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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Využití kultivačních metod v diagnostice zánětů mléčné žlázy ve vybraném chovu dojnic

ULMOVÁ, Kateřina January 2019 (has links)
The goal of my thesis was to evaluate origin of mastisis diseases and specify the best way to cure this disease with antibiotics. Secondary goal was to examin origin of things that cause these diseases, efficiency of the cure and how it is influenced by the stage of the illness. This research was made in cowshed, fron april to december 2018 with 136 specimen. During this period I took samples of milk, that had more than 800 000 somatic cells in 1ml of milk. Based of possitve NK test, samples of mammary gland were taken and cultivated on one used only Petri dish. Depending of the origin of the infection, the proper atibitics were chosen for the cure. After 7 to 14 days after antibiotics treatment, milk sample was taken from the cured part od mammary gland and It was tested to see, if the treatment was successful. 77% of the specimen were sick because of microorganisms and most of the specimen were afflicted the most during 1st lactation (36.8% to 47.1%). Following microorganisms caused mastisis - Staphylococcus spp. (KNS), Streptococcus uberis, Klebsiella oxytoca, Escherichia coli, Candida rugosa a Enterococcus faecalis. 36% of mastisis was caused by Staphylococcus spp. (KNS), followed by coliform bacteria (22%). 17% of mastisis was caused by Streptococcus uberis. 10.5% of specimen was infected by Enterococcus faecalis. Candida rugosa was found in 7.4% of the samples and in 9.5% of samples the diseasehad no specific microorganism responsible. From 105 infected cows, 68% of them fully recovered. At the end, based on the stage of the mastisis, efectivness of the treatmend was statistically evaluated. The evaluation showed, that stage of infection massively influence the result of the treatment.
42

Vybrané vlivy na reprodukci plemenic holštýnského skotu

ŠPAČKOVÁ, Vladislava January 2019 (has links)
The work deals with the evaluation of selected effects on reproduction of Holstein cattle breeds. The aim of the study was to evaluate reproductive parameters (insemination index, insemination interval, period service, interim, pregnancy after the first insemination) in a selected group of dairy cows. These reproductive indicators were subsequently evaluated depending on genotype, performance level, lactation order and age at first calving and used synchronization methods. The evaluation took place at the Vřesce farm, belonging to company Rynagro a.s. 260 Holstein breed cows and their hybrids were included. The results showed that some reproductive indicators (insemination interval, service period and interim) of the monitored group of dairy cows were lower than the average of the Czech Republic. When evaluating the genotype effect on reproductive parameters, a highly significant effect (p<0.01) of genotype on insemination interval was found. Holstein breed cows had a 7-day higher insemination interval than other crosses. In evaluating the effect of daily milk yield was not proven statistically significant differences (p>0.05) in period servis and interim. Statistically significant differences (p<0.05) in insemination index, insemination interval and pregnancy after the first insemination were proven in the performance evaluation. The p-value of the global null hypothesis was close to 0.05 and no significant differences between the compared groups were demonstrated in the subsequent multiple comparison. The effect of the order of lactation on reproductive parameters was not proven (p>0.05). However, interesting results were found by the impact of age at first calving. There was a statistically highly significant difference (p<0.01) between the groups in the insemination interval and the interim and a statistically significant difference (p<0.05) between the groups in the service period. Cows with a first calving age 23 months had all of these indicators lowest, the highest values were found within cows with a first calving age of 28 months. After evaluating the correlation analysis, a significant effect of age at first calving on insemination interval (p<0.05; r=0.13), on interim (p<0.01; r=0.17) and period service (p<0.01; r=0.17). Synchronization methods were used in 125 cows and the overall success rate after this treatment was 47%. The most commonly used protocol was the Ovsynch method. The calculations based on the extension of the service period quantified the theoretical loss for the extended cycle of dairy cows. This loss is 7 030, - CZK per cow and takes into account the losses for milk and the unborn calf, not the cost of further insemination and treatment of cows.
43

Can the dynamic of milk Ca content throughout lactation be an indicator of the effects of management system and diets on bone mobilization in dairy cows ? / L'évolution de la teneur en calcium du lait au cours de la lactation peut-elle être un indicateur de l'effet de l'alimentation sur les réserves osseuses des vaches laitières ?

Gaignon, Pierre 22 October 2018 (has links)
Au cours de leur lactation, les vaches laitières font face à d’importants besoins en calcium du fait de la production laitière. L'augmentation très rapide de ces besoins en début de lactation fait que l’organisme des vaches peut difficilement s’adapter par une hausse de l’ingestion et de l’absorption digestive de calcium. L’organisme doit puiser dans les réserves osseuses, qui seront reconstituées plus tard en fin de lactation. Ces cycles de mobilisation et reconstitution osseuses restent cependant impossibles à quantifier chez la vache laitière sur de larges effectifs et les conséquences d’une mauvaise reconstitution osseuse sur les lactations suivantes restent inconnues. Cette thèse avait pour objectif de développer un indicateur des phénomènes de mobilisation et reconstitution osseuse au cours de la lactation.Plusieurs facteurs de mobilisation osseuse ont pu être identifiés, comme la race, la parité ou l’alimentation. Cependant, les cycles de mobilisation et de reconstitution osseuse n’ont pas pu être reliés à des variations de la composition du lait en Ca et P. Il a cependant pu être montré, que contrairement à ce qui est décrit dans la littérature, un apport insuffisant en Ca en début de lactation n’est pas toujours accompagné d’une augmentation de la mobilisation osseuse, mais peut être compensé par une augmentation des capacités d’absorption digestive. Cette thèse montre aussi la nécessité de quantifier les conséquences d’un apport insuffisant de calcium alimentaire sur les performances de production et la santé des vaches laitières sur l’ensemble de la lactation. / During lactations, dairy cows faces huge calcium requirements due to milk production. Because of the fast increase in those requirements at the beginning of the lactation, the organism of dairy cows can hardly adapt by increasing intake and digestive calcium absorption. The organism must mobilize calcium from its storage pool, bones, which will replenish later in lactation. Those cycles of bone mobilization and reconstitution remain impossible to quantify for important number of dairy cows and the consequences of an incomplete bone reconstitution on following lactation remain unknown. The aim of this PhD was to develop an indicator of the phenomenon of bone mobilization and reconstitution during lactation.Several factors increasing bone mobilization have been identified, such as breed, parity or diet. However, the cycles of bone mobilization and reconstitution could not be related to variation in milk Ca and P content. However, it has been showed that, an insufficient Ca supply in early lactation does not always induce a higher bone mobilization, as it has been described in the literature, but can be compensated by an increase in digestive absorption capacity. The thesis also showed the need to quantify the consequences on insufficient dietary calcium supply on dairy cows’ milk production and health throughout lactation.
44

Determinação e avaliação de fatores que afetam a produtividade de vacas leiteiras: aspectos sanitários e reprodutivos. / Evaluation and determination of factors influencing dairy cows productivity: health and reproductive aspects.

Corassin, Carlos Humberto 01 April 2004 (has links)
O objetivo deste trabalho foi determinar e avaliar os fatores sanitários e reprodutivos capazes de afetar a produtividade de vacas leiteiras. Pesquisou-se por meio de dois estudos correlacionais os efeitos de ocorrências sanitárias no periparto e seus respectivos fatores de risco sobre a produção de leite no pico e aos 305 dias em lactação, e os fatores de riscos para falhas na concepção ao primeiro serviço pós-parto (CPS). Para concretizar o objetivo deste trabalho, foram coletados mensalmente durante os anos de 2001 e 2002 dados de um rebanho comercial de vacas leiteiras de raça holandesa, localizado no Estado de São Paulo. Para a realização do primeiro estudo foram usadas 15.613 observações e para a análise estatística dos dados foram utilizadas a regressão logística e a análise de regressão múltipla. Os resultados obtidos nestas análises demonstraram que as doenças do periparto e seus fatores de risco afetaram a produção de leite com diferentes efeitos em função do número de lactações, exigindo desta maneira maior cuidado com adoção de medidas profiláticas para serem evitadas doenças e para maximizar a produção de leite dos animais. Foram usadas no segundo estudo 13.594 observações e os dados foram analisados estatisticamente por meio de regressão logística, calculando-se a razão das chances no isolamento dos fatores de risco e na associação entre os riscos para sucesso ou falha na CPS. Os resultados obtidos indicaram que os principais fatores de risco foram o número da lactação, a época do ano ao primeiro serviço, a ocorrência de doenças no periparto, a relação entre as porcentagens de gordura e proteína do leite (RGP) e as alterações no escore de condição corporal (ECC). Os animais de primeira lactação apresentaram maior chance de sucesso ao primeiro serviço do que os animais multíparos. As vacas cobertas no período do inverno apresentaram, aproximadamente, cinco vezes mais chances de CPS do que as vacas cobertas no verão. Os animais que apresentaram doenças no periparto tiveram menor sucesso de concepção que os animais sadios. Os animais que apresentaram melhor condição ruminal, determinada pela RGP, principalmente durante o período de verão, tiveram melhor concepção do que os animais com RGP reduzida no verão. O ECC adequado nas diferentes fases produtivas das vacas (secagem, parto e cobertura) demonstrou ser uma importante ferramenta para identificar as vacas com risco de insucesso na concepção ao primeiro serviço. / These studies evaluate health and reproductive factors affecting dairy cows’ productivity. Through correlation studies were evaluated health occurrences and risk factors during peripartum for milk production at peak, after 305 days of lactation and conception failures on first service pos-partum (CFS). Using a commercial herd of "dairy holsteins cows" located in São Paulo state - Brazil, data were collect in 2001 and 2002. On the first study were used 15,613 observations, the statistical analyses data were processed on logistic regression and multiple regression analyses. The analyses showed that peripartum diseases and risk factors directly affected milk production, with different effects based on lactations times, requesting extra care on prophylactics to avoid diseases and improve milk production. On the second study were used 13,594 observations, the statistical analyses data were processed on logistic regression calculating chances ratio on risk factors isolation and risk factors association to success or failure on first service pos-partum. Results indicated as mainly risks factors: lactation times, year period that first service occurred, peripartum diseases, body score condition (BSC), milk protein and fat ratio (PFR). First lactation animals presented more chance of success to the first service than multiparous. Cows inseminated during winter time showed 5 times more chances of CFS than ones inseminated on summer time. Animals with peripartum diseases had less conception success than healthy ones. Cows with better rumminal condition (FPR) had a much better conception than ones with lower FPR. The correct BSC on different productive steps (dry-off, calving and breeding) showed to be an important tool to identify animals with higher risks of failure on first service conception.
45

Variantes genéticas de kappa-caseína em vacas leiteiras e características físico-químicas e de composição do leite / Kappa-casein polimorphism in dairy cows and, physico-chemical properties and composition of milk

Lima, Ygor Vinicius Real de 16 December 2005 (has links)
Os objetivos gerais do presente estudo foram avaliar o efeito do polimorfismo genético da kappa-caseína, da raça e da estação do ano sobre as características físico-químicas (acidez, pH e crioscopia), composição (gordura, lactose, sólidos totais, contagem de células somáticas, uréia, proteína bruta, proteína verdadeira, nitrogênio não protéico e nitrogênio não caseinoso) e estabilidade do leite. Foram selecionados 11 rebanhos leiteiros comerciais, sendo cinco deles da raça Holandesa e seis da raça Girolanda, dos quais foram amostradas em média 122 vacas em lactação por rebanho, totalizando 1350 vacas amostradas em três períodos: 2 no período seco e 1 no período chuvoso. As vacas selecionadas foram analisadas quanto a composição e propriedades físico-químicas do leite, assim como para a determinação do polimorfismo de kappa-caseína. O presente trabalho foi dividido em dois estudos, no primeiro avaliou-se os efeitos da raça e estação do ano sobre características físico-químicas, composição e estabilidade do leite. Foi observado efeito de raça sobre acidez titulável, pH, lactose, uréia e estabilidade do leite. O efeito de sazonalidade mostrou-se significativo sobre pH, crioscopia, teores de lactose, uréia, proteína bruta, sólidos totais, contagem de células somáticas, proteína verdadeira, caseína, nitrogênio não protéico e estabilidade térmica do leite. Em animais da raça Girolanda, foram observados no período seco maiores teores de sólido totais. O ponto crioscópico do leite sofreu efeito do período de coleta somente em animais da raça Holandesa, onde valores mais altos foram observados durante o período seco. Os teores de lactose apresentaram maiores médias no período seco em animais da raça Holandesa. Os teores de uréia sofreram efeito de raça e período de coleta estudado. A proteína bruta do leite sofreu efeito dos fatores raça e período de coleta, sendo que vacas da raça Holandesa e Girolanda apresentam maiores teores no período seco. A concentração de caseína do leite sofreu efeito significativo do período de coleta. A estabilidade térmica do leite sofreu influência da raça, pois o leite de vacas da raça Holandesa mostraram-se mais estáveis do que os da raça Girolanda. A sazonalidade é um fator determinante para a estabilidade do leite, pois o leite mostrou-se mais estável no período chuvoso que em período seco. No segundo estudo foram avaliados o polimorfismo genético da kappa-caseína em vacas Holandesas e Girolandas e o efeito deste sobre características físico-químicas, de composição e estabilidade térmica do leite. A freqüência do alelo A foi maior do que a do alelo B no que diz respeito ao gene da kappa-caseína. Com relação às características físico-químicas do leite, não houve efeito do polimorfismo do gene da kappa-caseína sobre teores de gordura, sólidos totais, lactose, contagem de células somáticas e uréia do leite. Não foram observados efeitos do polimorfismo genético do gene para kappa-caseína sobre a composição protéica do leite, sendo que teores de proteína bruta, nitrogênio não protéico, nitrogênio não caseinoso e proteína verdadeira não sofrem influência. A estabilidade do leite frente à prova do álcool não sofreu influencia do polimorfismo genético de kappa-caseína / The objective of this study were to determine the effects of kappa-casein gene polymorphisms, breed and season on physical-chemical properties (acidity, pH and cryoscopy), composition (fat, lactose, total solids, somatic cells count, urea, crude protein, true protein, non protein nitrogen and non casein nitrogen) and stability of milk. For this aim 11 dairy herds were selected, six of them composed of Girolando cows and five from Holstein cows, in average milk samples were taken of 112 cows from each herd, collected three times: twice in dry season and once on rainy season. Each cow were analyzed for milk composition, physico-chemical properties, and to determine its kappa-casein polymorphism. This study was divided in two, the first one analyzed possible breed and season effects over milk physico-chemical characteristics, composition and stability. Breed effect was observed over acidity, pH, lactose, urea and milk stability. Season effects was significant for pH, cryoscopy, lactose, urea, CP, total solids, SCC, TP, casein, EqNPN and heat milk stability. In cows Girolando it was observed highest total solids in dry season. Milk cryoscopy had season effects only on Holstein cows, with highest results in dry season. Lactose concentration was greatest in Holstein cow in dry season. Urea concentration showed breed and season effect on this study. Crude protein was affected by breed and season, in dry season the concentration were highest for Holstein and Girolanda. Casein milk concentration demonstrated season effect. Heat milk stability showed breed stability, milk from Holstein cow were more stable that milk from Girolanda cows. Season is a determinant factor for milk stability, milk showed more stable in rainy season than during dry period. The second study analyzed: kappa-casein gene polymorphisms in Holstein and Girolando cows and its effects over milk physico-chemical characteristics, milk composition and milk heat stability. Kappa-casein allele A had a higher frequency, than allele B, in Girolando and Holstein cows in comparison with other polymorphisms. No effect of kappa-casein polymorphism was observed on milk phisico-chemical characteristics and on milk fat, total solids, lactose, SCC, and milk urea. There were no difference for milk protein composition (EqNPN, NCNC, TP, casein and EqNCN) for kappa-casein polymorphism. Milk alcohol stability did not showed effect of gene polymorphism
46

Strategies for induction of ovulation for fixed-time AI in lactating dairy cows submitted to a novel presynchronization protocol / Estratégias para indução de ovulação por IA em tempo fixo em vacas leiteiras em lactação submetidas a um novo protocolo de pré-sincronização

Consentini, Carlos Eduardo Cardoso 08 February 2019 (has links)
The study evaluated strategies for induction of ovulation for fixed-time AI (FTAI) in lactating dairy cows submitted to Ovsynch-type protocols initiated after a novel presynchronization strategy. A total of 909 lactating dairy cows from 6 dairy herds were at 36.7 ± 0.28 d in milk, with body condition score of 3.16 ± 0.02 when they underwent presynchronization. On D-15, all cows received an intravaginal progesterone (P4) implant of 1.0 g P4 (new or used) or a used device of 2.0 g P4 and 7 d later (D-8) the P4 implant was removed and cows received 1.0 mg i.m. estradiol cypionate (EC) and 0.530 mg i.m. sodium cloprostenol (PGF). On D0, a synchronization of ovulation protocol for FTAI was initiated and cows were randomly assigned to 1 of 3 experimental groups, that differed only on the strategy to induce ovulation at the end of the protocol. The protocols initiated on D0 with 16.8 &mu;g i.m. of buserelin acetate (GnRH) concomitant with insertion of a 2.0 g (new or used) P4 device. On D6, every cow received 0.530 mg PGF followed by a second PGF on D7, concomitant with P4 device withdrawal. In Group EC, cows received 1.0 mg EC on D7 (time of P4 device withdrawal) as inducer of ovulation. In Group EC/G, cows received EC on D7 and 8.4 &mu;g GnRH administered 16 h before FTAI (56 h after the first PGF). Finally, in Group G, cows only received 8.4 &mu;g GnRH at 56 h after the first PGF. The FTAI was performed on D9 (48 h after P4 device withdrawal) in all experimental treatments and pregnancy diagnosis was performed 31 and 60 d after FTAI. The pregnancy per AI (P/AI) was not different between cows with or without CL on D-15 (44.7 vs. 38.7%) and on D0 (44.3 vs. 37.3), however, cows with CL on D6 had higher P/AI than cows without CL at PGF (45.9 vs. 17.7%). Estrus expression was greater in cows receiving EC compared to cows receiving only GnRH (80.0 vs. 46.1%). Moreover, cows expressing estrus had greater P/AI than cows not showing estrus on d31 (50.8 vs. 34.8) and on d60 (48.5 vs. 27.6%), however, estrus did not affect pregnancy loss. There were no differences between experimental treatments on P/AI on d30 with an overall P/AI of 40.4% (367/909). Pregnancy loss and P/AI on d60 did not differ between treatments. In conclusion, the reproductive program has potential to promote high fertility and the 3 strategies to induce the final synchronized ovulation produced similar fertility. Further research is needed to optimize the presynchronization strategy and to more definitively determine the effect of different methods of ovulation induction on P/AI and in particular on the pregnancy loss after the d30 pregnancy diagnosis. / O estudo avaliou estratégias para induzir a ovulação final em protocolos de IA em tempo fixo (IATF) em vacas leiteiras submetidas a protocolos do tipo Ovsynch iniciados após uma pré-sincronização. Um total de 909 vacas em lactação de seis diferentes fazendas estava com 36,7 ± 0,28 d em lactação e escore de condição corporal de 3,16 ± 0.02 quando iniciaram o protocolo de pré-sincronização. No D-15 todas as vacas receberam um implante de progesterona (P4) de 1,0 g (novo ou usado) ou de 2,0 g (usado), e 7 d após (D-8), o implante de P4 foi retirado e as vacas receberam 1,0 mg i.m. de cipionato de estradiol (CE) e 0,530 mg de cloprostenol sódico (PGF). No D0, iniciou-se o protocolo de sincronização da ovulação para a IATF a as vacas foram aleatoriamente distribuídas em 1 de 3 grupos experimentais, que diferiam somente na estratégia de indução da ovulação ao final do protocolo. Os protocolos se iniciaram no D0 com 16,8 &mu;g de acetato de buserelina (GnRH) concomitante com a inserção de um dispositivo de P4 de 2,0 g (novo ou usado). No D6, todas as vacas receberam 0,530 mg de PGF seguida de uma segunda PGF no D7, concomitante com a retirada do implante de P4. No Grupo CE, as vacas receberam 1,0 mg de CE no D7 (momento da retirada do dispositivo de P4) como indutor de ovulação. No Grupo CE/G, as vacas receberam 1,0 mg de CE no D7 e 8,4 &mu;g de GnRH 16 h antes da IATF (56 h após a primeira PGF). Por último, no Grupo G, as vacas receberam somente 8,4 &mu;g de GnRH no mesmo momento do grupo CE/G. A IATF foi realizada no D9 (48 h após a retirada do implante de P4) em todos os grupos e o diagnóstico de gestação ocorreu 31 e 60 d após a IATF. A prenhez por IA (P/IA) não diferiu entre vacas com ou sem CL no D-15 (44.7 vs. 38.7%) e no D0 (44.3 vs. 37.3), no entanto, vacas com CL no D6 apresentaram maior P/IA do que vacas sem CL na PGF (45.9 vs. 17.7%). Expressão de cio foi maior em vacas que receberam CE do que vacas que receberam somente GnRH (80.0 vs. 46.1%). Além disso, vacas que expressaram cio tiveram maio P/IA no d31 (50.8 vs. 34.8) e no d60 (48.5 vs. 27.6%), no entanto, expressão de cio não afetou perda gestacional. Não houve diferença entre os tratamentos experimentais na P/IA no d31, e a P/IA média foi 40.4% (367/909). Perda gestacional e P/IA aos 60 d não diferiram entres os grupos. Concluímos que o programa reprodutivo tem potencial para promover alta fertilidade e que as 3 estratégias para induzir a ovulação final do programa reprodutivo promoveram fertilidade similares. No entanto, é necessário que seja melhor estudado a interação entre expressão de cio e tratamentos nos parâmetros de fertilidade, assim como, estudar mais a fundo os efeitos dos tratamentos (indutores de ovulação) na fertilidade após o d30 e na perda gestacional.
47

Determinação e avaliação de fatores que afetam a produtividade de vacas leiteiras: aspectos sanitários e reprodutivos. / Evaluation and determination of factors influencing dairy cows productivity: health and reproductive aspects.

Carlos Humberto Corassin 01 April 2004 (has links)
O objetivo deste trabalho foi determinar e avaliar os fatores sanitários e reprodutivos capazes de afetar a produtividade de vacas leiteiras. Pesquisou-se por meio de dois estudos correlacionais os efeitos de ocorrências sanitárias no periparto e seus respectivos fatores de risco sobre a produção de leite no pico e aos 305 dias em lactação, e os fatores de riscos para falhas na concepção ao primeiro serviço pós-parto (CPS). Para concretizar o objetivo deste trabalho, foram coletados mensalmente durante os anos de 2001 e 2002 dados de um rebanho comercial de vacas leiteiras de raça holandesa, localizado no Estado de São Paulo. Para a realização do primeiro estudo foram usadas 15.613 observações e para a análise estatística dos dados foram utilizadas a regressão logística e a análise de regressão múltipla. Os resultados obtidos nestas análises demonstraram que as doenças do periparto e seus fatores de risco afetaram a produção de leite com diferentes efeitos em função do número de lactações, exigindo desta maneira maior cuidado com adoção de medidas profiláticas para serem evitadas doenças e para maximizar a produção de leite dos animais. Foram usadas no segundo estudo 13.594 observações e os dados foram analisados estatisticamente por meio de regressão logística, calculando-se a razão das chances no isolamento dos fatores de risco e na associação entre os riscos para sucesso ou falha na CPS. Os resultados obtidos indicaram que os principais fatores de risco foram o número da lactação, a época do ano ao primeiro serviço, a ocorrência de doenças no periparto, a relação entre as porcentagens de gordura e proteína do leite (RGP) e as alterações no escore de condição corporal (ECC). Os animais de primeira lactação apresentaram maior chance de sucesso ao primeiro serviço do que os animais multíparos. As vacas cobertas no período do inverno apresentaram, aproximadamente, cinco vezes mais chances de CPS do que as vacas cobertas no verão. Os animais que apresentaram doenças no periparto tiveram menor sucesso de concepção que os animais sadios. Os animais que apresentaram melhor condição ruminal, determinada pela RGP, principalmente durante o período de verão, tiveram melhor concepção do que os animais com RGP reduzida no verão. O ECC adequado nas diferentes fases produtivas das vacas (secagem, parto e cobertura) demonstrou ser uma importante ferramenta para identificar as vacas com risco de insucesso na concepção ao primeiro serviço. / These studies evaluate health and reproductive factors affecting dairy cows’ productivity. Through correlation studies were evaluated health occurrences and risk factors during peripartum for milk production at peak, after 305 days of lactation and conception failures on first service pos-partum (CFS). Using a commercial herd of “dairy holsteins cows” located in São Paulo state – Brazil, data were collect in 2001 and 2002. On the first study were used 15,613 observations, the statistical analyses data were processed on logistic regression and multiple regression analyses. The analyses showed that peripartum diseases and risk factors directly affected milk production, with different effects based on lactations times, requesting extra care on prophylactics to avoid diseases and improve milk production. On the second study were used 13,594 observations, the statistical analyses data were processed on logistic regression calculating chances ratio on risk factors isolation and risk factors association to success or failure on first service pos-partum. Results indicated as mainly risks factors: lactation times, year period that first service occurred, peripartum diseases, body score condition (BSC), milk protein and fat ratio (PFR). First lactation animals presented more chance of success to the first service than multiparous. Cows inseminated during winter time showed 5 times more chances of CFS than ones inseminated on summer time. Animals with peripartum diseases had less conception success than healthy ones. Cows with better rumminal condition (FPR) had a much better conception than ones with lower FPR. The correct BSC on different productive steps (dry-off, calving and breeding) showed to be an important tool to identify animals with higher risks of failure on first service conception.
48

Interrelations between feed, host and rumen microbiota in dairy cows

Schären, Melanie 16 November 2017 (has links)
No description available.
49

Effect of fat in comparison to starch in an isoenergetic diet on the metabolism of high yielding dairy cows

Gaafar, Khalid 17 December 2004 (has links) (PDF)
The aim of the present study was to investigate, firstly, whether the substitution of dietary starch by rumen-protected fat results in visible changes in the protein metabolism by increasing the urea flux and decreasing of AA levels in blood plasma as indicators for a change of AA oxidation, secondly, whether the fat-fed cows use predominantly long chain FA in the processes of milk fat synthesis or as an energy source in oxidation processes, and thirdly, whether the ratio of glucogenic to lipogenic nutrients could affect the supply of glucose in the metabolism of dairy cows. Two experiments were conducted. In either experiments, about 1.8 kg of starch in the ration of the control group were substituted by about 0.7 kg fat as protected fat (Ca salts of palm, soybean and sunflower oils in addition to protected soybeans) in the ration of the fat group. The first experiment was carried out on 32 multiparous high yielding dairy cows (16 Holstein-Friesian cows in each group) during the first 100 d of lactation. The second experiment was carried out in four periods in a cross-over design. Two cows were used in each period during the 6th to the 10th lactation weeks. The cows were infused intravenously with D-[U-13C6]-Glucose. The substitution of starch by protected fat tended to increase the milk production and milk lactose output and to decrease the microbial protein synthesis in the rumen and plasma glucose level. Also, the levels of ß-HBA and NEFA in plasma, the milk urea content and the total urea-flux were increased (P<0.05). Milk protein content but not yield and plasma levels of insulin, Met, Ser and His decreased (P<0.05) but the branched chain amino acids in plasma increased (P<0.05). The oxidation rate of FA was lower in comparison to other sub`strates. In the second experiment, the enrichment of milk fat and blood CO2 by 13C decreased but the recovery of 13C in milk lactose increased (P<0.065) due to high fat intake. The results indicate that the substitution of starch by protected fat can save glucose in the intermediary metabolism for lactose synthesis in the mammary gland and the cows used fatty acids predominantly for milk fat synthesis and not for oxidation.
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Stoffwechselmonitoring in kleinen und mittelgroßen Milchrindbetrieben im Emsland

Bothmann, Johanna 30 June 2015 (has links) (PDF)
Problemstellung: Die frühzeitige Erkennung von Störungen vor ihrer klinischen Manifestation ist das Grundanliegen der Prophylaxe. Da besonders die Krankheiten des Fettmobilisationsyndroms fütterungs- und damit stoffwechselbedingt sind, besitzt deren frühzeitige Feststellung durch Stoffwechselkontrollen im peripartalen Zeitraum herausragende Bedeutung. Ziel dieser Analyse war es, Erfahrungen für Indikationen, Durchführung und Ergebnisse mehrjähriger Stoffwechselkontrollen in kleinen und mittelgroßen Betrieben auszuwerten und zu dokumentieren. Dazu wurden die von einer tierärztlichen Gemeinschaftspraxis im Emsland betreuten Betriebe anamnestisch charakterisiert, die Indikationen für Untersuchungen, die Kontrollzeiträume in Laktations- und Jahreszeitverlauf sowie in der jährlichen Abfolge erfasst, die Art und Häufigkeit der untersuchten Parameter sowie ihre klinische Bedeutung insgesamt, betriebsweise sowie z.T. für einzelne Kühe bei Mehrfachkontrollen analysiert. Erfasst wurden auch die von den Landwirten eingeleiteten Maßnahmen sowie die Ergebnisse bezüglich des Gesundheitszustands der Kühe. Versuchsanordnung: Die Anamnesen von 53 Betrieben wurden per Fragebögen erhoben. Aus 60 Betrieben flossen 840 Proben aus 122 Einsendungen mit 793 Blutserumproben und 47 Harnproben von Oktober 2006 bis März 2011 in diese Untersuchung ein. Die Kühe wurden nach Laktationsstadium in die Gruppen ante partum (a. p.), 1. Woche (Wo) post partum (p. p.), 2 - 8 Wo p. p, 9 - 14 Wo p. p, mehr als 100 Tage p. p. und Färsen eingeteilt. Die Parameterauswahl trafen die behandelnden Hoftierärzte mit den Landwirten. Untersucht wurden im Blutserum in absteigender Zahl: Freie Fettsäuren (FFS), ß-Hydroxybutyrat (BHB), Se, Harnstoff, Cu, Ca, anorganisches Phosphat (Pi), Bilirubin, CK, Cholesterol, GLDH, GGT, ß-Carotin, Fe, AST, Total-Protein, Albumin, Na, K, Cl, Mg, Glucose, Gallensäuren, Zn, AP, Kreatinin, Mn, Coeruloplasmin sowie die Trolox Äquivalente Antioxidative Kapazität (TEAC). Harnparameter sind selten untersucht worden. Die Betriebe sind fast ausschließlich Milcherzeugerbetriebe und hatten zwischen 24 und 270 Kühe überwiegend der Rasse Deutsche Holsteins mit einer mittleren Milchleistung von 8718 kg pro Jahr. Ergebnisse: Die häufigsten Merzungsgründe waren schlechte Fruchtbarkeit, Klauen- und Gliedmaßen- sowie Eutererkrankungen. Die Gründe für die Stoffwechselkontrollen waren die Abfrage des aktuellen Stoffwechselstatus sowie das vermehrte Auftreten von Fruchtbarkeitsproblemen, Festliegern, Ketosen und Euterproblemen. Maßnahmen nach der Stoffwechselauswertung waren überwiegend Futterumstellungen sowie die Substitution von Mineralstoffen. Die Einsendungsschwerpunkte lagen jeweils im ersten Jahresquartal. Die mittlere Probenan-zahl/Einsendung sank im Untersuchungszeitraum von 9,7 auf 5,1 ab. Im Durchschnitt wurden 9,9 Parameter/Einsendung untersucht. Bei annähernd 80 % der Einsendungen gaben 40 % bis 70 % der Parameter einen Hinweis auf eine Gesundheitsgefährdung des Bestandes. Im Laktationsverlauf hatten die FFS a. p. mit 56,7 % die häufigsten Abweichungen. Nach der Kalbung bis 8 Wo p. p. sanken sie auf 36 % bis 38 % und im weiteren Verlauf auf < 11 % ab. Die BHB-Abweichungen waren gegensätzlich und lagen in der gesamten Laktation über 68 %. Die FFS-, BHB- sowie Bilirubin-Medianwerte stiegen in der 1. Wo p. p auf 438 μmol/l, 0,86 mmol/l sowie 4,3 μmol/l und sanken dann kontinuierlich im Laktationsverlauf wieder ab. Die Cholesterol-Medianwerte sanken in der 1. Wo p. p. auf 2,16 mmol/l ab und stiegen im Laktationsverlauf bis auf 3,93 mmol/l an. 40 % bis 50 % der Kühe hatten in der Mittel- und Spätlaktation einen Harnstoffüberschuss. Ca und Pi hatten in der 1. Wo p. p. den typischen Konzentrationsabfall auf 2,27 bzw. 1,88 mmol/l, gefolgt von einem kontinuierlichem Anstieg in der Laktation. Hypocalzämien traten zu 13,2 % in der 1. Wo p. p. auf, Hyperphosphatämien überwiegen a. p. mit 24,9 % und in der 1. Wo p. p. mit 22,4 %. Die CK-Mediane betrugen in der 1. Wo p. p. 175,6 U/l; a.p. sowie ab 1. Wo p. p. waren sie > 100 U/I. Ähnlich verhielten sich die CK-Abweichungen mit 60,4 % a. p. und 73,6 % bis 90,9 % ab der 2. Wo p. p. Die CK-Aktivitäten der Färsen sind zu 100 % > 100 U/I. Cu-Mangelzustände wurden bei 12,5 % a. p. und 14,8 % der Kühe in der Spätlaktation beobachtet. Färsen zeigten mit 21,3 % am häufigsten Cu-Unterversorgungen. A. p. bestand zu 20,6 % Se-Unterversorgungen, p. p. hingegen zu 30,1 bis 37% eine Se-Überversorgung. ß-Carotin-Mangelzustände betrugen a. p. 50 % und p. p. 47,1 – 77,8 %. Die TEAC zeigte bei keinen Kontrollen einen Antioxidantienmangel an. Bei den meisten Parametern waren z.T. signifikante Unterschiede zwischen den einzelnen Untersuchungsjahren festzustellen. Bei den FFS und ß-Carotin bestand ein ansteigender Trend an Abweichungen, ein sinkender Trend bei Pi- Abweichungen. In den sechs Kontrolljahren konnte bei 80 % der Betriebe eine Verbesserung der Stoffwechselsituation dokumentiert werden. Bei den Parametern Ca, Pi, Harnstoff, Cholesterol, BHB, Bilirubin, CK und Cu stieg die Zahl physiologischer Werte im Einsendungsverlauf an; nur bei FFS und Se war eine Abnahme zu verzeichnen. Schlussfolgerungen: In kleinen und mittelgroßen Betrieben lieferten systematische Stoffwechselanalysen im peripartalen Zeitraum frühzeitig kausale Hinweise für die häufigsten Krankheiten und Merzungsursachen. Als informative Parameter bewährten sich Indikatoren des Energiestoffwechsels FSS, BHB und Bilirubin, weiterhin Harnstoff, das Se sowie das ß-Carotin. Die systematischen Analysen trugen im Analysenzeitraum zu Verbesserungen in den Betrieben bei. In kleineren Betrieben haben peripartale Einzeltieranalysen besonderen Informationswert über den Herdenzustand.

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