (HBV) worldwide. Mother-to-child transmission accounts for the majority of new chronic HBV carriers, especially in Asia. HBV can be transmitted in utero, during delivery or during infancy and later. About 80–90% of infants infected at birth will develop a chronic HBV infection, and will have a high risk of developing serious complications including liver fibrosis, cirrhosis, hepatocellular carcinoma (HCC) and liver-related death during adult age. We aimed at assessing the percentage of infants successfully immunized in two major hospitals in Vientiane, Lao People's Democratic Republic (Lao PDR) where HB immune globulin (HBIg) is not available. Methods: We studied a prospective cohort of chronically HBV infected pregnant women and their infants until 6 months post-partum from January 2015 to March 2017. All infants received the HB vaccine at birth and 6, 10 and 14 weeks thereafter, and their HBV status was assessed at 6 months of age. HBV surface gene sequencing was performed in infected mother-infant pairs.Results: Of 153 mothers with HB surface antigen (HBsAg), 60 (39%) had detectable serum HBe antigen (HBeAg). HBeAg positive pregnant women were younger than those negative (median age 26 versus 28 years; p=0.02) and had a significantly higher HBV viral load at delivery (median 8.0 versus 4.0 log10 IU/mL, p <0.001). A total of 141 infants including a pair of twins were included in the study and information at the time of vaccine administration after birth was available for 112 newborns. Of these, 110 (98%) received the HepB-BD within 24 hours after birth. One newborn received the vaccine 26 hours after birth because the vaccine was not available at the delivery room, and another newborn 3 days after birth due to fetal distress, which was erroneously considered to be a vaccine contra-indication. Among the 120 infants assessed at 6 months of age, 5 (4%) were positive for HBsAg and had a detectable HBV viral load by polymerase chain reaction. All were born to mothers with HBeAg and a viral load >8.5 log10 IU/mL. However, only four (3.3%, 95% CI 0.5% to 7.0 %) had a virus strain closely related to their mother’s strain. HBV surface gene mutations were detected in 4 of the 5 infected infants (G145G/R, G145G/A, M133T, M133I). Anti-HBs antibody level was above 10 IU/L in 105 (88%) infants at 6 months of age. Conclusions: Mother-to-child transmission occurred less frequently than expected without the use of HBIg. Adding HBIg and/or maternal antiviral prophylaxis may have prevented some of these infections. The observation of unsatisfactory levels of anti-HBs antibodies in 9% of the uninfected infants at 6 months highlights the need for improvement of the universal immunization procedures

O presente estudo foi desenvolvido em dois experimentos: 1) Tipo de processamento do milho e a relação PDR:PNDR sobre a fermentação ruminal, comportamento alimentar e seletividade ingestiva de vacas leiteiras cujos objetivos foram: a) avaliar o efeito do tipo de processamento do milho (floculado ou moído) e a relação da proteína degradável (PDR) e não degradável no rúmen (PNDR) (alta ou baixa) sobre a fermentação ruminal, o comportamento alimentar e a seletividade ingestiva de vacas leiteiras durante o período experimental; b) avaliar o efeito a curto prazo da troca da dieta contendomilho moído ou floculado e alta ou baixa relação PDR:PNDR sobre o consumo de matéria seca, produção e estabilidade do leite (teste do álcool, pH, cálcio iônico, estabilidade térmica e alcoólica) de vacas leiteiras durante período de adaptação. Foram utilizadas 20 vacas da raça Holandesa, com 162 &#177; 70 DEL, 666 &#177; 68 kg de peso corporal, 3,15 &#177; 0,48 de escore de condição corporal e 36,0 &#177; 7,78 kg/vaca/ dia de produção de leite. Os resultados de metabolismo ruminal indicaram que o milho floculado reduziu a relação acetato:propionato e a concentração de ácido acético (%) e aumentou as concentrações dos ácidos valérico (&micro;mol/L) e de propiônico (%) e o pH fecal em relação ao milho moído. Quanto ao comportamento alimentar, observou-se que o uso de milho floculado associado à alta relação PDR:PNDR e a utilização de milho moído associado à baixa relação PDR:PNDR reduziram os tempos de alimentação (TAL/ kg de MS ingerida) e de ruminação (TRU/ kg de MS ingerida) entretanto, o uso de milho floculado associado à alta ou à baixa relação PDR:PNDR aumentaram o tempo de ruminação (TRU/ kg de FDN consumido). Já para índice de seleção notou-se que a rejeição de partículas longas (&gt; 19,0 mm) foi menor em vacas alimentadas com milho floculado em relação às alimentadas com moído. 2) Efeito a curto prazo da troca da dieta sobre a produção e estabilidade do leite de vacas da raça Holandesa que teve por objetivo avaliar o efeito do dia de troca da dieta com diferentes fontes de carboidrato não fibroso associado ou não a inclusão de tamponante/alcalinizante sobre CMS, produção e estabilidade do leite (teste do álcool, pH, cálcio iônico, estabilidade térmica e alcoólica). Foram utilizadas 16 vacas da raça Holandesa, com 130 &#177; 81 DEL, peso corporal de 660 &#177; 62 kg e produção média de leite de 28,5 &#177; 4,79 kg/vaca/dia. O milho moído associado à alta ou à baixa relação PDR:PNDR aumentou o CMS, entretanto o fornecimento de dieta contendo a alta relação PDR:PNDR associada ao milho moído ou floculado apresentaram redução na PL. O uso de milho floculado associado à alta relação PDR:PNDR aumentou o valor de pH das amostras de leite e em todos os tratamentos testados a concentração de Cai apresentou redução. O uso de milho floculado associado ao aumento da relação PDR:PNDR causou redução na estabilidade alcoólica do leite e o uso do milho moído associado a baixa relação PDR:PNDR aumentou a estabilidade do leite ao teste do álcool. O CMS foi a única variável que apresentou efeito da dieta, em que o uso de milho moído sem a inclusão de tamp/alc aumentou o CMS. Sendo assim, durante o período de adaptação, o efeito a curto prazo de troca foi mais nítido nas dietas contendo milho processado associado à proteínas de diferentes degradabilidades ruminal do que nas dietas contendo fontes de carboidratos não fibrosos associados à inclusão ou não de tamp/alc. / The present study was developed in two experiments: 1) Corn processing type and the RDP:RUP ratio on ruminal fermentation, feeding behavior and ingestive selectivity of dairy cows. The objectives were: to evaluate the effect of corn processing type (flocculated or ground) and the ratio (hight or low) of degradable (RDP) and non-degradable protein (RUP) on ruminal fermentation, feed behavior and ingestive selectivity of dairy cows during the experimental period. Indeed to evaluate the short-term effect of dietary exchange containing either ground or flocculated corn and high or low RDP: RUP ratio on dry matter intake, milk yield and stability (alcohol test, pH, ionic calcium, of dairy cows during adaptation period. Twenty Holstein cows were used, with 162 &#177; 70 DIM, 666 &#177; 68 kg body weight, 3.15 &#177; 0.48 body condition score and 36.0 &#177; 7.78 kg / cow / day of milk yield. The results of ruminal metabolism indicated that the flocculated corn reduced the acetate: propionate ratio and the acetic acid concentration (%) and increased the concentrations of valeric (&micro;mol / L) and propionic acid (%) and fecal pH in relation to ground corn. As regards feed behavior, it was observed that the use of flocculated corn associated with high RDP:RUP ratio and the use of milled corn associated with low RDP:RUP ratio reduced feeding times (TAL / kg of intake DM) and rumination (TRU / kg of DM ingested). However, the use of flocculated corn associated with high or low RDP:RUP ratios increased rumination time (TRU / kg of NDF consumed). For the selection index, it was noted that the rejection of long particles (&gt; 19.0 mm) was lower in cows fed flocculated maize than those fed with milled corn. 2) Short-term effect of the diet change on the production and stability of Holstein cows milk that aimed to evaluate the effect of the diet change day with different sources of non-fibrous carbohydrate associated or not with the inclusion of buffer / alkalinizing on DMI, milk production and stability (alcohol test, pH, ionic calcium, thermal and alcoholic stability). Sixteen Holstein cows, 130 &#177; 81 DIM, body weight of 660 &#177; 62 kg and mean milk yield of 28.5 &#177; 4.79 kg / cow / day were used. Ground corn associated with high or low RDP:RUP ratios increased of intake DM; however, the diet containing the high RDP:RUP ratio associated to ground or flocculated corn showed a decrease in milk yield. The use of flocculated corn associated with high RDP:RUP ratio increased the pH value of milk samples; and in all tested treatments; the concentration of Cai presented reduction. The use of flocculated corn associated with the increase of the RDP:RUP ratio caused a decrease in the milk alcoholic stability while the use of ground corn associated with a low RDP:RUP ratio increased this variable. The intake DM was the only variable that presented a dietary effect, in which the use of ground corn without the inclusion of buffer/alk increased intake DM. Thus, during the adaptation period, the short-term effect of exchange was more pronounced in diets containing processed corn associated with proteins of different ruminal degradability than in diets containing sources of non-fibrous carbohydrates associated with the inclusion of buffer/alk .