Orientador: José Luiz Moraes Vasconcelos / Resumo: Os objetivos foram avaliar o efeito da remoção de bezerros (RB) no desenvolvimento folicular e na indução de ciclicidade e a eficácia do MGA precedendo protocolos de IATF, que utilizam GnRH ou BE, nas taxas de concepção a IATF e gestação. Foram utilizadas 163 vacas paridas em anestro da raça Nelore com 80 ± 29 dias pós-parto e ECC de 3,0 ± 0,29, divididas em 4 grupos: G1: (n=40, controle); G2: (n=42, RB): RB (60 h) 11 dias antes da estação de monta (EM); G3: (n=43, MGA + GnRH): MGA (MGA PREMIX®, 0,5 mg/dia, v.o.) por 10 dias, seguido por RB (60 h), após este período receberam GnRH (CYSTORELIN®, 50 mcg, i.m). Após 6,5 dias, PGF2α (LUTALYSE®, 25 mg, i.m.) que foi seguida por outra RB (54h). Após a RB, todos os animais receberam GnRH e foram inseminados; G4: (n=38, MGA + BE): MGA por 10 dias, seguido por RB (60h), após este período receberam BE (Estrogin , 1,0 mg, i.m.). Após 7 dias, PGF2α que foi seguida por outra RB (54h). Após 24 horas da PGF2α, os animais receberam BE e foram inseminados 30 horas depois. Após a IATF, nos 4 grupos, foi realizado observação de cio e IA (30 d) e por monta natural por mais 32 dias. A ciclicidade, o efeito do MGA e RB no desenvolvimento folicular, as taxas de sincronização, concepção e gestação foram determinados por exames ultra-sonográficos. A variável dias para ficar gestante foi analisada pela curva de sobrevivência, enquanto que as variáveis binomiais e contínuas foram analisadas por regressão logística e pelo GLM do SAS, respectivamente. Foram incluídos no modelo efeito de tratamento, ordem, sexo da cria e suas interações e ECC como co-variável. O MGA foi fornecido, ao G3 e G4, diariamente e os animais ingeriram, em média, 0,99 mg/dia de MGA. O MGA aumentou (P<0,05) o diâmetro do maior folículo (11,2 ± 0,28 vs. 10,3 ± 0,29 mm, respectivamente), que também foi maior (P<0,05) na associação MGA + RB... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objectives of this trial were to evaluate the effects of calf removal (CR) on follicular development and its ability to induce cyclicity and the effects of melengestrol acetate (MGA) preceding TAI protocols, with GnRH or EB on conception and pregnancy rates. Suckled anestrous Nellore cows (n=163) with 80 ± 29 days postpartum and BCS of 3.0 ± 0.29 were assigned into one of four groups: G1: (n=40, control); G2: (n=42, CR): calf removal (60 h) 11 days before the breeding season (BS). G3: (n=43, MGA + GnRH): MGA (MGA PREMIX®, 0.5 mg/day, v.o.) per 10 days, followed by CR (60 h), and GnRH (CYSTORELIN®, 50 mcg, i.m) after CR. Cows received by PGF2α (LUTALYSE®, 25 mg, i.m.) 6.5 days later, and another CR (54h) followed by GnRH and TAI; G4: (n=38, MGA + EB): MGA per 10 days, followed by CR (60h) and injection of EB (Estrogin , 1.0 mg, i.m.) after CR. Cows received PGF2α 7 days later and 24 hours after that, all animals received another EB and were TAI 30 hours later. Calf removal was performed between PGF2α and EB (54 h). After TAI, in all groups, was performed heat detection and AI (30 d) and natural service per more 32 days. Cyclicity status, effect of MGA supplementation and CR on follicular development, synchronization, conception and pregnancy rates were determined by ultrasound. The variable days to pregnancy was analyzed by survival analyses and the binomial and continuous variables were analyzed by logistic regression and GLM of SAS, respectively. The effects of treatment, parity, calf gender and interactions were included in the model, BCS was included as covariable. The MGA was offered to G3 and 4 daily (mixed into the mineral) and the average consumption was 0.99 mg/day. MGA supplementation increased (P<0.05) follicular diameter (11.2 ± 0.28 vs. 10.3 ± 0.29 mm, respectively) Follicular diameter was also increased (P<0.05) when MGA was associated with CR (11.3 ± 0.26 mm)... (Complete abstract click electronic access below) / Mestre

Theme of this work is breeding of cattle meat breed Hereford breed and their crossbreds with Charolais and Czech spotted cattle. We monitored the influence of sex, breed of father and mother, parity and month of calving on the average weight of calves at 120, 210 and 365 days of animal age. Growth of calves in individual cross combinations were evaluated too. The study was performed on the selected herd of 215 pieces of cattle: 85 of Hereford breed, 68 of Charolais breed and 62 of Czech spotted cattle breed. The herd is bred on the private farm with a total area 90ha of pastures located in the South Bohemian village Lhota near Mladosovice. We used information and performance of the herd of cattle between the years: 2017 and 2018. This diploma thesis confirms that higher average weights can be attain as crossbreeding of meat breeds and also by crossbreeds with dual purpose cattle breeds. Calves born in the late months of the year come up to higher average weights too. From the statistical analysis it is possible to prove the influence of the parent combination on the average weights of calves and their weight gains. The lowest weight gains were observed in calves of crossbred combination of Charolais vs. Czech spotted cattle (0.83 kg per day) and the highest values were detected in calves of Charolais vs. Hereford breeds (1 kg per day).

In cattle breeding, it is necessary to pay great attention to calves, especially to the quality of their housing. Calf rearing is one of the riskiest parts of the whole breed. This requires a thorough development of biological, nutritional, ethological and technological factors of breeding. The aim of this thesis was to compare two different ways of housing calves (individually vs. pairs) in roofed outdoor individual boxes with feedeng twice a day and evaluate their influence on the course of growth and health from birth to weaning. The experiment was carried out at the Číčov farm, which i sone of the centers of Alimex a.s. Nezvěstice, farming in the district of Plzeň - South. The actual monitoring of the calves took place from 1. 1. 2018 to 31. 7. 2018. Both groups of calves included in the experiment were fed the same amount of feed (native milk, milk replacer, TMR). Each group had the same number of pieces - 12 calves (heifers) of the Holstein cattle breed. At the end of the reporting period, calves that were raised together in pairs at average weight of 227.17 kg during the dairy period, while calves reared individually during the same period reached a final weight of 215 kg. The average daily increase in calves with a common rearing was 0.89 kg, in calves of the second group this value was lower, namely 0.83 kg. However, tthe difference between the mean final weights of both groups was not statistically significant (p > 0.05). All calves included tn the exxperiment were fed with appropriate quality colostrum (immunoglobulin content of 100 g/l or more) within 2 hours of delivery. Immunity of all experimental calves was sufficient, so the level of immunoglobulins did not fall below 50 g/l, with more than 85 % of calves having an immunoglobulin content above 55 g/l. In calves reared individually during the experiment, diarrhea was noted in three animals and respiratory disease in four animals. In rearing together, there was diarrhea in five calves. Respiratory disease occured in four calves. In both experimental groups of calves, it was observed that immediately after drinking, the animals were mutually sucking mules, but the calves housed together with a lower frequency also licked the polypropylene plates separating the VIB and nibbled empty buckets.

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)

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

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.

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.

<p>Heart rate variability (<b>HRV</b>), or the variation in time between adjacent heart beats over time, is a non-invasive proxy measure of autonomic nervous system (<b>ANS</b>) function that has been used regularly in studies focused on evaluating livestock stress and welfare. The autonomic nervous system regulates involuntary physiological processes (<i>e.g.</i> respiration and heart rate) and consists of two main components, the parasympathetic (<b>PNS</b>), and sympathetic (<b>SNS</b>) branches, which act to maintain bodily homeostasis (PNS) or stimulate the “fight-or-flight” response after exposure to a stressor (SNS). Traditional linear HRV measures provide an estimation of overall autonomic activity or changes to the balance between the PNS and SNS branches by evaluating changes to the mean, variance, or frequency spectra of the R-R intervals. </p><p>To interpret HRV data obtained via linear HRV measures, particularly spectral HRV analysis, a linear assumption has to be assumed where SNS and PNS activity act in a purely antagonistic manner. However, this assumption is not always met. In many cases, ANS activity is altered in a nonlinear manner, which is reflected to some degree in the variability of heart rate output. Therefore, HRV measures that evaluate nonlinear changes to organizational or structural aspects of the R-R interval variability may be a useful compliment to traditional linear HRV measures for distinguishing between stressed and non-stressed states. The purpose of this dissertation was to evaluate the use of nonlinear HRV measures for evaluating dairy calf disbudding pain, piglet castration pain, growing pig heat stress, and as potential indicators of the subsequent immune response to a lipopolysaccharide (<b>LPS</b>) challenge in growing pigs.</p><p>Chapter 1 provides a knowledge base for understanding HRV and its use as a measure of autonomic stress in studies with livestock species. A brief explanation of animal welfare science, measures used to evaluate an animal’s welfare, and a demonstration of need for non-invasive physiological measures is provided before discussing the physiological basis of HRV. Relevant linear and nonlinear HRV measures are explained and examples of their use in livestock stress research are provided. Finally, a rationale for the studies conducted in this dissertation is presented.</p><p>Chapter 2 evaluates the use of HRV as an indicator of castration pain in 9-d-old piglets over a 3-d experimental period. Compared to sham castrated piglets, surgically castrated piglets exhibited greater low frequency to high frequency ratios (<b>LF/HF</b>), reduced sample entropy (<b>SampEn</b>), and greater percent determinism (<b>ÞT</b>) during the post-castration period. However, postural behavior was not different between treatments and serum cortisol concentrations only tended to differ between treatments at 1 and 24 h post-castration treatment, with surgically castrated pigs having numerically greater serum cortisol concentrations at both timepoints. These results demonstrate the ability of nonlinear HRV measures (SampEn and ÞT) to complement the physiological interpretation of linear HRV measures (LF/HF) in response to castration. Specifically, pigs who were surgically castrated exhibited more regularity (SampEn) and periodicity (ÞT) in their HRV data, and potentially more sympathetic activity (LF/HF) compared to sham castrated piglets, indicating greater pain-related stress. Additionally, HRV was a more sensitive measure of the stress response to castration than readily identifiable behaviors such as posture and the serum cortisol response.</p><p>Chapter 3 evaluates the use of HRV as an indicator of disbudding pain in dairy heifer calves (4 to 7-wk of age) over a 5-d experimental period. Calves who were given lidocaine and meloxicam prior to disbudding exhibited lower mean R-R interval (<b>RR</b>) values and a greater short-term detrended fluctuation analysis scaling exponent (<b>DFAα₁</b>) than sham disbudded calves. Together, these results indicate that calves who received pain mitigation exhibited greater pain-related stress (RR) and reduced physiological complexity in their heart rate signal (DFAα₁). Calves who were disbudded without pain mitigation had an intermediate response compared to sham disbudded calves and calves provided lidocaine and meloxicam. However, their numerical values closely followed those of calves provided lidocaine and meloxicam. These results demonstrate the usefulness of nonlinear HRV measures (DFAα₁) for evaluating nonlinear and correlational aspects of physiological complexity in response to disbudding. Additionally, the HRV results suggest that the provision of meloxicam does not reduce the amount of pain-related stress experienced by calves following disbudding.</p><p>Chapter 4 evaluates the use of HRV as an indicator of heat stress in growing pigs exposed to an acute heat episode. Heat stressed pigs exhibited greater body temperatures and spent less time in an active position compared to thermoneutral control pigs. Additionally, heat stressed pigs displayed an altered nonlinear HRV response to the acute heat phase compared to non-heat stressed control pigs. Specifically, heat stressed pigs exhibited lower SampEn and tended to exhibit greater ÞT, but no alterations to linear measures were observed in response to the acute heat episode. The low frequency to high frequency ratio was higher in heat stressed pigs during the period following the acute heat phase. Therefore, nonlinear HRV measures (particularly SampEn) may be more sensitive to the immediate physiological stress response to increased environmental temperature than traditional linear HRV measures.</p><p>Chapter 5 evaluates the use of baseline HRV as a potential indicator of the subsequent cortisol and pro-inflammatory cytokine response to an LPS challenge in growing pigs. The time for a pig to approach a human (<b>approach time)</b> prior to LPS administration was inversely related to baseline standard deviation of the R-R intervals (<b>SDNN</b>), and directly related to RR and the mean length of diagonal lines in a recurrence plot (<b>Lmean</b>). This result may have implications for the use of HRV as a measure of temperament in livestock species, since pigs with lower baseline SDNN (<i>i.e.</i> greater stress) and greater baseline Lmean (<i>i.e.</i> increased periodicity length in HRV data; greater stress) values took longer to approach a human observer before LPS administration (which occurred 1 d after HRV measurement). Area under the curve values for approach time following LPS administration were inversely related to high frequency spectral power (<b>HF</b>) and directly related to body weight, where pigs with low baseline HF values (<i>i.e. </i>lower parasympathetic activity) and higher body weights were slower to approach a human observer following LPS administration. Additionally, pigs with greater Lmean values had a greater change in body temperature following LPS administration. In conclusion, while baseline HRV measures were not directly representative of the cortisol or cytokine response following an LPS challenge, HF and Lmean may be useful indicators for evaluating certain aspects (sickness behavior and fever) of the innate immune response to an LPS challenge. <b></b></p><p> In conclusion, these studies demonstrate the usefulness of nonlinear HRV measures for evaluating livestock stress. Measures such as sample entropy and those derived from recurrence quantification analysis (ÞT, Lmean) seem to be particularly useful for complementing traditional linear HRV measures and, in some cases, are more sensitive measures of the physiological stress response (see chapter 4). Therefore, their inclusion in future studies on livestock HRV is warranted. However, further work is needed to fully elucidate the physiological significance of nonlinear HRV measures and their response to stress.</p>

Com o avanço de novas biotécnicas da reprodução (TE, FIV e Clonagem), exige-se o controle mais acurado da gestação e do parto, em razão dos problemas obstétricos decorrentes do nascimento de produtos com crescimento exacerbado ou com menor vitalidade por disfunções placentárias. Desta forma, a redução da mortalidade neonatal justifica-se por acompanhar o aprimoramento na área, visando ao bem-estar materno e neonatal, como também aos interesses do mercado pecuário. As distocias podem comprometer o fluxo sangüíneo materno-fetal e a ocitocina utilizada como agente ecbólico nas atonias uterinas pode aumentar o estresse do parto. Os objetivos deste estudo foram: identificar alterações do escore Apgar de vitalidade neonatal, temperatura corpórea, hemogasometria arterial, glicemia e cortisol ao nascimento e 1 hora pós-parto de neonatos nascidos em distintas condições obstétricas e verificar modificações da pressão arterial (PA), freqüência cardíaca, eletrocardiograma, glicemia e cortisol de vacas no pré-parto, intra-parto, pós-parto imediato e após 1 hora. Foram utilizadas 30 fêmeas bovinas e 30 bezerros da raça Holandesa subdivididos em: Grupo Eutocia (G EUT; n=10); Grupo Distocia com extração fetal forçada moderada a intensa (G DIST; n=10) e Grupo Atonia ou hipotonia uterina com infusão de Ocitocina (50UI) (G OCT; n=10). As vacas apresentaram hiperglicemia de estresse apenas 1 hora pós-parto no G EUT e G OCT, no entanto, já no intra-parto no G DIST. A distocia também elevou os níveis de cortisol no pós-parto imediato. Houve acréscimo significativo da PA no intra-parto do G DIST, decorrente de contrações uterinas e abdominais mais intensas. Os traçados eletrocardiográficos denotaram ritmo sinusal normal em todos os períodos. Os resultados demonstram adaptação hemodinâmica materna frente às alterações do parto, mesmo com infusão exógena de ocitocina. Os neonatos do G DIST ao nascimento apresentaram menor vitalidade (escore Apgar) e maior estresse (nível de cortisol) em relação aos demais grupos. Os bezerros apresentaram normotermia, a despeito da redução da temperatura corpórea 1 hora pós-parto, e mantiveram-se normoglicêmicos. Ainda, os valores de base-excess, HCO3- e pO2 eram baixos, enquanto os níveis de Anion-gap e pCO2, elevados. No entanto, apenas no G DIST observou-se acidose mista (metabólica e respiratória) evidente (pH<7,20), indicando maior grau de sofrimento fetal e redução do suprimento sangüíneo durante o parto. Os bezerros do G OCT apresentaram pCO2 superior e pO2 inferior aos demais grupos ao nascimento. A infusão de ocitocina pode promover padrões de contração uterina diferenciados, comprometendo ainda mais a oxigenação fetal. A ocitocina alterou momentaneamente as variáveis hemodinâmicas maternas com possível efeito bradicárdico e hipotensor intra-parto, promovendo menor adaptabilidade respiratória neonatal e, portanto, impondo assistência mais criteriosa ao nascimento. Todos os bezerros apresentaram reduzidos valores de hematócrito e hemoglobina, em decorrência da eritropoiese imatura e intensa metabolização de eritrócitos fetais. Após 60 minutos de vida, os bezerros apresentaram recuperação satisfatória do desequilíbrio ácido-base e capacidade evidente de termorregulação e manutenção glicêmica. A condição obstétrica ao nascimento é crítica para o desempenho clínico do neonato, comprometendo sua vitalidade inicial e influenciando a circulação materno-fetal nos casos de distocias. As alterações circulatórias maternas ocasionadas pela ocitocina são consideradas momentâneas, reversíveis e não comprometeram o êxito neonatal. / The novel reproductive biotechnologies (ET, IVF and Cloning) require more accurate control of pregnancy and parturition, due to obstetrical problems as a result of the large offspring syndrome or reduced calf vitality associated with placental anomalies. Hence, the reduction in neonatal mortality is justifiable as research in this area progresses, aiming maternal and neonatal well-being and livestock economic concernment. Dystocia may compromise dam-fetal blood flow and induces severe hypoxia at birth. Oxytocin employed as ecbolic treatment for uterine inertia can enhance calving stress. Therefore, the aims of this study were to identify abnormalities in neonatal Apgar score, body temperature, arterial blood gas analysis, glucose and cortisol assay at birth and after 1 hour of calving under distinct obstetrical conditions and to verify the changes on blood pressure (BP), heart rate, electrocardiogram record, glucose and cortisol assay of cows during the first stage of labor, intra-partum, immediately after calving and 1 hour later. Thirty Holstein cows and 30 Holstein calves were grouped according to the obstetrical condition into: Eutocia Group (EUT G; n=10); Dystocia Group with mild to severe obstetric assistance (DIST G; n=10) and Uterine Inertia Group treated with oxytocin (50UI) (OCT G; n=10). EUT G and OCT G cows showed stress-induced hyperglycemia 1 hour after calving. On the other hand, DIST G presented hyperglycemia yet during intra-partum. Dystocia also increased cortisol levels shortly after calving. During labor, DIST G presented significantly higher BP, due to uterine and abdominal strengthened contractions. Electrocardiogram recordings denoted normal sinus rhythm at all time points. DIST G neonates presented lower vitality (Apgar score) and higher stress (cortisol level) at birth compared to other groups. Calves were normothermic, despite the significative decrease in body temperature after 1 hour of birth, and remained normoglycemic. Moreover, base-excess, HCO3- and pO2 results were low, while Anion-gap and pCO2 were high, comparing to standard values. However, mixed acidosis (metabolic and respiratory; pH<7,2) was only noticeable in DIST G, suggesting higher fetal distress during calving and reduced blood supply (oxygenation). In addition, OCT G calves presented increased pCO2 and decreased pO2 at birth. Oxytocin infusion may cause a distinct pattern of uterine contraction, compromising neonatal hypoxia even more. The oxytocin infusion altered transitorily the maternal hemodynamic variables with a possible bradicardiac effect and intrapartum hypotension, causing lower neonatal respiratory adaptability, demanding more intensive care at birth. All newborns showed low hematocrit and hemoglobin concentration due to immature erythropoiesis and intense fetal erythrocyte metabolism. The present results indicate full maternal adaptation to labors requirement. Calves showed stark acid-base recovery during the critical period of adaptation to ex utero life, with also evident thermoregulation and glucose maintenance 1 hour after birth. The obstetrical condition presented at birth was determinant to neonatal clinical demeanor. Dystocia mainly compromised blood flow and oxygen supply and ultimately interfered with newborn vitality. Ponctual maternal circulatory alterations caused by oxytocin infusion were reversible and did not compromise neonatal outcome.

Com o avanço de novas biotécnicas da reprodução (TE, FIV e Clonagem), exige-se o controle mais acurado da gestação e do parto, em razão dos problemas obstétricos decorrentes do nascimento de produtos com crescimento exacerbado ou com menor vitalidade por disfunções placentárias. Desta forma, a redução da mortalidade neonatal justifica-se por acompanhar o aprimoramento na área, visando ao bem-estar materno e neonatal, como também aos interesses do mercado pecuário. As distocias podem comprometer o fluxo sangüíneo materno-fetal e a ocitocina utilizada como agente ecbólico nas atonias uterinas pode aumentar o estresse do parto. Os objetivos deste estudo foram: identificar alterações do escore Apgar de vitalidade neonatal, temperatura corpórea, hemogasometria arterial, glicemia e cortisol ao nascimento e 1 hora pós-parto de neonatos nascidos em distintas condições obstétricas e verificar modificações da pressão arterial (PA), freqüência cardíaca, eletrocardiograma, glicemia e cortisol de vacas no pré-parto, intra-parto, pós-parto imediato e após 1 hora. Foram utilizadas 30 fêmeas bovinas e 30 bezerros da raça Holandesa subdivididos em: Grupo Eutocia (G EUT; n=10); Grupo Distocia com extração fetal forçada moderada a intensa (G DIST; n=10) e Grupo Atonia ou hipotonia uterina com infusão de Ocitocina (50UI) (G OCT; n=10). As vacas apresentaram hiperglicemia de estresse apenas 1 hora pós-parto no G EUT e G OCT, no entanto, já no intra-parto no G DIST. A distocia também elevou os níveis de cortisol no pós-parto imediato. Houve acréscimo significativo da PA no intra-parto do G DIST, decorrente de contrações uterinas e abdominais mais intensas. Os traçados eletrocardiográficos denotaram ritmo sinusal normal em todos os períodos. Os resultados demonstram adaptação hemodinâmica materna frente às alterações do parto, mesmo com infusão exógena de ocitocina. Os neonatos do G DIST ao nascimento apresentaram menor vitalidade (escore Apgar) e maior estresse (nível de cortisol) em relação aos demais grupos. Os bezerros apresentaram normotermia, a despeito da redução da temperatura corpórea 1 hora pós-parto, e mantiveram-se normoglicêmicos. Ainda, os valores de base-excess, HCO3- e pO2 eram baixos, enquanto os níveis de Anion-gap e pCO2, elevados. No entanto, apenas no G DIST observou-se acidose mista (metabólica e respiratória) evidente (pH<7,20), indicando maior grau de sofrimento fetal e redução do suprimento sangüíneo durante o parto. Os bezerros do G OCT apresentaram pCO2 superior e pO2 inferior aos demais grupos ao nascimento. A infusão de ocitocina pode promover padrões de contração uterina diferenciados, comprometendo ainda mais a oxigenação fetal. A ocitocina alterou momentaneamente as variáveis hemodinâmicas maternas com possível efeito bradicárdico e hipotensor intra-parto, promovendo menor adaptabilidade respiratória neonatal e, portanto, impondo assistência mais criteriosa ao nascimento. Todos os bezerros apresentaram reduzidos valores de hematócrito e hemoglobina, em decorrência da eritropoiese imatura e intensa metabolização de eritrócitos fetais. Após 60 minutos de vida, os bezerros apresentaram recuperação satisfatória do desequilíbrio ácido-base e capacidade evidente de termorregulação e manutenção glicêmica. A condição obstétrica ao nascimento é crítica para o desempenho clínico do neonato, comprometendo sua vitalidade inicial e influenciando a circulação materno-fetal nos casos de distocias. As alterações circulatórias maternas ocasionadas pela ocitocina são consideradas momentâneas, reversíveis e não comprometeram o êxito neonatal. / The novel reproductive biotechnologies (ET, IVF and Cloning) require more accurate control of pregnancy and parturition, due to obstetrical problems as a result of the large offspring syndrome or reduced calf vitality associated with placental anomalies. Hence, the reduction in neonatal mortality is justifiable as research in this area progresses, aiming maternal and neonatal well-being and livestock economic concernment. Dystocia may compromise dam-fetal blood flow and induces severe hypoxia at birth. Oxytocin employed as ecbolic treatment for uterine inertia can enhance calving stress. Therefore, the aims of this study were to identify abnormalities in neonatal Apgar score, body temperature, arterial blood gas analysis, glucose and cortisol assay at birth and after 1 hour of calving under distinct obstetrical conditions and to verify the changes on blood pressure (BP), heart rate, electrocardiogram record, glucose and cortisol assay of cows during the first stage of labor, intra-partum, immediately after calving and 1 hour later. Thirty Holstein cows and 30 Holstein calves were grouped according to the obstetrical condition into: Eutocia Group (EUT G; n=10); Dystocia Group with mild to severe obstetric assistance (DIST G; n=10) and Uterine Inertia Group treated with oxytocin (50UI) (OCT G; n=10). EUT G and OCT G cows showed stress-induced hyperglycemia 1 hour after calving. On the other hand, DIST G presented hyperglycemia yet during intra-partum. Dystocia also increased cortisol levels shortly after calving. During labor, DIST G presented significantly higher BP, due to uterine and abdominal strengthened contractions. Electrocardiogram recordings denoted normal sinus rhythm at all time points. DIST G neonates presented lower vitality (Apgar score) and higher stress (cortisol level) at birth compared to other groups. Calves were normothermic, despite the significative decrease in body temperature after 1 hour of birth, and remained normoglycemic. Moreover, base-excess, HCO3- and pO2 results were low, while Anion-gap and pCO2 were high, comparing to standard values. However, mixed acidosis (metabolic and respiratory; pH<7,2) was only noticeable in DIST G, suggesting higher fetal distress during calving and reduced blood supply (oxygenation). In addition, OCT G calves presented increased pCO2 and decreased pO2 at birth. Oxytocin infusion may cause a distinct pattern of uterine contraction, compromising neonatal hypoxia even more. The oxytocin infusion altered transitorily the maternal hemodynamic variables with a possible bradicardiac effect and intrapartum hypotension, causing lower neonatal respiratory adaptability, demanding more intensive care at birth. All newborns showed low hematocrit and hemoglobin concentration due to immature erythropoiesis and intense fetal erythrocyte metabolism. The present results indicate full maternal adaptation to labors requirement. Calves showed stark acid-base recovery during the critical period of adaptation to ex utero life, with also evident thermoregulation and glucose maintenance 1 hour after birth. The obstetrical condition presented at birth was determinant to neonatal clinical demeanor. Dystocia mainly compromised blood flow and oxygen supply and ultimately interfered with newborn vitality. Ponctual maternal circulatory alterations caused by oxytocin infusion were reversible and did not compromise neonatal outcome.