Orientador: José Luiz Moraes Vasconcelos, / Banca: Mario Binelli / Banca: Ricarda Maria dos Santos / Resumo: Objetivou-se com este estudo avaliar a utilização de dois dispositivos intravaginais de P4 (CIDR®, Zoetis) em vacas Holandesas em lactação sem CL e com P4 ≤1,0 ng/mL no início de um protocolo de sincronização da ovulação à base de E2/P4 para IATF (exp 1) ou TETF (exp 2) no sucesso da prenhez. Estes experimentos foram realizados em 9 fazendas, sendo 4 destinadas a IATF (n = 341) e 5, a TETF (n = 356). O protocolo utilizado nos experimentos foi: d-10 2mg IM BE (2,0mL de Estrogin, Farmavet, SP, Brasil) + CIDR (1,9g de P4, CIDR®, Zoetis, SP, Brasil); d-3 25mg IM Dinoprost Trometamina (5,0mL de Lutalyse®, Zoetis, SP, Brasil); d-2 remoção do CIDR + 1mg IM de Cipionato de Estradiol (0,5mL ECP®, Zoetis, SP, Brasil); d 0 IATF (exp1) ou d 7 TETF (exp 2). No d-10, os animais sem corpo lúteo à ultrassonografia (US) foram distribuídos aleatoriamente para receberem 1 CIDR (1CIDR) ou 2 CIDR (2CIDR). O diâmetro do folículo ovulatório [d0 (exp 1)] e presença de CL [d7 (exp 1 e 2)] foram avaliados por US. Amostras de sangue foram colhidas para dosagem de P4 nos dias -10, -3 e 7. Foram consideradas sincronizadas vacas com CL 7 dias após a IA (d7) ou com CL no momento da TE, consistente com a ovulação do folículo ovulatório; no exp 2, apenas vacas com CL (d7) que receberam embrião foram utilizadas. Diagnósticos de gestação foram realizados por US aos 32 e 60 d. Para avaliar as variáveis binomiais, foi utilizado o PROC GLIMMIX, e as contínuas, o PROC MIXED. Efeitos foram considerados significantes quando P ≤0,05 e tendência quando P >0,05 e P ≤0,10. Não houve efeito do tratamento na taxa de sincronização [1CIDR = 74,1% (329/451) vs. 2CIDR = 71,1% (298/423)]. A concentração de P4 no d-10 não diferiu entre os tratamentos (1CIDR = 0,59 ± 0,12 ng/mL vs. 2CIDR = 0,68 ± 0,12 ng/mL)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the use of two progesterone (P4) intravaginal devices (CIDR ®, Zoetis) in lactating Holstein cows without CL with P4 ≤ 1.0 ng / mL at the start of a E2/P4 ovulation synchronization protocol for TAI (exp 1) or TET (exp 2) on pregnancy success. These experiments were conduced in 9 farms, 4 destined to TAI (n = 341) and 5 TET (n = 356). The protocol used in the experiments was: d-10 2 mg IM EB (2.0 mL Estrogin, Farmavet, SP, Brazil) + CIDR (1.9 g of P4, CIDR ®, Zoetis, SP, Brazil); d-3 25 mg dinoprost tromethamine IM (5.0 mL Lutalyse ®, Zoetis, SP, Brazil), d-2 CIDR removal + 1 mg estradiol cypionate IM (0.5 mL, ECP ®, Zoetis, SP, Brazil); TAI d0 (exp 1) or TET d7(exp 2). On d-10, animals without a corpus luteum detected by ultrasonography (US) were randomly divided into groups to receive 1 CIDR (1CIDR) or 2 CIDR (2CIDR). The ovulatory follicle diameter [d0 (exp 1)] and presence of CL [d7 (exp 1 and 2)] were evaluated by US. Blood samples were collected for P4 measurement on days -10, -3 and 7. Were considered synchronized cows when they had CL 7 days after AI (d7) or CL at the time of ET, consistent with ovulation of detected ovulatory follicle; In exp 2 only cows CL (d7) receiving embryo were used. Pregnancy diagnosis were performed using US on days 32 and 60. Was used to evaluate binomial variables PROC GLIMMIX and PROC MIXED for continuous. Effects were considered significant when P ≤ 0.05 and tendency when P> 0.05 and P ≤ 0.10. There was no effect of treatment on synchronization rate [1CIDR = 74.1% (329/451) vs. 2CIDR = 71.1% (298/423). P4 concentration on d-10 did not differ between treatments (1CIDR = 0.59 ± 0.12 ng/mL vs. 2CIDR = 0.68 ± 0.12 ng/mL). P4 concentration was higher for 2CIDR treatment (2.14 ± 0.31 ng / mL) compared to 1CIDR (1.71 ± 0.28 ng / mL) at d-3 (PGF moment)... (Complete abstract click electronic access below) / Mestre

Orientador: Mário De Beni Arrigoni / Coorientador: Danilo Domingues Millen / Banca: Rodrigo Dias Lauritano Pacheco / Banca: Marco Aurélio Factori / Resumo: O objetivo foi avaliar os efeitos da duração de protocolos de adaptação a dietas de alto teor de concentrado sobre o comportamento ingestivo, desempenho, características de carcaça e saúde ruminal de bovinos Nelore confinados. Machos não castrados da raça Nelore (n = 120), com 352,03 ± 19,61 kg de peso vivo (PV), foram mantidos por 84 dias em 24 baias. O delineamento experimental foi em blocos casualizado, com arranjo fatorial 2 × 2 (protocolos e durações), constituindo os seguintes tratamentos: adaptação em escada por 6 (E6) ou 9 dias (E9) e protocolo de restrição por 6 (R6) ou 9 dias (R9), sendo 6 baias por tratamento. Houve efeito de protocolo de adaptação no ganho de peso médio e ingestão de massa seca (IMS) em porcentagem do PV, sendo maiores na adaptação em escada no período final. Para incidência de rumenite, teve efeitos de duração e protocolo, sendo o protocolo R9 com maior lesão da parede ruminal. Na avaliação morfológica do epitélio ruminal foi encontrado efeito de duração na fase de adaptação para área média de papilas. Nas variáveis histológicas houve diferença entre as fases (adaptação e terminação) para altura, largura e espessura de queratina das papilas ruminais. No comportamento ingestivo, todos os itens avaliados apresentaram efeitos significativos, destacando-se, a IMS na adaptação e terminação, e variação de consumo na adaptação, em que o protocolo de escada proporcionou maior ingestão e menor variação. Contudo, na adaptação de Bovinos Nelore confinados alimentados com dietas de alto teor concentrado, recomenda-se o protocolo de escada com 9 dias de duração / Abstract: The objective was to evaluate the effects of duration of protocols to adapt to diets high concentrate diets on feeding behavior, performance, carcass characteristics and rumen health of confined Nellore. Uncastrated male Nelore (n = 120), with 352.03 ± 19.61 kg, were kept for 84 days in 24 bays. The experimental design was randomized blocks, with 2 × 2 factorial arrangement (protocols and durations), constituting the following treatments: adaptation for in steps 6 (E6) or 9 days (E9) and protocol restriction for 6 (R6) or 9 days ( R9), being 6 pen per treatment. There was no effect of protocol adaptation in average weight gain and dry matter intake (DMI) as a percentage of BW, with greater adaptation ladder in the final period. Incidence of ruminites had significant effects and protocol, with the largest lesions R9 protocol with the rumen wall. In the morphology of the ruminal epithelium was not found in the effect of duration adaptation phase to average area of papillae. In histological variables was no difference between the phase (adaptation and finishing) for height, width and thickness of keratin of rumen papillae. In feeding behavior, all items presented significant effects, especially in DMI during adaptation and finishing, and variation in intake in the adaptation, where the step up protocol provided higher intake and lower variation. All in all, in the adaptation for feedlot Nellore cattle fed to high-concentrate diets, indicated the 9 days in steps / Mestre

Orientador: Paulo Henrique Franceschini / Banca: Francisco Guilherme Leite / Banca: Erika da Silva Carvalho Morani / Resumo: O objetivo deste trabalho foi avaliar o efeito do meloxicam sobre a taxa de concepção inicial (TCi), final (TCf) e perda gestacional (PG) de vacas Holandesas de alta produção submetidas à Transferência de Embrião (TE) Inseminação Artificial (IA) e Inseminação Artificial em Tempo Fixo (IATF). Na TE foram utilizadas, como receptoras de embrião, 492 vacas em lactação repetidoras de serviço. Na IA (n=312) e IATF (n=336) foram incluidas no estudo somente fêmeas recém paridas (com pelo menos 60 dias em lactação). Todas as fêmeas foram avaliadas e alocadas em um de dois grupos experimentais: Grupo Controle (GC) e Grupo Tratado (GT). O tratamento consistiu na administração i.m. de meloxicam injetável 2% (0,5mg/kg de peso) nos dias 7, 8 e 9 após a inovulação das receptoras de embrião, e nos dias 14, 15 e 16 da possível gestação das fêmeas submetidas a IA e IATF. Amostras de sangue foram colhidas nos D14 e D21 para posterior dosagem de progesterona (P4). O diagnóstico de gestação ocorreu aos 25-38 e 39-52 dias. O tratamento com o antiinflamatório não incrementou as TCi, TCf e tampouco diminuiu a PG em nenhuma das três biotecnologias. Contudo, observou-se que receptoras de embrião inovuladas com embriões congelados/descongelados do GT tiveram TCi e TCf menores que as do GC (GT= 25,8% v. GC=37,8%) .Não houve diferença na concentração sérica de progesterona de vacas do GC e do GT no D21. Contudo, houve efeito da estação do ano sobre as concentrações de P4 no D14 e D21 tanto na TE como na IA e IATF. Ainda, vacas gestantes apresentaram maiores concentrações de P4 que vacas não gestantes no D21. Conclui-se que o tratamento com meloxicam não incrementou as TCi, TCf, tampouco reduziu a PG de vacas Holandesas de alta produção / Abstract: The aim of this study was to evaluate the effect of meloxicam on initial conception rate, final conception rate and pregnancy loss of high-producing Holstein cows submitted to embryo transfer (ET), artificial insemination (AI) and timed artificial insemination (TAI). On ET, 492 repeat breeders in milk were used as recipients. On AI (n=312) and TAI (n=336) only freshly calved cows (with at least 60 days in milk) were included in the study. The animals were evaluated and allocated in one of two experimental groups: Control Group (CG) and Treated Group (TG). The treatment consisted on administration of meloxicam 2% i.m. (0.5mg/kg of weight) on days 7, 8 and 9 after inovulation of embryo recipients, and on days 14, 15 and 16 of the possible pregnancy of females submmited to AI and TAI. Blood samples were collected on D14 and D21 for progesterone assay. The diagnosis of pregnancy was done on days 25-38 and 39-52. The treatment with the antiinflamatory did not increase initial conception rates and final conception rates, nor decreased pregnancy loss of animals in all three biotechnologies. However, recipients of TG inovulated with frozen/thawed embryos had lesser initial and final conception rates than CG (TG= 25.8% v. CG=37.8%) There was no difference on progesterone serum concentration of cows from TG and CG on D21. However, there was a season effect on P4 concentrations on D14 and 21 for ET, AI and TAI. Pregnant cows had higher P4 concentrations than non-pregnant cows. In conclusion, the treatment with meloxicam did not increase initial and final conception rates, neither decreased pregnancy loss of high producing Holstein cows / Mestre

Orientador: Vera Fernanda Martins Hossepian de Lima / Coorientador: Rubens Paes de Arruda / Coorientador: Ricarda Maria dos Santos / Banca: Gisele Zoccal Mingoti / Banca: Sony Dimas Bicudo / Banca: Ed Hoffmann Madureira / Banca: Eneiva Carla Carvalho Celeghini / Resumo: Tem sido frequentemente demonstrado que variadas taxas de concepção podem ser obtidas de acordo com o sêmen utilizado, evidenciando uma importante variabilidade individual do reprodutor com relação à fertilidade. Além disso, as grandes dimensões dos rebanhos, associado ao intenso e crescente uso dos protocolos de IATF no Brasil, tem estimulado, cada vez mais, a prática do descongelamento simultâneo de diversas palhetas de sêmen em um mesmo descongelador. Entretanto, sob essas condições, o banho-maria do descongelador poderia atuar como ambiente de incubação para o sêmen, o que poderia influenciar a viabilidade do espermatozoide. Assim, o presente estudo teve por objetivos: 1) determinar o efeito da sequência de inseminação, após descongelamento simultâneo de diversas palhetas de sêmen, na taxa de concepção e na qualidade seminal; 2) investigar a fertilidade in vivo, bem como diversas características espermáticas in vitro, do sêmen de diferentes reprodutores utilizados no mesmo programa de IATF; 3) identificar, dentre as diversas análises laboratoriais realizadas, o grupo de características espermáticas consideradas importantes na predição da taxa de concepção. Para tal, o presente experimento foi realizado em duas etapas. A primeira etapa consistiu em um estudo a campo delineado para determinar a taxa de concepção após IATF de fêmeas pós-parto da raça Nelore (n=947), utilizando sêmen de três partidas de cada um dos três touros da raça Angus (n=9). A segunda etapa consistiu em um estudo laboratorial delineado para investigar diversas características espermáticas das doses de sêmen utilizadas no respectivo programa de IATF, utilizando as mesmas condições de descongelamento do estudo a campo. As seguintes análises laboratoriais foram realizadas: análise computadorizada do movimento... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: It has been reported that different conception rates can be obtained according to the semen used, indicating a significant variability regarding sire fertility. Furthermore, the large size of reproductive herds associated with the intense use of Timed-AI protocols in Brazil, has stimulated the routine practice of simultaneous thawing of multiple semen straws in the same thawing-bath. However, under these conditions, the thawing-bath could act as an incubator environment for the semen, which could influence the sperm viability. Thus, this study aimed to: 1) determine the effect of sequence of insemination after simultaneous thawing of multiple semen straws on conception rate and semen quality; 2) investigate the in vivo fertility, as well as several in vitro sperm characteristics, from different sires used in the same Timed-AI program; 3) identify, among the several in vitro sperm variables evaluated in laboratory, the group of sperm characteristics considered important in the prediction of conception rate. Hence, this study was conducted in two experiments. The first experiment was a field study designed to determine conception rate after Timed-AI of suckled multiparous Nelore cows (n = 944) using three semen batches from three Angus bulls (n = 9). The second experiment was a laboratory study designed to investigate several sperm characteristics of semen used in the Timed-AI program, using the same thawing conditions applied in the field experiment. The following laboratory analyses were performed: computer assisted semen analysis, hypo-osmotic swelling test, sperm resistance after 2 hours of thermal incubation, sperm morphology, integrity of plasma and acrosomal membranes, plasma membrane stability, lipid peroxidation, sperm morphology and chromatin condensation. According to the present experiment, it was concluded that... (Complete abstract click electronic access below) / Doutor

A series of in vitro studies were conducted to evaluate the effect of poly-l-lysine concentration, molecular weight, and encapsulation temperature on the post encapsulation survivability of spermatozoa. Viability of spermatozoa encapsulated at 2012 C using four poly-l-lysine concentrations (.05%, .15%, .25%, and .35%) did not differ over the 8 h incubation period. However, the viability of each of the four treatments was lower than that of the unencapsulated control (p<.05 and p<.01; percentage motility and percentage intact acrosomes, respectively), indicating spermatozoal damage occurred during the encapsulation process. Capsule wall thickness and integrity for the .15%, .25%, and .35% concentrations were greater (p<.Ol) than that of the .05% capsules. / Master of Science

This study was designed to : 1) Determine the effects of fresh vs frozen semen at a high inseminate dosage (lOOxl06sperm) contrasted to their effects at a conventional dosage (20xl06 sperm) on accessory sperm per ovum and 2) Evaluate the relationship between accessory sperm number per embry%vum and fertilization status/embryo quality if accessory sperm number were affected by treatment. In this study semen from four bulls routinely giving a minimum of 700/0 morphologically normal and 600/0 motile sperm cells were used. Ejaculates of these bulls were split and prepared for use as fresh and frozen semen at either 100xl06 or 20xI06 cells per dose in.5 mL French straws. Half of the total semen filled straws were frozen in liquid nitrogen at -196°C and half were stored at 5°C for 4 days after collection and used as unfrozen. Cows in standing heat were inseminated with fresh or frozen semen at either high (IOOxl06 sperm) or conventional dose (20xl06 sperm). Ova/embryos were recovered non surgically on day 6 after breeding. Accessory sperm were counted in the recovered embryos/ova after partial digestion with Pronase followed by compression of the embryo/ovum with a cover slip. From 129 inseminations to normally cycling cows, 98 embryos/ova were recovered. To reduce male effects, embryos/ova used were randomly balanced across treatments, by ejaculate within bull for evaluation of frozen vs fresh semen (n = SO) and by bull for evaluation of high vs low dosage treatments (n = 76). No difference (P > 0.05) in accessory sperm was observed for fresh vs frozen semen at either the high or low dosage. The mean accessory sperm values for fresh high dose (n=21), frozen high dose (n=21), fresh low dose (n= 19), and frozen low dose (n= 19) were 26.S1±30.23 (SD), 36.05±44.74 (SD), 29.37± 55.97 (SD) and 30.l6± 70.18 (SD) respectively. When data for embryos/ova resulting from fresh and frozen semen were pooled within dosage, a significant difference was observed between the median accessory sperm values for high and low doses of semen (P < .05). Mean ± SD and median values for accessory sperm were: 37.8± 38.3 and 27.5; 28.9± 62.8 and 3.0, for the high and low dose, respectively. Increasing accessory sperm number by the higher dosage improved the fertilization status/embryo quality (P < .05). Percentage unfertilized ova, degenerate embryos and embryos classified poor to fair and good to excellent were: 3, 5, 24, 68; and 21, 16, 18, 45, for the high and low dose, respectively. Overall, embryos/ova classified good to excellent, poor to fair, degenerate and unfertilized had median accessory sperm values of 18, 9.5, 5.5 and 0, respectively. However, the lack of accessory sperm in unfertilized ova was significantly different from excellent-good quality embryos (P < .05). / Master of Science

Four experiments were conducted to evaluate the viability and fertility of bovine spermatozoa encapsulated in microcapsules and microgels. In Experiment I, one of two morphologically distinct sperm types i.e. marker or unmarked bull spermatozoa (100 x 10⁶ sperm/bull) were encapsulated in protamine sulfate microcapsules and simultaneously inseminated with the reciprocal sperm type unencapsulated. Insemination of both sperm types unencapsulated served as a control. Accessory sperm embedded in the zona pellucida were counted and morphologically classified 6 to 7 d post insemination. From microencapsulated inseminates, accessory sperm populations did not increase over the unencapsulated controls, but contributed 25.7% of the accessory sperm population. ln Experiment 2, an in vitro study was performed to evaluate the maintenance of viability for bovine spermatozoa encapsulated in PIPES, HEPES, or saline microgels. Neat semen was pooled from five bulls (50 x 10° sperm/bull), encapsulated in alginate microgels, and incubated at 37 C for 8 h. The unencapsulated control displayed greater maintenance of viability for percent intact acrosomes and motility when compared to all treatments. By 8 h incubation, PlPES and HEPES were not significantly different, but demonstrated greater maintenance of viability when compared to saline microgel treatments. In Experiment 3, PIPES microgels were heterospermically inseminated with equal numbers (20 x l0⁶ sperm/bull) of frozen-thawed marker bull and normal bull spermatozoa as explained in Experiment 1. Microencapsulated treatments contributed significantly lower numbers of accessory sperm when compared to unencapsulated controls. In Experiment 4, one of the two morphologically distinct sperm types (20 x l0⁶ frozen-thawed sperm/bull) were encapsulated in protamine sulfate microcapsules and the reciprocal sperm type was encapsulated in PIPES microgels. A total of 21 accessory sperm were recovered from 30 embryos which demonstrates the ability of microencapsulated spermatozoa to fertilize an oocyte. / Master of Science

Thesis (M. Tech. (Agriculture)) - Central University of Technology, Free state, 2013 / The study was carried out to establish whether or not a decrease in the progesterone concentration of an intravaginal device used to synchronize oestrous in Beefmaster heifers and cows would lead to an increase in conception rates. The study evaluated the effect of different intravaginal progesterone device doses on the conception rates of Beefmaster cows and heifers following fixed time artificial insemination (FTAI). A total of 100 stud Beefmaster cows (Cow group) and 100 stud Beefmaster heifers (Heifer group) were used in the study. The animals were year round grazing residents of the farm Oribilaagte near the town of Vrede in the Free State province of South Africa. The Cow and Heifer groups were split into four experimental groups, respectively, and treated with either a 0.5 g, 1.0 g, 1.9 g or 1.9 g re-used intravaginal progesterone device during the spring synchronization program (P4 device insertion and 2 mg i.m. oestradiol benzoate treatment on d 0, 250 μg s.c. PGF2_ treatment on d 7, P4 device removal on d 8, 1 mg i.m. oestradiol benzoate treatment on d 9, and FTAI on d 10). Blood samples were taken on the day of intravaginal insert removal (d 8), and on the day of FTAI (d 10), to monitor the blood serum P4 concentrations (solid phase RIA analysis) between the experimental groups. The experimental groups were examined for pregnancy 5 months post AI by means of rectal palpation. The Cow group recorded a pregnancy rate of 65%, 75%, 67% and 68% for the 0.5 g, 1.0 g, 1.9 g and 1.9 g re-used intravaginal progesterone device groups respectively. The Heifer group recorded a pregnancy rate of 19%, 39%, 41% and 47% for the 0.5 g, 1.0 g, 1.9 g and 1.9 g re-used intravaginal progesterone device groups respectively. The study concluded that a decrease in the progesterone concentration in the intravaginal device did not affect the serum progesterone concentrations in the Heifer and Cow groups on the day of the FTAI, and did not negatively affect the synchronization program. The study further concluded that, although a decrease in the progesterone concentration in the intravaginal device did not statistically influence the conception rates in the Heifer and Cow groups, the Cow group did record a higher numerical conception rate when the progesterone concentrations in the intravaginal devices were reduced.

Made available in DSpace on 2015-03-26T13:47:24Z (GMT). No. of bitstreams: 1 texto completo.pdf: 425505 bytes, checksum: c9e905b211c38a1ec8e1bb112c85e570 (MD5) Previous issue date: 2014-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was aimed to investigate the effects that different protocols for induction and synchronization of estrus and ovulation, with the use of eCG, BE, CE or GnRH associated with progestin could have on the follicle growth and pre-ovulatory follicle diameter. Furthermore the relationship with progesterone, LH, insulin, cortisol in the follicular fluid concentration and progesterone, cortisol, insulin serum concentrations of cows submitted to protocols. Ninety Nelore suckled cows were divided into six groups, 15 cows per protocol. The protocols consisted in the placement and removal of an intravaginal progesterone device (IPD) (0.75g of progesterone) in the first and eighth day respectively; application of prostaglandin (PGF2 &#61537;) on the eighth day, and except in protocol 1 was used estradiol benzoate (EB) on day 1. The other differences in the delineation of protocols were: Protocol 1 day 1 and day 8 (GnRH); Protocol 2 day 6 (PGF2 &#61537;), day 8 (PGF2 &#61537; + estradiol cypionate (EC)); Protocol 3 day 8 (eCG + EC); Protocol 4 day 8 (eCG + EB); Protocol 5 day 8 (eCG), day 9 (EB); Protocol 6 day 9 (EB). Overall 93.3% (84/90) of cows responded to synchronization protocol. However, it was observed that 28.9% of cows (26/90) did not have a synchronization of a new follicular wave, checked by the number of cows which have not developed a dominant follicle (5/26), cows with early ovulation (15/26) and cows that had a dominant follicle in regression process (6/26). There was no statistical difference in growth and diameter of the pre-ovulatory follicle between protocols. Progesterona, LH, insulina, cortisol concentrations on follicular fluid, as well as in cortisol and insulin serum concentration did nor differ with the protocols used. Although, in protocol 2, lower progesterone concentrations (P<0.05) were observed in the withdrawal of IPD. Twenty seven oocytes were recovered, which were classified according to quality: 1 (n=12), 2 (n=6), 3 (n=7) e 4 (n=2). The antecipation in the prostaglandin application in two days from IPD withdrawal result in lower progesterone concentrations. / O objetivo desse estudo foi verificar os efeitos que diferentes protocolos de indução e sincronização do estro e da ovulação, com utilização de eCG, BE, CE ou GnRH associados a um progestágeno, podem ter sobre o crescimento e diâmetro do folículo pré-ovulatório, e suas relações com a concentração, no fluido folicular, de progesterona, LH, insulina e cortisol, e com a concentração sérica de progesterona, cortisol e insulina das vacas submetidas aos protocolos. Foram utilizadas 90 vacas Nelore solteiras, com mais de nove meses pós-parto, divididas em seis protocolos, sendo 15 vacas por protocolo. Todos os protocolos consistiam na colocação e retirada de um dispositivo intravaginal de progesterona (DIP) (0,75 gramas de progesterona) no primeiro e no oitavo dia, respectivamente; aplicação de prostaglandina (PGF2&#61537;) no oitavo dia; e exceto no protocolo 1, foi utilizado benzoato de estradiol (BE) no dia 1. As outras diferenças no esquema dos protocolos foram: protocolo 1 dia 1 e dia 8 (GnRH); protocolo 2 Dia 6 (PGF2&#61537;), dia 8 (PGF2&#61537;&#61472;&#61483;&#61472;cipionato de estradiol (CE)); protocolo 3 dia 8 (eCG + CE); protocolo 4 dia 8 (eCG + BE); protocolo 5 dia 8 (eCG), dia 9 (BE); protocolo 6 dia 9 (BE). Em geral, 93,3 % (84/90) de vacas responderam ao protocolo de sincronização. Entretanto, foi observado que 28,9 % das vacas (26/90) não apresentaram sincronização eficiente de uma nova onda folicular, constatado pelo número de vacas que não desenvolveram folículo dominante (5/26), as vacas que ovularam precocemente (15/26), e as vacas que tiveram um folículo dominante que estava em processo de regressão (6/26). Não houve diferença estatística no crescimento e diâmetro do folículo pré-ovulatório entre os protocolos. Não houve efeito, entre os protocolos, na concentração no fluido folicular de progesterona, LH, insulina, cortisol, bem como na concentração sérica de cortisol e insulina. Contudo, no protocolo 2, foi verificada menor concentração sérica (P < 0,05) de progesterona na retirada do DIP. Foram recuperados 27 ovócitos, que foram classificados de acordo com a qualidade em 1 (n=12), 2 (n=6), 3 (n=7) e 4 (n=2). A antecipação na aplicação de vprostaglandina, em dois dias da retirada do DIP, resulta em menor concentração de progesterona circulante.

Made available in DSpace on 2015-03-26T14:02:19Z (GMT). No. of bitstreams: 1 texto completo.pdf: 425125 bytes, checksum: dda98e31d22621b390e8f374215f6249 (MD5) Previous issue date: 2014-06-30 / Brazil has the largest commercial cattle herd in the world; however, the adoption rate of artificial insemination (AI) in the country is still low. This study aimed to characterize the profile of milk and beef cattle producers of the northwest region of the state of Minas Gerais regarding the use of artificial insemination (AI) and see which are the most relevant factors in the perception of producers in the adoption process of artificial insemination. During the months from January to April 2014, 97 milk and beef cattle producers associated to milk cooperatives of the municipalities of northeastern state of Minas Gerais were interviewed. Of those interviewed farmers, 61.3% did not use artificial insemination. The majority (92.48%) of respondents were male and 48.88% were over 53 years of age, with low schooling, incomplete primary education (28.57%) or complete primary education (25.97%). Among the respondents, 66.67% had over 20 years experience in dairy farming. The average matrix by property was 99 and the average size of properties was 73 hectares (ha). The analysis of the data related to the perception of producers was done by classical methods of analysis of textual content, which included the following steps: pre-analytical, analytical and inferential, all in the presence of three technical assessors. Each information was considered a basic context unit (BCU). The units, divided into thematic groups, gave rise to the categories and subcategories appointed by the a posteriori method. In general, it was found that personal motivation is the main determinant for the adoption of AI and is more linked to positive expectations generated by the phenotype of the animals than to economic factors. The prerequisites for adoption of AI are in the background and, among them, manpower, infrastructure and animal handling are highlighted, followed by social influence, evidenced by entities and persons involved in AI and in the ranchers's daily life. Little emphasis on people management and use of scientific knowledge may have affected the adoption of biotechnology, resulting in low utilization. It is also possible to associate the advanced age of farmers to the resistance to the use of reproductive biotechnologies. / O Brasil possui o maior rebanho comercial de bovinos do mundo, entretanto, a taxa de adoção da inseminação artificial (IA) no País ainda é baixa. Objetivou-se caracterizar o perfil dos bovinocultores de leite da região noroeste do estado de Minas Gerais quanto à utilização da inseminação artificial (IA) e verificar quais são os fatores mais relevantes, na percepção dos produtores, no processo de adoção da inseminação artificial. Durante os meses de janeiro a abril de 2014, foram entrevistados 97 bovinocultores de leite associados a cooperativas de leite dos municípios da região noroeste do estado de Minas Gerais. Do total de produtores entrevistados, 61,3% não utilizavam a inseminação artificial. A maioria (92,48%) dos entrevistados era do sexo masculino e 48,88% possuíam mais de 53 anos de idade, com baixo grau de escolaridade, ensino fundamental incompleto (28,57%) ou fundamental completo (25,97%). Entre os entrevistados, 66,67% possuíam mais de 20 anos de experiência na atividade leiteira. A média de matrizes por propriedade foi de 99 e o tamanho médio das propriedades, 73 hectares (ha). A análise dos dados relacionados à percepção dos produtores foi feita por meio de metodologia clássica de análise de conteúdo textual, que incluiu as seguintes etapas: pré-analítica, analítica e inferencial, todas na presença de três técnicos avaliadores. Cada informação foi considerada uma unidade de contexto elementar (UCE). As unidades, divididas em grupos temáticos, deram origem às categorias e subcategorias, nomeadas pelo método a posteriori. De modo geral, verificou-se que a motivação pessoal é o principal fator determinante da adoção da IA e está mais atrelada aos pontos fortes do uso da biotécnica e às expectativas positivas geradas pelo fenótipo dos animais que a fatores econômicos. Os pré-requisitos para adoção da IA estão em segundo plano e, entre eles, destacam-se a mão de obra, a infraestrutura e o manejo animal, seguidos da influência social, evidenciada pelas entidades e pessoas envolvidas na IA e no cotidiano dos pecuaristas. A pequena ênfase na gestão de pessoas e no uso do conhecimento científico pode ter afetado na adoção da biotécnica, resultando em baixa utilização. Ainda é possível associar a idade avançada dos produtores rurais à resistência ao uso de biotecnologias reprodutivas.