No description available.

Thirty-six multiparous Holstein cows were assigned to one of three dietary levels of lasalocid· 0, 180, or 360 mg/hd/d in a completely randomized design Cows were assigned to treatments I wk postcalving and remained on treatment until II wk postcalving Basal diets were composed of ground corn, alfalfa hay, alfalfa haylage, corn silage, and soybean meal, fortified with vitamins and minerals as needed. All ingredients were ground and fed as a total mixed ration Daily rations were fed in two equal portions at 0500 and I 700 h at a rate to allow a 5- 10% refusal. Daily measurements included milk production and dry matter intake (OM 1). Milk composition (fat, protein, and somatic ii cells) was analyzed twice per week on Tuesdays and Fridays. Cow body weight (BW) and visual body condition were measured weekly. Production during previous lactation was used as a covariate in analyzing the data. Although milk production was not affected by dietary treatment, lasalocid tended to increase daily milk production by approximately 2.5 kg/d (P 13) at both the 180 and 360 mg/hd/d levels Percent milk fat and protein were not afl'ected by dietary lasalocid (P 84 and 78, respectively). Somatic cell count of the milk was not affected by dietary lasalocid (/' 17). Dietary lasalocid reduced DMI by approximately I 5 kg/d at both the 180 and 360 mg/hdld levels (P .02). At the 180 and 360 mg/hdld levels, lasalocid increased amount of milk produced per kg of DM consumed by 16 kg (I' 08). either BW (P 89) nor body condition (P = 90) were affected by dietary lasalocid at either level. No effect of treatments was observed on blood metabolites Glucose, nonesterified fatty acids, P-hydroxybutyrate, and cholesterol all tell within the normal ranges of blood serum.

No description available.

No description available.

<p>Period rane laktacije odlikuje se nagatvnim energetskim bilansom i stanjem metaboličkog stresa. Ovakvo stanje nastaje kao posledica smanjenog unosa hrane, porođaja i započinjanja laktacije. Usled negativnog energetskog bilansa organizam povećano tro&scaron;i sopstvene reserve I ulazi u fazu katabolizma. Cilj ove disertacije je da se ispita metabolička, hematolo&scaron;ka, celularna i proizvodna adaptacija krava u funkciji delovanja anaboličkih i kataboličkih indikatora stresa. Katabolički indikatori stresa su: neesterifikovane masne kiseline (čija koncentracija raste kao posledica povećane lipidne mobilizacije) i kortizol (čija vrednost raste usled stresa tokom porođaja). Anabolički indikatori su: insulin (anabolički hormone u organizmu sisara) i IGF-I (indikator anaboličkog delovanja STH). Krave su klasifikovane na osnovu pojedinačnog i kombinovanog delovanja anaboličkih i kataboličkih indikatora stresa. Upotreba četiri odabrana indikatora metaboličkog stresa (insulin, IGF-I, NEFA i kortizol) u prvoj nedelji posle teljenja može pomoći u analizi metaboličkog stresa i produktivnosti krava, &scaron;to se zaključuje na osnovu delovanja indikatora<br />Created by Simpo PDF Creator Pro (unregistered version) http://www.simpopdf.com<br />c<br />stresa na metabolički profil, krvnu sliku, imunolo&scaron;ke i celularne parametre, telesnu kondiciju, proizvodnju mleka i reproduktivnu efikasnost krava. Vrednosti anaboličkih i kataboličkih indikatora se mogu koristiti samostalno ili u kombinaciji, a najbolju mogućnost procene daje upotreba NEFA bilo da se radi o pojedinačnoj ili kombinovanoj upotrebi indikatora.Određivanjem koncentracije navedena četiri indikatora metaboličkog stresa u prvoj nedelji posle teljenja možemo predvideti karakter metabolizma, dubinu metaboličkog stresa i proizvodnju krava u laktaciji koja sledi.</p> / <p>Early lactation period is characterized by negative energy balance and metabolic stress condition. This situation arises as a consequence of reduced food intake, birth and initiation of lactation. Due to negative energy balance increased body using own reserves and is entering to a phase of catabolism. The goal of this dissertation is to examine the metabolic, hematologic, and cellular adaptation of cows in production function and anabolic activity of catabolic stress indicators. Catabolic stress indicators are nonesterified fatty acids - NEFA (whose concentration increases as a result of increased lipid mobilization) and cortisol (the value of which increases due to stress during labor). Anabolic indicators were: insulin (anabolic hormones in mammals) and IGF-I (an indicator of anabolic activity STH). Cows were classified on the basis of individual and combined effects of anabolic and catabolic stress indicators. Using the four selected indicators of metabolic stress (insulin, IGF-I, NEFA and cortisol) in the first week after calving can help in the analysis of metabolic stress and productivity of cows, which<br />Created by Simpo PDF Creator Pro (unregistered version) http://www.simpopdf.com<br />f<br />concludes on the basis of indicators of stress effects on metabolic profile, blood count, and cellular immune parameters, body condition, milk production and reproductive efficiency of cows. Anabolic and catabolic values of indicators may be used singly or in combination, and provides the best opportunity to assess the use of NEFA either a single or combined use of indicators. It is possible to use concentrations of the four indicators of metabolic stress in the first week after calving predict the nature of metabolism, metabolic stress and depth of production in cows in the next lactation.</p>

Galactopoietic effects of somatotropin are the result of IGF-I and require high-quality nutrient intake. This study investigated short-term partitioning effects during recombinant bovine somatotropin (bST) administration in high yielding early lactation dairy cows. Administration of recombinant bST has been shown generally to alter results of metabolic tests in the face of unchanged basal glucose and insulin concentrations. Ten multiparous Holstein cows were subjected to rbST (Lactotropin®) and/or feed intake restriction to 80% of predicted ME requirement (80% ME). Responses to insulin challenge (0.1 IU porcine insulin/kg BW. 210 min) and hyperglycaemic clamp (+50 mg/dL whole blood, 120 min) were tested during weeks 8 (control), 9 (rbST ), 11 (80% ME) and 12 (rbST + 80% ME) postpartum. Plasma and whole blood samples were assayed for glucose concentrations. The rbST treatment decreased fasting whole-blood glucose concentration by 9.4% (P<0.0001), which was likely a remnant of control hyperglycaemia. Maximum glucose response was 4.0 mg/dL (21.7%) lower (P<0.0038) and took 6.5 minutes longer to attain (P<0.0037). Steady-state glucose infusion rate (SSGIR) decreased by 8.1 % (P<0.0001). The 80% ME treatment decreased glucose availability by 5 to 6% (P<0.0100), while no glucose responses were affected. Restricted energy intake during treatment with rbST resulted in plasma glucose increase by 5.5% (P<0.0001). Peripheral uptake and utilization of glucose increased by 5.1 % (P<0.0005). Compared to energy restriction, 80%ME + rbST did not alter effects of nutrient restriction on responses to exogenous insulin challenge. Effects were small and inconsistent. SSGIR decreased by 5.0% in the 80% ME + rbST compared to the 80% ME period (P<0.0004) and the change in the hyperglycaemic clamp in the absence of an effect in the insulin challenge may be due to differences in endogenous insulin secretion. The conclusion was that rbST treatment resulted in altered glucose metabolic responses, even with restricted energy intake. / Dissertation (MSc(Agric))--University of Pretoria, 2008. / Animal and Wildlife Sciences / unrestricted

Increasing the milking frequency of early lactation dairy cows increases their milk yield, both during increased milking and after the cows are returned to a normal twice-daily milking schedule. When milked four times a day (4X) for only the first twenty-one days of lactation, the right udder half produces 3 kg/d more milk than the left half, which is milked only two times a day (2X) over the course of lactation (Hale et al., 2003). Alterations to this increased milking frequency (IMF) approach have been investigated in order to maximize production of the animals and determine the most efficient practice for producers. The aim of this study was to determine the appropriate duration of early lactation IMF treatment by increasing milking frequency of early lactation cows for various lengths of time, and subsequently increasing the use of this management practice on Virginia dairy farms. The right udder half of twenty-three primiparous and multiparous Holstein cows were milked 4X for 10, 20, or 40 days at the beginning of lactation, and the left udder half 2X for the entire lactation. Udder-half milk yields were measured at various time points throughout lactation and used to calculate the difference between right (4X) and left (2X) udder halves. Overall, treatment did not have a significant effect on milk yield difference throughout the entire lactation; the udder half differences for each group were -0.45 kg, 1.92 kg and 4.62 kg for the 10 d, 20 d and 40 d treatments (P > 0.05). In addition to the IMF portion of the experiment, two different methodologies were used to investigate the possible mechanism of local regulation of milk yield in response to IMF treatment. Milk fatty acid analysis was performed on milk samples obtained from the above experiment. Three different groups of fatty acids were analyzed to detect potential changes in the right udder half (4X) when compared to the left (2X); the three groups were denovo, C16, and preformed fatty acids. There was no significant effect of treatment on fatty acid composition of right and left udder halves for any of the three groups (P > 0.05). The second methodology used to explore a possible mechanism behind increased milk yield following IMF treatment was immunohistochemistry of mammary gland tissue samples obtained after IMF treatment in a previous experiment. The key target investigated was a component of the Hippo signaling pathway, Yes-associated protein (YAP). Intensity of YAP staining in the cytoplasmic area of mammary epithelial cells (MEC) and number of YAP-positive stained nuclei located in the MEC were quantified for each of the images obtained. There was no effect of treatment or day on intensity of staining (P > 0.05) with no difference in the intensity of staining between 4X and 2X samples or d 21 and d 60 samples. However, the interaction for treatment x day tended to be significant (P < 0.06), with the d 60 samples tending to have higher intensity of staining than d 21 samples. For YAP-positive nuclei, there was a significant effect of day (P < 0.05), with d 60 samples having significantly more YAP positive nuclei. There was not a significant effect of treatment or treatment x day interaction (P > 0.05) with 2X and 4X samples having the same number of YAP positive nuclei. Results from the first experiment reveal that 40 d of IMF during early lactation is sufficient to produce an increase in milk and component yields throughout lactation. This practice could be implemented on Virginia dairy farms as a way to increase efficiency and milk yield per cow. Results from the second half of this research indicates that further research is needed to investigate the fatty acid content of milk from cows subject to IMF treatment during early lactation. In addition, YAP potentially plays a role in the changes occurring in the mammary gland, with increased intensity of YAP staining and increased number of YAP positive nuclei observed at 60 DIM. Understanding of this protein and its involvement in the mammary gland could lead to identifying a mechanism for which this increase in milk yield and components following IMF is occurring. Further research needs to be done to provide results supporting the current experiment. / MSLFS

Objetivou-se avaliar o efeito da suplementação prolongada de grão de soja cru e integral (GSI) como fonte de ácido graxo &#937;6 sobre o desempenho produtivo, perfil metabólico, qualidade oocitária e embrionária e função imune de vacas leiteiras no período de transição e início de lactação. Foram selecionadas 44 vacas da raça Holandesa, multíparas e gestantes, com parto previsto para 90 dias após o início da avaliação e fornecimento das dietas experimentais, porém em razão da ocorrência de enfermidades metabólicas ou infecciosas (3 abortos; 3 deslocamentos de abomaso; 3 enfermidades podais; 4 distocias) 13 animais foram retirados do experimento. As vacas foram distribuídas aleatoriamente em quatro grupos experimentais diferindo entre eles o início do fornecimento de grão de soja cru e integral (GSI) durante o pré-parto. A dieta era baseada na inclusão de 12% de GSI %MS, com aproximadamente 5,1% de extrato etéreo (EE) o início de seu fornecimento foi conforme descrito a seguir: Grupo 0: Animais não receberam dieta contendo GSI no pré-parto; Grupo 30: Início do fornecimento de dieta com GSI nos 30 dias finais da gestação; Grupo 60: Início do fornecimento de dieta com GSI nos 60 dias finais da gestação; Grupo 90: Início do fornecimento de dieta com GSI nos 90 dias finais da gestação. Após o parto, todas as vacas receberam dieta única com 5,1% de EE, baseada na inclusão de 12% de GSI %MS até 90 dias de lactação. Os animais foram arraçoados de acordo com o consumo de matéria seca no dia anterior, de forma a ser mantido porcentual de sobras das dietas, diariamente, entre 5 e 10%. As amostras dos alimentos e sobras foram coletadas diariamente e armazenadas a -20ºC. Semanalmente as amostras coletadas diariamente foram misturadas e foi retirada uma amostra composta referente a um período de uma semana, a fim de mensurar o consumo de matéria seca e nutrientes. Amostras de fezes foram coletadas nos dias -56, -21, 21, 56 e 84 dias em relação ao parto, com o propósito de mensurar a digestibilidade da matéria seca e nutrientes. A produção de leite foi mensurada diariamente e para a composição dos teores de gordura, proteína, lactose e perfil de ácidos graxos amostras foram coletadas semanalmente. As amostras de sangue para análise dos metabólitos sanguíneos foram coletadas semanalmente. Amostras de sangue para mensurar a atividade do sistema imune foram coletadas na semanas -8, -4, -2, -1 em relação ao parto, parto, +1, +2, +4 e +8 semanas no período pós-parto. Nos dias 21, 42, 63 e 84 do período pós-parto foram realizadas aspirações foliculares, com posterior fertilização in vitro dos oócitos. Todas as variáveis mensuradas foram analisadas pelo procedimento PROC MIXED do SAS 9.4 através de regressão polinomial, utilizando efeito fixo de tratamento, semana, interação tratamento*semana e efeito de animal dentro de tratamento como aleatório. Utilizou nível de 5% de significância. Foi observado efeito (P<0,05) linear crescente para CEE no pré-parto. Não foi observado diferenças no CMS e nutrientes no pós-parto. Não houve alteração da digestibilidade nos períodos pré e pós-parto. Não houve alteração no balanço de energia e nitrogênio nos periodos pré e pós-parto. Não foi observado diferença na produção, composição e teor dos componentes totais do leite. No perfil de ácidos graxos do leite houve efeito (P<0,05) linear descrescente para as concentrações de C16:1cis, C18:1 cis, total de C:18 insaturado, total de AG monoinsaturados, insaturados e a relação do total de AGS:AGI. Foi observado efeito linear (P<0,05) crescente para o total de AG aturado e efeito (P<0,05) quadrático para C18:2, CLAcis9-trans11, e total de AGPI. Foi observado efeito linear crescente (P<0,05) para colesterol total, LDL no préparto e linear decrescente (P<0,05) para GGT nos períodos pré e pós-parto. Foi observado efeito quadrático (P<0,05) para HDL no pré-parto e AST no pós-parto. Em relação a atividade do sistema imune foi observado efeito linear (P<0,05) crescente para o percentual de CD3+ ativos no pós-parto, para o percentual de monócitos que produziram espécie reativa de oxigênio (ERO) no pós-parto quando foram estimulados por S.aureus e E.coli e para a intensidade de imunofluorescência de ERO para ganulócitos no pós-parto quando estimulados por S.aureus. Foi observado efeito (P<0,05) quadrático para o percentual de granulócitos, mononucleares, CD8+ ativos no pós-parto e para o percentual de granulócitos que produziram ERO no pós-parto quando estimulados por E.coli. A suplementação prolongada com GSI no pré-parto melhora a atividade do sistema imune, não melhora a qualidade oocitária e embrionária bem como não influencia negativamente os parametros produtivos de vacas leiteiras no período de transição e início de lactação / The objective was to evaluate the effect of prolonged supplementation with whole soybean grain (WSG) as a source of &#937;6 fatty acid on the productive performance, metabolic profile, oocyte and embryo quality, and immune function of dairy cows during the transition period and early lactation. Forty-four multiparous, pregnant Holstein cows, with calving predicted to 90 days after the beginning of the evaluation and supply of the experimental diets were selected. However, due to the occurrence of metabolic or infectious disorders (3 abortions, 3 displaced abomasums, 3 foot disorders, 4 dystocias), 13 animals were removed from the experiment. Cows were randomly assigned to one of four experimental groups, which differed in period of supply of whole soybean grains during the prepartum. The diet was based on 12% of WSG (%DM) and had approximately 5.1% of ether extract (EE). Diet supply was as follows: Group 0) control diet not containing WSG; Group 30) WSG supply starting 30 days before predicted calving date; Group 60) WSG supply starting 60 days before predicted calving; Group 90) WSG supply starting 90 days before predicted calving date. After calving, all cows received a single diet with 5.1% EE, based on inclusion of 12% WSG (%DM) until 90 days of lactation. Animals were fed ad libitum to ensure between 5 and 10% orts daily. Dry matter and nutrients intake were evaluated. Samples of feeds and orts were collected daily and stored at -20°C. Samples were composited weekly and analyzed for chemical and bromatological characteristics. Feces samples were collected on days -56, -21, 21, 56, 84 (related to the predicted calving), in order to measure the digestibility of dry matter and nutrients. Milk yield was measured daily and milk samples were collected weekly for evaluation of fat, protein and lactose percentages, and fatty acids profile. Blood samples were taken weekly for analysis of blood metabolites. To measure the activity of the immune system, blood samples were collected at weeks -8, -4, -2, -1 prepartum, at calving, and at weeks +1, +2, +4, +8 postpartum. On days 21, 42, 63 and 84 postpartum, follicular aspirations were performed, with subsequent in-vitro fertilization of the oocytes. All measured variables were analyzed using PROC MIXED of SAS 9.4 through polynomial regression, considering as fixed effects the dietary treatment, week and interaction treatment*week, and animal as random effect. The 5% level of significance was considered. A crescent linear effect was observed (P <0.05) for prepartum ether extract intake. There was no difference in dry matter and nutrients intake during the postpartum period. There were no differences in digestibility pre and postpartum. No difference in energy and nitrogen balance during pre and postpartum periods was observed. Milk production and composition did not differ among dietary treatments. When evaluating the milk fatty acids profile, a decreasing linear effect was noted (P<0.05) for the concentrations of C16:1 cis, C18:1 cis, total unsaturated C18, total monounsaturated fatty acids, total unsaturated fatty acids and total SFA:UFA ratio. There was an increasing linear effect (P<0.05) for the total of saturated fatty acids and a quadratic effect (P<0.05) for C18:2, CLAcis9-trans11, and total PUFA. It was observed increasing linear effect (P<0.05) for total cholesterol and LDL in the prepartum period, and decreasing linear effect (P<0.05) for GGT in the pre and postpartum. We observed a quadratic effect (P<0.05) for HDL in prepartum and for AST during the postpartum. Regarding the activity of the immune system, there was a crescent linear effect (P<0.05) for the percentage of active CD3+ in the postpartum period, for the percentage of monocytes producing reactive oxygen species (ROS) during postpartum period when stimulated by S. aureus and E. coli, and for granulocytes ROS immunofluorescence intensity during postpartum when stimulated by S. aureus. Quadratic effect was observed (P<0.05) for the percentage of granulocytes, mononuclear cells, active CD8+ in the postpartum period and the percentage of granulocytes that produced ROS when stimulated by E. coli. Prolonged supplementation with RWS in the prepartum improves the activity of the immune system, however it does not improve oocyte and embryo quality and does not adversely affect the production performance of dairy cows during the transition period and early lactation

Objetivou-se avaliar o efeito da suplementação prolongada de grão de soja cru e integral (GSI) como fonte de ácido graxo &#937;6 sobre o desempenho produtivo, perfil metabólico, qualidade oocitária e embrionária e função imune de vacas leiteiras no período de transição e início de lactação. Foram selecionadas 44 vacas da raça Holandesa, multíparas e gestantes, com parto previsto para 90 dias após o início da avaliação e fornecimento das dietas experimentais, porém em razão da ocorrência de enfermidades metabólicas ou infecciosas (3 abortos; 3 deslocamentos de abomaso; 3 enfermidades podais; 4 distocias) 13 animais foram retirados do experimento. As vacas foram distribuídas aleatoriamente em quatro grupos experimentais diferindo entre eles o início do fornecimento de grão de soja cru e integral (GSI) durante o pré-parto. A dieta era baseada na inclusão de 12% de GSI %MS, com aproximadamente 5,1% de extrato etéreo (EE) o início de seu fornecimento foi conforme descrito a seguir: Grupo 0: Animais não receberam dieta contendo GSI no pré-parto; Grupo 30: Início do fornecimento de dieta com GSI nos 30 dias finais da gestação; Grupo 60: Início do fornecimento de dieta com GSI nos 60 dias finais da gestação; Grupo 90: Início do fornecimento de dieta com GSI nos 90 dias finais da gestação. Após o parto, todas as vacas receberam dieta única com 5,1% de EE, baseada na inclusão de 12% de GSI %MS até 90 dias de lactação. Os animais foram arraçoados de acordo com o consumo de matéria seca no dia anterior, de forma a ser mantido porcentual de sobras das dietas, diariamente, entre 5 e 10%. As amostras dos alimentos e sobras foram coletadas diariamente e armazenadas a -20ºC. Semanalmente as amostras coletadas diariamente foram misturadas e foi retirada uma amostra composta referente a um período de uma semana, a fim de mensurar o consumo de matéria seca e nutrientes. Amostras de fezes foram coletadas nos dias -56, -21, 21, 56 e 84 dias em relação ao parto, com o propósito de mensurar a digestibilidade da matéria seca e nutrientes. A produção de leite foi mensurada diariamente e para a composição dos teores de gordura, proteína, lactose e perfil de ácidos graxos amostras foram coletadas semanalmente. As amostras de sangue para análise dos metabólitos sanguíneos foram coletadas semanalmente. Amostras de sangue para mensurar a atividade do sistema imune foram coletadas na semanas -8, -4, -2, -1 em relação ao parto, parto, +1, +2, +4 e +8 semanas no período pós-parto. Nos dias 21, 42, 63 e 84 do período pós-parto foram realizadas aspirações foliculares, com posterior fertilização in vitro dos oócitos. Todas as variáveis mensuradas foram analisadas pelo procedimento PROC MIXED do SAS 9.4 através de regressão polinomial, utilizando efeito fixo de tratamento, semana, interação tratamento*semana e efeito de animal dentro de tratamento como aleatório. Utilizou nível de 5% de significância. Foi observado efeito (P<0,05) linear crescente para CEE no pré-parto. Não foi observado diferenças no CMS e nutrientes no pós-parto. Não houve alteração da digestibilidade nos períodos pré e pós-parto. Não houve alteração no balanço de energia e nitrogênio nos periodos pré e pós-parto. Não foi observado diferença na produção, composição e teor dos componentes totais do leite. No perfil de ácidos graxos do leite houve efeito (P<0,05) linear descrescente para as concentrações de C16:1cis, C18:1 cis, total de C:18 insaturado, total de AG monoinsaturados, insaturados e a relação do total de AGS:AGI. Foi observado efeito linear (P<0,05) crescente para o total de AG aturado e efeito (P<0,05) quadrático para C18:2, CLAcis9-trans11, e total de AGPI. Foi observado efeito linear crescente (P<0,05) para colesterol total, LDL no préparto e linear decrescente (P<0,05) para GGT nos períodos pré e pós-parto. Foi observado efeito quadrático (P<0,05) para HDL no pré-parto e AST no pós-parto. Em relação a atividade do sistema imune foi observado efeito linear (P<0,05) crescente para o percentual de CD3+ ativos no pós-parto, para o percentual de monócitos que produziram espécie reativa de oxigênio (ERO) no pós-parto quando foram estimulados por S.aureus e E.coli e para a intensidade de imunofluorescência de ERO para ganulócitos no pós-parto quando estimulados por S.aureus. Foi observado efeito (P<0,05) quadrático para o percentual de granulócitos, mononucleares, CD8+ ativos no pós-parto e para o percentual de granulócitos que produziram ERO no pós-parto quando estimulados por E.coli. A suplementação prolongada com GSI no pré-parto melhora a atividade do sistema imune, não melhora a qualidade oocitária e embrionária bem como não influencia negativamente os parametros produtivos de vacas leiteiras no período de transição e início de lactação / The objective was to evaluate the effect of prolonged supplementation with whole soybean grain (WSG) as a source of &#937;6 fatty acid on the productive performance, metabolic profile, oocyte and embryo quality, and immune function of dairy cows during the transition period and early lactation. Forty-four multiparous, pregnant Holstein cows, with calving predicted to 90 days after the beginning of the evaluation and supply of the experimental diets were selected. However, due to the occurrence of metabolic or infectious disorders (3 abortions, 3 displaced abomasums, 3 foot disorders, 4 dystocias), 13 animals were removed from the experiment. Cows were randomly assigned to one of four experimental groups, which differed in period of supply of whole soybean grains during the prepartum. The diet was based on 12% of WSG (%DM) and had approximately 5.1% of ether extract (EE). Diet supply was as follows: Group 0) control diet not containing WSG; Group 30) WSG supply starting 30 days before predicted calving date; Group 60) WSG supply starting 60 days before predicted calving; Group 90) WSG supply starting 90 days before predicted calving date. After calving, all cows received a single diet with 5.1% EE, based on inclusion of 12% WSG (%DM) until 90 days of lactation. Animals were fed ad libitum to ensure between 5 and 10% orts daily. Dry matter and nutrients intake were evaluated. Samples of feeds and orts were collected daily and stored at -20°C. Samples were composited weekly and analyzed for chemical and bromatological characteristics. Feces samples were collected on days -56, -21, 21, 56, 84 (related to the predicted calving), in order to measure the digestibility of dry matter and nutrients. Milk yield was measured daily and milk samples were collected weekly for evaluation of fat, protein and lactose percentages, and fatty acids profile. Blood samples were taken weekly for analysis of blood metabolites. To measure the activity of the immune system, blood samples were collected at weeks -8, -4, -2, -1 prepartum, at calving, and at weeks +1, +2, +4, +8 postpartum. On days 21, 42, 63 and 84 postpartum, follicular aspirations were performed, with subsequent in-vitro fertilization of the oocytes. All measured variables were analyzed using PROC MIXED of SAS 9.4 through polynomial regression, considering as fixed effects the dietary treatment, week and interaction treatment*week, and animal as random effect. The 5% level of significance was considered. A crescent linear effect was observed (P <0.05) for prepartum ether extract intake. There was no difference in dry matter and nutrients intake during the postpartum period. There were no differences in digestibility pre and postpartum. No difference in energy and nitrogen balance during pre and postpartum periods was observed. Milk production and composition did not differ among dietary treatments. When evaluating the milk fatty acids profile, a decreasing linear effect was noted (P<0.05) for the concentrations of C16:1 cis, C18:1 cis, total unsaturated C18, total monounsaturated fatty acids, total unsaturated fatty acids and total SFA:UFA ratio. There was an increasing linear effect (P<0.05) for the total of saturated fatty acids and a quadratic effect (P<0.05) for C18:2, CLAcis9-trans11, and total PUFA. It was observed increasing linear effect (P<0.05) for total cholesterol and LDL in the prepartum period, and decreasing linear effect (P<0.05) for GGT in the pre and postpartum. We observed a quadratic effect (P<0.05) for HDL in prepartum and for AST during the postpartum. Regarding the activity of the immune system, there was a crescent linear effect (P<0.05) for the percentage of active CD3+ in the postpartum period, for the percentage of monocytes producing reactive oxygen species (ROS) during postpartum period when stimulated by S. aureus and E. coli, and for granulocytes ROS immunofluorescence intensity during postpartum when stimulated by S. aureus. Quadratic effect was observed (P<0.05) for the percentage of granulocytes, mononuclear cells, active CD8+ in the postpartum period and the percentage of granulocytes that produced ROS when stimulated by E. coli. Prolonged supplementation with RWS in the prepartum improves the activity of the immune system, however it does not improve oocyte and embryo quality and does not adversely affect the production performance of dairy cows during the transition period and early 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.