• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 50
  • 33
  • 19
  • 13
  • 9
  • 6
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 193
  • 43
  • 33
  • 30
  • 29
  • 27
  • 24
  • 19
  • 17
  • 17
  • 16
  • 16
  • 15
  • 15
  • 14
  • 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.
101

Desempenho e eficiência econômica de novilhos em pastagem de Brachiaria brizantha cv. Marandu na transição águas/seca submetidos a diferentes regimes alimentares / Performance and economic efficiency of calves in pasture of Brachiaria brizantha cv. Marandu during wet-dry transition subjected to different diets

Melo, Adilson Antonio de 12 July 2011 (has links)
Made available in DSpace on 2015-03-26T14:02:16Z (GMT). No. of bitstreams: 1 texto completo.pdf: 710241 bytes, checksum: 4ae2321162f69d0466dfa2b74c54cf95 (MD5) Previous issue date: 2011-07-12 / This study used 60 Nelore calves, with average initial body weight of 285 kg. The treatments were: (MS) Mineral Supplement, SUP1 Protein-Energy-Mineral Supplement, being the source of non-protein nitrogen (NPN) slow-release urea, with average daily intake of 0.7% of body weight (BW) in dry matter (DM), SUP2 Protein-Energy-Mineral Supplement, being the source of NPN conventional urea with an average daily intake of 0.7% of the BW in DM. The type of experimental design used applied was randomizedPerformance and economic efficiency of calves in pasture of Brachiaria brizantha cv. Marandu during wet-dry transition subjected to different diets. blocks with three treatments and four replications. It was used the Duncan test for statistical analysis on the animals performance. There was a difference in the results of SUP1 and SUP2 compared with the MS, with average daily gains of 0.367 and 0.458 kg/animal/day for SUP1 and SUP2 respectively and 0.166 kg/animal/day for the MS (P<0.05). There was no difference in average daily gain (ADG) (P>0.05) between the SUP1 and SUP2. The animals supplemented with protein-energy-mineral supplementation had greater gains than those submitted to mineral supplement during the period of transition water-dry. There were positive economic results for all treatments, and the best results came from the calves that received the protein-energy supplementation (SUP1 and SUP2). The highest gross margin was observed for animals in the treatment SUP2, R$45.12 animal/period, compared to the control treatment, R$ 29.81 animal/period, suggesting that protein-energy supplementation promoted higher economic return. Thus, there was no statistical difference (p>0,05) between SUP1 and SUP2 to for weight gain and also for additional intake of CP and TDN, and the two treatments showed superior results to the SM. The SUP2 treatment was superior economically to SUP2 and SM and SUP1, as for it had higher gross margin left to the experiment. / Neste trabalho foram utilizados 60 novilhos Nelore inteiros, com média de peso corporal inicial (PCI) de 285 kg. Os tratamentos foram: SM suplemento mineral; SUP1 suplemento proteico-energético-mineral, sendo a fonte de nitrogênio não proteico (NNP) a ureia de liberação lenta (ULL), com ingestão média diária de 0,7% do peso corporal (PC) na matéria seca (MS); SUP2 suplemento proteico-energético-mineral, sendo a fonte de NNP a ureia convencional, com ingestão média diária de 0,7% do PC na MS. O delineamento utilizado foi o de blocos ao acaso, com três tratamentos e quatro repetições. Foi usado o teste de Duncan para análise estatística referente ao desempenho dos animais. Houve diferença nos resultados do SUP1 e SUP2, comparados com o SM, com ganhos médios diários de 0,367 e 0,458 kg/animal/dia para SUP1 e SUP2, respectivamente, e de 0,166 kg/animal/dia para o SM (P<0,05). Não ocorreu diferença no ganho médio diário (GMD) (P>0,05) entre SUP1 e SUP2. Os animais alimentados com a suplementação proteico-energético-mineral obtiveram ganhos superiores aos submetidos ao suplemento mineral, no período de transição água-seca. Houve resultados econômicos positivos para todos os tratamentos, e os melhores foram verificados em novilhos que receberam a suplementação proteico-energética (SUP2). A maior margem bruta foi observada nos animais do tratamento SUP2, R$45,12 animal/período, em relação ao tratamento controle, R$29,81 animal/período, sugerindo que a suplementação proteico-energética possibilitou maior retorno econômico. Assim, não houve diferença estatística (P>0,05) entre SUP1 e SUP2 para ganho de peso médio, bem como para ingestão adicional de PB e NDT; os dois tratamentos apresentaram resultados superiores ao SM. O tratamento SUP2 foi superior economicamente a SM e SUP1, pois deixou maior margem bruta ao experimento.
102

Vliv mortality telat na ekonomický výsledek chovu skotu / The influence of calf mortality on economic efficiency of cattle breeding

SVOBODNÁ, Hedvika January 2007 (has links)
The purpose of this thesis was to analyse mortality in calf rearing.I found out that the most important causes of the calf mortality are: course of calving, order of calving, seasonal character and climatic conditions.The casualties in calf rearing were about 24 %. Economic loss which was evoked by calf death affected trading income in whole cattle breeding. The main aim of the both farms is to achieve high level in calf rearing which essentially decides about profitability and efficiency of cattle breeding.
103

Taxa de prenhez em vacas Nelore pós-parto, submetidas ou não a aplicação de eCG 2 dias antes e/ou 14 dias após a IATF / Pregnancy rate in portpartum Nelore cows treated or not with eCG 2 days before and/or 14 days after TAI

Amanda Prudêncio Lemes 02 October 2012 (has links)
O presente trabalho foi delineado com o intuito de identificar os efeitos da inclusão da Gonadotrofina Coriônica Equina (eCG) antes e após a IA em vacas de corte submetidas a protocolos de IATF e conduzido na Fazenda Rancho 60, pertencente ao Grupo Agropecuária Fazenda Brasil (Barra do Garças, MT, Brasil). Para tanto, 901 vacas Nelores multíparas com média de 44 dias pós-parto foram sincronizadas, inseminadas em tempo fixo utilizando-se três touros (Aberdeen Angus) e nove inseminadores. Além disso, as vacas foram monitoradas por exames ultrassonográficos e/ou colheitas de sangue até os 30 dias após a IA. Taxas de sincronização, prenhez aos 30 e 60 dias foram mensuradas e as amostras de sangue foram avaliadas quanto à concentração de progesterona sérica. Foram avaliados os efeitos da inclusão de 300 UI de gonadotrofina coriônica equina (eCG) 2 dias antes e/ou 14 dias depois da IA e posteriormente avaliou-se também a influência do grupo genético e sexo dos bezerros no desempenho reprodutivo. Em suma, o tratamento com eCG após a IA não melhorou a fertilidade em vacas Nelore pós-parto, entretanto pode-se observar um incremento nas taxas de ovulação, prenhez aos 60 dias e aumento nas concentrações séricas de P4 nos animais que receberam eCG no D8. Quanto à influência da progênie na fertilidade das mães conclui-se que pode haver uma relação entre o sexo e raça dos bezerros na concentração circulante de P4 das progenitoras, entretanto estas variáveis não influenciaram na fertilidade da vaca submetida à IATF no período pós-parto. / The present work was designed to identify the effects of a treatment with equine chorionic gonadotropin (eCG) before and post-AI in beef cows submitted to TAI protocols. The experiment was conducted at Rancho 60 Farm, belonging to Grupo Agropecuaria Fazenda Brasil (Barra do Garças, MT, Brazil). For this, 901 multiparous Nellore cows with 44 days post-partum were synchronized, inseminated at fixed time using semen of three bulls (Angus). In addition, cows were monitored by ovarian ultrasonography and/or blood sampling until 30 days post AI. Ovulation rate, and pregnancy rates at 30 and 60 days were evaluated and blood samples were analyzed for serum progesterone concentration. The effects of treatment with 300 IU of eCG 2 days before and/or 14 days after AI were evaluated, as well as the influence of the breed and gender of their calves in the reproductive performance. In general, treatment with eCG after AI did not improve fertility in post-partum Nelore cows, however, it was detected an improvement in ovulation rate and pregnancy rate at 60 days and an increase in serum progesterone concentrations in cows that received eCG at Day 8. There was no effect of gender and breed of calves on fertility of the dams; however these variables influenced circulating progesterone post AI.
104

Influência etária na resposta imunológica de bezerros à vacinação intranasal / Age influence on immune response of calves to intranasal vaccination

Renata Caminha Gomes 29 April 2016 (has links)
Devido à intensa oscilação de funções e mecanismos de defesa respiratórios evidenciados nos primeiros meses de vida dos bezerros, o discernimento do limiar etário para a resposta vacinal intranasal efetiva, atrelado ao risco de infecção e perfil da vacina são fundamentais para a pecuária racional. Diante disto, o estudo buscou comparar a resposta imune humoral e mediada por células, local e sistêmica, entre bezerros vacinados intranasalmente aos 15 ou 45 dias de vida com vacina polivalente contendo vírus sincicial respiratório bovino vivo modificado, cepas quimicamente alteradas de herpesvirus bovino tipo 1 e vírus da parainfluenza tipo 3, vírus da diarreia viral bovina tipos 1 e 2 inativados, além de culturas inativadas dos cinco sorotipos de Leptospira e adjuvante Quil-A. Foram utilizados 16 bezerros holandeses alocados em três grupos, o grupo GA composto por seis animais primovacinados aos 15 dias de idade, o grupo GB composto por cinco animais primovacinados aos 45 dias de idade e o grupo controle composto por cinco animais não vacinados. Os animais vacinados receberam uma segunda dose vacinal 21 dias após a primeira. Para avaliação da interferência da vacinação intranasal no estado geral dos bezerros, na expressão das populações leucocitárias, na capacidade fagocítica e microbicida, além da investigação de anticorpos humorais e locais, foram realizados exames clínicos e colhidas amostras de sangue e lavado broncoalveolar (LBA) antes da primeira e da segunda dose vacinal, bem como uma terceira colheita 21 dias após a segunda dose. Foi observado que após a vacinação a maioria dos animais vacinados apresentou manifestações clínicas respiratórias, acompanhadas de leucograma com declínio de leucócitos totais e linfócitos nos animais do GA em relação ao CTLA. Nos animais do GB além das manifestações clínicas, foi encontrada somente uma tendência ao aumento de neutrófilos em relação ao CTLB. Houve diminuição de macrófagos alveolares e aumento de neutrófilos sanguíneos e alveolares tanto na citologia do LBA quanto na imunofenotipagem dos animais do GA em relação ao CTLA e diminuição de macrófagos na citologia do LBA ao longo dos momentos do GA, enquanto que nos animais do GB houve diminuição de monócitos-like CD14+ ao longo dos momentos. Simultaneamente ao aumento de monócitos CD14+ ao longo dos momentos, foi notado o aumento de linfócitos TCD3+ CD4- CD8- nos animais do GA ao longo dos momentos e em relação ao CTLA. Além disso, a porcentagem de linfócitos sanguíneos TCD3+ aumentou no GA em relação ao CTLA, porém não acompanhada pelo aumento na porcentagem de células TCD4+ ou TCD8+ mas sim pelas populações TCD3+CD4-CD8- ao longo dos momentos e em relação ao CTLA e TCD3+ CD4+ CD8+ em relação ao CTLA. No LBA a porcentagem de células CD4+ diminuiu em relação ao CTLA. Nos animais do GB não houve diferença entre essas populações celulares, somente a diminuição de células CD4+ CD8+ em relação ao CTLB no LBA. Ao se avaliar as funções de fagocitose e microbicida dos grupos vacinados, foi constatada diminuição expressiva na maioria das avaliações após a vacinação, principalmente em relação ao GA. Em relação à resposta humoral por anticorpos, o estudo demonstrou que a resposta vacinal por via intranasal não sofreu influência de anticorpos colostrais, tampouco induziu imunidade sérica específica por anticorpos, no entanto, no LBA foi capaz de induzir aumento de IgA nos animais do GA e uma tendência ao aumento em animais do GB. Diante dos resultados, conclui-se que: a resposta à vacina utilizada por via intranasal em bezerros com 15 dias de idade é diferente de quando utilizada aos 45 dias, e que causou alterações de exame clínico, leucograma e citologia do LBA mais intensas nos animais vacinados aos 15 dias de idade. Embora não apresente resposta anticorpo específica sistêmica em ambos os casos, aos 15 dias apresentou resposta neutrofílica e monocítica sistêmica acompanhada de aumento de linfócitos T duplo negativos e duplo positivos, enquanto a resposta local celular foi pobre em macrófagos e rica em neutrófilos e IgA, porém com comprometimento das funções celulares. Dessa forma, a vacina utilizada nesse período, por via intranasal, em especial aos 15 dias de idade pode predispor o animal a infecções bacterianas secundárias. No entanto, deve-se ficar claro que este resultado se aplica somente a estas condições de vacina, via e idade / Due to the intense oscillating of functions and respiratory defense mechanisms evidenced in the first months of life of calves, the discernment about the age threshold for the effective intranasal vaccine response, linked to the risk of infection and vaccines profile are fundamental to rational livestock. In view of this, the study aimed to compare the humoral immune response and local and systemic cell-mediated among calves vaccinated intranasally to 15 or 45 days of life with polyvalent vaccine containing bovine respiratory syncytial modified live virus, chemically altered strains of bovine herpesvirus type 1 and parainfluenza virus type 3, inactivated bovine viral diarrhea types 1 and 2, inactivated cultures of five Leptospira serovars and Quil-A adjuvant. 16 Holstein calves were allocated in three groups, the GA group consisting of six animals vaccinated at 15 days of age, the GB group consisting of five animals vaccinated at 45 days of age and the control group of five animals not vaccinated. Vaccinated animals received a second immunization dose 21 days after the first one. To evaluate the impact of intranasal vaccination in the general condition of the calves, in the expression of leukocyte populations, phagocytic and microbicide capacity, as well as research of humoral and local antibodies, clinical examinations were performed and blood and bronchoalveolar lavage (BAL) samples were collected before the first and second vaccine vaccination, as well as a third sample 21 days after the second dose. It was observed that after vaccination most vaccinated animals showed respiratory clinical manifestations, accompanied by white blood cell count with decline of total leukocytes and lymphocytes in GA animals compared to CTLA. In GB animals beyond the clinical manifestations, it was only found a tendency to increase in neutrophils in relation to CTLB. There was a decrease in alveolar macrophages and increased blood and alveolar neutrophils in both BAL cytology and immunophenotyping of GA animals compared to the CTLA and reduction of macrophages in BAL cytology over the times in GA animals, whereas in GB animals there was a decreased in CD14+ monocyte-like along time. Simultaneously with the increase in CD14+ monocytes over the time, it was noted an increase in TCD3+CD4-CD8- lymphocytes in GA animals along time and compared to CTLA. Furthermore, the percentage of TCD3+ blood lymphocytes increased in GA compared to the CTLA but it was not accompanied by an increase in the percentage of CD4+ or CD8+ T cells but by TCD3+ CD4- CD8- population along time and compared to the CTLA and TCD3+ CD4+ CD8+ cells compared to CTLA. In BAL the percentage of CD4+ cells decreased compared to CTLA. In animals GB there was no difference between these cell populations, only the reduction of CD4+ CD8+ BAL cells compared to CTLB. When evaluating the phagocytosis and microbicidal functions of the vaccinated groups it was observed significant decrease in most evaluations after vaccination, especially in relation to GA. Regarding the humoral antibody response, the study demonstrated that the vaccine response by intranasally rout was not influenced by colostral antibodies, either induced serum specific immunity antibodies, however, in BAL was able to induce increase of IgA in GA animals and a tendency to increase in GB animals. Given the results, it is concluded that: the response to the vaccine used intranasally in 15 days old calves is different than when used at 45 days, and it caused clinical examination, WBC and BAL fluid cytology more intense changes in animals vaccinated at 15 days of age. Although it has not systemic specific antibody response in both cases, after 15 days showed neutrophilic and monocytic systemic response accompanied by increase of double negative and double positive T lymphocytes, while the local cell response was poor in macrophages and rich in neutrophils and IgA, but with impairment of cellular functions. Thus, the vaccine used intranasally in that period, particularly at 15 days of age may predispose an animal to secondary bacterial infections. However, it should be clear that this result applies only to these conditions of vaccine, route and age
105

Ventilação mecânica em bezerros clonados: bases para sua utilização nos distúrbios respiratórios de neonatos bovinos / Mechanical ventilation in cloned calves: Bases for use in respiratory disorders of newborns calves

Melina Marie Yasuoka 05 December 2016 (has links)
A monitorização após o parto é necessária a manutenção da vida nos bezerros clonados. É imperativo que os protocolos e procedimentos, bem como a avaliação clínica dos sistemas cardiovascular e respiratório sejam aprimorados para a sobrevida dos clones. As avaliações que permitam averiguar a capacidade de oxigenação dos pulmões são de crucial importância na assistência ao neonato, sendo que para essa finalidade tem-se recomendado a utilização da hemogasometria. O estudo foi dividido em quatro capítulos, sendo o 1 º Capítulo: Comparação das diferenças da adaptação neonatal de bezerros da raça Nelore(n=10) e de bezerros da raça Holandesa(n=10) nas trocas gasosas e nos parâmetros hemodinâmicos obtidos por meio do cateter de Swan-Ganz, o 2 º Capítulo: Avaliação da hemodinâmica e da hemogasometria de bezerros clonados(n=3), e o 3º Capítulo: Relato da utilização da ventilação mecânica não invasiva - modo CPAP- no tratamento de hipóxia neonatal em 10 bezerros e o 4º Capítulo: Avaliação hemodinâmica e hemogasométrica de bezerros neonatos com distúrbios respiratórios submetidos a ventilação mecânica não invasiva com mascara facial modo ventilatório CPAP (n=12). O objetivo deste trabalho será padronizar a utilização de ventiladores em bezerros neonatos dando o suporte respiratório necessário, avaliando hemodinâmicas da pressão da artéria pulmonar, freqüência cardíaca, débito cardíaco por meio da utilização do cateter de Swan-Ganz, a hemogasometria de sangue arterial para avaliação dos distúrbios respiratórios e obtenção dos valores de normalidade dos parâmetros, além de conhecer a adaptação neonatal das raças Nelore e holandesa. Foram determinadas média pressão artéria pulmonar, pressão artéria pulmonar ocluída, pressão ventrículo direito, pressão átrio direito, temperatura, pH, pCO2, pO2, HCO3, BE, SO2. Os animais foram ventilados modo CPAP- ventilação mecânica não invasiva com mascara facial com pressão positiva no final da expiração(PEEP). / Monitoring after calving is required for the maintenance of life in cloned calves. It is imperative that protocols and procedures, as well as the clinical assessment of cardiovascular and respiratory systems are improved for the survival of clones. Evaluations in order to verify the oxygenation capacity of lungs are crucial in neonatal care, and for this purpose has recommended the use of blood gas analysis. The study was divided into four chapters, the 1st chapter: Comparison of differences in neonatal adaptation of Nellore calves (n = 10) and Holstein calves (n = 10) in gas exchange and hemodynamic parameters obtained by through the Swan-Ganz, the 2nd Chapter: hemodynamic evaluation and blood gas analysis of cloned calves (n = 3), and the 3rd Chapter: Reporting the use of noninvasive mechanical ventilation - CPAP- in the treatment of neonatal hypoxic 10 calves and Chapter 4: hemodynamic evaluation and hemogasometric of newborn calves with respiratory disorders underwent noninvasive ventilation with face mask ventilation mode CPAP (n = 12). The purpose of this study is to standardize the use of mechanical ventilators in newborn calves giving the required respiratory support, evaluating hemodynamic pulmonary artery pressure, heart rate, cardiac output by using of the Swan-Ganz catheter, arterial blood gas analysis to evaluation of respiratory disorders and obtaining the parameters normal values, and know the neonatal adaptation of Nellore and Hostein Frisian races. They were determined means of pulmonary artery pressure, pulmonary artery wedge pressure, right ventricular pressure, right atrial pressure, temperature, pH, pCO2, pO2, HCO 3, BE, SO 2. The animals were ventilated CPAP- noninvasive ventilation mode with face mask with positive pressure at the end of expiration (PEEP)
106

The antichlamydial effects of drugs used in cardiovascular diseases

Yan, Y. (Ying) 04 December 2009 (has links)
Abstract Chronic Chlamydia pneumoniae infections have been associated with cardiovascular diseases (CVD), but the treatment is difficult. Some drugs used for CVD have been found to have an inhibitory effect on the C. trachomatis infection, which is not considered to be associated with CVD. The purpose of this study was to investigate the effects of heparan sulfate-like glycosaminoglycans, COX inhibitors and rapamycin on the C. pneumoniae infection with cell culture methods. Almost any conceivable factors may affect the results of cell cultures. This study showed the complex interaction between temperature, time and medium during the pre-treatment before inoculation. The influences of these factors on the results overlapped and interlaced. The simple washing procedure could enhance the infectivity of C. pneumoniae although it is generally considered to cause the loss of chlamydial EBs and sequentially decrease the chlamydial infectivity. Although the detailed mechanisms were not studied, the results of this study showed that selective COX inhibitors and rapamycin can inhibit the infectivity of C. pneumoniae by inhibiting the growth and maturation, whereas heparan sulfate-like glycosaminoglycans perhaps inhibit the attachment of C. pneumoniae EBs onto the host cells. Recovery and repassage results showed that the growth can be only delayed by selective COX inhibitors, and it can recover to normal level once the drugs were removed. However, rapamycin inhibited the maturation of chlamydial EBs and therefore the infectivity fell down further even when the rapamycin was removed. This study also presented the variations of pathogenicity between different C. pneumoniae strains in vitro. This study is based on in vitro experiments with an acute infection model. Thus, any definite conclusions on the possible antichlamydial effects of the drugs tested in the treatment of cardiovascular diseases which are associated with chronic C. pneumoniae infections cannot be drawn on the basis of this study.
107

Biosecurity and risk analysis for cow-calf enterprises: a simulation model for Bovine Viral Diarrhea Virus

Smith, Rebecca Lee January 1900 (has links)
Master of Science / Department of Clinical Sciences / Michael W. Sanderson / A Monte Carlo model was developed to determine the cost-effectiveness of different biosecurity strategies for Bovine Viral Diarrhea Virus (BVDV) on cow-calf farms. Where possible, risk distributions were defined in the course of a critical literature review covering all publications since 1990 relevant to BVDV on cow-calf farms. The prevalence of persistent infections (PIs) in adult cows was unknown, so a survey of viremia in 2,990 adult cows for sale in the Midwest during 2006 was performed; prevalence was calculated to be 0.07%. In order to validate a newly developed RT-nPCR for pooled serum used for the survey, sensitivity was determined based on 100 known viremic serum samples; sensitivity was 95%, with no detectable effect of strain type. A Monte Carlo model was developed to calculate the risk of introducing BVDV to a cow-calf herd and number of PIs introduced in one year, based on herd imports and biosecurity strategies. The results of that model were integrated with a stochastic SIR model for the spread and impact of BVDV through a cow-calf herd over 10 years, based on herd size and control strategies. The resulting model was integrated with a stochastic model for the cost of both the biosecurity and control measures used and the financial impact of BVDV infection on the herd over 10 years. The lowest risk option of 14 biosecurity strategies were calculated for 400-, 100-, and 50-head herds with 8 different import profiles, and management factors that increase financial risk due to BVDV were determined.
108

Effects of body condition, body weight and calf removal on productive and reproductive characteristics of extensive beef cattle in Mozambique

Escrivao, Rafael Jose Airone 07 September 2012 (has links)
The objectives of the present research were to study the factors that influence postpartum reproductive characteristics of suckling beef cows in extensive production systems in Mozambique and to develop new management strategies to improve their reproductive efficiency. The effects and interactions between post-partum BW, BCS, age and parity number on plasma concentrations of estradiol, progesterone, creatinine, urea and cortisol around oestrus and the related conception rates of Bos indicus cows in extensive production system were analysed as well as the minimum BCS at the beginning of breeding to maximise the subsequent conception rates. Thirty-five days prior to the breeding season cows were synchronised using Crestar. During the second oestrus after synchronisation, 18 blood samples were collected per animal for hormonal analysis, from 24 hr before oestrus to 24 hr after oestrus. The hormonal pattern of estradiol and progesterone around oestrus were similar to that observed in Bos taurus cows under intensive conditions. Conception rates of cows in the experimental group were 90.5%. Better results on estradiol pattern and conception rates were related to a BCS of ≥ 2.5 and it was thus concluded that the post-partum management of extensive Bos inducus cows should aim to achieve at least a BCS of 2.5 at the beginning of the breeding season. Twelve-hour and 48-hr calf removal were conducted separately to evaluate their effects on conception rates of Bos indicus beef cows in extensive production systems and to quantify the related effects on calf-weaning weights. The 12-hr calf removal was performed from 45 days post-partum to the beginning of the breeding season, and the 48-hr calf removal was performed preceding the onset of the breeding season. It was concluded that 12-hr calf separation at night enhance the energy balance (3%), increases the conception rates (80%) and improves the calf-weaning weights, whereas 48-hr calf removal increases conception rates (76%) and does not affect calf weaning weights. Both calf removal management strategies concentrate conceptions in the early part of the breeding season and stress the importance of the effect of BCS and estradiol on conception rates in Bos indicus beef cows in extensive production systems. / Thesis (PhD)--University of Pretoria, 2012. / Animal and Wildlife Sciences / unrestricted
109

Aminoácidos limitantes para o desempenho de bezerros leiteiros: avaliação de teores ótimos e via de fornecimento / Limiting amino acid for the performance of dairy calves: evaluation of optimal levels and feeding route

Jackeline Thaís da Silva 13 October 2014 (has links)
O objetivo neste trabalho foi avaliar a concentração de aminoácidos essenciais (Lisina e Metionina) considerada na literatura como ideal, de acordo com a via de fornecimento (sucedâneo ou concentrado inicial), e sua associação com a suplementação de Glutamato e Glutamina, para bezerros em dois sistemas de aleitamento: convencional ou programado. No primeiro experimento foi realizado o levantamento da composição bromatológica e em aminoácidos dos principais sucedâneos comercializados no Brasil. Nos segundo e terceiro experimentos foram utilizados 45 bezerros da raça Holandês, em delineamento de blocos casualizados distribuídos nos tratamentos: 1) Controle: sem suplementação; 2) Suplementação de lisina e metionina para atingir consumo de 17 e 5,3 g/d, respectivamente, com correção feita com base na análise do sucedâneo, 3) Suplementação de lisina e metionina, para atingir consumo de 17 e 5,3 g/d, respectivamente, com correção feita com base na análise do concentrado inicial. A diferença entre os experimentos foi o sistema de aleitamento ao qual os bezerros foram submetidos: no segundo experimento os animais receberam 6L/d de sucedâneo; enquanto no terceiro estudo os animais foram submetidos ao sistema de aleitamento programado (4L/d até a 2ª semana; 8L/d da 3ª a 6ª semana; 4L/d da 7ª a 8ª semana). No quarto experimento o mesmo delineamento foi utilizado para avaliar, em sistema de aleitamento convencional, os tratamentos: 1) Controle: sem suplementação; 2) Sucedâneo lácteo suplementado com Lisina e Metionina, para atingir consumo de 17 e 5,3g/d, respectivamente + 1% na MS de produto contendo 10% de glutamato e de glutamina; 3) Sucedâneo lácteo suplementado com Lisina e Metionina para atingir consumo de 17 e 5,3g/d + 0,6% na MS de produto contendo 10% de glutamato e de glutamina. Os animais foram alojados em abrigos individuais, com livre acesso a água e concentrado inicial. O consumo de concentrado inicial e o escore fecal dos animais foram registrados diariamente. Semanalmente, foram realizadas pesagens e medidas de crescimento corporal. Nas semanas 2, 4, 6, 8 e 10 de vida foram realizadas colheitas de sangue para determinação de metabólitos como marcadores do status protéico dos animais (albumina, proteína total, N-ureico), status energético (glicose e ?-hidroxibutirato), crescimento ósseo (fosfatase alcalina) e crescimento muscular (creatinina). A composição em aminoácidos dos sucedâneos comercializados no Brasil foi menor que o esperado para dieta que substitui o leite integral. Nos experimentos 2 e 3 a suplementação com lisina e metionina no sucedâneo ou no concentrado inicial para bezerros não resultou em benefícios no desempenho ou no metabolismo. No estudo 4, a suplementação do sucedâneo com lisina, metionina em associação com glutamato e glutamina não alterou o desempenho, a saúde intestinal ou o metabolismo de bezerros leiteiros. / The aim in this work was to evaluate the concentration of essential amino acids (Lysine and Methionine) considered in the literature as ideal, according to feeding route (milk replacer or starter concentrate), and its association with the supplementation of glutamate and glutamine to calves in two feeding systems: conventional or step-down. In the first study, the chemical composition was analyzed and in amino acids of main milk replacer marketed in Brazil. In the second and third studies, 45 Holstein calves were used, in randomized blocks distributed in treatments: 1) Control: without supplementation; 2) Supplementation with lysine and methionine to reach consumption of 17 and 5.3 g/d, respectively, with correction based on the analysis basis of the milk replacer, 3) Supplementation of lysine and methionine to reach consumption of 17 and 5.3 g/d, respectively, with correction based on the analysis basis of starter concentrate. The difference between the experiments was the feeding system applied to the calves: in the second study, the animals received 6 L/d of milk replacer; while in the third study, the animals were submitted to the step-down system (4L/d until the 2nd week; 8L/d of the 3nd to 6th week; 4L/d of the 7th to 8th week). In the fourth study, the same experimental design was used to evaluate, in a conventional feeding system, treatments: 1) Control: without supplementation; 2) AminoGut 0.6%: milk replacer supplemented with Lysine and Methionine, to reach consumption 17 and 5.3g/d, respectively + 0.6% product containing 10% of glutamate and glutamine; 3) AminoGut 1%: milk replacer supplemented with Lysine and Methionine to reach consumption 17 and 5.3g/d + 0.6% product containing 10% of glutamate and glutamine. The animals were housed in individual hutches, with free access to water and starter concentrate. The consumption of starter concentrate and fecal scores of animals were monitored daily. Body growth was weighed and measured weekly. In weeks 2, 4, 6, 8 and 10, blood samples were collected to determine the metabolites as markers of protein status of animals (albumin, total protein, N-urea), energy status (glucose and BHBA), bone growth (alkaline phosphatase) and muscular growth (creatinine). The composition of amino acids of the milk replacer marketed in Brazil was lower than expected for diet that replaces the whole milk. In study 2 and 3, the supplementation of the milk replacer or starter concentrate with lysine and methionine resulted in no benefit on dairy calves performance or metabolism. In study 4 the supplementation of the milk replacer with lysine and methionine in association with glutamate and glutmine had no effect on performance, gut health nor metabolism of dairy calves.
110

Efeitos do colostro comercial em pó na primeira mamada na saúde e desempenho de bezerras mestiças das raças Holandês (H) x Gir (G) /

Vasconcelos, Paula Carneiro January 2019 (has links)
Orientador: Mateus José Rodrigues Paranhos da Costa / Resumo: Objetivou-se avaliar a eficácia do uso do colostro comercial em pó como substituto do colostro de vaca na primeira mamada de bezerras. Foram utilizadas 31 bezerras mestiças Holandês (H) x Gir (G), provenientes dos grupos genéticos 3/4HG, 5/8HG, 7/8HG e LA, divididas em dois grupos experimentais: G1 (n=15) 2L de colostro de vaca e G2 (n=16) 470g de colostro comercial em pó (SCCL, Saskatoon, SK, Canadá) diluídos em 1,5L de água morna, ambos fornecidos nas primeiras três horas de vida, e posteriormente recebendo mais 2L de colostro de vaca em até 12 horas após o nascimento. As concentrações de IgG presentes (p=0,006) foram maiores no colostro comercial em pó, enquanto as médias da β- caseína (p<0,0001), haptoglobina (p<0,0001) e α1-glicoproteína ácida (p=0,002) foram maiores nos colostros de vaca. As concentrações séricas de PT (G1 = 7,70 ± 1,00g/dL e G2 = 6,73 ± 0,65g/dL; p=0,003) e IgG (G1 = 2110,25 ± 595,03mg/dL e G2 = 1567,6 ± 418,25mg/dL; p=0,004) demonstraram diferenças estatísticas entre os grupos de manejo, com maiores médias para o G1. Houve diferenças significativas para a concentração de albumina sérica (p=0,005), com maiores médias para o G1 (4660,7 ± 384,61mg/dL). Não ocorreu diferença significativa para a haptoglobina sérica (p=0,29), porém suas concentrações médias se apresentaram bem mais altas em ambos os grupos de manejo (G1 = 33,86 ± 4,90 e G2 = 29,31 ± 5,63mg/dL). As enfermidades com maior ocorrência foram diarreia e pneumonia, sendo registrados também casos ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The purpose of this study was value the effectiveness in commercial colostrum powder using as a cow colostrum substitute in the first calf suckling. Twenty-one Holstein (H) x Gir (G) crossbred calves from 3/4HG, 5/8HG, 7/8HG and LA genetic groups were divided into two experimental groups: G1 (n = 15) 2L of cow colostrum and G2 (n = 16) 470g of commercial powdered colostrum (SCCL, Saskatoon, SK, Canada) diluted in 1.5L of warm water, both supplied within the first three hours of life, and subsequently receiving an additional 2L of cow colostrum in up to 12 hours after birth. Present IgG concentrations (p = 0.006) were higher in commercial powdered colostrum, while mean β-casein (p < 0.0001), haptoglobin (p <0.0001) and α1-acid glycoprotein (p = 0.002) were higher in cow colostrums. Serum concentrations of PT (G1 = 7.70 ± 1.00 g/dL and G2 = 6.73 ± 0.65 g/dL; p = 0.003) and IgG (G1 = 2110.25 ± 595.03 mg/dL and G2 = 1567.6 ± 418.25 mg/dL; p = 0.004) demonstrated statistical differences between management groups, with higher means for G1. There were significant differences in serum albumin concentration (p = 0.005), with higher means for G1 (4660.7 ± 384.61mg / dL). There was no significant difference for serum haptoglobin (p = 0.29), but its mean concentrations were much higher in both management groups (G1 = 33.86 ± 4.90 and G2 = 29.31 ± 5.63 mg/dL). The most common diseases were diarrhea and pneumonia, with cases of parasitic sadness and omphalitis, and two deaths in G2. Althou... (Complete abstract click electronic access below) / Mestre

Page generated in 0.1227 seconds