No description available.

No description available.

No description available.

Tableau d'honneur de la Faculté des études supérieures et postdorales, 2014-2015 / Cette étude a pour objectif de déterminer les impacts de la l’anémie ferriprive (AF) modérée durant la gestation et la lactation, sur les fonctions neurophysiologiques des voies auditives, ainsi que sur les fonctions métaboliques de la progéniture du cochon d’Inde (Cavia porcellus). Elle s’articule selon 2 volets d’études distincts (protocoles 1 et 2), basés tant sur la composition en fer des diètes, que sur la nature des acides gras (AG) qui les composent. Ainsi, les diètes du 1er protocole sont soit suffisantes en fer (SF : 144 mg / Kg), soit déficientes en ce dernier (DF : 11,7 mg / Kg), mais toutes deux exemptes d’AG polyinsaturés à longue chaîne (AGPI-LC) et présentant un ratio n-6:n-3 de 59:1. Dans le 2ème protocole, les diètes sont également SF (146 mg / Kg) ou DF (12,7 mg / Kg), mais intègrent des AGPI-LC et présentent un ratio n-6:n-3 de 11:1, afin de mimer un profil d’AG proche de celui de la diète nord-américaine. La terminologie « +AGPI » (SF+AGPI et DF+AGPI) reflétera cette diète. Les mères cobayes ont reçu leur alimentation respective durant les périodes d’habituation, reproduction, gestation et jusqu’au jour post-natal (JPN) 9. Les nouveau-nés ont été sevrés au JPN9 avec leur diète contrôle respective. Les potentiels évoqués auditifs du tronc cérébral (PEATC) et les prélèvements de tissus ont eu lieu au JPN24, moment où le statut hématologique des cobayes était restauré. Les PEATC des fratries DF ont présenté de profondes altérations auditives périphériques, caractérisées par une perte d’audition de type neurosensorielle (affectant particulièrement les basses fréquences), associée à un retard dans la vélocité de conduction du nerf auditif et à une sur-stimulation neurale (hyperacousie, chez les femelles uniquement). Parallèlement, l’expression cérébrale de la Δ6-désaturase, et les niveaux de cyclo-oxygénase II (COX II) et de prostaglandines (PG) étaient inchangés par rapport aux fratries SF. Au niveau central (Encephalum), une incorporation importante d’AG (essentiellement sous forme d’AGPI n-6) était caractérisée au sein des phospholipides (PL) des fratries DF. Chez ces derniers, une élévation marquée des AG totaux, saturés, monoinsaturés et AGPI n-6 plasmatiques était parallèlement caractérisée. Au sein du 2ème protocole, les fratries DF+AGPI et SF+AGPI ne présentaient pas de différence dans les temps de transmission périphérique (nerf auditif) et plus centrale (tronc cérébral), ainsi qu’au niveau de la synchronisation neurale. Malgré une similarité avec les fratries SF+AGPI dans l’acuité auditive, une forte proportion de perte d’audition neurosensorielle s’illustrait parmi le groupe DF+AGPI. Au sein de ce dernier, l’ARNm encéphalique de la Δ6-désaturase présentait une tendance à la diminution et seule la concentration en PGE2 était significativement réduite. Parallèlement, les AG des différents PL du cerveau apparaissaient faiblement affectés, alors que les concentrations érythrocytaires en AG totaux, AGS, AGPI-LC n-3 (dont l’ADH) étaient réduites. Les AG hépatiques ne subissaient aucun changement. En dépit de la réplétion en fer, ces études révèlent que la magnitude des effets de la DF gestationnelle sur les altérations neurophysiologiques et biochimiques chez la progéniture est étroitement liée au métabolisme lipidique. Les variations dans le profil en AGPI-LC des diètes DF peuvent induire des altérations particulièrement marquées au niveau des organes sensoriels périphériques chez la progéniture. Les mécanismes mis en jeu, ainsi que leurs incidences au niveau central restent à déterminer. / This research aims to determine the impacts of a moderate iron deficiency anæmia (IDA) during gestation and lactation on neurophysiological functions of the auditory pathways, as well as metabolic functions of the offspring in the guinea pig (Cavia porcellus). This thesis consists of 2 distinct studies (protocols 1 and 2), based on both the content of iron and the nature of the fatty acids (FA) in the diets. Thus, the diets of the 1st protocol are iron sufficient (IS: 144 mg / kg) or iron deficient (IDA: 11.7 mg / kg), but both are devoid of long chain polyunsaturated fatty acids (LC-PUFA) and have a ratio of n-6:n-3 equivalent to 59:1. In the 2nd protocol, diets are also IS (146 mg / kg) or IDA (12.7 mg / kg), but contain LC-PUFA and have a n-6:n-3 ratio of 11:1, in order to mimic a FA profile close from the one of the Northern-American diet. The « +PUFA » terminology (SF+PUFA and IDA+PUFA) will reflect this diet. Guinea pig dams received their respective diet during the periods of habituation, reproduction, gestation and until postnatal day (PNd) 9. Offspring were weaned at post-natal day (PNd) 9 with their respective control diet. Auditory brainstem response (ABR) and tissue samples took place at PNd24, a time point indicating when the hæmatological status of guinea pigs was restored. The ABR from IDA siblings showed profound peripheral auditory impairments, characterized by a sensorineural hearing loss type (particularly affecting the low frequencies), associated with a delay in the conduction velocity of the auditory nerve and increased neural stimulation (hyperacusis, in females only). Furthermore, brain expression of the Δ6-desaturase, and cyclooxygenase II (COX II) and prostaglandins (PG) levels were unchanged compared with siblings IS. At the central level (Encephalum), a significant FA incorporation (mainly in the form of n-6 PUFA) was characterized in phospholipids (PL) from IDA siblings. In the latter, a marked plasma elevation of total, saturated, monounsaturated FA and n-6 PUFA was characterized in parallel. In the second protocol, siblings IDA+PUFA and SF+PUFA showed no difference in peripheral (auditory nerve) and central (brainstem) transmission times, and in the neural synchronization. Despite a similarity with IS+PUFA siblings’ auditory acuity, a large proportion of sensorineural hearing loss was noted in the IDA+PUFA group. Within the latter, the brain Δ6-desaturase mRNA showed a trend to be decreased and only the PGE2 concentration was significantly reduced. Furthermore, FA from different brain PL appeared weakly affected, whereas concentrations of total FA, saturated FA (SFA), n-3 LC-PUFA (including docosahexænoic acid, DHA) in erythrocytes were reduced. Liver FA underwent no change. Despite iron repletion, these studies show that the magnitude in the impact of a gestational IDA on neurophysiological and biochemical alterations of offspring is closely related to their lipid metabolism. Changes in the offspring’s LC-PUFA profile following the gestational IDA diets may induce alterations particularly marked in their peripheral sensory organs. The mechanisms involved and their impact at the central level remain to be determined.

A methodology for ageing foetal and neonatal cattle is developed, involving radiographic examination of infant mandibles for early developmental stages in molariform teeth; tooth-wear methodologies are imprecise at this stage before wear commences. Known-age modern bovine foetal and neonate material are collected as a control assemblage for method development (n=73); six Neolithic to Norse era assemblages from Orkney are examined using the modified technique together with standard tooth-wear analysis and other methodologies. Foetal and died-at-birth material is diagnosed at most sites using the new technique, together with a range of other peri-natal age-groups. Ageing at this early stage is highly relevant in the diagnosis of milking as a palaeoeconomy: the accepted view is that unwanted (male) calves were slaughtered to maximise milk for human consumption, hence a surfeit of neonate calf remains, as at the study sites. The diagnosis of foetal and died-at-birth material challenges this view, suggesting that attritional causes may have contributed to deaths at this stage. Although milking was probably carried out at most of the study sites, this may have been combined with slaughter of cattle for meat in a pragmatic exploitation strategy. Literary research shows possible attritional causes of abortion and early death in calves, in particular dietary insufficiency in pregnant cows, microbial infections, and also inadequate colostrum uptake. Additionally, research is used to consider the challenges to health that early milking might have posed, to the calf as mentioned, but also to the cow, where three main health issues are highlighted: infertility, mastitis and lameness.

O milho sempre ocupou lugar de destaque na alimentação de vacas leiteiras no Brasil como principal fonte energética. Entretanto, é crescente o interesse por suplementos alternativos, dentre eles alguns subprodutos da agroindústria, como a polpa cítrica e a raspa de mandioca, com o objetivo de reduzir os custos de alimentação. Este trabalho avaliou a substituição do milho moído fino por polpa cítrica ou raspa de mandioca, variando os teores de amido total da dieta e de amido degradável no rúmen, para vacas no terço final de lactação. Os parâmetros avaliados foram consumo de alimento, produção e composição de leite e condição corporal.O experimento foi conduzido nas instalações do Departamento de Zootecnia da "Escola Superior de Agricultura Luiz de Queiroz". Foram utilizadas 24 vacas HPB no terço final de lactação, mantidas em free-stall. Os animais foram agrupados em oito Quadrados Latinos 3x3, de acordo com o número de lactações (primípara ou multípara), dias em lactação e a produção de leite, medida durante os 10 dias do período pré-experimental. Foram utilizados 3 lotes do free-stall, com 8 vacas em cada grupo. O experimento teve a duração de 60 dias, com 3 períodos de 20 dias cada. Os 10 primeiros dias de cada período foram utilizados para adaptação e os 10 dias restantes para coleta de dados. As dietas utilizadas foram isoprotéicas e continham silagem de milho, resíduo de cervejaria, farelo de soja, uréia, mistura mineral e vitamínica e os diferentes suplementos energéticos testados: T1 - milho moído fino; T2 - milho moído fino + polpa cítrica peletizada (50:50) e T3 raspa de mandioca + polpa cítrica peletizada (50:50). Houve tendência de redução de CMS (P<0,13) quando o milho (T1) foi substituído pela mistura de raspa de mandioca + polpa cítrica peletizada (T3). As produções de leite e LCG, os teores e produções de proteína e gordura, lactose e sólidos totais, a eficiência alimentar, o teor de N-uréico e a condição corporal das vacas não foram afetadas pelos tratamentos (P>0,05). / Corn is the major energy supplement for dairy cows in Brazil. However, its increasing price during the last years, has increased the interest for cheaper energy sources, especially by-products as citrus pulp and tapioca meal, to reduce feed costs. The objective of this trial was to evaluate the replacement of fine ground corn by peleted citrus pulp and/or tapioca meal, varying the total and rumen degradable starch levels in the diet for late lactation cows. Group dry matter intake and individual milk yield and composition and body condition score were measured. The trial was conducted at the dairy farm of the Animal Science Department of the Escola Superior de Agricultura "Luiz de Queiróz" - Universidade de São Paulo, in Brazil. Twenty four lote lactation Holstein cows, managed in a free-stall housing were grouped in eight 3x3 Latin Square, according to their number of lactation (primiparous x multiparous), days in milk and milk production measured during a 10 days pre- trial period. Three pens were used with 8 cows each. Total trial lasted 60 days, with three 20 days experimental periods. The first 10 days of each period were use for cows adaptation to treatments, and the last 10 days for data collection. As feed intake was measured for group and not individual cows, the DMI and feed efficiency were analyzed considering every group of 8 cows as an experimental unit (a single 3x3 Latin Square). All the others data were analyzed as eight 3x3 Latin Square design. Diets were isonitrogenous and were composed by corn silage, brewers grains, soybean meal, urea, mineral and vitamin mix and one of the energy sources: fine ground corn (T1); fine ground corn + citrus pulp (50:50) (T2) and citrus pulp + tapioca meal (50:50) (T3). There was a tendency (<0,13) for decrease in dry matter intake when fine ground corn (T1) was replaced by citrus pulp + tapioca meal (T3). Milk and 3,5% fat corrected milk, yields, content and yields of fat, protein, lactose and total solids, feed efficiency, milk urea-N and body condition score were not affected by treatments(P>0,05).

O objetivo do presente estudo foi estabelecer os valores de referência do proteinograma de soro lácteo por meio da técnica de eletroforese SDS-PAGE para a lactação plena e avaliar os efeitos do processo de secagem da glândula mamária, fase colostral e primeiro mês de lactação, fase de lactação, número de lactações, isolamento bacteriano e infecção pelo VCAE nas proteínas da secreção láctea de cabras da raça Saanen. Foram analisadas, entre 2007 e 2010, 545 amostras de leite provenientes de 185 cabras em diversas fases da lactação. Durante a lactação plena, baseado nos resultados dos intervalos de confiança, foram determinados os seguintes valores de referência: proteína total entre 2.940,0 e 3.050 mg/dL; proteína do soro lácteo entre 903,0 e 973,0 mg/dL; lactoferrina entre 68,0 e 77,0 mg/dL; albumina entre 88,0 e 97,0 mg/dL; imunoglobulina cadeia pesada entre 93,3 e 103,0 mg/dL; imunoglobulina cadeia leve entre 132,7 e 146,0 mg/dL; &beta;-lactoglobulina entre 299,0 e 329,0 mg/dL e &alpha;-lactoalbumina entre 213,0 e 229,5 mg/dL. Os valores absolutos de proteína total, proteína do soro e frações protéicas aumentam durante a secagem da glândula. Antes da secagem predominavam as frações de &beta;-Lg e &alpha;-La, a partir do 3&ordm; dia, ocorre o surgimento das novas frações e a alteração do perfil protéico sem que haja o predomínio de nenhuma fração. A fase colostral, primeiras 24 horas de lactação, determinam as maiores concentrações de proteína total, proteína do soro e frações protéicas que diminuem após as primeiras 12 horas de lactação estabilizando após o 5&ordm; dia. No colostro as imunoglobulinas são predominantes, e após o período de transição do colostro para o leite as frações &beta;-Lg e &alpha;-La são predominantes. Nos primeiros 15 dias de lactação, devido à influência da fase colostral, observa-se que as concentrações de proteína total e proteína do soro lácteo são maiores. A partir desse momento permanecem estáveis voltando a aumentar no final da lactação. As frações protéicas do soro de leite (lactoferrina, albumina sérica, imunoglobulina de cadeia pesada, imunoglobulina de cadeia leve, &beta;-Lg e &alpha;-La) também são máximas nos primeiros 15 dias de lactação e diminuem ao longo do período. A concentração de proteína do soro e suas frações em cabras primíparas foi menor quando comparadas com cabras pluríparas. O isolamento bacteriano não influencia as concentrações de proteína total do leite e proteína do soro lácteo de cabras, contudo a concentração de lactoferrina é maior e as concentrações de &beta;-Lg e &alpha;-La são menores em amostras com isolamento bacteriano. O CAEV não influencia as concentrações de proteína total do leite e proteína do soro lácteo de cabras, contudo a concentração de lactoferrina é maior e a concentração de e &alpha;-La é menor em cabras sororeagentes positivas ao VCAE. / The aim of this study was to establish reference values of the whey protein through the technique of SDS-PAGE for the full lactation and to evaluate the effects of the dry period of the mammary gland, colostral phase and first month of lactation, lactation, lactation number, bacterial isolation and VCAE infection in proteins of milk secretion in Saanen goats. Were analyzed between 2007 and 2010, 545 milk samples from 185 goats at different stages of lactation. During full lactation, based on the results of the confidence intervals were determined the following reference values: total protein between 2,940.0 and 3,050 mg / dL; whey protein between 903.0 and 973.0 mg / dL; lactoferrin between 68.0 and 77.0 mg / dL, serum albumin between 88.0 and 97.0 mg /dL, immunoglobulin heavy chain between 93.3 and 103.0 mg / dL, immunoglobulin light chain between 132.7 and 146, 0 mg / dL, &beta;-lactoglobulin between 299.0 and 329.0 mg / dL and &alpha;-lactalbumin between 213.0 and 229.5 mg / dL. The absolute values of total protein, whey protein and protein fractions increase during the dry period. Prevailed prior to dry period the fractions of &beta;-Lg and &alpha;-La from the 3rd day, occurs the emergence of new fractions and protein profile changes without the predominance of any fraction The colostral phase, the first 24 hours of lactation, determine the highest concentrations of total protein, whey protein and protein fractions that decrease after the first 12 hours of lactation stabilized after the 5th day. Immunoglobulin in colostrum is prevalent, and after the period of transition from colostrum to milk fractions &beta;-Lg and &alpha;-La are predominant. In the first 15 days of lactation, due to the influence of colostral phase, it is observed that the concentrations of total protein and whey protein are higher. From then remain stable before rising again in late lactation. The protein fractions of whey (lactoferrin, serum albumin, immunoglobulin heavy chain, immunoglobulin light chain, &beta;-Lg and &alpha;-La) are also maximal in the first 15 days of lactation and decrease during the period. The concentration of whey protein and protein fractions in heifers are smaller when compared with multiparous goats. Bacteria isolation does not influence the concentrations of total protein from milk and whey protein of goats, but the concentration of lactoferrin is increased and the concentrations of &beta;-Lg and &alpha;-La is smaller in samples with bacterial isolation. The CAEV does not influence the concentrations of total protein and whey protein in goat, but the concentration of lactoferrin is higher and concentration of &alpha;-La is less in goat positive by the CAEV.

As práticas de manejo das pastagens tropicais recomendadas para utilização intensiva da planta permitem ao animal colher material de boa qualidade. O objetivo do trabalho foi avaliar se a proteína bruta (PB) proveniente do capim seria suficiente para atender as exigências de vacas leiteiras no terço médio da lactação, tornando desnecessária a utilização de suplementos protéicos no concentrado. Buscou-se também a caracterização da PB do capim e a adequação protéica da dieta, visando otimizar a eficiência de utilização do nitrogênio. No primeiro estudo, 33 vacas holandesas e mestiças (HPBxJersey), no terço médio da lactação, produzindo em média 20 L dia-1, foram agrupadas em 11 blocos, de acordo com composição racial, dias em lactação e produção de leite e receberam suplemento concentrado com três níveis de PB durante 76 dias. Os concentrados continham milho moído fino, minerais, vitaminas e os três níveis de proteína (T1: 8,7%; T2: 13,4%; T3: 18,1% MS) foram obtidos substituindo-se parte do milho por farelo de soja. O capim elefante foi adubado com 50 kg N ha-1 por pastejo e apresentou teor médio de PB de 18,5%. As produções de leite e de leite corrigido para 3,5% de gordura, os teores e produções de gordura, proteína e caseína no leite, a síntese de proteína microbiana e o consumo de matéria seca (CMS) não foram influenciados (P>0,05) pelos teores de PB dos concentrados. A concentração de nitrogênio uréico no leite aumentou linearmente (P<0,01) com o aumento dos teores de PB dos concentrados. A excreção de N pela urina foi maior (P<0,05) para os concentrados contendo farelo de soja (T2 e T3) em relação ao concentrado contendo apenas milho (T1). No segundo estudo, 4 vacas holandesas secas, fistuladas no rúmen, foram distribuídas em um quadrado latino 4x4 e submetidas aos mesmos tratamentos do primeiro estudo, acrescidos de um quarto concentrado (T4) com 13,4% de PB, tendo uréia como fonte de nitrogênio. O CMS foi maior para o T4 (P<0,05), sugerindo deficiência de PDR nos outros tratamentos. Entretanto, essa hipótese não foi confirmada pelos parâmetros ruminais (pH, e ácidos graxos de cadeia curta) e síntese microbiana, que não sofreram efeito dos teores e fontes de PB no concentrado. A concentração de N amoniacal no rúmen foi menor (P<0.05) para T1 do que para os demais tratamentos. A excreção total de N no ambiente acompanhou numericamente o teor de PB dos concentrados, mas as diferenças não foram detectadas pela análise estatística. O terceiro estudo utilizou os mesmos animais e tratamentos do segundo para avaliar a cinética de degradação ruminal da MS, PB e FDN do capim por meio de ensaio in situ. Os concentrados protéicos (T2, T3 e T4) não melhoraram a degradação ruminal do capim, em relação ao concentrado energético (T1), confirmando que a proteína do pasto foi suficiente para maximizar a fermentação ruminal. O fornecimento de farelo de soja no concentrado de vacas em terço médio de lactação, mantidas em pastagens tropicais manejadas intensivamente, não resultou em nenhum benefício produtivo e aumentou a excreção de N no ambiente. / Grazing management techniques are improving the quality of the forage consumed by grazing dairy cows. The objective of this study was to determine if forage crude protein (CP) would be sufficient to achieve the nutritional requirements of midlactating dairy cows, making unnecessary the use of protein supplements on the concentrate. It also aimed to characterize the forage CP fractions and to balance the diet protein content to optimize nitrogen use efficiency. In the first trial, 33 Holstein and crossbred (Holstein X Jersey) mid-lactating dairy cows, producing 20 L d-1, were grouped in 11 blocks, according to breed, days in milk and milk yield and were fed three levels of CP on the concentrate supplement for 76 days. Concentrates contained fine ground corn, minerals, vitamins and three CP levels (T1:8.7, T2:13.4 and T3:18.1% DM) that were achieved by replacing corn with soybean meal. Pasture was fertilized with 50 kg N ha-1 after each grazing cycle and averaged 18.5% CP. There was no difference (P>0.05) in milk yield, fat corrected milk, fat, protein and casein content and yield, microbial synthesis and dry matter (DM) intake among treatments. Milk urea nitrogen increased linearly (P<0.01) as the concentrate CP content increased. The N urine excretion was greater (P<0.05) with the soybean meal concentrates (T2 and T3) than with the corn concentrate (T1). In the second trial, 4 rumen cannulated Holstein dry cows were used in a 4x4 Latin square and assigned to the same treatments used in the first study plus a fourth concentrate (T4) with 13,4% CP, containing urea instead of soybean meal as the N source. Dry matter intake was greater for T4 (P<0.05), suggesting a PDR deficiency in the other treatments. However, this hypothesis was not confirmed by ruminal parameters (pH and short chain fatty acids concentration) neither by microbial synthesis, that were not affected by the levels or sources of CP on the concentrate. Ruminal ammonia N content numerically increased as the concentrate CP content increased, but no differences were detected by the statistic analysis. The third study used the same animals and treatments of the second study to evaluate the ruminal kinetics of DM, CP and NDF of Elephant grass by an in situ assay. Protein concentrates (T2, T3 and T4) didnt improve forage ruminal degradation in relation to the energy concentrate (T1), confirming that the forage protein content was sufficient to optimize ruminal fermentation. The inclusion of soybean meal in the concentrate of midlactating dairy cows grazing intensively managed tropical grasses didnt result in productive advantage and increased the N excretion to the environment.

Os efeitos do consumo de sal durante a gestação e a lactação sobre a prole na vida adulta foram avaliados. Ratas Wistar foram alimentadas, durante o período perinatal, com dieta hipossódica (HO), normossódica (NR), hipersódica 1 (HR1) ou hipersódica 2 (HR2). A pressão arterial direta foi maior em prole masculina e feminina cujas mães foram submetidas à dieta HR2 e HR1. A sensibilidade à insulina foi menor e o colesterol e triacilgliceróis plasmáticos foram maiores somente em prole masculina de mães submetidas à dieta HO. Pressão arterial, sensibilidade à insulina e alteração do perfil lipídico na vida adulta são influenciados pelo consumo de sal durante a gestação e a lactação / The objective was to evaluate the influences of salt consumption during pregnancy and lactation in adult offspring. Female Wistar rats were fed a low (LSD), normal (NSD), high 1 (HSD1), or high 2 (HSD2) salt diet, during the perinatal period. Intra-arterial mean blood pressure was higher in both male and female offspring from HSD1 and HSD2 mothers. Insulin sensitivity was lower only in male offspring from LSD mothers. Higher cholesterol and triacylglycerol concentrations were observed only in male offspring from LSD dams. In conclusion, blood pressure, insulin sensitivity, and plasma lipid profile in adulthood are influenced by maternal salt intake during pregnancy and lactation

Das allgemeine Ziel der vorliegenden Doktorarbeit war es, den Zusammenhang von Fressverhalten, Futteraufnahme, Milchproduktion und Stoffwechselkrankheiten bei Milchkühen in der Frühlaktation zu untersuchen. Dafür wurden Daten von 70 laktierenden Deutschen Holstein-Friesischen Milchkühen (1. -7. Laktation) gesammelt. Das Fressverhalten wurde mittels eines elektronischen Fütterungssystems überwacht, welches die elektronische Kennung jeder einzelnen Kuh beinhaltete. Während der ersten Studie dieser Arbeit basierte die Analyse des Fressverhaltens der Milchkühe auf jedem Einzelbesuch; dabei war ein Besuch als die Zeit definiert, in der eine einzelne Kuh mit ihrem Kopf im Trog verweilte, unabhängig davon, wie die Kuh diese Zeit verbrachte. Während der zweiten und dritten Studie wurden die Besuche in Mahlzeiten unterteilt, die auf einem Mahlzeitenkriterium basieren, welches wie folgt berechnet wurde: Eine Mischung aus zwei normalen Verteilungen wurde an die Verteilungen der Intervallängen zwischen den Besuchen, die mittels des natürlichen Logarithmuses umgerechnet wurden waren, angepasst. Innerhalb dieser Studien wurde der Einfluss der Laktation, des Laktationsstatus und des Milchleistungsniveaus auf das Fressverhalten und die Futteraufnahme untersucht. Die letzte Studie bestimmte die Auswirkungen von Stoffwechselkrankheiten auf das Fressverhalten, die Futteraufnahme und die Milchproduktion. Die Ergebnisse deuten darauf hin, dass die Mahlzeit die wichtigere Einheit als der Einzelbesuch ist, um das Fressverhalten zu beschreiben. Laktationsnummer, Laktationsstatus und Milchleistungsniveau waren entscheidend für die Charakteristika des Fressverhaltens und die Futteraufnahme. Die höher Korrelation zwischen Fressverhalten, z.B. Dauer und Umfang einer Mahlzeit, verweisen darauf, dass das Messen der Fresszeit für das Berechnen der Futteraufnahme genutzt werden kann. Stoffwechselkrankheiten hatten einen entscheidenen Einfluss auf das Fressverhalten, die Futteraufnahme und die Milchproduktion. Die Beobachtung der Charakteristika des Fressverhaltens könnte bei der Früherkennung des bei Kühen bestehenden erhöhten Risikos an Stoffwechselstörungen hilfreich sein. / The overall objective of this PhD thesis was to investigate the relationships between feeding behaviour, feed intake, milk production, and metabolic-related production diseases of dairy cows during early lactation. Data from 70 lactating German Holstein Friesian dairy cows (parity 1 to 7) were collected. The feeding behaviour monitoring was conducted by using an electronic feeding system, which was equipped with an electronic identification of each individual cow. In the first study of this dissertation, the feeding behaviour of dairy cows was analysed based on the individual visits, with a visit being defined as the time spent by an individual cow with her head in one of the troughs regardless of how the cow spent that time. In the second and third studies, the visits were clustered in meals based on a “meal criterion”, which was calculated by fitting a mixture of two normal distributions to the distributions of the natural logarithm (LN)-transformed lengths of the interval between visits. In these studies, the effects of parity, stage of lactation, and milk yield level on feeding behaviour and feed intake were investigated. The final study determined the effects of metabolic-related production diseases on feeding behaviour, feed intake, and milk production. The results suggested that the meal is the more relevant unit than the individual visit for describing feeding behaviour. Parity, stage of lactation, and milk yield level had significant effects on feeding behaviour characteristics and feed intake. The high correlation between feeding behaviour such as meal duration and feed intake (meal size) suggests that measuring the time spent eating could be used to estimate the feed intake. Metabolic-related production diseases had significant effects on feeding behaviour, feed intake, and milk production. The monitoring of feeding behaviour characteristics might be helpful to detect the cows’ risk for metabolic-related production diseases at an early stage.