Low versus high antral follicle count on the fertility of timed AI Nelore heifers / Baixa versus alta contagem de folículos antrais na fertilidade de novilhas Nelore inseminadas em tempo-fixo

This study aimed to determine the effect of antral follicle count (AFC), and pubertal status on the fertility of beef heifers. In this study, 230 Nelore heifers, 20±2 months of age, were subjected to an estradiol progesterone-based timed artificial insemination (TAI) program. On Day 0 of the TAI protocol, the heifers were examined by transrectal ultrasound to record videos of the ovaries. Later, in the darkroom of the laboratory of images, the videos were analyzed for AFC (≥ 3 mm) of each ovary. Females who failed the first TAI were resynchronized with the same hormonal protocol. The pregnancy status was evaluated by ultrasonography 30 days after each FTAI. The general mean of the AFC was 22.0 follicles. Thus, the heifers were divided into 2 groups according to AFC: Low AFC (˂ 22 follicles, n = 114), and High AFC (≥ 22 follicles, n = 116). No differences (P > 0.05) in the pregnancy per AI (P/AI) were observed between the Low and High AFC groups, and between pubertal and prepubertal categories. The P/AI was not different between heifers that displayed or did not estrus (P = 0.2). However, considering the estrus response of each AFC group, High AFC heifers that displayed estrus had greater P/AI (P = 0.01) than High AFC heifers that did not display estrus. In summary, AFC and pubertal status did not affect the fertility of Nelore heifers. In contrast, the P/AI of heifers that did not display estrus was lower than heifers observed in estrus only in the High AFC group.(AU)

Esse estudo teve como objetivo determinar o efeito da contagem de folículos antrais (CFA) e da maturidade sexual na fertilidade de novilhas de corte. Neste estudo, 230 novilhas Nelore, com 20 ± 2 meses de idade, foram submetidas a um protocolo de inseminação em tempo-fixo (IATF) a base de estradiol e progesterona. No Dia 0 do protocolo de IATF as novilhas foram examinadas por ultrassonografia transretal e vídeos dos ovários foram gravados para posterior CFA (≥ 3 mm) realizada na sala escura do laboratório de imagens. Trinta dias após a ultrassonografia, as fêmeas que falharam na primeira IATF foram ressincronizadas com o mesmo protocolo hormonal. A prenhez foi avaliada por ultrassonografia 30 dias após cada IATF. A média geral da CFA foi de 22 folículos; assim, as novilhas foram divididas em 2 grupos de acordo com a CFA: CFA baixa (˂ 22 folículos, n=114) e CFA alta (≥ 22 folículos, n=116). A prenhez por IA (P/IA) foi semelhante (P > 0,05) entre os grupos CFA baixa e alta e entre novilhas púberes e pré-púberes. A P/IA não foi diferente entre as novilhas que apresentaram ou não cio (P = 0,2). No entanto, novilhas com CFA alta que apresentaram cio tiveram maior P/IA (P = 0,01) do que novilhas com CFA alta que não apresentaram cio. Em conclusão, a CFA e a maturidade sexual não afetaram a fertilidade de novilhas. Por outro lado, a P/IA das novilhas que apresentaram cio foi maior do que das novilhas não observadas em cio apenas no grupo CFA alta.(AU)

Use of estradiol cypionate to induce ovulation in buffalo raised in floodplain areas of Itacoatiara, Amazonas / [Uso do cipionato de estradiol na indução da ovulação de búfalas criadas em várzea da região de Itacoatiara, Amazonas]

This study aimed to determine the efficiency of estradiol cypionate (EC) as an ovulation inducer in a Timed Artificial Insemination protocol. 69 buffalo cows received an intravaginal progesterone device and 2mg of estradiol benzoate (EB) at D0. On D9, the intravaginal device was removed and 0.53mg of prostaglandin (PGF2α) and 400UI of equine chorionic gonadotrophin (eCG) were applied. The cows were distributed into two groups: the first group received 1mg of EC (ECG) in D9, and the second group received 1mg of EB (EBG) in D10. Inseminations occurred on D11. Ovarian activity and pregnancy diagnosis were analyzed by ultrasonography. There was no difference (P>0.05) in follicular diameter (9.6 ± 0.89mm vs. 10.7 ± 1.12mm; P=0.06), in ovulation rate (90.9% vs. 90.9%; P=1) and pregnancy rate (58.8% vs. 62.9%; P=0.79), however, buffalo cows from the ECG treatment have less time between P4 removal and ovulation when compared to EBG buffalos (37.4h vs. 52.8h; P=0.001), respectively. Thus, it was concluded that the implantation of TAI in the floodplain of Amazonas is feasible and the use of EC results in successful rates, similar to EB.(AU)

O objetivo deste trabalho foi determinar a eficiência do cipionato de estradiol (CE) como indutor de ovulação em um protocolo de inseminação artificial de tempo fixo. Para isso, 69 búfalas receberam no D0 um dispositivo intravaginal de progesterona e 2mg de benzoato de estradiol (BE). No D9, o dispositivo intravaginal foi removido e foram aplicados 0,53mg de prostaglandina (PGF2α) e 400UI de gonadotrofina coriônica equina (eCG), para, então, os animais serem divididos em dois grupos: um deles (GCE) recebeu 1mg de CE no D9, e o outro (GBE) recebeu 1mg de BE 24h após. As inseminações ocorreram no D11. A atividade ovariana e o diagnóstico de prenhez foram avaliados por ultrassonografia. Não houve diferença (P>0,05) no diâmetro folicular (9,6 ± 0,89mm vs. 10,7 ± 1,12mm; P=0,06), na taxa de ovulação (90,9% vs. 90,9%; P=1) e na taxa de prenhez (58,8% vs. 62,9%; P=0,79), no entanto búfalas do tratamento GCE apresentaram menor tempo entre a remoção da P4 e a ovulação, quando comparadas com as búfalas do GBE (37,4h vs. 52,8h; P=0,001), respectivamente. A implantação da IATF nas várzeas do Amazonas é viável e a utilização do CE resulta em taxas de sucesso similares ao BE.(AU)

Influence of transcervical infusion of seminal plasma on the farrowing rate and litter size in artificially inseminated sows / [Influência da infusão transcervical de plasma seminal na taxa de partos e tamanho da ninhada em porcos inseminados artificialmente]

Recent studies have focused on the use of seminal plasma to increase sow fertility after classical intracervical artificial insemination (AI). The aim of the present study was to investigate the influence of seminal plasma infusion, prior to the application of conventional AI dose, on the fertility rate in sows. A total of 114 sows were treated with intrauterine infusion of 30ml seminal plasma (SP), while 114 control sows were infused by physiological solution (PS), immediately before the application of conventional AI dose. The experiment was conducted at one commercial pig farm in Serbia, which is comprised of 1,500 sows in the breeding herd. Intrauterine infusion of seminal plasma produced significantly (P<0.05) higher farrowing rate (93.8%) and significantly (P<0.01) more live-born piglets per litter (12.27), compared with the control sows (83.33% farrowing rate and 10.48 piglets). The present results show that intrauterine infusion of seminal plasma can be a useful tool for increasing the fertility rate in artificially inseminated sows, under the conditions of practical intensive pig production.(AU)

Estudos recentes concentraram no uso de plasma seminal para aumentar a fertilidade de porcos após inseminação artificial intracervical clássica (AI). O objetivo do presente estudo foi investigar a influência da infusão de plasma seminal, antes da aplicação da dose de AI convencional, na taxa de fertilidade de porcas. 114 porcas foram tratadas com infusão intrauterina de 30ml plasma seminal, e 114 porcas de controle receberam infusão de solução fisiológica (PS) imediatamente antes da aplicação da dose convencional de AI. O experimento foi realizado em uma fazenda de porcos comercial na Serbia, que é composta de 1.500 porcas no rebanho de reprodução. A infusão intrauterina de plasma seminal produziu uma taxa de fertilidade (93,8%) significativamente maior (P<0.05), e significativamente mais (P<0.01) leitões nascidos vivos por ninhada (12,27) comparado com as porcas de controle (83,33% taxa de fertilidade e 10,48 leitões). Os resultados mostram que infusão intrauterina com plasma seminal pode ser uma ferramenta útil para aumentar a taxa de fertilidade em porcas inseminadas artificialmente, sob as condições de prática de produção intensiva de porcos.(AU)

Influência da dificuldade de inseminação, temperamento e cortisol plasmático sobre a taxa de concepção de vacas e novilhas da raça Nelore inseminadas em tempo fixo / Influence of difficulty of insemination, temperament and plasma cortisol on conception rate of Nelore cows and heifers in timed AI

O objetivo do presente experimento foi avaliar efeito do estresse e da dificuldade de inseminação (DifIA) sobre a taxa de concepção (TC) de vacas (n=93) e novilhas (n= 72) Nelore submetidas à IATF. No D9, anotou-se nota de temperamento (NTe) e tempo da saída do brete (TSB) de todos os animais e coletou-se sangue das novilhas. No dia da IATF (D11), anotou-se NTe, TSB, DifIA e tempo de IA. A TC foi 36% para vacas e 46% para novilhas (P>0,05). Não foi observado efeito de Nte sobre TC (P>0,05). Porém, houve tendência para maior (P<0,10) TC nos animais que não apresentaram dificuldade de inseminação (DifIA1; TP=42%) em comparação aos animais com moderada ou alta dificuldade (DifIA2+DifIA3; TP=27%). Foi observado menor (P<0,05) tempo de IA para animais DifIA1 (17:31±06:02s) que animais DifIA2-3 (30:10±15:45s). Novilhas com maiores (P<0,05) níveis de cortisol apresentaram maior NTe (P<0,05). Entretanto, TC (59%) das novilhas menos reativas (cortisol=4,12±1,12ng/mL; NTe=3,2±0,6) não diferiu da TC (41%; P>0,05) das mais agitadas (cortisol=7,76±1,33ng/mL; NTe=3,82±0,79). Concluiu-se que avaliações de temperamento se relacionaram com nível de estresse, embora esses parâmetros não tenham afetado a TC deste trabalho. A maior dificuldade e/ou tempo necessário para se completar a IA demonstrou ser um potencial fator para a redução da fertilidade na IATF.(AU)

The objective was to evaluate the influence of stress and difficulty of insemination (DifIA) on conception rate (CR) of Nellore cows (n= 93) and heifers (n= 72) in Timed-AI. On D9, temperament (NTe) and time for chute exit (TSB) were recorded for all animals, and blood samples were colected from heifers. On the day of Timed-AI (D11), NTe, TSB, DifIA and time for AI were recorded. For cows, CR was 36% and for heifers 46% (P> 0.05). No effect (P> 0.05) of NTe was observed on CR. However, a tendency (P< 0,10) for higher CR was observed in animals with no difficulty for insemination (DifIA1; CR=42%) compared to animals that presented moderate or high difficulty (DifIA2+DifIA3, CR=27%). Time required for AI was lower (P< 0.05) in animals DifIA1 (17:31±06:02sec) than in animals DifIA2-3 (30:10±15:45sec). Heifers with greater (P< 0.05) cortisol levels presented higher Nte (P< 0.05). However, CR (59%) of less reactive heifers (cortisol=4,12±1,12ng/mL; NTe=3,2±0,6) did not differ from CR (41%; P> 0.05) of stressed animals (cortisol=7,76±1,33ng/mL; NTe=3,82±0,79). It was concluded that assessments of temperament were related to stress level, although these parameters did not affect the CR of this study. However, the higher difficulty and/or time to complete AI showed to be a potential factor for reducing fertility after timed-AI.(AU)

Development of fixed-time artificial insemination protocols for locally adapted Curraleiro Pé-Duro cows / Desenvolvimento de protocolos de inseminação artificial em tempo fixo em vacas da raça localmente adaptada Curraleiro Pé-Duro

Two experiments were conducted aiming to evaluate the effects of two ovulatory inducers (Exp.1) and equine chorionic gonadotropin (eCG; Exp.2) on follicular and luteal dynamics in a fixed-time AI (FTAI) protocol in locally adapted Curraleiro Pé-Duro cows. In Exp. 1 multiparous cows (n=12) received an intravaginal device containing 1g of progesterone (P4) for 8 days and 2mg of estradiol benzoate (EB) intramuscularly (IM) at device insertion (Day 0). At device removal (Day 8) 0.150mg of Sodium D-Cloprostenol was administered IM and the cows were randomly assigned to receive 1mg of EB (EB8) or 1mg of estradiol cypionate (EC8) IM, or to not receive any ovulatory inducer (Control). All the animals participated in all treatments (crossover). The interval from P4 removal to ovulation was shorter and less variable in the EB8 treatment group (P≤0.05). In Exp. 2 (crossover), multiparous cows (n=12) received the same hormonal treatment as the EB8 group in Exp.1. At device removal (Day 8) cows were randomly assigned to receive 300UI of eCG IM or to not receive eCG (Control). No difference was ascertained on follicular and luteal parameters in Exp. 2 (P>0.05). We concluded that EB can be used as the ovulatory inducer (Exp. 1) in a FTAI protocol in Curraleiro Pé-Duro cows. However, eCG (Exp. 2) was not able to stimulate follicular and luteal development. This result is probably due to the adaptive capacity of Curraleiro Pé-Duro cows that maintained a satisfactory body condition score even in dry and hot environments.(AU)

Foram realizados dois experimentos com o objetivo de avaliar o efeito de dois indutores da ovulação e da gonadotrofina coriônica equina (eCG) na dinâmica folicular e luteal, em um protocolo de inseminação artificial em tempo fixo (IATF) em vacas localmente adaptadas da raça Curraleiro Pé-Duro. No experimento 1, vacas pluríparas receberam um dispositivo intravaginal contendo 1g de progesterona (P4) durante oito dias e 2mg de benzoato de estradiol (BE) intramuscular (IM) no momento da inserção do dispositivo (dia zero). Na retirada do dispositivo (dia oito), as vacas receberam 0,150mg de D-cloprostenol sódico IM e foram separadas aleatoriamente para receber 1mg de BE IM (BE8) ou 1mg de cipionato de estradiol IM (CE8), ou nenhum indutor da ovulação (controle). Todos os animais participaram de todos os tratamentos (crossover). O intervalo entre a retirada da P4 e a ovulação foi menor e menos variável no tratamento BE8 (P≤0,05). O momento da ovulação foi mais precoce e mais concentrado nos animais do grupo BE 8. No experimento 2 (crossover), vacas pluríparas receberam o mesmo tratamento hormonal do grupo BE8 do experimento1. Na retirada do dispositivo (dia 8), as vacas foram separadas aleatoriamente para receberem 300UI de eCG IM, enquanto o controle não. Não houve diferença nos parâmetros foliculares e luteais avaliados no experimento 2 (P>0,05). Em conclusão, o BE pode ser utilizado como indutor da ovulação (experimento 1) em protocolos de IATF em vacas Curraleiras Pé-Duro. Entretanto, o eCG (experimento 2) não foi capaz de estimular o desenvolvimento folicular e luteal. Esse resultado é devido provavelmente à capacidade adaptativa das vacas Curraleiras Pé-Duro em manter uma condição corporal satisfatória mesmo em condições de clima seco e quente.(AU)

Effect of pertubation on pregnancy rates before intrauterine insemination treatment in patients with unexplained infertility

The aim of this study was to determine the relationship between marital violence and distress level among women with a diagnosis of infertility. In this prospective randomized study, a total of 180 patients were included in the study. Amongst these, pertubation of the uterine cavity was carried out in 79 patients prior to insemination. One patient in the pertubation group was later excluded because insemination could not be performed due to cycle cancellation. There were no significant differences in demographic characteristics between the study and control groups. When the pregnancy rates of both groups were evaluated, 14[17.8%] patients in the study group achieved pregancy. Three [3.8%] had a biochemical pregnancy, 1[1.3%] miscarried and 10[12.7%] had live births. In the control group, a total of 24[23.8%] pregnancies were achieved, amongst which one [1%] had a biochemical pregnancy, 3[3%] miscarried and 20[19.8%] resulted in live births. There was no significant difference between groups in terms of total pregnancy and live birth rates [p>0.05]. There was a 21% total pregnancy loss rate. There was no significant difference between the control and study groups in terms of pregnancy loss rates [p>0.05]. This study on a homogenous group of unexplained infertile patients determined that the addition of pertubation to a controlled ovarian hyperstimulation plus intrauterine insemination [COH+IUI] treatment protocol did not affect pregnancy rates

Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination

Synchronization of estrus and ovulation are of paramount importance in modern livestock improvement programs. These methods are critical for assisted reproduction technologies, including artificial insemination and embryo transfer, that can increase productivity. In the current study, subcutaneous implants containing norgestomet were placed for long (14 days), medium (9 days), and short (5 days) periods of time in 70 crossbred ewes undergoing fixed-time artificial insemination. The resulting effects on estrus synchronization and conception rates were subsequently evaluated. Among the synchronized ewes, 85.7% (60/70) underwent estrus over a period of 72 h after progestagen treatment ceased. The shortest mean interval between withdrawal of the device and onset of estrus (34.2 +/- 8.9 h) was observed in the G14 days of P4 group (p < 0.05). The conception rate of the G14 days of P4 group was statistically higher than that of the other groups (83.3% vs. 60.9% vs. 47.8%; p < 0.05). In conclusion, 14 days of norgestomet treatment produced higher conception rates and a greater number of pregnancies at the beginning of the breeding season.

Brote de influenza A (H1N1) humano en pavos en un criadero comercial, Valparaíso, Chile: 2009 / Outbreak of human A (H1N1) influenza in turkeys of a commercial poultry farm, Valparaiso, Chile: August 2009

The Chilean Ministry of Health (MINSAL) led an investigation to identify associated factors to human influenza A (H1N1) infection in turkeys from poultry farms, Valparaíso. The Agriculture and Livestock Farming Service (SAG) informed the detection of influenza A (low pathogenicity) in turkeys and the Public Health Institute (ISP) confirmed influenza A (H1N1).The study included 100% of operative wards: 31% presented positive event (influenza A (H1N1)); 60% if considered only reproductive wards. Dissemination and dispersion velocity of 13 wards in 18 days evidenced a continuous common source. Interviews were performed to 89% of workers of whom 20% presented influenza-like disease: 26% from reproductive wards and 4% from raising and rearing farms. Of15 risk factors studied insemination and age in females showed statistically significant RR in low oviposition index wards. A man-bird transmission is proposed, through direct transmission of saliva during manual insemination or indirect transmission through contaminated semen. To the authors, this is the first turkey 2009 influenza H1N1 outbreak detected worldwide,in this case with a documented cloacal transmission path.

El MINSAL lideró una investigación para identificar factores asociados a infección por influenza A(H1N1) en pavos de planteles avícolas, Valparaíso. El Servicio Agrícola Ganadero informó la detección de influenza A (baja patogenicidad) en pavos y el ISP confirmó influenza A(H1N1). El estudio incluyó 100% de los pabellones operativos: 31% presentó evento positivo (influenza A(H1N1); 60% al considerar sólo pabellones de reproducción. La diseminación y velocidad de dispersión de 13 pabellones en 18 días evidenció una fuente común continua. Se entrevistó a 89% de los trabajadores y 20% presentó ETI: 26% de pabellones de reproducción y 4% de granjas de cría y recría. De 15 factores analizados, inseminación y edad de las hembras mostraron RR estadísticamente significativos en los planteles con baja ovipostura. Se plantea transmisión hombre-ave directa por saliva en inseminación manual o transmisión indirecta por semen contaminado. Es el primer brote de influenza A(H1N1) 2009 en pavos detectado en el mundo y que se comprueba vía de transmisión cloacal.

Inseminación intrauterina / Intrauterine insemination

La Inseminación Intrauterina (IIU) es un procedimiento utilizado para el tratamiento de la infertilidad. En la actualidad las dos principales indicaciones para la IIU son el factor masculino leve y la infertilidad de causa desconocida. Los resultados obtenidos de la medicina basa en evidencias recomiendan que la IIU se realice en ciclos estimulados, en los cuales se gatille la ovulación con Gonadotropina Coriónica humana (hCG) y se suplemente la fase lútea con progesterona. Igualmente, se recomienda una monitorización ecográfica del crecimiento folicular y la realización de dos inseminaciones por cada ciclo de tratamiento. Para realizar la IIU se requiere de la indemnidad anatómica de los genitales internos de la mujer y de una separación espermática > 1,0 - 1,5 millones de espermatozoides conmotilidad progresiva. Las evidencias muestran que las mejores probabilidades de embarazo se producen cuando la mujer es menor de 35 años y la infertilidad es menor a cinco años. Nuestra tasa global de embarazo por ciclo con IIU en parejas infértiles es de 14,1 por ciento. Por otro lado, la tasa cumulativa de embarazo con IIU no recomienda realizar más de 4 a 6 ciclos de tratamiento, ya que las posibilidades de éxito después de ese tiempo son mínimas.

Intrauterine insemination (IUI) is procedure used for the treatment of infertility. At present, there are two principal indications for IUI: mild male factor and unexplained infertility. Results obtained through evidence based medicine, recommend IUI to be performed in stimulated cycles, triggering ovulation with human Chorionic Gonadotrophin (hCG) and giving a luteal phase supplementation with Progesterone. Ultrasound monitoring of the follicular growth and two inseminations per treatment cycle, are also recommended. In order to perform an IUI, a normal woman internal genital tract and a sperm count > 1,0 - 1,5 million with progressive motility after sperm preparation, are required. Evidence suggests that pregnancy is more likely in women less than 35 years and with infertility of 5 years, at the most. Our overall pregnancy rate per cycle with IUI in infertile couples is 14.1 percent. On the other hand, the cumulative pregnancy rate with IUI does not recommend performing more than 4 to 6 treatment cycles, since the probability of success after that is minimal.

Serum progesterone concentration and conception rate of beef cows supplemented with ground corn after a fixed-time artificial insemination protocol / Concentração sérica de progesterona e taxa de concepção em vacas de corte suplementadas com milho moído após inseminação artificial em tempo fixo

The effects of different levels of finely ground corn (FC) supplementation to grazing beef cows after fixed-time AI (TAI) on serum progesterone (P4) concentrations on day 7 and conception rates on day 28 after TAI were investigated. Three hundred and sixty-four lactating multiparous Brangus cows had follicular and luteal activity synchronized by treatment with estradiol benzoate (Estrogin; 2.0mg IM) and insertion of intra-vaginal P4 releasing device (CIDR) on day -11, followed by treatment with PGF2α (Lutalyse; 25mg IM) on day -4, CIDR and calf removal on day -2, and treatment with GnRH (Fertagyl; 100µg IM) TAI and calf return on day 0. On day 0, cows were randomly allotted in one of the following FC supplement treatments: G1 - 2kg/day from day 0 to 21; G2 - 2kg/day from day 0 to 7, and 6kg/day from day 8 to 21; G3 -6kg/day from day 0 to 7, and 2kg/day from day 8 to 21; and G4 -6kg/day from day 0 to 21. Blood samples were collected on day 7, and pregnancy was determined by ultrasonography indicating the presence of a fetus on day 28. Cows supplemented with 2kg/d of FC had higher serum concentration of P4 on day 7 than cows supplemented with 6kg/d (1.58 vs. 1.28ng/mL; P<0.01; SEM = 0.08). Cows from G4 had higher conception rates compared to G1 cows (58.4 vs. 41.9 percent, respectively; P<0.05). The level of supplemental energy intake after TAI is negatively associated with following serum P4 concentrations, but positively associated with conception rates of grazing beef cows.

Avaliaram-se os efeitos de diferentes níveis de ingestão de suplemento com milho moído finamente (MF) em vacas de corte, mantidas em pasto, após inseminação artificial em tempo fixo (IATF), sobre a concentração sérica de progesterona (P4) no dia 7, e sobre a concepção no dia 28 pós IATF. Trezentas e sessenta e quatro vacas Brangus, multíparas lactantes, tiveram as atividades folicular e luteal sincronizadas por tratamento com benzoato de estradiol (Estrogin; 2,0mg IM) e inserção de dispositivo intravaginal de P4 (CIDR) no dia -11, seguido por tratamento com PGF2 α (Lutalyse; 25mg IM) no dia - 4, retirada do CIDR e remoção temporária de bezerros no dia -2, e tratamento com GnRH (Fertagyl; 100 µ g IM), IATF e retorno dos bezerros no dia 0. No dia 0, as vacas foram aleatoriamente distribuídas para receber um dos quatro tratamentos: G1 -2kg/dia de MF do dia 0 ao dia 21; G2 -2kg/dia de MF do dia 0 ao dia 7, e 6kg/dia de MF do dia 8 ao dia 21; G3 -6kg/dia de MF do dia 0 ao dia 7, e 2kg/dia de MF do dia 8 ao dia 21; G4 -6kg/dia de MF do dia 0 ao dia 21. Amostras de sangue foram colhidas no dia 7, e o diagnóstico de gestação foi realizado por ultrassonografia no dia 28. As vacas suplementadas com 2kg/dia de MF apresentaram maior concentração sérica de P4 no dia 7 em relação às vacas suplementadas com 6kg/dia (1,58 vs. 1,28ng/mL; P<0,01, EPM=0,08). As vacas do G4 apresentaram maior taxa de concepção em relação às vacas do G1 (58,4 vs. 41,9 por cento, respectivamente; P<0,05). O nível de consumo do suplemento energético após a IATF é negativamente associado às concentrações séricas de P4, porém positivamente associado à taxa de concepção em vacas de corte em pasto.

[ effect of two different periods of CIDR supplementation on the second service conception rate of repear breeder dairy cows]

Repeat breeding [RB] is a syndrome and several factors have been identified as its causes. Luteal insufficiency is a known cause of embryonic mortality. The aim of this study was to assess the effect of two periods of P4 therapy on the Second service and also their effects on the First plus the second service conception rates [CR] of repeat breeder dairy cows. Cows included in the study were in their first to filth lactation and had 3 to 6 unsuccessful inseminations within the current lactation. They were inseminated according to the AM/PM rule relative to estrus onset, and randomly assigned into 3 groups: [A] CIDR on day 5 after insemination that was removed on day 9 of the cycle [n=40]; [B] CIDR on days 5 after insemination that was removed on day 19 of the cycle [n=36]; and [C] untreated controls [n=40]. Pregnancy diagnosis was conducted by rectal palpation about 45 days after Al in cows no observed in estrus. The second service CR and overall CR in groups A, B and C were 61.7, 42.9.21.4 and 82.5, 66.7, 45 percent, respectively. Group A showed higher level compared to the controls [p<0.05]. In conclusion, repeat breeder cows in groups A and B benefited from progesterone supplementation, but significant effects of treatment for improvement of conception rate was seen in short term treatment [4 days treatment]

Effect of type of insemination on embryonic mortality and stillbirth in dairy cattle and heifers

The aim of this work was to evaluate the rate of embryonic mortality in early pregnancy period and rate of stillbirths at calving period in naturally and artificially inseminated dairy cattle and heifers. The study was carried out in October, 2007-November, 2008 in a cattle farm located at Alex desert road, El Behera province. Animals divided into two groups: The first one naturally inseminated [20 cows and 8 heifers]. Group two [34 cows and 12 heifers] were artificially inseminated. Pregnancy diagnosis was carried out by ultrasonography on days 28 and 35 then, confirmed rectally on day 45 post insemination. Animals that were pregnant on day 28 but not on day 35 were considered to have undergone embryonic mortality [EM]. The rate of embryonic mortality in Heifers those naturally inseminated had significant variance [p<0.05] from day 35 [0.0] to day 45[16.67%] post insemination rather than artificial insemination on day 35 [12.50%] to day 45[14.29%]. While, cows those naturally inseminated had significant variance [p<0.05] from day 35 [7.69%] to day 45[16.67%] post insemination rather than artificial insemination on day 35 [4.35%] to day 45[4.55%]. Stillbirth in calves without regarding to the type of animals [Cows or Heifers] had significant increase [p<0.05] with natural insemination [33.33%] rather than artificial insemination [22.22%]. In conclusion, the use of AI needs to be mandatory strategies in order to obtain high fertilization rates and maintenance of pregnancy in cattle and consequently lead to reduction of dystocia and improvements in calf health and survival. Future studies should attempt to biotechnologies of AI techniques as well as other traits that contribute to lifetime profitability, because precise knowledge of such parameters is needed to develop efficient and effective dairy crossbreeding systems

Avaliação da reutilização de implantes contendo progestágenos na taxa de prenhez em vacas de corte / Evaluation of used progestagen implants on pregnancy rate in beef cows

Duzentos e vinte e uma vacas (78 paridas com bezerros entre 40 e 90 dias de idade e as demais secas vazias) Nelore (Bos taurus indicus) e mestiças Charolês (Bos taurus taurus) foram utilizadas para avaliar a reutilização de implantes auriculares de silicone impregnados com progestágenos para controle farmacológico do ciclo estral e ovulação sobre a taxa de prenhez. Os tratamentos experimentais consistiram de três protocolos para sincronização do cio e inseminação artificial em tempo fixo (IATF). No tratamento 1 (T1; n=73) as vacas receberam um implante auricular de Crestar® (3 mg de norgestomet); no tratamento 2 (T2; n= 75) as vacas receberam um implante auricular de Crestar® já utilizado previamente; e no tratamento 3 (T3; n=73) as vacas receberam dois implantes auriculares de Crestar® também utilizados previamente. Além dos implantes, as vacas receberam aplicação intramuscular (i.m) 2 mL de progesterona (25 mg/mL) + 2 mL de benzoato de estradiol i.m (1 mg/mL) no momento da colocação dos implantes. Os implantes foram removidos após 8 dias junto a uma aplicação de 2,0 mL de Preloban® i.m (150 g de D-cloprostenol). Após 24 h da remoção do implante, aplicou-se 1 mL de Estrogin® i.m (1 mg de benzoato de estradiol). A IATF foi realizada 54-56 h após a retirada dos implantes. Não houve diferença na taxa de prenhez das vacas, sendo 39,72%, 34,21% e 36,98% para os tratamentos T1, T2 e T3, respectivamente. A reutilização de implantes com progestágeno (Crestar®) não alterou a taxa de prenhez de vacas aptas à reprodução.

Two-hundred and twenty-one (78 suckling - 40 to 90 days and 143 not suckling ) Nelore (Bos taurus indicus) and crossbred Charolais (Bos taurus taurus) cows were used to evaluate the reutilization of progestagen implants to pharmacological control of the estrus cycle and ovulation on pregnancy rate. Cows were randomly assigned to one of three protocols for estrous synchronization and pre-fixed time artificial insemination (FTAI) was performed. In treatment 1 (T1; n=73) cows were implanted with Crestar® (3 mg de norgestomet); in treatment 2 (T2; n= 75) cows were implanted with already used Crestar®, and in treatment 3 (T3; n=73) cows received two Crestar® implants, also both previously used. All cows were injected with 2 mL of progesterone (25mg/mL) + 1 mL estradiol benzoate (1 mg/mL i.m.) at the time of implants insertion, intramuscular (i.m). Implants were removed after 8 days and 2 mL of Preloban® (150 g de D-cloprostenol) were administered i.m. Twenty-four hours after implants removal, cows were injected with 1 mL (i.m.) of Estrogin® (1mg of estradiol benzoate). The FTAI was performed 54-56 h after implants removal. There was no difference (P>0.05) on cow’s pregnancy rate among treatments. Pregnancy rates were 39.72, 34.21 and 36.98% for T1, T2 and T3, respectively. Progestagen implants reutilization (Crestar®) did not affected pregnancy rate in beef cows ready for reproduction.

Situação epidemiológica da brucelose bovina no Estado do Espírito Santo / Epidemiological situation of bovine brucellosis in the State of Espírito Santo, Brazil

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina no Estado do Espírito Santo. O Estado foi dividido em dois circuitos produtores. Em cada circuito foram amostradas aleatoriamente cerca de 300 propriedades e, dentro dessas, foi escolhido de forma aleatória um número pré-estabelecido de animais, dos quais foi obtida uma amostra de sangue. No total, foram amostrados 5.351 animais, provenientes de 622 propriedades. Em cada propriedade amostrada foi aplicado um questionário epidemiológico para verificar o tipo de exploração e as práticas de criação e sanitárias que poderiam estar associadas ao risco de infecção pela doença. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado e o reteste dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo quando pelo menos um animal foi reagente às duas provas sorológicas. Para o Estado, as prevalências de focos e de animais infectados foram, respectivamente, de 9,0 por cento [7,0-11,6 por cento] e 3,5 por cento [1,9-6,4 por cento]. Para os circuitos, as prevalências de focos e de animais infectados foram, respectivamente, de: circuito 1, 6,8 por cento [4,5-10,2 por cento] e 3,4 por cento [1,3-8,6 por cento]; circuito 2, 10,9 por cento [7,9 por cento-14,8 por cento] e 3,7 por cento [2,1-6,3 por cento]. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: utilização de inseminação artificial (OR = 7,05 [2,51-19,82]) e confinamento/semiconfinamento dos animais (OR = 2,98 [1,22-7,26]). A vacinação de fêmeas entre três e oito meses de idade foi um fator protetor (OR = 0,03 [0,01-0,1]).

A study to characterize the epidemiological status of brucellosis was carried out in the State of Espírito Santo. The State was divided in two regions. Three hundred herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 5,351 serum samples from 622 herds were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as husbandry and sanitary practices that could be associated with the risk of infection. The serum samples were screened for antibodies against Brucella spp. by the Rose-Bengal Test (RBT), and all positive sera were re-tested by the 2-mercaptoethanol test (2-ME). The herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. The prevalence of infected herds and animals in the State were, respectively, 9.0 percent [7.0-11.6 percent] and 3.5 percent [1.9-6.4 percent]. The prevalence of infected herds and animals in the regions were, respectively: region 1, 6.8 percent [4.5-10.2 percent] and 3.4 percent [1.3-8.6 percent]; and region 2, 10.9 percent [7.9-14.8 percent] and 3.7 percent [2.1-6.3 percent]. The risk factors (odds ratio, OR) associated with the presence of the infection were: use of artificial insemination (OR = 7.05 [2.51-19.82]) and intensive/semi-intensive management systems (OR = 2.98 [1.22-7.26]). Vaccination of heifers from three to eight months of age was a protective factor (OR = 0.03 [0.01-0.1]).

Situação epidemiológica da brucelose bovina no Estado do Mato Grosso do Sul / Epidemiological situation of bovine brucellosis in the State of Mato Grosso do Sul, Brazil

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina no Estado de Mato Grosso do Sul. Foram definidos três estratos (regiões): Pantanal-corte, Planalto-corte e Planalto-leite, este último subdividido em Bolsão, Campo Grande e Dourados. Em cada estrato foram amostradas aleatoriamente propriedades e, dentro dessas, foi escolhido, de forma aleatória, um número pré-estabelecido de animais, dos quais foi obtida uma amostra de sangue. No total, foram amostrados 14.849 animais, provenientes de 1.004 propriedades. Em cada propriedade amostrada foi aplicado um questionário epidemiológico para verificar suas características e também para detectar transtornos reprodutivos que poderiam estar associados à infecção brucélica. O teste utilizado foi o do antígeno acidificado tamponado. O rebanho foi considerado positivo se pelo menos um animal foi reagente à prova sorológica. Para o Estado, a prevalência de focos foi de 41,5 por cento [36,5-44,7 por cento]. As prevalências de focos e de animais infectados por estrato foram, respectivamente, de: 59,0 por cento [52,8-64,9 por cento] e 12,6 por cento [9,1-17,2 por cento] para o estrato Pantanal-corte, e 40,6 por cento [35,8-45,5 por cento] e 4,5 por cento [2,1-9,0 por cento] para Planalto-corte. No estrato Planalto-leite, a prevalência de focos foi de 33,1 por cento [28,4-38,1 por cento]. Os fatores de risco (odds ratios, OR) associados à condição de foco foram: ter ≥500 vacas (OR = 2,46 [1,81-3,34]), ocorrência de bezerros fracos (OR = 1,20 [0,87-1,65]) e uso da inseminação artificial (OR = 0,71 [0,50-1,01]).

A study to characterize the epidemiological status of bovine brucellosis in the State of Mato Grosso do Sul was carried out. The State was divided in three regions: beef cattle Pantanal, beef cattle Plateau, and dairy cattle Plateau. Herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 14,849 serum samples from 1,004 herds were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as clinical signs that could be associated with the brucellosis infection. The serum samples were tested for antibodies against Brucella spp. by the Rose-Bengal test. The herd was considered positive if at least one animal was positive. The prevalence of infected herds in the State was 41.5 percent [36.5-44.7 percent]. The prevalence of infected herds in the regions were, respectively: 40.6 percent [35.8-45.5 percent] for beef cattle Plateau, 59.0 percent [52.8-64.9 percent] for beef cattle Pantanal, and 33.1 percent [28.4-38.1 percent] for dairy cattle Plateau. The risk factors (odds ratio, OR) associated with the presence of the infection were: herd size larger than 500 cows (OR = 2.46 [1.81-3.34]), birth of weak calf (OR = 1.20 [0.87-1.65]), and use of artificial insemination (OR = 0.71 [0.50-1.01]).

Situação epidemiológica da brucelose bovina no Estado de Sergipe / Epidemiological situation of bovine brucellosis in the State of Sergipe, Brazil

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina no Estado de Sergipe. O Estado foi estratificado em dois circuitos produtores. Em cada circuito produtor foram amostradas aleatoriamente cerca de 300 propriedades e, dentro dessas foi escolhido de forma aleatória um número pré-estabelecido de animais, dos quais foi obtida uma amostra de sangue. No total foram amostrados 4.757 animais, provenientes de 590 propriedades. Em cada propriedade amostrada foi aplicado um questionário epidemiológico para verificar o tipo de exploração da propriedade e as práticas zootécnicas e sanitárias que poderiam estar associadas ao risco de infecção pela doença. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado e a confirmação dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo, se pelo menos um animal foi reagente às duas provas sorológicas. A prevalência de focos e a de animais foram: 12,6 por cento [9,2-16,0 por cento] e 3,4 por cento [2,3-4,4 por cento], respectivamente. As prevalências de focos e de animais infectados para os circuitos pecuários foram: circuito 1, 11,1 por cento [7,9-15,0 por cento] e 2,6 por cento [1,6-3,5 por cento]; circuito 2, 12,9 por cento [9,1-17,6 por cento] e 6,2 por cento [3,0-9,5 por cento]. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: assistência veterinária (OR= 2,89 [1,15-7,23]), tamanho do rebanho ≥30 fêmeas adultas (OR= 1,88 [1,07-3,28]) e uso de inseminação artificial (OR= 1,92 [0,84-4,38]).

A study to characterize the epidemiological situation of bovine brucellosis in the State of Sergipe was carried out. The State was divided in two regions. Around three hundred herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 4,757 serum samples from 590 herds were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as husbandry and sanitary practices that could be associated with the risk of infection. The serum samples were screened by the Rose-Bengal Test (RBT) and positive sera were re-tested by the 2-mercaptoethanol test (2-ME). The herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. The prevalences of infected herds and animals in the State were, respectively: 12.6 percent [9.2-16.0 percent] and 3.4 percent [2.3-4.4 percent]. The prevalences of infected herds and animals in the regions were, respectively: region 1, 11.1 percent [7.9-15.0 percent] and 2.6 percent [1.6-3.5 percent]; and region 2, 12.9 percent [9.1-17.6 percent] and 6.2 percent [3.0-9.5 percent]. The risk factors associated with the presence of the infection were: veterinary assistance (OR= 2.89 [1.15-7.23]), herd size ≥30 adult females (OR= 1.88 [1.07-3.28]), and use of artificial insemination (OR=1.92 [0.84-4.38]).

Situação epidemiológica da brucelose bovina no Estado de São Paulo / Epidemiological situation of bovine brucellosis in the State of São Paulo, Brazil

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina no Estado de São Paulo. O Estado foi estratificado em sete circuitos produtores de bovinos, e 150 rebanhos com atividade reprodutiva foram aleatoriamente selecionados em cada um deles. No total, foram amostrados 1.073 rebanhos. Foram aletoriamente coletadas amostras de soro de 10 ou 15 fêmeas bovinas com idade ³24 meses, totalizando 8.761 animais. Os soros foram submetidos a um protocolo de testes em série, tendo o teste do antígeno acidificado tamponado como método de triagem e o da fixação de complemento como confirmatório. A prevalência estimada de rebanhos com pelo menos um animal soropositivo foi de 9,7 por cento [7,8-11,6 por cento], enquanto a prevalência estimada de animais soropositivos foi de 3,8 por cento [0,7-6,9 por cento], no Estado. Em cada rebanho foi aplicado um questionário epidemiológico para avaliar o grau de associação de possíveis fatores de risco (odds ratio, OR) com a doença. Propriedades com 87 ou mais bovinos (OR= 2,25) e compra de reprodutores (OR= 1,56) foram as variáveis mais associadas à condição de foco de brucelose.

A study to characterize the epidemiological situation of bovine brucellosis in the State of São Paulo was carried out. The state was stratified in seven cattle production regions and 150 herds with reproductive activity were randomly selected within each one. A total of 1,073 herds were sampled. In a second stage, 10 or 15 cows older than 24 month age (in herds with <100 cows and herds ≥100 cows, respectively) were bled at random. A total of 8,761 animals were bled. Sera were tested using a serial testing procedure with the Rose Bengal test as the screening method and the Complement Fixation as the confirmatory method. The estimated prevalence of herds with at least one positive animal was 9.7 percent [7.8-11.6 percent], whereas the estimated prevalence of positive cattle was 3.8 percent [0.7-6.9 percent] in São Paulo State. An epidemiological questionnaire was applied in each farm, allowing the evaluation of the association of selected risk factors with the disease. The characteristics associated with the brucellosis infected herds were farms with more than 87 bovines (OR= 2.25) and introduction of breeding cattle (OR= 1.56).

Situação epidemiológica da brucelose bovina no Estado do Tocantins / Epidemiological situation of bovine brucellosis in the State of Tocantins, Brazil

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina no Estado do Tocantins, entre fevereiro de 2002 e agosto de 2003. O Estado foi dividido em seis áreas com características produtivas homogêneas (circuitos produtores). Para cada área, foi calculada uma amostragem simples aleatória de 300 propriedades, com o objetivo de estimar a prevalência de focos de brucelose além da prevalência de fêmeas bovinas adultas soropositivas. Para isso, foram amostradas de 10 a 15 vacas com idade superior a dois anos em cada propriedade. Um total de 20.908 soros foi obtido de 1.842 propriedades. A prevalência de focos de brucelose foi de 21,2 por cento [19,3-23,1 por cento] e a prevalência de fêmeas bovinas adultas soropositivas de 4,4 por cento [3,6-5,3 por cento] para o Estado. Quando se considerou o circuito produtor, observou-se que os circuitos 1, 2, 3 e 5 tiveram prevalência de focos significativamente maior que os circuitos 4 e 6. Os resultados da prevalência nos circuitos 1, 2, 3 e 5 foram de: 16,0 por cento [12,1-20,6 por cento], 37,6 por cento [32,1-43,4 por cento], 26,4 por cento [21,5-31,7 por cento] e 29,3 por cento [24,3-34,7 por cento], respectivamente. Nos circuitos 4 e 6, foram de 5,8 por cento [3,5-9,1 por cento] e 8,6 por cento [5,7-12,2 por cento], respectivamente. Em cada propriedade, foi aplicado um questionário epidemiológico, com o objetivo de avaliar o grau de associação de possíveis fatores de risco com a doença. Os fatores de risco (odds ratio, OR) associados à condição de foco de brucelose foram: rebanho com mais de 120 vacas (OR= 2,0) e abate de reprodutores na propriedade (OR= 1,52). Vacinação contra brucelose (OR= 0,37), presença de piquete de parição (OR= 0,72) e exploração de leite (OR= 0,63) apresentaram-se como fatores de proteção.

A study was carried out to characterize the epidemiological situation of brucellosis in the State of Tocantins from February 2002 to August 2003. The State was divided into six regions with a homogeneous productive system. For each region, a simple random sample was calculated to estimate the prevalence both in farms and cows older than two-year. To achieve this, from 10 to 15 adult cows (older than two-year) were sampled. A total of 20,908 sera from 1,842 farms were obtained. For the whole State of Tocantins, the prevalence of positive farms (or farms with at least one positive animal) was 21.2 percent [19.3-23.1 percent]. When the production regions were considered, the prevalences for the regions 1, 2, 3, and 5 were: 16.0 percent [12.1-20.6 percent], 37.6 percent [32.1-43.4 percent], 26.4 percent [21.5-31.7 percent], and 29.3 percent [24.3-34.7 percent], respectively. In the regions 4 and 6, the prevalences were 5.8 percent [3.5-9.1 percent] and 8.6 percent [5.7-12.2 percent], respectively. In each visited farm, a questionnaire was applied, in order to evaluate the association between with possible risk factors and the brucellosis. The risk factors (odds ratio, OR) associated with the infected herds were number of cows above 120 (OR= 2.0) and slaughtering of breeding animals in the farm (OR= 1.52). Vaccinating against brucellosis (OR= 0.37), presence of birth pen (OR= 0.72), and dairy farm (OR= 0.63) presented as protective factors.

Efficacy of ovsynch protocol on pregnancy in lactating dairy cattle during summer season

The objective of the present work was to determine the effect of Ovsynch protocol on pregnancy rate in lactating dairy cattle subjected to synchronization of ovulation during summer season.Induction of ovulation for timed artificial insemination [TAT] with Ovsynch protocol was conducted on forty Holstein Friesian cows from a commercial dairy herd in Alexandria disert road [Dina farm],Egypt during the summer season of 2004. Animals were assigned to four groups according to lactation number: G I 1[st]lactation n=13'',G II"2[nd] lactation n=7",G III"3[rd] lactation n=14" and GIV" 4[th] lactation n=6".The mean number of days postpartum [DM] at the start of treatment was 89.38, 77.28, 90.42and 84.66 for group I, II, III and IV, respectively. The frozen-thawed semen used for AI was of good quality. Pregnancy diagnosis was checked by rectal palpation 45 to 55 d after insemination. The pregnancy rate per AI was defined as the percentage of cows that were confirmed pregnant after one AI. High pregnancy rate [50%] was recorded for animals in G IV followed by G H and G HI [42.85%]. Low pregnancy rate [30.7%] was reported in Group I .The overall pregnancy rate was 40% . r From this investigation it could be concluded that synchronization of ovulation with GnRH and PGF2 a provided an effective way to manage reproduction in lactating dairy cattle exposed to heat stress during summer

Efeito do eCG ou benzoato de estradiol associado ao norgestomet na taxa de concepção de vacas de corte submetidas à IATF no pós-parto / Effect of eCG or estradiol benzoate associated with norgestomet on the conception rate of beef cows submitted to FTAI in the postpartum

Este estudo objetivou comparar as taxas de concepção, em vacas de corte no período pós-parto (PPP), tratadas com Gonadotrofina Coriônica Eqüina (eCG) ou Benzoato de Estradiol (BE), após o uso de Norgestomet submetidas à inseminação artificial em tempo fixo(IATF). A hipótese é que a administração de eCG ou BE aumenta as taxas de concepção. Vacas Nelore (n=138) e Brangus (n=63), lactantes,entre 26 e 118 dias do PPP, foram divididas em três grupos homogêneos e dentro de cada grupo subdivididas em dois blocos, um com um PPP < 45 dias (PPP1; n=107) e outro > 45 dias (PPP2;n=94). Todas as fêmeas receberam um implante auricular contendo 3mg de Norgestomet (Crestar®), seguido pela administração de 5mg de Valerato de Estradiol. Os implantes auriculares foram mantidos durante 10 dias. Na retirada dos implantes, as fêmeas receberam 1mL de solução fisiológica (n=68; Grupo Controle) ou 500 UI de eCG (Folligon®; n=67; Grupo eCG) ou 1mg de Benzoato de Estradiol (Index; n=66; Grupo BE) 24 horas após a retirada do implante. AIATF foi realizada 54 horas após a retirada do implante. O diagnóstico de gestação foi realizado por ultra- sonografia 30 dias após a IATF. Houve interação entre os tratamentos e o PPP. No PPP1, a taxa de concepção foi maior no grupo eCG comparado ao BE (47,22% vs.15,38%; P<0,01). No PPP2, as taxas de concepção dos grupos eCG eBE foram maiores que no grupo controle (41,93%, 44,44% vs.22,22%; P<0,01). Conclui-se que vacas, com até 45 dias do PPP, o eCG associado ao Norgestomet aumenta as taxas de concepção.

This study aimed to compare conception rates at the post partum period (PPP) in beef cows which were administered either Equine Chorionic Gonadotrophin (eCG) or Estradiol Benzoate (EB) after Norgestomet and submitted to fixed-time artificial insemination(FTAI). The hypothesis was that the administration of eCG or E Benhances the conception rate. Lactating Nelore cows (n=138) and Brangus (n = 63), between 26 and 118 days of post partum period(PPP) were divided into three homogeneous groups, and subdividedin two blocks, inside each group one of them with a PPP d” 45 days (PPP1; n=107) and another with a PPP > 45 days (PPP2; n=94). Allcows received an auricular implant containing 3mg Norgestomet(Crestar®), followed by the administration of 5mg Estradiol Valerate.The auricular implants were kept during 10 days. Cows received 1mL saline solution (n=68, Control Group) or 500IU eCG (Folligon®;n=67; eCG Group) or 1mg Estradiol Benzoate (Index, n=66; EB Group) 24 hours after the removal of the implant. FTAI was made 54 hours after the implant removal. The pregnancy diagnosis was carried through ultrasonography 30 days after FTAI. There was an interaction between treatments and PPP. In the PPP1, the conception rate was higher in the eCG Group than in the EB Group (47.22% vs.15.38%; Pd”0.01). In the PPP2, the conception rates of the eCG and EB Groups were higher than in the Control Group (41.93%, 44.44%vs. 22.22%: Pd”0.01). It was concluded that in cows up to 45 days of PPP, the eCG associated with Norgestomet enhances the conception rates.