No description available.

No description available.

This research explores the influence of pregnancy loss and coping strategies employed while connecting to the fetus in a subsequent pregnancy following a late term loss. Nine participants were interviewed using a qualitative, phenomenological methodology to determine participant's experience. Four themes emerged within the data: (1) support network – participants acknowledged who was there for them and who was not, (2) emotional ups and downs – participants reported the emotional ups and downs from loss to the subsequent pregnancy to delivery and after birth, and how they connected during this process (3) coping – participants describe coping strategies used throughout their experience, and (4) moving forward – participants reported their process of finding their new normal and how this event changed their perspective on life. Limitations, future research and clinical implications were all identified and discussed. / Master of Science

Faculty of health sciences School of Public Health 0204521g dgresie@yahoo.co.uk;dgresie@hotmail.com / Ethylene oxide is used widely in hospitals as a gaseous sterilant for heat-sensitive medical items, surgical instruments and other objects and fluids that come into contact with biological tissues. Although ethylene oxide is recognised as a reproductive toxicant in humans, so far few studies have been carried out to investigate the association between exposure to ethylene oxide and the occurrence of adverse reproductive outcomes (Hemminki et al 1982 and 1983; Rowland et al, 1996; Yakubova et al, 1976). The results of these studies suggested that ethylene oxide is capable of causing reproductive dysfunction and that further research is needed in order to understand its effects on reproductive health. This study investigated the association between exposure to ethylene oxide during pregnancy and adverse reproductive outcome in women sterilising staff working in sterilising units using ethylene oxide in Gauteng province, South Africa. The study had the following objectives: 1) to describe the extent and nature of ethylene oxide use in sterilising units operational in medical facilities in Gauteng; 2) to assess the current exposure to ethylene oxide in sterilising units in Gauteng; 3) to collect information on the last recognised pregnancy using a questionnaire; 4) to assess the validity of the information on the evolution and outcome of the last recognised pregnancy collected by the means of the questionnaire; 5) to assess the association between occupational exposure to ethylene oxide during pregnancy and adverse reproductive outcome. The study population was represented by singleton pregnancies that: 1) occurred in women currently working in sterilising units using ethylene oxide in Gauteng province, South Africa; 2) were the last recognised pregnancy occurring in these women after the 1st January 1992; 3) occurred while the mother was employed. The adverse reproductive outcome was defined as the occurrence of any the following: spontaneous abortion, still birth, pregnancy loss (spontaneous abortion or still birth), low birth weight and combined adverse reproductive outcome (spontaneous abortion, still birth or low birth weight). The study enrolled 68.8% of the medical facilities in Gauteng that were using ethylene oxide to sterilise medical equipment. The majority of the employees working in the sterilising units included in the study were women (96.6%) and they were employed in one of the following jobs: technician (operator), instrument packer and cleaner. xiii Most of the sterilising units participating in the study used ethylene oxide sterilisation daily and only 15.4% of them reported that the employees operating the ethylene oxide steriliser used protective clothing. Recorded levels of ethylene oxide were provided by 46.2% of the sterilising units; they were all bellow 0.25 ppm (the South African long-term exposure limit for occupational exposure to ethylene oxide is 5 ppm). Changes in ethylene oxide sterilisation equipment and or technology were reported by 42.3% of the sterilising units and they were all engineering control measures aimed at reducing exposure to ethylene oxide. Measurements of the current levels of ethylene oxide were performed at the time of the study by the National Institute for Occupational Health using hydrobromic acid-coated petroleum charcoal tubes connected to calibrated Gilian pumps through which air containing ethylene oxide was drawn. The samples were analysed by the Analytical Services of the National Institute for Occupational Health. A total of 418 samples were collected (100 blank samples, 97 personal samples and 221 static samples). Quality control was ensured by the following methods: 1) verification by an Approved Inspection Authority; 2) collection of duplicate samples; 3) collection of blank samples. These measurements showed that exposure to ethylene oxide still occurred in sterilising units (ethylene oxide was detected in 9 out of the 10 public hospitals) and that the employees most exposed are the ones working with the ethylene oxide steriliser (technician or operator). There were 113 women working in the sterilising units enrolled in the study who had been pregnant after the 1st January 1992; 109 of them agreed to participate in the study and to complete the questionnaire. Information on exposure to ethylene oxide during pregnancy was obtained from three sources: walk-through survey, questionnaire-collected data and measurements of the levels of ethylene oxide in sterilising units at the time of the study. Information on the evolution and outcome of these pregnancies was gathered from the mother using a questionnaire. The questionnaire collected demographic data, reproductive history, medical data, risk factors for the adverse reproductive outcome (environmental and occupational exposures, lifestyle), and data regarding the evolution and outcome of the last recognised pregnancy. The questionnaire also collected detailed information on the job held at the time of the last recognised pregnancy (if the woman was working with ethylene oxide, she was asked to provide a complete list of daily tasks she was performing). Prior to administration, the questionnaire was tested on a small sample of working women. xiv The validity of the questionnaire-collected information on the evolution and outcome of the last recognised pregnancy was assessed by comparing this information against medical records (considered the “gold standard”). The assessment showed that mothers’ recall was accurate for the following variables: medical facility were the pregnancy was recorded, date of the reproductive event, gestation length, vital status of the newborn, number of foetuses, child gender, disease/medical problems during pregnancy and treatment received during pregnancy. There was an error in the mothers’ reporting of the birth weight of their babies. The possible misclassification of outcome resulting from this error was shown to be nondifferential (the proportion of subjects misclassified on outcome did not depend on exposure). Therefore, this misclassification could bias the effect estimate towards the null value or it could not produce any bias at all. The analysis carried out to detect possible associations between exposure to ethylene oxide and adverse reproductive outcomes included 98 of the initial 109 pregnancies on which information had been collected (11 pregnancies were excluded from the analysis for the following reasons: 2 were multiple pregnancies, 4 were conceived before 1st January 1992 and 5 were conceived while the mother was not employed). Amongst the 98 singleton pregnancies included in the analysis, 19 were classified as exposed and 79 as unexposed to ethylene oxide. The relative risk for spontaneous abortion was RR=16.63 (95%CI=1.97-140.42; p=0.004), for stillbirths RR=3.47 (95%CI=0.63-19.01; p=0.18), for pregnancy loss RR=6.24 (95%CI=1.95- 19.93; p=0.003), for low birth weight RR=0.61 (95%CI=0.09-4.30; p=0.51) and for combined adverse reproductive outcome RR=2.09 (95%CI=1.00-4.36; p=0.06). No confounders were detected for any of the associations between exposure to ethylene oxide and the adverse reproductive outcomes under study. For the association between exposure to ethylene oxide and combined adverse reproductive outcome the analysis detected three effect modifiers: paternal age (father aged 40 or older at conception), passive smoking and maternal age (mother aged 35 or older at conception). In conclusion, this study, the first in South Africa on ethylene oxide exposure and adverse reproductive outcomes, confirmed the widespread use of ethylene oxide, exposure to this agent in public sector hospitals and associations between exposure to ethylene oxide and spontaneous abortion and between exposure to ethylene oxide and pregnancy loss (either spontaneous abortion or stillbirth). xv Moreover, the study provided data on reproductive outcomes in employed women (on which scant data are available in South Africa) and added information on the validity of selfreported pregnancy data relative to medical records. The findings of the study support the conclusions of the previous studies that had suggested that exposure to ethylene oxide during pregnancy could lead to adverse reproductive outcomes. The study detected no associations between exposure to ethylene oxide and stillbirth, low birth weight or between exposure to ethylene oxide and combined adverse reproductive outcome.

No description available.

No description available.

Os objetivos da tese foram comparar a dinâmica folicular e luteínica (Experimento 1), bem como a eficiência reprodutiva (Experimento 2) de búfalas leiteiras submetidas a protocolos de IATF à base de progesterona/estrógeno (P4/E2) e eCG durante as estações reprodutivas favorável (ERF; maio, junho e julho) e desfavorável (ERD; novembro, dezembro e janeiro) do ano. No Experimento 1 foram utilizadas 51 búfalas leiteiras de uma propriedade e no Experimento 2, 351 búfalas leiteiras de 5 propriedades. Para comparar o efeito das ER, cada propriedade teve semelhante número de animais submetidos à IATF nas respectivas ERF e ERD, tanto no Experimento 1 (n=25 vs. n=26) quanto no Experimento 2 (n=168 vs. n=183). Todas as propriedades se localizavam na região do Vale do Ribeira, Estado de São Paulo. Em dias aleatórios do ciclo estral (D-12; 16:00 h), todas as búfalas receberam um dispositivo intravaginal contendo 1 g de P4 (iP4; Sincrogest&reg;, Ourofino Agronegócio) mais 2,0 mg de benzoato de estradiol i.m. (Sincrodiol&reg;, Ourofino Agronegócio). No D-3 (16:00 h), as fêmeas receberam 0,53 mg de PGF2&#945; i.m. (Cloprostenol, Sincrocio&reg;, Ourofino Agronegócio) e 400 UI de eCG i.m. (Novormon&reg; MSD Saúde Animal), seguido de remoção do dispositivo de progesterona. No D-1 (16:00 h), 10 &micro;g de acetado de buserelina (GnRH, Sincroforte&reg; Ourofino Agronegócio) foram administrados i.m. A IATF foi realizada 16 horas após a administração de GnRH (D0; 8:00 h). No D0 foram determinados o intervalo de dias em lactação (DEL) e o escore de condição corporal das fêmeas (ECC; 1-5). Avaliações ultra-sonográficas (Chison D600Vet, China) foram realizadas no Experimento 1 para determinar: diâmetro do folículo dominante entre a retirada do iP4 e a IATF (&#216;FD), o diâmetro do folículo ovulatório (&Oslash;FO), o momento da ovulação, a dispersão das ovulações, a presença e o diâmetro do corpo lúteo (&#216;CL) após a ovulação. No Experimento 2, determinaram-se a taxa de ciclicidade (presença de corpo lúteo no D-12 e/ou no D-3); o diâmetro do folículo dominante nos D-3 e D0 (&#216;FD); a taxa de ovulação e diâmetro do corpo lúteo 10 dias após a IATF (&#216;CL D+10); os diagnósticos de gestação aos 30 (P/IA 30 d) e 45 dias (P/IA 45 d) após a IATF, além da taxa de mortalidade embrionária (ME) entre 30 e 45 dias, a mortalidade fetal (MF) entre 45 dias e o nascimento e a perda gestacional (PG) entre 30 dias e o nascimento. As variáveis contínuas foram apresentadas como média e erro padrão da média (média±EPM) e as frequências como porcentagem [% (n/n)]. A comparação entre as variáveis foi realizada por análise de variância (ANOVA), por meio do programa SAS&reg;. Foi considerada diferença quando P < 0,05. No Experimento 1, observou-se que a dinâmica ovariana não foi influenciada pelas respectivas ERF e ERD para as seguintes variáveis: &#216;FD (0 h 10,3±0,4 vs. 9,9±0,5 mm; 24 h 11,8±0,5 vs. 12,0±0,4; 48 h 12,8±0,5 vs. 13,2±0,4; e 60 h 13,8±0,6 vs. 13,1±0,5; P=0,80); &#216;FO (14,3±0,4 vs. 14,2±0,3 mm; P=0,94); momento da ovulação (76,5±1,9 vs. 72,0±2,5 h; P=0,85); dispersão das ovulações (24 |- 48 h 0,0 vs. 0,0%; 48 |- 60 h 12,5 vs. 37,5%; 60 |- 72 h 41,7 vs. 33,3%; 72 |- 84 h 41,7 vs. 25,0%; 84 |- 96 h 4,2 vs. 0,0%; e 96 |- 108 h 0,0 vs. 4,2%; P=0,18) e &#216;CL (D+6 17,3±0,5 vs. 16,9±0,4; D+10 21,5±0,6 vs. 18,4±0,5; e D+14 20,6±0,6 vs.19,9±0,6; P=0,06). No Experimento 2, pôde-se observar que apesar das búfalas apresentarem semelhança em DEL (111,1±8,8 vs. 144,3±8.6 dias; P=0,27) e ECC (3,3±0,0 vs. 3,3±0,0; P=0,41) nas respectivas ERF e ERD, houve diferença nas taxas de ciclicidade [76,2 (128/168) vs. 42,6% (78/183); P=0,02]. Nenhuma das outras respostas diferiu entre as ERF e ERD, respectivamente: &#216;FD D-3 (9,6±0,2 vs. 9,8±0,2 mm; P=0,35); &#216;FD D0 (13,1±0,2 vs. 13,2±0,2 mm; P=0,47); taxa de ovulação [86,9 (146/168) vs. 82,9% (152/182); P=0,19]; &#216;CL D+10 (19,0±0,3 vs. 18,4±0,3 mm; P=0,20); P/IA 30 d [66,7 (112/168) vs. 62,7% (111/177); P=0,31]; P/IA 45 d [64,8 (107/165) vs. 60,2% (106/176); P=0,37]; ME [1,8 (2/111) vs. 3,6% (4/110); P=0,95]; MF [21,9 (18/82) vs. 8,0% (7/87); P=0,13]; e PG [23,8 (20/84) vs. 12,1% (11/91); P=0,13]. Foi possível concluir que búfalas leiteiras apresentam semelhantes respostas ovarianas ao protocolo de sincronização e equivalente eficiência reprodutiva nas ERF e ERD do ano, quando submetidas a programas de IATF à base de P4/E2 e eCG. / This thesis aimed to compare the follicular and luteal dynamics (Experiment 1) and reproductive efficiency (Experiment 2) of dairy buffaloes submitted to TAI protocols based on progesterone/estrogen (P4/E2) and eCG during the breeding (On-BS; May, June and July) and nonbreeding seasons (Off-BS; November, December and January). In Experiment 1, 51 dairy buffalo of one farm were used, and in Experiment 2, 351 dairy buffaloes of 5 farms were used. To compare the effect of BS, each property had similar number of animals submitted to TAI in each, both in Experiment 1 (n = 25 vs. n = 26) as in Experiment 2 (n = 168 vs. n = 183). All properties were located in the Vale do Ribeira, State of São Paulo, Brazil. On random days of the estrous cycle (D-12; 4:00 PM), all buffaloes received an intravaginal device containing 1 g of P4 (Sincrogest&reg;, Ourofino Agronegócio) plus 2.0 mg of estradiol benzoate im (Sincrodiol&reg;, Ourofino Agronegócio). On D-3 (4:00 PM), females received 0.53 mg of PGF2&#945; im (Cloprostenol, Sincrocio&reg;, Ourofino Agronegócio) and 400 IU of eCG im (Novormon&reg;, MSD Animal Health), followed by removal of progesterone device. On D-1 (4:00 PM), 10 mg of buserelin acetate (GnRH Sincroforte&reg;, Ourofino Agronegócio) were administered im. The TAI was performed 16 hours after application of GnRH (D0; 8:00 AM). At the beginning of each protocol (D-12), it was recorded the number of days in milk (DIM) and body condition score of females (BCS, 1-5). Ultrasonography (Chison D600Vet, China) were performed in Experiment 1 to determine: the diameter of the dominant follicle between withdraw of iP4 and TAI (&#216;DF), the diameter of the ovulatory follicle (&#216;OF), the time of ovulation, the dispersion of ovulation, and the presence and diameter of the corpus luteum (&#216;CL) after ovulation. In Experiment 2, was determined cyclicity rate (the presence of corpus luteum in the D-12 and/or D-3), diameter of the dominant follicle in the D-3 and D0 (&#216;DF), ovulation rate, diameter of the corpus luteum 10 days after artificial insemination (&#216;CL D+10); pregnancy rates to 30 (P/AI 30 d) and 45 days (P/AI 45 d) after TAI, embryonic mortality (EM) between 30 and 45 days, fetal mortality (FM) between 45 days and birth, and pregnancy loss (PL) between 30 days and birth. Continuous variables were presented as mean and standard error of the mean (mean±SEM) and frequencies as a percentage [% (n/n)]. The comparison between variables was performed through analysis of variance (ANOVA) using the SAS&reg; program. Difference was considered when P < 0.05. In Experiment 1, it was found that the ovarian dynamics was not influenced by the respective On-BS and Off-BS for the following variables: &#216;DF (0 h 10.3±0.4 vs. 9.9±0.5 mm; 24 h 11.8±0.5 vs. 12.0±0.4; 48 h 12.8±0.5 vs. 13.2±0.4; and 60 h 13.8±0.6 vs. 13.1±0.5; P = 0.80); &#216;OF (14.3 ± 0.4 vs. 14.2 ± 0.3 mm; P = 0.94); timing of ovulation (76.5 ± 1.9 vs. 72.0 ± 2.5 h; P = 0.85); dispersion of ovulations (24 |- 48 h 0.0 vs. 0.0%; 48 |- 60 h 12.5 vs. 37.5%; 60 |- 72 h 41.7 vs. 33.3%; 72 |- 84 h 41.7 vs. 25.0%; 84 |- 96 h 4.2 vs. 0.0%; and 96 |- 108 h 0.0 vs. 4.2%; P = 0.18) and &#216;CL (D+6 17.3±0.5 vs. 16.9±0.4; D+10 21.5±0.6 vs. 18.4±0.5; and D+14 20.6±0.6 vs.19.9±0.6; P = 0.06). In Experiment 2, it was observed that despite the similarity of DIM (111.1 ± 8.8 vs. 144.3 ± 8.6 d, P = 0.27) and BCS (3.3 ± 0.0 vs. 3.3 ± 0.0; P = 0.41) on respective On-BS Off-BS, buffalo females showed different cyclicity rates [76.2 (128/168) vs. 42.6% (78/183); P = 0.02]. None of the other answers differ between On-BS and Off-BS respectively: &#216;DF D-3 (9.6 ± 0.2 vs. 9.8 ± 0.2 mm; P = 0.35); &#216;DF D0 (13.1 ± 0.2 vs. 13.2 ± 0.2 mm; P = 0.47); ovulation rate [86.9 (146/168) vs. 82.9% (152/182); P = 0.19]; &#216;CL + D 10 (19.0 ± 0.3 vs. 18.4 ± 0.3 mm, P = 0.20); P/AI d 30 [66.7 (112/168) vs. 62.7% (111/177); P = 0.31]; P/AI d 45 [64.8 (107/165) vs. 60.2% (106/176); P = 0.37]; EM [1,8 (2/111) vs. 3.6% (4/110); P = 0.95]; FM [21.9 (18/82) vs. 8.0% (7/87); P = 0.13]; and PL [23.8 (20/84) vs. 12.1% (11/91); P = 0.13]. It was concluded that dairy buffaloes have similar responses to ovarian synchronization protocol and equivalent reproductive efficiency during OnBS and OffBS, when subjected to TAI programs based on P4 / E2 and eCG.

Este estudo avaliou os efeitos da administração de diferentes doses de eCG em dois momentos distintos no protocolo de sincronização da ovulação para inovulação em tempo fixo. No dia 0, as receptoras foram tratadas com dispositivo intravaginal contendo progesterona (DIP) e 2,0 mg de Benzoato de Estradiol (BE) associados a 50 mg de progesterona (P4) IM. A partir desse momento, os animais foram divididos homogeneamente para receberem 0,15 mg de d-cloprostenol (PGF2&#945;) e 400, 500 ou 600 UI de eCG no dia 5 (G-400d5, n=101; G-500d5, n=98; G-600d5, n=100, respectivamente) ou no dia 8 (G-400d8, n=100; G-500d8, n=99; G-600d8, n=96, respectivamente; fatorial 3x2). O DIP foi retirado no dia 8 e foi administrado 1 mg de BE no dia 9. No dia 17 os animais foram submetidos a ultra-sonografia ovariana e os que apresentaram mais que um corpo lúteo (CL) ou CL único maior que 18 mm de diâmetro receberam um embrião produzido in vitro. Em um grupo de animais, colheu-se amostras de sangue no dia 17 para determinação da concentração plamática de P4 (CPP4). Os animais tratados com eCG no dia 5 apresentaram maior taxa de aproveitamento [87,0 (260/299) vs. 81,7% (241/295), P<0,05], tendência de maior taxa de concepção [51,8 (132/255) vs. 45,0% (108/295), P=0,07], maior taxa de prenhez [44,1 (132/299) vs. 36,6% (108/295), P<0,05], maior número de CL (1,74 ± 0,09 vs. 1,13 ± 0,03, P<0,05) e maior proporção de receptoras com CL único de maior tamanho [CL 22: 65,7 (111/169) vs. 43,1% (94/218), P<0,05] que os tratados no dia 8. Não se observou efeito de dose sobre a taxa de aproveitamento [400: 82,1 (165/201) vs. 500: 83,8 (165/197) vs. 600: 87,2% (171/196), P<0,05], de concepção [400: 51,8 (85/164) vs. 500: 44,1 (71/161) vs. 600: 49,4% (84/170), P<0,05], de prenhez [400: 42,3 (85/201) vs. 500: 36,0 (71/197) vs. 600: 42,9% (84/196), P<0,05] e sobre a quantidade de receptoras com CL único de maior tamanho [400: 46,8 (65/139) vs. 500: 54,9 (73/133) vs. 600: 57,4 (66/115), P<0,05]. Os animais tratados com 600 UI de eCG apresentaram maior número de CL que os que receberam 400 ou 500 UI (400: 1,17 ± 0,03 vs. 500: 1,33 ± 0,06 vs. 600: 1,82 ± 0,12, P<0,05). No grupo que se determinou a CPP4 verificou-se que os animais que receberam eCG no dia 5 apresentaram maiores CPP4 que os do dia 8 (4,68 ± 0,43 vs. 2,73 ± 0,17 ng/ml, P<0,05). As novilhas tratadas com 600 UI de eCG apresentaram maiores CPP que as tratados com 400 ou 500 UI (400: 2,96 ± 0,22 vs. 500: 3,45 ± 0,38 vs. 600: 4,69 ± 0,55, P<0,05). Receptoras com mais de 1 CL apresentaram tendência de menores perdas gestacionais entre 30 e 60 dias de gestação que as com CL único [10,2 (4/49) vs. 17,5% (33/189), P=0,0547]. Os resultados são indicativos de maior eficiência do protocolo de sincronização da ovulação para transferência de embriões em tempo fixo com o uso de eCG no dia 5. A dose de eCG não influenciou na eficiência do tratamento / The aim of this study was to compare the effects of different doses of eCG administrated at two moments in a fixed-time embryo transfer protocol. On day 0, the heifers received a progesterone releasing vaginal insert (PRVI) and an injection of 2.0 mg Estradiol Benzoate (EB) associated with 50 mg progesterone (P4) i.m. The animals were randomly assigned to six treatment groups in a tree by two factorial design to receive 0.15 mg d-cloprostenol (PGF2&#945;) i.m. and 400, 500 or 600 IU eCG on day 5 (G-400d5, n=101; G-500d5, n=98; G-600d5, n=100, respectively) or on day 8 (G-400d8, n=100; G-500d8, n=99; G-600d8, n=96, respectively). On day 8, the PRVI was removed and an injection of 1 mg EB was administered on day 9. On Day 17, all heifers were examined by ultrasonography to determine the number of CL and those with more than one CL or a single CL with a diameter ?18 mm received an in vitro produced embryo. A subset of heifers were bled on day 17 for plasma P4 determination. The animals treated with eCG on day 5 presented higher proportion of heifers selected/treated [87.0 (260/299) vs. 81.7% (241/295), P<0.05], tendency to higher proportion of heifers pregnant/transferred [51.8 (132/255) vs. 45.0% (108/295), P<0.1], higher proportion of heifers pregnant/treated [44.1 (132/299) vs. 36.6% (108/295), P<0.05], higher CL number (1.74 ± 0.09 vs. 1.13 ± 0.03, P<0.05) and higher proportion of recipients with larger single CL [CL 22: 65.7 (111/169) vs. 43.1% (94/218), P<0.05] than those treated with eCG on day 8. Dose effects were not observed in the proportion of heifers selected/treated [400: 82.1 (165/201) vs. 500: 83.8 (165/197) vs. 600: 87.2% (171/196), P<0.05], pregnant/transferred [400: 51.8 (85/164) vs. 500: 44.1 (71/161) vs. 600: 49.4% (84/170), P<0.05], pregnant/treated [400: 42.3 (85/201) vs. 500: 36.0 (71/197) vs. 600: 42.9% (84/196), P<0.05] and proportion of recipients with larger single CL [400: 46.8 (65/139) vs. 500: 54.9 (73/133) vs. 600: 57.4 (66/115), P<0.05]. The animals that received 600 IU eCG presented higher CL number than those received 400 and 500 IU (400: 1.17 ± 0.03 vs. 500: 1.33 ± 0.06 vs. 600: 1.82 ± 0.12, P<0.05). In a subset of heifers that was performed a plasma P4 determination, the group that received eCG on day 5 presented higher plasmatic P4 concentration than those received eCG on day 8 (4.68 ± 0.43 vs. 2.73 ± 0.17 ng/ml, P<0.05). The use of 600 IU eCG presented higher plasmatic P4 concentration than 500 and 600 IU (400: 2.96 ± 0.22 vs. 500: 3.45 ± 0.38 vs. 600: 4.69 ± 0.55, P<0.05). Recipients with more than 1 CL tended to present lower pregnancy losses between 30 and 60 days than those with a single CL [10.2 (4/49) vs. 17.5% (33/189), P=0.0547]. The results suggest higher efficiency in the synchronization of ovulation protocol for fixed-time embryo transfer with eCG administration on day 5. The dose of eCG did not affect the efficiency of treatment

Este estudo avaliou os efeitos da administração de diferentes doses de eCG em dois momentos distintos no protocolo de sincronização da ovulação para inovulação em tempo fixo. No dia 0, as receptoras foram tratadas com dispositivo intravaginal contendo progesterona (DIP) e 2,0 mg de Benzoato de Estradiol (BE) associados a 50 mg de progesterona (P4) IM. A partir desse momento, os animais foram divididos homogeneamente para receberem 0,15 mg de d-cloprostenol (PGF2&#945;) e 400, 500 ou 600 UI de eCG no dia 5 (G-400d5, n=101; G-500d5, n=98; G-600d5, n=100, respectivamente) ou no dia 8 (G-400d8, n=100; G-500d8, n=99; G-600d8, n=96, respectivamente; fatorial 3x2). O DIP foi retirado no dia 8 e foi administrado 1 mg de BE no dia 9. No dia 17 os animais foram submetidos a ultra-sonografia ovariana e os que apresentaram mais que um corpo lúteo (CL) ou CL único maior que 18 mm de diâmetro receberam um embrião produzido in vitro. Em um grupo de animais, colheu-se amostras de sangue no dia 17 para determinação da concentração plamática de P4 (CPP4). Os animais tratados com eCG no dia 5 apresentaram maior taxa de aproveitamento [87,0 (260/299) vs. 81,7% (241/295), P<0,05], tendência de maior taxa de concepção [51,8 (132/255) vs. 45,0% (108/295), P=0,07], maior taxa de prenhez [44,1 (132/299) vs. 36,6% (108/295), P<0,05], maior número de CL (1,74 ± 0,09 vs. 1,13 ± 0,03, P<0,05) e maior proporção de receptoras com CL único de maior tamanho [CL 22: 65,7 (111/169) vs. 43,1% (94/218), P<0,05] que os tratados no dia 8. Não se observou efeito de dose sobre a taxa de aproveitamento [400: 82,1 (165/201) vs. 500: 83,8 (165/197) vs. 600: 87,2% (171/196), P<0,05], de concepção [400: 51,8 (85/164) vs. 500: 44,1 (71/161) vs. 600: 49,4% (84/170), P<0,05], de prenhez [400: 42,3 (85/201) vs. 500: 36,0 (71/197) vs. 600: 42,9% (84/196), P<0,05] e sobre a quantidade de receptoras com CL único de maior tamanho [400: 46,8 (65/139) vs. 500: 54,9 (73/133) vs. 600: 57,4 (66/115), P<0,05]. Os animais tratados com 600 UI de eCG apresentaram maior número de CL que os que receberam 400 ou 500 UI (400: 1,17 ± 0,03 vs. 500: 1,33 ± 0,06 vs. 600: 1,82 ± 0,12, P<0,05). No grupo que se determinou a CPP4 verificou-se que os animais que receberam eCG no dia 5 apresentaram maiores CPP4 que os do dia 8 (4,68 ± 0,43 vs. 2,73 ± 0,17 ng/ml, P<0,05). As novilhas tratadas com 600 UI de eCG apresentaram maiores CPP que as tratados com 400 ou 500 UI (400: 2,96 ± 0,22 vs. 500: 3,45 ± 0,38 vs. 600: 4,69 ± 0,55, P<0,05). Receptoras com mais de 1 CL apresentaram tendência de menores perdas gestacionais entre 30 e 60 dias de gestação que as com CL único [10,2 (4/49) vs. 17,5% (33/189), P=0,0547]. Os resultados são indicativos de maior eficiência do protocolo de sincronização da ovulação para transferência de embriões em tempo fixo com o uso de eCG no dia 5. A dose de eCG não influenciou na eficiência do tratamento / The aim of this study was to compare the effects of different doses of eCG administrated at two moments in a fixed-time embryo transfer protocol. On day 0, the heifers received a progesterone releasing vaginal insert (PRVI) and an injection of 2.0 mg Estradiol Benzoate (EB) associated with 50 mg progesterone (P4) i.m. The animals were randomly assigned to six treatment groups in a tree by two factorial design to receive 0.15 mg d-cloprostenol (PGF2&#945;) i.m. and 400, 500 or 600 IU eCG on day 5 (G-400d5, n=101; G-500d5, n=98; G-600d5, n=100, respectively) or on day 8 (G-400d8, n=100; G-500d8, n=99; G-600d8, n=96, respectively). On day 8, the PRVI was removed and an injection of 1 mg EB was administered on day 9. On Day 17, all heifers were examined by ultrasonography to determine the number of CL and those with more than one CL or a single CL with a diameter ?18 mm received an in vitro produced embryo. A subset of heifers were bled on day 17 for plasma P4 determination. The animals treated with eCG on day 5 presented higher proportion of heifers selected/treated [87.0 (260/299) vs. 81.7% (241/295), P<0.05], tendency to higher proportion of heifers pregnant/transferred [51.8 (132/255) vs. 45.0% (108/295), P<0.1], higher proportion of heifers pregnant/treated [44.1 (132/299) vs. 36.6% (108/295), P<0.05], higher CL number (1.74 ± 0.09 vs. 1.13 ± 0.03, P<0.05) and higher proportion of recipients with larger single CL [CL 22: 65.7 (111/169) vs. 43.1% (94/218), P<0.05] than those treated with eCG on day 8. Dose effects were not observed in the proportion of heifers selected/treated [400: 82.1 (165/201) vs. 500: 83.8 (165/197) vs. 600: 87.2% (171/196), P<0.05], pregnant/transferred [400: 51.8 (85/164) vs. 500: 44.1 (71/161) vs. 600: 49.4% (84/170), P<0.05], pregnant/treated [400: 42.3 (85/201) vs. 500: 36.0 (71/197) vs. 600: 42.9% (84/196), P<0.05] and proportion of recipients with larger single CL [400: 46.8 (65/139) vs. 500: 54.9 (73/133) vs. 600: 57.4 (66/115), P<0.05]. The animals that received 600 IU eCG presented higher CL number than those received 400 and 500 IU (400: 1.17 ± 0.03 vs. 500: 1.33 ± 0.06 vs. 600: 1.82 ± 0.12, P<0.05). In a subset of heifers that was performed a plasma P4 determination, the group that received eCG on day 5 presented higher plasmatic P4 concentration than those received eCG on day 8 (4.68 ± 0.43 vs. 2.73 ± 0.17 ng/ml, P<0.05). The use of 600 IU eCG presented higher plasmatic P4 concentration than 500 and 600 IU (400: 2.96 ± 0.22 vs. 500: 3.45 ± 0.38 vs. 600: 4.69 ± 0.55, P<0.05). Recipients with more than 1 CL tended to present lower pregnancy losses between 30 and 60 days than those with a single CL [10.2 (4/49) vs. 17.5% (33/189), P=0.0547]. The results suggest higher efficiency in the synchronization of ovulation protocol for fixed-time embryo transfer with eCG administration on day 5. The dose of eCG did not affect the efficiency of treatment

O presente experimento foi realizado com o objetivo de avaliar o impacto da inseminação artificial em tempo fixo (IATF) na eficiência reprodutiva de vacas de leite de alta produção inseminadas no período pós-parto. Vacas Holandesas com média de 50 dias pós-parto foram distribuídas homogeneamente em um de dois grupos experimentais, levando em consideração a presença ou ausência de corpo lúteo (CL), o escore de condição corporal e a produção de leite. No grupo Controle (G-Controle; n = 490), as vacas foram submetidas à observação do comportamento de aceitação de monta (duas vezes ao dia por uma hora) e inseminadas 12 horas após a primeira detecção. No grupo IATF (G-IATF; n = 495), as vacas receberam um implante auricular de norgestomet, mantido por oito dias, e 2 mg de benzoato de estradiol IM no dia 0 (D0; dia aleatório do ciclo estral). No momento da retirada do implante (D8) foram administrados 150 &micro;g de prostaglandina F2&alpha;, 400 UI de gonadotrofina coriônica eqüina e 1 mg de cipionato de estradiol. A IATF foi realizada de 54 a 56 h após a retirada do implante auricular, concomitante à administração de 100 &micro;g de gonadorelina. Após a IATF, as vacas foram submetidas à observação de cio com subseqüente inseminação, seguindo os mesmos critérios descritos para o G-Controle. Amostras de sangue foram colhidas de um subgrupo de animais (G-Controle, n = 50; G-IATF, n = 58) 5 e 11 dias após a primeira inseminação artificial (IA) para dosagem de progesterona (P4) circulante. Todos os animais foram mantidos no experimento até a terceira IA ou 150 dias após o parto e os tratamentos foram realizados no inverno e no verão. O diagnóstico de gestação foi realizado aos 30 dias pós-IA por ultrassonografia e aos 60 dias pós-IA por palpação transretal. Os dados binomiais foram analisados por regressão logística utilizando o PROC GLIMMIX e as variáveis contínuas por ANOVA utilizando PROC GLM do SAS. Não se verificou interação entre estação do ano e tratamento na análise das taxas de concepção, perda gestacional, intervalo entre IAs, intervalo parto-concepção (IPC) e taxa de prenhez aos 150 dias pós-parto. Os resultados são indicativos de que não existem diferenças nas taxas de concepção entre os diferentes grupos após as IAs (primeira, segunda e terceira). A perda gestacional relativa à primeira IA foi maior nas vacas do G-IATF. Os intervalos parto-primeira IA, parto-segunda IA e parto-concepção foram inferiores para as vacas do G-IATF. Entretanto, o intervalo entre a primeira e a segunda IA foi maior para o G-IATF. Não houve diferença na taxa de prenhez aos 150 dias entre os grupos. Ainda, a taxa de serviço (TS) nos primeiros 21 dias após o período voluntário de espera (PVE) foi maior para o grupo IATF. Entretanto, a TS entre 21 e 42 dias após o PVE foi maior para o G-Controle. As concentrações circulantes de P4 não diferiram entre os grupos e as estações do ano. Concluiu-se que o emprego da IATF 60 dias pós-parto foi eficiente para diminuir o IPC. Contudo, a porcentagem de vacas prenhes aos 150 pós-parto foi semelhante entre os dois tratamentos (Controle e IATF) / The aim of the present study was evaluate the impact of fixed-time artificial insemination (FTAI) on reproductive efficiency of high-producing dairy cows inseminated during the postpartum period. Holstein cows with average 50 days in milk were allocated to one of two groups considering the presence or absence of corpus luteum (CL), body condition score and milk production. On Control group (Control-G; n = 490), the cows were submitted to estrus detection twice per day for one h and were inseminated 12 hours after the first detection. On FTAI group (FTAI-G; n = 495), the cows received a norgestomet ear implant (kept for eight days) plus administration of 2 mg of estradiol benzoate i.m. on Day 0 (random day of the estrous cycle). The implant was removed on Day 8 followed by FTAI 54 to 56 h later and the administration of 100 &micro;g of gonadorelin. On Day 8, cows received 400 IU eCG, 150 &micro:g of prostaglandin F2&alpha; and 1 mg of estradiol cypionate. After FTAI, cows were submitted to estrus detection and artificial insemination (AI) 12 h after. Blood samples were collected from a subset of animals (Control-G, n = 50; FTAI-G, n = 58) on Day 5 and 11 after the first AI to investigate serum progesterone concentration (P4). All animals were maintained on the experiment until 150 days post-partum and the treatments were conducted during the winter and summer. Pregnancy diagnosis was performed by ultrasonography 30 days after AI (Day 30) and by rectal palpation 60 days after AI (Day 60). Binomial data were analyzed by logistic regression using the PROC GLIMMIX and continuous variables by ANOVA using PROC GLM of SAS. No interaction was found between season and treatment when conception rate, pregnancy loss, interval between inseminations, interval from calving to conception and pregnancy rate 150 post-partum were analysed. The results indicate no differences on conception rate among both experimental groups after AI (first, second and third). However, the interval from calving to first and second AI and interval from calving to conception were lower on FTAI-G. No difference on pregnancy rate 150 days post-partum was found among groups. Pregnancy loss after first AI was greater on FTAI-G. The interval from calving to first AI, from calving to second AI and the interval from calving to conception were shorter on FTAI-G. However, the interval between first and second AI was longer on FTAI-G. There was no difference on pregnancy rate 150 days post-partum among treatments. Also, the service rate (SR) 21 days after the voluntary waiting period (VWP) was greater on FTAI-G compared to Control-G. Conversely, the SR was lower between 21 and 42 days after the VWP on FTAI-G. No difference was found in serum concentration of P4 among treatment groups and season. Thus, the use of FTAI 60 days post-partum was efficient to anticipate the conception of high-producing dairy cattle by reducing the interval from calving to conception, but did not increase the pregnancy rate 150 days post-partum