Management of dairy calves and heifers and the economic impact on first lactation / Manejos de bezerras e novilhas leiteiras e seu impacto econômico na primeira lactação

Management of calves and heifers directly influence the future productivity of dairy animals. However, the pre-production stage is often neglected by farmers, as young cows do not yet produce milk and, therefore, revenue, while representing an important part of the total cost of the property. This study aimed to identify and determine the economic value of factors influencing the production in the first lactation of heifers in a herd. This was a case study carried out on a family property in the municipality of Patrocínio, state of Minas Gerais, using data from 54 heifers. Qualitative characteristics (sire, maternal grandsire, amount of colostrum consumed, antibiotics use on the first day of life; application of prostaglandin to induce estrus, application of prostaglandin for resynchronization, use of progesterone implant for resynchronization, occurrence of retention of placenta and/or abortion, induction of lactation) and quantitative characteristics (weight at 90 days, average daily gain at 90 days and age at first mating) were evaluated. Variables influencing the production in the first lactation were the application of antibiotics, retained placenta, induction of lactation and age at mating. The differences in milk revenue were -R$ 2,381.21 for the use of antibiotics in each female, -R$ 299.85 for each heat loss for the first mating, -R$ 5,043.11 for each lactation induction, -R$6,841.16 for each retained placenta with abortion and - R$1,060.96 for each case of retained placenta without abortion. Knowing the productive and economic consequences of each of these items provides the producer with subsidies for decision making, such as planning management strategies that avoid such losses, and choosing options to maximize the economic efficiency of production.

O manejo e os cuidados com as bezerras e novilhas influenciam diretamente a produtividade futura das fêmeas leiteiras. No entanto, muitas vezes a fase pré-produtiva é negligenciada pelos produtores, pois ao mesmo tempo que representam uma parcela importante do custo total da propriedade, as fêmeas jovens ainda não produzem leite e, portanto, receita. Objetivou-se identificar e determinar o valor econômico de fatores que influenciam na produção na primeira lactação de novilhas em um rebanho. O estudo de caso foi realizado em uma propriedade familiar na cidade de Patrocínio/MG, utilizando os dados de 54 novilhas. Foram avaliadas características qualitativas (pai, avô materno, quantidade de colostro consumida, uso de antibiótico no primeiro dia de vida; aplicação de prostaglandina para indução do cio, aplicação de prostaglandina para ressincronização, uso de implante de progesterona para ressincronização, ocorrência de retenção de placenta e/ou aborto, indução de lactação) e quantitativas (peso aos 90 dias, ganho médio diário aos 90 dias e idade à primeira cobertura). As variáveis que influenciaram a produção na primeira lactação foram a aplicação de antibióticos, retenção de placenta, indução à lactação e idade cobertura. As diferenças na receita do leite foram de -R$ 2.381,21 para o uso de antibióticos em cada fêmea, -R$ 299,85 para cada cio perdido para a primeira cobertura, -R$ 5.043,11 para cada indução de lactação, de -R$ 6.841,16 para cada ocorrência de retenção de placenta com aborto e de -R$ 1.060,96 para cada caso de retenção de placenta sem aborto. Conhecer as implicações produtivas e econômicas de cada um destes itens fornece ao produtor tem subsídios para tomadas de decisão, como planejar estratégias de manejo que evitem tais prejuízos, e escolher as opções que maximizem a eficiência econômica da produção.

Intravaginal progesterone device (1. 9g) and estradiol benzoate for follicular control in the mare during spring and summer / [Implante intravaginal de progesterona (1, 9g) e benzoato de estradiol no controle folicular de éguas durante a primavera e o verão]

The objective of this study was to evaluate follicular growth and ovulatory rates in mares treated with an intravaginal progesterone device (P4) during the 10-day period, associated with the use of estradiol benzoate (EB). The results were compared during the transition period (ET) in the spring and the breeding season in the summer (ER). The variables were submitted to ANOVA (Tukey's test), considering P<0.05. No ovulation occurred during the permanence of the P4 implant in both experimental periods. The ovulatory rate in the ER was 100% (n = 8) and in the ET 62.5% (n = 5; P = 0.0547). Significant differences were observed (<0.001), in both periods, comparing follicular growth rates during the permanence of P4 device (ER: 1.33 ± 0.89mm/d; ET: 1.00 ± 0.81mm/d) to the period without P4 (ER: 3.63 ± 1.33 mm/d; ET: 3.31 ± 1.66 mm/d). The present study demonstrated applicability and efficiency of a hormonal protocol using P4 intravaginal device and EB for follicular control in mares, both during ET and ER.

O objetivo deste trabalho foi avaliar a taxa de crescimento folicular e a taxa ovulatória em éguas tratadas com dispositivo intravaginal de progesterona (P4) durante o período de 10 dias, associado à utilização de benzoato de estradiol (BE). Os resultados foram comparados durante o período de transição (ET) da primavera com a época de reprodução no verão (ER). As variáveis foram submetidas à ANOVA (teste de Tukey), considerando-se P<0,05. Nenhuma ovulação ocorreu durante a permanência do dispositivo de P4 em ambos os períodos experimentais. A taxa ovulatória na ER foi de 100% (n = 8) e na ET, de 62,5% (n=5; P=0,0547). Diferença significativas (<0,001) foram observadas, em ambos os períodos experimentais, comparando as taxas de crescimento folicular durante a permanência da P4 (ER: 1,33 ± 0,89mm/d; ET: 1,00 ± 0,81mm/d) com o período sem P4 (ER: 3,63 ± 1,33mm/d; ET: 3,31 ± 1,66mm/d). O presente estudo demonstrou aplicabilidade e eficiência do protocolo hormonal utilizando dispositivo intravaginal de P4 e BE para controle folicular de éguas, tanto na ET quanto na ER.

Retirada de corpo estranho (dispositivo impregnado com progesterona) da cavidade abdominal de novilha da raça Jersey ­ relato de caso / Removal of a foreign body (progesterone impregnated device) from the abdominal cavity of a Jersey heifer ­ a case report / Extracción de cuerpo extraño (dispositivo impregnado con progesterona) de la cavidad abdominal de novilla raza Jersey - reporte de caso

A inseminação artificial em tempo fixo (IATF) é uma biotécnica com inúmeras vantagens para a produção de bovinos. Para a realização da IATF, as fêmeas bovinas devem receber um protocolo farmacológico que induz a ovulação de forma sincronizada. Esse protocolo inicia com a inserção de um dispositivo impregnado com progesterona que deve permanecer no fundo vaginal da fêmea por tempo determinado. O presente relato tem por objetivo descrever a remoção de um implante impregnado com progesterona que foi encontrado na cavidade abdominal de uma novilha. Durante um atendimento reprodutivo de rotina em uma propriedade rural, uma novilha da raça Jersey, recém-adquirida, com histórico de ter sido submetida à IATF, foi avaliada para diagnóstico de gestação. No exame a novilha não estava gestante e apresentava um cisto folicular ovariano. A novilha foi submetida novamente à IATF em que foi inserido e removido um implante, com isso o cisto regrediu e ao inseminar a novilha não foi possível passar a cérvix com o aplicador. Vinte dias após a inseminação a novilha manifestou estro e ao ser avaliada para nova inseminação, foi identificado um implante solto na cavidade abdominal da novilha. Foi realizada uma laparotomia pelo flanco esquerdo e o implante foi removido. Após a recuperação da cirurgia a novilha foi inseminada e novamente e ficou gestante. Os protocolos de IATF devem ser realizados por profissionais capacitados para evitar problemas como a presente situação em que um implante foi encontrado na cavidade abdominal de uma novilha.(AU)

The fixed-time artificial insemination (FTAI) is a biotechnique with numerous advantages for cattle production. In order to perform the FTAI, the cows must receive a pharmacological protocol to induce ovulation in a synchronized way. This protocol begins with the insertion of a device impregnated with progesterone that must remain in the vaginal fundus of the cow for a specific period of time. This report aims at describing the removal of a progesterone impregnated implant that was found in the abdominal cavity of a heifer. During a routine reproductive service in a rural property, a recently acquired Jersey heifer, with history of having been submitted to FTAI, was evaluated for pregnancy diagnosis. At the exam, it was observed that the heifer was not pregnant and presented an ovarian follicular cyst. The heifer was then submitted to FTAI again, where an implant was inserted and removed. This made the cyst to recede, and upon subsequent insemination, the applicator was not able to pass the cervix. Twenty days after insemination, the heifer was in estrus and when it was evaluated for insemination, a loose implant was identified in the abdominal cavity of the heifer. A laparotomy was performed through the left flank and the implant was removed. After recovery from the surgery, the heifer was inseminated again and became pregnant. The FTAI protocols should only be carried out by trained professionals to avoid problems such as the one presented herein, where an implant was found in the abdominal cavity of a heifer.(AU)

La inseminación artificial a tiempo fijo (FTAI) es una biotécnica con numerosas ventajas para la producción de ganado. Para realizar FTAI, las hembras bovinas deben recibir un protocolo farmacológico que induzca la ovulación de forma sincronizada. Este protocolo comienza con la inserción de un dispositivo impregnado con progesterona que debe permanecer en el fondo vaginal de la hembra durante un tiempo específico. Este informe tiene como objetivo describir la extracción de un implante impregnado de progesterona que se encontró en la cavidad abdominal de una novilla. Durante la atención reproductiva de rutina en una propiedad rural, se evaluó el diagnóstico de preñez de una novilla de Jersey recién adquirida con antecedentes de someterse a FTAI. En el examen, la novilla no estaba embarazada y tenía un quiste folicular ovárico. La novilla fue nuevamente sometida a FTAI, en la cual se insertó y removió un implante, con esto el quiste retrocedió y al inseminar a la novilla no fue posible pasar el cérvix con el aplicador. Veinte días después de la inseminación, la vaquilla manifestó estro y cuando se evaluó para una nueva inseminación, se identificó un implante suelto en la cavidad abdominal de la vaquilla. Se realizó una laparotomía a través del flanco izquierdo y se extrajo el implante. Después de recuperarse de la cirugía, la novilla fue inseminada y nuevamente quedó embarazada. Los protocolos FTAI deben ser realizados por profesionales capacitados para evitar problemas como la situación actual donde se encontró un implante en la cavidad abdominal de una novilla.(AU)

Use of cooled buffalo semen as a strategy to increase conception rates in fixed-time artificial insemination programs during unfavorable reproductive periods / [Uso de sêmen resfriado de búfalo como estratégia para aumentar as taxas de concepção em programas de inseminação artificial em tempo fixo, durante períodos reprodutivos desfavoráveis]

The objective of this study was to compare the reproductive efficiency of dairy buffaloes undergoing fixed-time artificial insemination (FTAI) protocols based on progesterone/estrogen (P4/E2) and eCG during unfavorable breeding season using cooled (CS) and frozen semen (FS). A total of 446 buffaloes (> 40 days postpartum) were randomly distributed into four blocks (years): B1-2014 (n = 143), B2-2015 (n = 34), B3-2016 (n = 90), and B4-2017 (n = 179). Each block was subdivided into two (AI with CS and FS using the same ejaculate of each bull). Thus, the block subdivision was as follows: B1 (CS = 71 and FS = 72); B2 (CS = 18 and FS = 16); B3 (CS = 47 and FS = 43); and B4 (CS = 90 and FS = 89). The ejaculates of eight Murrah bulls collected using an artificial vagina were divided into two aliquots: one aliquot was diluted in Botu-Bov® commercial extender and cooled (BB-CS), and the other was diluted in the same extender and frozen (BB-FS). BB-CS aliquots were cooled at 5 °C/24 h using a refrigerator. BB-FS group aliquots were also cooled, and after equilibrating at 5 °C for 4 h, were placed in a 21-L Styrofoam box, 5 cm above the surface of liquid nitrogen. In the afternoon (A) on D0 (2:00 p.m.) the animals received EB 2.0 mg IM (Estrogin®) and an ear implant (CRESTAR® 3.0 mg P4). At D9 (A), the implant was removed, and the animals received eCG 400 IU IM (Folligon® 5000) + Cloprostenol PGF2α 0.530 mg IM (Sincrocio®). At D10 (A), the animals received EB 1.0 mg IM (Estrogin®), and at D12 (8:00 a.m.), AI was performed. At D42, pregnancy was diagnosed via ultrasonography. Total CRs were 48.2% CS and 34.6% FS for years 2014 to 2017, with a significant difference of 13.7% (P<0.05). In conclusion, cooled semen resulted in higher CR than frozen semen in dairy buffaloes under the P4/E2 and eCG FTAI during the unfavorable reproductive season.(AU)

O objetivo deste estudo foi comparar a eficiência reprodutiva de búfalas leiteiras submetidas a protocolos de inseminação artificial em tempo fixo (IATF) à base de progesterona/estrogênio (P4/E2) e eCG, durante a estação reprodutiva desfavorável, usando-se sêmen resfriado (SR) e congelado (SC) Um total de 446 búfalas (> 40 dias após o parto) foi distribuído aleatoriamente em quatro blocos (anos): B1-2014 (n = 143), B2-2015 (n = 34), B3-2016 (n = 90) e B4-2017 (n = 179). Cada bloco foi subdividido em dois (IA com SR e SC utilizando-se a mesma ejaculação de cada touro). Assim, a subdivisão do bloco foi a seguinte: B1 (SR = 71 e SC = 72); B2 (SR = 18 e SC = 16); B3 (SR = 47 e SC = 43); e B4 (SR = 90 e SC = 89). Os ejaculados de oito touros Murrah coletados com vagina artificial foram divididos em duas alíquotas: uma alíquota diluída em diluente comercial Botu-Bov® e resfriada (BB-SR), e a outra diluída no mesmo diluente e congelada (BB-SC). As alíquotas de BB-SR foram resfriados a 5°C/24h usando-se um refrigerador. As alíquotas do grupo BB-SC também foram resfriadas e, após equilíbrio a 5°C por 4h, foram colocadas em uma caixa de isopor de 21L, 5 cm acima da superfície do nitrogênio líquido. À tarde (A), no D0 (14h), os animais receberam BE 2,0 mg IM (Estrogin®) e um implante auricular (Crestar® 3,0 mg P4). No D9 (A), o implante foi retirado e os animais receberam eCG 400 UI IM (Folligon® 5000) + cloprostenol PGF2α 0,530 mg IM (Sincrocio®). No D10 (A), os animais receberam BE 1,0mg IM (Estrogin®), e, no D12 (8h da manhã), foram realizadas as IAs. No D42, a gestação foi diagnosticada por ultrassonografia. As taxas de concepção (TC) totais foram 48,2% SR e 34,6% SC para os anos de 2014 a 2017, com uma diferença significativa de 13,7% (P<0,05). Em conclusão, o sêmen resfriado resultou em maior TC do que o sêmen congelado em bubalinos leiteiros sob P4/E2 e eCG FTAI durante a estação reprodutiva desfavorável.(AU)

Saliva crystallization in sheep subjected to estrus induction and synchronization protocols

Background: The crystallization of bodily fluids, primarily saliva, has been the subject of study in many species and is asimple alternative to detect estrus because it demands neither a significant financial investment nor qualified professionalsto execute the examination. Fern pattern crystallization has been described in the cervical and nasal mucus, saliva andtear secretion, and in colostrum. Changes in salivary crystallization during the reproduction cycle are related to differenthormonal concentrations in this period. Thus, the present study has evaluated the patterns of saliva crystallization in sheepsubjected to estrus induction and synchronization protocols.Materials, Methods & Results: The sample consisted of 11 crossbreed Corriedale sheep, which were evaluated during twoexperimental periods (spring and autumn), and that underwent induction and synchronizing estrus protocols. In a randomphase of the estrus cycle (day 0), each sheep was implanted with an intravaginal device (Primer®), impregnated with 0.36g of progesterone for seven days. This device was inserted according to manufacturer’s instructions of the manufacturerand with the assistance of a specific applicator. On the day of device removal (day 7), the animals received 0.0375 mg ofD-Cloprostenol (Prolise®) and 10 mg of Folltropin® extracted from the swine pituitary (NIH-FSH-P1 of Folltropin-V) byintramuscular administration. The saliva was collected at six points during the experimental periods: day 1 (3 days beforeplacement of the implant); day 4 (day of insertion of the implant); day 9 (5 days after the insertion of the implant); day11 (day of removal of the implant and application of hormones); day 12 (24 h after removal of the implant [presumableestrus]); and day 13 (48 h after removal of the implant). Smears containing 10 µL of saliva were observed under an opticallight microscope...

Saliva crystallization in sheep subjected to estrus induction and synchronization protocols

Background: The crystallization of bodily fluids, primarily saliva, has been the subject of study in many species and is asimple alternative to detect estrus because it demands neither a significant financial investment nor qualified professionalsto execute the examination. Fern pattern crystallization has been described in the cervical and nasal mucus, saliva andtear secretion, and in colostrum. Changes in salivary crystallization during the reproduction cycle are related to differenthormonal concentrations in this period. Thus, the present study has evaluated the patterns of saliva crystallization in sheepsubjected to estrus induction and synchronization protocols.Materials, Methods & Results: The sample consisted of 11 crossbreed Corriedale sheep, which were evaluated during twoexperimental periods (spring and autumn), and that underwent induction and synchronizing estrus protocols. In a randomphase of the estrus cycle (day 0), each sheep was implanted with an intravaginal device (Primer®), impregnated with 0.36g of progesterone for seven days. This device was inserted according to manufacturers instructions of the manufacturerand with the assistance of a specific applicator. On the day of device removal (day 7), the animals received 0.0375 mg ofD-Cloprostenol (Prolise®) and 10 mg of Folltropin® extracted from the swine pituitary (NIH-FSH-P1 of Folltropin-V) byintramuscular administration. The saliva was collected at six points during the experimental periods: day 1 (3 days beforeplacement of the implant); day 4 (day of insertion of the implant); day 9 (5 days after the insertion of the implant); day11 (day of removal of the implant and application of hormones); day 12 (24 h after removal of the implant [presumableestrus]); and day 13 (48 h after removal of the implant). Smears containing 10 µL of saliva were observed under an opticallight microscope...(AU)

Influência da progesterona injetável na taxa de prenhez de novilhas receptoras de embriões bovinos / Influence of injectable progesterone on the pregnancy rate of heifers receiving bovine embryos

Background: In vitro embryo production (IVEP) allows the spread of superior animal genetics, but pregnancy rates show a high variability with this biotechnique. In the initial stage of pregnancy, progesterone plays a fundamental role in uterine preparation, acting on embryonic growth, implantation, and development. However, on the day of the IVEP transfer to the recipients, progesterone levels may be lower than that expected, influencing the uterine environment and, consequently, the pregnancy rate. Therefore, the objective of this study was to evaluate the pregnancy rate in heifers after the administration of injectable progesterone (P4) in the fixed-time embryo transfer (FTET) protocol. Materials, Methods & Results: The experiment was conducted inside a rural property near the city of Rio Branco, Acre, Brazil. The experimental group consisted of 232 animals, including 78 zebuine (Bos indicus) and 154 mixed (½ blood B. indicus and ½ blood B. taurus) animals, aged between 16 and 24 months, with a mean weight of 300 and 330 kg for zebuine and mixed animals, respectively. The selected animals were previously synchronized using the progesteroneestrogen-prostaglandin-estrogen protocol. Embryo transfer was performed on day 18 of the protocol, which was 9 days after the removal of intravaginal progesterone implant. On day 15 of the protocol, that is, 144 h (6 days) after the device removal, the animals were randomly distributed into two experimental groups: Control Group (CG; 0.5 mL of 0.9% saline solution, intramuscular) and Treated Group (P4G; 0.5 mL of injectable P4, 150 mg, intramuscular). Chi-square test was used for the statistical analysis of the pregnancy rate at a 5% probability. After 23 days of embryo transfer, pregnancy was diagnosed by ultrasonography. The general pregnancy rate, considering all groups (CG and P4G) and breeds included, was 55.17% (128/232). The pregnancy rates of the P4G and CG groups, regardless of breeds, were...

Diferentes momentos de aplicação de gonadotrofina coriônica equina em protocolo de inseminação artificial em tempo fixo para vacas de leite / Different times of application of equine chorionic gonadotropin in fixed-time artificial insemination protocols for dairy cows

Avaliaram-se diferentes momentos de aplicação da gonadotrofina coriônica equina (eCG) em protocolos de inseminação artificial em tempo fixo (IATF) para vacas de leite. Foram utilizadas 76 fêmeas, as quais receberam, no dia zero (D0) do protocolo, dispositivos intravaginais de progesterona, sendo esses retirados no D9, e os animais foram, então, distribuídos aleatoriamente em três tratamentos: T1 - aplicação de eCG no momento da retirada dos dispositivos; T2 e T3 - aplicação de eCG 48h e 24h antes da retirada dos dispositivos, respectivamente. No D10 os animais receberam 1mg de GnRH, e a IATF foi realizada 52 horas após a retirada do implante. Não houve diferença (P>0,05) para intervalo entre a retirada do implante à ovulação (72,56±3,92h), o diâmetro do maior folículo no D9 (10,88±1,49mm), o diâmetro do folículo ovulatório (15,15±1,16mm) e do segundo maior folículo (7,49±0,52mm), a taxa de crescimento folicular (1,38±0,04mm/dia), a taxa de ovulação (96,67%), o intervalo entre diâmetro final e inicial do folículo dominante (73,49±3,84h), a área de corpo lúteo (2,27±0,43cm²), a porcentagem de CL no ovário direito (53,00%) e no esquerdo (26,33%) e a taxa de gestação (33,33%). O momento da aplicação da eCG não influenciou na eficiência do protocolo. Recomenda-se a utilização da eCG no momento da retirada do implante por otimização do manejo.(AU)

Different times of application of equine chorionic gonadotropin (eCG) in Fixed-Time Artificial Insemination (FTAI) protocols for dairy cows were evaluated. A total of 76 females were used, which received intravaginal progesterone devices on day zero (D0) of the protocol, which were withdrawn on D9, and the animals were then randomly distributed in three treatments: T1- application of eCG at the time of device withdrawal; T2 and T3 - application of eCG 48h and 24h before withdrawal of the devices, respectively. On D10 the animals received 1mg of GnRH and the FTAI was carried out 52 hours after the removal of the implant. There was no difference (P>0.05) for interval from implant removal to ovulation (72.56±3.92h), diameter of the largest follicle of D9 (10.88±1.49mm), diameters of ovulatory follicle (15.15±1.16mm) and of the second largest follicle (7.49±0.52mm), follicle growth rate (1.38±0.04mm/day), ovulation rate (96.67%), interval between final diameter and initial diameter of dominant follicle (73.49±3.84h), corpus luteum area (2.27±0.43cm²), percentage of CL in right ovary (53.00%) and in left ovary (26.33%) and pregnancy rate (33.33%). The time of the application of eCG did not influence the efficiency of the protocol. We recommend the use of eCG at the time of the removal of the implant for management optimization.(AU)

Diferentes momentos de aplicação de gonadotrofina coriônica equina em protocolo de inseminação artificial em tempo fixo para vacas de leite / Different times of application of equine chorionic gonadotropin in fixed-time artificial insemination protocols for dairy cows

Avaliaram-se diferentes momentos de aplicação da gonadotrofina coriônica equina (eCG) em protocolos de inseminação artificial em tempo fixo (IATF) para vacas de leite. Foram utilizadas 76 fêmeas, as quais receberam, no dia zero (D0) do protocolo, dispositivos intravaginais de progesterona, sendo esses retirados no D9, e os animais foram, então, distribuídos aleatoriamente em três tratamentos: T1 - aplicação de eCG no momento da retirada dos dispositivos; T2 e T3 - aplicação de eCG 48h e 24h antes da retirada dos dispositivos, respectivamente. No D10 os animais receberam 1mg de GnRH, e a IATF foi realizada 52 horas após a retirada do implante. Não houve diferença (P>0,05) para intervalo entre a retirada do implante à ovulação (72,56±3,92h), o diâmetro do maior folículo no D9 (10,88±1,49mm), o diâmetro do folículo ovulatório (15,15±1,16mm) e do segundo maior folículo (7,49±0,52mm), a taxa de crescimento folicular (1,38±0,04mm/dia), a taxa de ovulação (96,67%), o intervalo entre diâmetro final e inicial do folículo dominante (73,49±3,84h), a área de corpo lúteo (2,27±0,43cm²), a porcentagem de CL no ovário direito (53,00%) e no esquerdo (26,33%) e a taxa de gestação (33,33%). O momento da aplicação da eCG não influenciou na eficiência do protocolo. Recomenda-se a utilização da eCG no momento da retirada do implante por otimização do manejo.(AU)

Different times of application of equine chorionic gonadotropin (eCG) in Fixed-Time Artificial Insemination (FTAI) protocols for dairy cows were evaluated. A total of 76 females were used, which received intravaginal progesterone devices on day zero (D0) of the protocol, which were withdrawn on D9, and the animals were then randomly distributed in three treatments: T1- application of eCG at the time of device withdrawal; T2 and T3 - application of eCG 48h and 24h before withdrawal of the devices, respectively. On D10 the animals received 1mg of GnRH and the FTAI was carried out 52 hours after the removal of the implant. There was no difference (P>0.05) for interval from implant removal to ovulation (72.56±3.92h), diameter of the largest follicle of D9 (10.88±1.49mm), diameters of ovulatory follicle (15.15±1.16mm) and of the second largest follicle (7.49±0.52mm), follicle growth rate (1.38±0.04mm/day), ovulation rate (96.67%), interval between final diameter and initial diameter of dominant follicle (73.49±3.84h), corpus luteum area (2.27±0.43cm²), percentage of CL in right ovary (53.00%) and in left ovary (26.33%) and pregnancy rate (33.33%). The time of the application of eCG did not influence the efficiency of the protocol. We recommend the use of eCG at the time of the removal of the implant for management optimization.(AU)

Efeito do uso de eCG em protocolo de inseminação artificial em tempo fixo em vacas mestiças leiteiras / Effect of using eCG in the fixed-time artificial insemination protocol in mixed-race dairy cows

No Brasil, cerca de 5% do rebanho bovino é reproduzido através da biotecnologia de inseminação artificial (IA). O sucesso da IA depende de fatores inerentes à fêmea, ao sêmen e a habilidade do inseminador. Dentre os fatores inerentes a fêmea destaca-se: escore corporal, estado sanitário, estado reprodutivo e protocolo hormonal utilizado. A literatura relata diferentes resultados entre os diversos protocolos hormonais. Desta forma, este trabalho teve por objetivo verificar a eficácia do uso do eCG em protocolos de inseminação artificial em tempo fixo (IATF) em bovinos. Foram utilizadas vacas mestiças Girolando (n=4886), com peso médio de 500kg, as quais foram divididas em dois grupos, IATF 1 (n=2,535) e IATF 2 (n=2,351). Os dados das amostras foram coletados dasUnidades Produtoras de Leite (UPLs), as quais fazem parte do complexo leiteiro da Fazenda. As vacas foram divididas em dois grupos, IATF 1 e IATF 2 a cada trimestre. Ambos os protocolos de IATF foram realizados durante um período de dez dias. No dia 0 foi administrado o implante intrauterino impregnado com progesterona (1g), o qual permaneceu durante oito dias e administrado 2 mL de Benzoato de Estradiol pela via intramuscular. Após a remoção do implante no D8, administrou-se por via intramuscular 2 mL de prostaglandina F2α (PGF2α) juntamente com 1 mL de Cipionato de Estradiol. Nas fêmeas IATF 1 com folículos menos desenvolvidos aplicou-se 2 mL de gonadrotofina coriônica equina (eCG) por via intramuscular. Concluiu-se que a utilização de eCG elevou as taxas de fertilização em vacas com folículos menores, porém foi desnecessário para as fêmeas que apresentaram condições uterinas normais.

In Brazil, about 5% of the cattle herd reproduces through artificial insemination (AI) biotechnology. The success of AI depends on factors inherent to the female, inherent to the semen and the inseminator's ability. Among the factors inherent to the female are: body score, health status, reproductive status and hormonal protocol used. The literature reports different results among the various hormonal protocols. Therefore, the objective of this study was to verify the efficacy of eCG in fixed-time artificial insemination (IATF) protocols in cattle. Girolando crossbred cows (n=4886), with an average weight of 500 kg, were divided into two groups, IATF 1 (n=2.535) and IATF 2 (n=2.351). The data of the samples were collected from the Milk Producing Units (UPLs) - Campo Grande, Colmalândia, Ouro Branco and Ouro Verde - that are part of Fazenda dairy complex. Cows were divided into two groups, IATF 1 and IATF 2 each quarter. Both IATF protocols were performed over a ten day period. On day 0, the progesterone-impregnated intrauterine implant (1g) was administered, which remained for eight days and administered 2 mL of Estradiol Benzoate intramuscular. After removal of the implant in the D8, 2 mL of prostaglandin F2α (PGF2α) were administered intramuscularly together with 1 mL of Estradiol Cypionate. It was concluded that the use of eCG increased fertilization rates in cows with smaller follicles, but was unnecessary for females that presented normal uterine conditions.

Efeito do uso de eCG em protocolo de inseminação artificial em tempo fixo em vacas mestiças leiteiras / Effect of using eCG in the fixed-time artificial insemination protocol in mixed-race dairy cows

No Brasil, cerca de 5% do rebanho bovino é reproduzido através da biotecnologia de inseminação artificial (IA). O sucesso da IA depende de fatores inerentes à fêmea, ao sêmen e a habilidade do inseminador. Dentre os fatores inerentes a fêmea destaca-se: escore corporal, estado sanitário, estado reprodutivo e protocolo hormonal utilizado. A literatura relata diferentes resultados entre os diversos protocolos hormonais. Desta forma, este trabalho teve por objetivo verificar a eficácia do uso do eCG em protocolos de inseminação artificial em tempo fixo (IATF) em bovinos. Foram utilizadas vacas mestiças Girolando (n=4886), com peso médio de 500kg, as quais foram divididas em dois grupos, IATF 1 (n=2,535) e IATF 2 (n=2,351). Os dados das amostras foram coletados dasUnidades Produtoras de Leite (UPLs), as quais fazem parte do complexo leiteiro da Fazenda. As vacas foram divididas em dois grupos, IATF 1 e IATF 2 a cada trimestre. Ambos os protocolos de IATF foram realizados durante um período de dez dias. No dia 0 foi administrado o implante intrauterino impregnado com progesterona (1g), o qual permaneceu durante oito dias e administrado 2 mL de Benzoato de Estradiol pela via intramuscular. Após a remoção do implante no D8, administrou-se por via intramuscular 2 mL de prostaglandina F2α (PGF2α) juntamente com 1 mL de Cipionato de Estradiol. Nas fêmeas IATF 1 com folículos menos desenvolvidos aplicou-se 2 mL de gonadrotofina coriônica equina (eCG) por via intramuscular. Concluiu-se que a utilização de eCG elevou as taxas de fertilização em vacas com folículos menores, porém foi desnecessário para as fêmeas que apresentaram condições uterinas normais.(AU)

In Brazil, about 5% of the cattle herd reproduces through artificial insemination (AI) biotechnology. The success of AI depends on factors inherent to the female, inherent to the semen and the inseminator's ability. Among the factors inherent to the female are: body score, health status, reproductive status and hormonal protocol used. The literature reports different results among the various hormonal protocols. Therefore, the objective of this study was to verify the efficacy of eCG in fixed-time artificial insemination (IATF) protocols in cattle. Girolando crossbred cows (n=4886), with an average weight of 500 kg, were divided into two groups, IATF 1 (n=2.535) and IATF 2 (n=2.351). The data of the samples were collected from the Milk Producing Units (UPLs) - Campo Grande, Colmalândia, Ouro Branco and Ouro Verde - that are part of Fazenda dairy complex. Cows were divided into two groups, IATF 1 and IATF 2 each quarter. Both IATF protocols were performed over a ten day period. On day 0, the progesterone-impregnated intrauterine implant (1g) was administered, which remained for eight days and administered 2 mL of Estradiol Benzoate intramuscular. After removal of the implant in the D8, 2 mL of prostaglandin F2α (PGF2α) were administered intramuscularly together with 1 mL of Estradiol Cypionate. It was concluded that the use of eCG increased fertilization rates in cows with smaller follicles, but was unnecessary for females that presented normal uterine conditions.(AU)

Evaluation of buffaloes' follicular dynamics and stress state under different ovulation synchronization protocols

The aims of the present study were to analyze the effect of different hormonal protocols using an implant containing Norgestomet, at the ovulation synchronization in buffaloes and to verify the effect of the stress caused by manipulation of the herd during the experiment. Twenty-four female Murrah breed buffaloes, lactating, multiparous, aged from three to eight years, with a body condition score of 3.5 or higher (0 to 5) and with more than 45 days post partum, were used. These females were randomly distributed into one of the three groups (group 1, group 2 and group 3) with eight subjects in each. On day 0 (day 0), all animals received an ear progesterone implant with 3.0 mg of Norgestomet and an intramuscular (IM) injection with 2.0 mg of estradiol benzoate (EB). The implants were removed after nine days (day 9) and one single dose of PGF2α (0.15 mg d-cloprostenol, IM) was administered to all animals. On the same day, the group ́1 and group 3 buffaloes were treated with 500 UI of eCG (IM). Two days later (day 11), 1000UI of hCG (IM) were administered to the group 1 and group 2 buffaloes. After the implant had been removed, an ultrasound evaluation was performed every 12 h, in order to access the ovarian follicular dynamics, using an Aloka 500 equipment with a 5 MHz transrectal probe. Blood samples were also taken on days 0, 9 and 11 to determine the plasmatic concentrations of cortisol and progesterone. No difference was observed in the ovulation rate (group 1: 62.5%, group 2: 50%, group 3: 75%). However, the size of the preovulatory follicles and the plasmatic concentration of cortisol had (P <0.05). G3 was the most efficient group in promoting the ovulation synchronization, which suggests that this protocol can be used in Fixed Timed Artificial Insemination programs (FTAI) among postpartum, lactating Murrah breed buffaloes’.

Evaluation of buffaloes' follicular dynamics and stress state under different ovulation synchronization protocols

The aims of the present study were to analyze the effect of different hormonal protocols using an implant containing Norgestomet, at the ovulation synchronization in buffaloes and to verify the effect of the stress caused by manipulation of the herd during the experiment. Twenty-four female Murrah breed buffaloes, lactating, multiparous, aged from three to eight years, with a body condition score of 3.5 or higher (0 to 5) and with more than 45 days post partum, were used. These females were randomly distributed into one of the three groups (group 1, group 2 and group 3) with eight subjects in each. On day 0 (day 0), all animals received an ear progesterone implant with 3.0 mg of Norgestomet and an intramuscular (IM) injection with 2.0 mg of estradiol benzoate (EB). The implants were removed after nine days (day 9) and one single dose of PGF2α (0.15 mg d-cloprostenol, IM) was administered to all animals. On the same day, the group ́1 and group 3 buffaloes were treated with 500 UI of eCG (IM). Two days later (day 11), 1000UI of hCG (IM) were administered to the group 1 and group 2 buffaloes. After the implant had been removed, an ultrasound evaluation was performed every 12 h, in order to access the ovarian follicular dynamics, using an Aloka 500 equipment with a 5 MHz transrectal probe. Blood samples were also taken on days 0, 9 and 11 to determine the plasmatic concentrations of cortisol and progesterone. No difference was observed in the ovulation rate (group 1: 62.5%, group 2: 50%, group 3: 75%). However, the size of the preovulatory follicles and the plasmatic concentration of cortisol had (P <0.05). G3 was the most efficient group in promoting the ovulation synchronization, which suggests that this protocol can be used in Fixed Timed Artificial Insemination programs (FTAI) among postpartum, lactating Murrah breed buffaloes.(AU)

Influence of follicular growth stimulation on fertility of beef cows treated with eCG or FSH in FTAI protocols / Influência da estimulação do crescimento folicular na fertilidade de vacas de corte tratadas com eCG ou FSH em protocolos de IATF

Background: The pregnancy rate in fixed-time insemination (FTAI) programs in beef cattle is affected by several factors, including the size of ovulatory follicle (OF). Induced ovulation of small OF (≤11 mm) reduces the chance of pregnancy after FTAI when compared to ovulation of larger follicles (≥12 mm). Hormonal treatments to enhance the follicle growth have been widely used in comercial beef cattle systems, aiming to improve the development of a dominant follicle. The objective of this experiment was to evaluate the effect of treatment with eCG or FSH at the time of progesterone implant removal on the diameter of OF, final follicle growth and pregnancy rate in beef cows.Materials, Methods & Results: Three hundred and seven suckled beef cows with body condition score 2.80 ± 0.24 (1 to 5 scale) and 45 to 70 days postpartum were synchronized to FTAI. On day 0, intravaginal implants containing 1 g of progesterone, were inserted and administered 2 mg of estradiol benzoate (EB), i.m. On day 7, intravaginal implants were removed and 150 µg of D-cloprostenol were administered i.m. At this time, three groups were assigned according to the treatments: eCG (400 UI eCG, i.m.), FSH (25 UI FSH, i.m.) and Control (1 mL Saline, i.m.). On day 8, all cows were injected with 1mg EB i.m. and were inseminated 52 to 56 h after the implant removal. Transrectal ultrasonography exams of ovaries were performed at the time of implant removal and before FTAI to determine the diameter of the largest follicle and the follicular daily growth. Pregnancy exams were conducted by transretal ultrasonography 30 days after FTAI. Statistical analyzes were performed by Chi-square test for pregnancy rate. Ovarian diameters and follicular daily growth were analyzed by ANOVA with means compared by Tukey test considering significant P value < 0.05.[...]

Influence of follicular growth stimulation on fertility of beef cows treated with eCG or FSH in FTAI protocols / Influência da estimulação do crescimento folicular na fertilidade de vacas de corte tratadas com eCG ou FSH em protocolos de IATF

Background: The pregnancy rate in fixed-time insemination (FTAI) programs in beef cattle is affected by several factors, including the size of ovulatory follicle (OF). Induced ovulation of small OF (≤11 mm) reduces the chance of pregnancy after FTAI when compared to ovulation of larger follicles (≥12 mm). Hormonal treatments to enhance the follicle growth have been widely used in comercial beef cattle systems, aiming to improve the development of a dominant follicle. The objective of this experiment was to evaluate the effect of treatment with eCG or FSH at the time of progesterone implant removal on the diameter of OF, final follicle growth and pregnancy rate in beef cows.Materials, Methods & Results: Three hundred and seven suckled beef cows with body condition score 2.80 ± 0.24 (1 to 5 scale) and 45 to 70 days postpartum were synchronized to FTAI. On day 0, intravaginal implants containing 1 g of progesterone, were inserted and administered 2 mg of estradiol benzoate (EB), i.m. On day 7, intravaginal implants were removed and 150 µg of D-cloprostenol were administered i.m. At this time, three groups were assigned according to the treatments: eCG (400 UI eCG, i.m.), FSH (25 UI FSH, i.m.) and Control (1 mL Saline, i.m.). On day 8, all cows were injected with 1mg EB i.m. and were inseminated 52 to 56 h after the implant removal. Transrectal ultrasonography exams of ovaries were performed at the time of implant removal and before FTAI to determine the diameter of the largest follicle and the follicular daily growth. Pregnancy exams were conducted by transretal ultrasonography 30 days after FTAI. Statistical analyzes were performed by Chi-square test for pregnancy rate. Ovarian diameters and follicular daily growth were analyzed by ANOVA with means compared by Tukey test considering significant P value < 0.05.[...](AU)

Eficácia da associação dupla dose PGF2 alfa-eCG no proestro de vacas leiteiras mestiças submetidas à IATF / Efficacy of the double PGF2 alpha dose-eCG association in proestrus of crossbred dairy cows submitted to IATF

Objetivou-se avaliar o efeito de uma ou duas doses de prostaglandina F2α (PGF2α) associada ou não a gonadotrofina coriônica equina (eCG) sobre a dinâmica folicular, a função luteal pré-ovulatória, assim como as características morfofuncionais pós-ovulatórias do corpo lúteo (CL) em fêmeas mestiças cíclicas submetidas a um protocolo de inseminação artificial em tempo fixo (IATF). Para tanto, 29 vacas 3/4 Gir x Holandês multíparas foram submetidas ao exame de ultrassonografia (US) transretal e após a detecção do CL iniciou-se um protocolo de IATF em um dia denominado zero (D0), por meio da inserção do implante de progesterona (P4) associado à aplicação de 2,0mg de benzoato de estradiol. No D7 esses animais receberam 12,5mg de dinoprost trometamina. No D9 realizou a remoção dos dispositivos de P4 e aplicou 0,6mg de cipionato de estradiol. Nesse momento, as fêmeas foram subdivididas nos seguintes tratamentos: Grupo Controle (n=7), foi administrado 2,5mL de solução fisiológica; Grupo 2PGF (n=7), aplicou 12,5mg de dinoprost trometamina; Grupo eCG (n=7), administrou-se 300UI de eCG; Grupo 2PGF+eCG (n=8), realizou a aplicação de 300UI de eCG e 12,5mg de dinoprost trometamina. Para avaliar a dinâmica folicular foram realizados exames de US em modo B e power doppler (Mindray Z5, Shenzhen, China) a cada 12h do D7 até o momento da ovulação ou 96h após a remoção dos implantes de P4, mensurando-se o diâmetro folicular (DFOL), a área da parede folicular (AFOL) e a área de perfusão sanguínea da parede folicular (VFOL). Concomitante a cada exame, foram coletadas amostras de sangue sendo determinada a concentração sérica de P4 pré-ovulatória por meio da metodologia de quimioluminescência. No D24 foi realizada a US modo B e doppler analisando-se o diâmetro luteal (DCL), área luteal (ACL) e área de perfusão sanguínea do CL (VCL), assim como, foi coletada amostra de sangue para averiguar a concentração sérica de P4 pós-ovulatória.(AU)

The study aimed to evaluate the effect of one or two prostaglandin doses F2α (PGF2a) with or without equine chorionic gonadotropin (eCG) in the follicular dynamics, the preovulatory luteal function, as well as the structural and functional characteristics post-ovulatory of the corpus luteum (CL) in cyclic crossbred females subjected to a fixed time artificial insemination (FTAI) protocol. For this, 29 multiparous 3/4 Gyr x Holstein cows were subjected to transrectal ultrasound examination (US) and upon detection of CL initiated a FTAI protocol on day called zero (D0) by the insertion of progesterone implant (P4) associated with the application of 2.0mg estradiol benzoate. On D7, these animals received 12.5mg of dinoprost tromethamine. At D9 happened the removal of the P4 devices and was applied 0.6mg of estradiol cypionate. At that time, the females were divided into the following treatments: control group (n=7) - which received 2.5mL of saline solution, 2PGF group (n=7) - received 12.5mg of dinoprost tromethamine, eCG group (n=7) - was administered 300IU eCG and eCG+2PGF group (n=8) - which received 300 IU eCG and 12.5mg of dinoprost tromethamine. To assess follicular dynamics were performed US scans B-mode and power doppler (Mindray Z5, Shenzhen, China) each 12h on D7 until the time of ovulation or until 96h after removal of the P4 implants, considering the follicular diameter (DFOL), the area of the follicular wall (AFOL) and the blood perfusion area of the follicular wall (VFOL). Concomitant with each test, blood samples were collected to determine the serum concentration of P4 preovulatory by chemiluminescence methodology. In D24 had held US B-mode and doppler to analyse the luteal diameter (DCL), luteal area (ACL) and blood perfusion area CL (VCL). (AU)

Eficácia da associação dupla dose PGF2 alfa-eCG no proestro de vacas leiteiras mestiças submetidas à IATF / Efficacy of the double PGF2 alpha dose-eCG association in proestrus of crossbred dairy cows submitted to IATF

Objetivou-se avaliar o efeito de uma ou duas doses de prostaglandina F2α (PGF2α) associada ou não a gonadotrofina coriônica equina (eCG) sobre a dinâmica folicular, a função luteal pré-ovulatória, assim como as características morfofuncionais pós-ovulatórias do corpo lúteo (CL) em fêmeas mestiças cíclicas submetidas a um protocolo de inseminação artificial em tempo fixo (IATF). Para tanto, 29 vacas 3/4 Gir x Holandês multíparas foram submetidas ao exame de ultrassonografia (US) transretal e após a detecção do CL iniciou-se um protocolo de IATF em um dia denominado zero (D0), por meio da inserção do implante de progesterona (P4) associado à aplicação de 2,0mg de benzoato de estradiol. No D7 esses animais receberam 12,5mg de dinoprost trometamina. No D9 realizou a remoção dos dispositivos de P4 e aplicou 0,6mg de cipionato de estradiol. Nesse momento, as fêmeas foram subdivididas nos seguintes tratamentos: Grupo Controle (n=7), foi administrado 2,5mL de solução fisiológica; Grupo 2PGF (n=7), aplicou 12,5mg de dinoprost trometamina; Grupo eCG (n=7), administrou-se 300UI de eCG; Grupo 2PGF+eCG (n=8), realizou a aplicação de 300UI de eCG e 12,5mg de dinoprost trometamina. Para avaliar a dinâmica folicular foram realizados exames de US em modo B e power doppler (Mindray Z5, Shenzhen, China) a cada 12h do D7 até o momento da ovulação ou 96h após a remoção dos implantes de P4, mensurando-se o diâmetro folicular (DFOL), a área da parede folicular (AFOL) e a área de perfusão sanguínea da parede folicular (VFOL). Concomitante a cada exame, foram coletadas amostras de sangue sendo determinada a concentração sérica de P4 pré-ovulatória por meio da metodologia de quimioluminescência. No D24 foi realizada a US modo B e doppler analisando-se o diâmetro luteal (DCL), área luteal (ACL) e área de perfusão sanguínea do CL (VCL), assim como, foi coletada amostra de sangue para averiguar a concentração sérica de P4 pós-ovulatória. Os dados foram avaliados pelo Two-way ANOVA e análise de medidas repetidas considerando os efeitos do eCG, 2PGF e interação eCG*2PGF, P<0,05. Não houve diferença significativa entre os protocolos de sincronização para as variáveis DFOL, AFOL e VFOL ao longo do tempo da dinâmica folicular. Os grupos experimentais apresentaram uma concentração sérica de P4 pré-ovulatória semelhante em cada momento da avaliação. Não foi observada distinção da ACL e VCL entre os tratamentos hormonais, contudo o Grupo eCG demonstrou tendência (P=0,08) a apresentar maior DCL em relação ao Grupo 2PGF e 2PGF+eCG. Adicionalmente a estes achados, também foi constatado tendência (P=0,07) a maiores concentrações de progesterona no dia 24 do protocolo nos animais do Grupo eCG (11,00±3,32ng/mL) em relação ao Grupo 2PGF (6,37±1,31ng/mL), enquanto o Controle e 2PGF+eCG demonstraram resultados intermediários que se assemelham a ambos os grupos, com concentrações de 8,43±3,85 e 9,18±2,82ng/mL, respectivamente. As tentativas de ajustes no proestro foram incapazes de melhorar a qualidade folicular e minimizar a função luteal pré-ovulatória, assim como não incrementaram a morfologia do CL e a função luteal pós-ovulatória, sugerindo que em animais cíclicos mestiços protocolos de IATF com a utilização de uma única dose PGF2α e sem o suporte gonadotrófico da eCG parece promover adequada resposta folicular e luteal.(AU)

The study aimed to evaluate the effect of one or two prostaglandin doses F2α (PGF2a) with or without equine chorionic gonadotropin (eCG) in the follicular dynamics, the preovulatory luteal function, as well as the structural and functional characteristics post-ovulatory of the corpus luteum (CL) in cyclic crossbred females subjected to a fixed time artificial insemination (FTAI) protocol. For this, 29 multiparous 3/4 Gyr x Holstein cows were subjected to transrectal ultrasound examination (US) and upon detection of CL initiated a FTAI protocol on day called zero (D0) by the insertion of progesterone implant (P4) associated with the application of 2.0mg estradiol benzoate. On D7, these animals received 12.5mg of dinoprost tromethamine. At D9 happened the removal of the P4 devices and was applied 0.6mg of estradiol cypionate. At that time, the females were divided into the following treatments: control group (n=7) - which received 2.5mL of saline solution, 2PGF group (n=7) - received 12.5mg of dinoprost tromethamine, eCG group (n=7) - was administered 300IU eCG and eCG+2PGF group (n=8) - which received 300 IU eCG and 12.5mg of dinoprost tromethamine. To assess follicular dynamics were performed US scans B-mode and power doppler (Mindray Z5, Shenzhen, China) each 12h on D7 until the time of ovulation or until 96h after removal of the P4 implants, considering the follicular diameter (DFOL), the area of the follicular wall (AFOL) and the blood perfusion area of the follicular wall (VFOL). Concomitant with each test, blood samples were collected to determine the serum concentration of P4 preovulatory by chemiluminescence methodology. In D24 had held US B-mode and doppler to analyse the luteal diameter (DCL), luteal area (ACL) and blood perfusion area CL (VCL). Also, a blood sample was collected to determine the serum concentration of P4 post-ovulatory. All data was evaluated by Two-way ANOVA and repeated measures analysis considering the effects of eCG, 2PGF and eCG*2PGF, P<0.05. There was not significant difference between the synchronization protocols for DFOL, AFOL and VFOL variables over time of follicular dynamics. Experimental groups had a serum concentration of P4 preovulatory similar in every moment of evaluation. There wasn't distinction of ACL and VCL between hormone treatments. However, the eCG group showed a tendency (P=0.08) to present higher DCL compared to the 2PGF and 2PGF+eCG groups. In addition to these findings, there was also a tendency (P=0.07) to higher concentrations of P4 on D24 of the protocol in the animals of the eCG group (11.00±3.32ng/mL) compared to the 2PGF group (6,37±1.31ng/mL), meanwhile the Control and 2PGF+eCG showed intermediate results that resembled both groups, with concentrations of 8.43±3.85 and 9.18±2.82ng/mL, respectively. Attempts to adjust proestrus were unable to improve follicular quality and minimize preovulatory luteal function, nor did they increase CL morphology and post-ovulatory luteal function, suggesting that in cyclic animals, FTAI protocols using a single PGF2α dose and without the gonadotrophic support of eCG seems to promote adequate follicular and luteal responses.(AU)

Efficiency of different methods of estrus synchronization followed by fixed time artificial insemination in Persian downy does

For evaluating different methods of long term estrous synchronization followed by fixed time artificial insemination and to select the most efficient method, during the breeding season 160 Persian downy does were equally allocated to groups (n = 20/group). Estrus Was synchronized using controlled internal drug release devices alone (CIDR) or with equine chorionic gonadotropin (CIDR-eCG), intravaginal sponge impregnated with 45 mg fluorgestone acetate alone (Sponge) or with eCG (Sponge-eCG),subcutaneous auricular implant of 2 mg norgestomet alone (Implant) or with eCG (Implant-eCG) or two intramuscular injections of 10 mg prostaglandin F2α10 days apart alone (PGF) or accompany with eCG (PGF-eCG). The dose of eCG was 400 IU and injected intramuscularlly at the end of treatments. Heat detection and fixed time artificial insemination were done 12 and 4 hours after the end of the treatments, respectively. The estrus was detected in 94.7-100% of the does who received different forms of progestagens and estrus response was not affected by eCG. Estrus response in PGF-based groups was significantly lower (P <0.05) than progesterone-based groups. Injection of eCG did not affect fertility, fecundity and prolificacy rates in CIDR, Sponge and Implant groups. It also did not affectparturition rate in implant group. Finally, with respect to estrus response, fertility rate, costs and the simplicity of methods it can be concluded that the use of intravaginal CIDR For 16 days without administration of eCG may be a more efficient method for estrus synchronization in fixed-time artificial insemination programs in Persian downy does.

Efficiency of different methods of estrus synchronization followed by fixed time artificial insemination in Persian downy does

For evaluating different methods of long term estrous synchronization followed by fixed time artificial insemination and to select the most efficient method, during the breeding season 160 Persian downy does were equally allocated to groups (n = 20/group). Estrus Was synchronized using controlled internal drug release devices alone (CIDR) or with equine chorionic gonadotropin (CIDR-eCG), intravaginal sponge impregnated with 45 mg fluorgestone acetate alone (Sponge) or with eCG (Sponge-eCG),subcutaneous auricular implant of 2 mg norgestomet alone (Implant) or with eCG (Implant-eCG) or two intramuscular injections of 10 mg prostaglandin F2α10 days apart alone (PGF) or accompany with eCG (PGF-eCG). The dose of eCG was 400 IU and injected intramuscularlly at the end of treatments. Heat detection and fixed time artificial insemination were done 12 and 4 hours after the end of the treatments, respectively. The estrus was detected in 94.7-100% of the does who received different forms of progestagens and estrus response was not affected by eCG. Estrus response in PGF-based groups was significantly lower (P <0.05) than progesterone-based groups. Injection of eCG did not affect fertility, fecundity and prolificacy rates in CIDR, Sponge and Implant groups. It also did not affectparturition rate in implant group. Finally, with respect to estrus response, fertility rate, costs and the simplicity of methods it can be concluded that the use of intravaginal CIDR For 16 days without administration of eCG may be a more efficient method for estrus synchronization in fixed-time artificial insemination programs in Persian downy does.(AU)

Carcass characteristics and meat quality of Nellore females reared in an intensive system using progesterone ear implant / Características da carcaça e qualidade da carne de fêmeas Nelore criadas em sistema intensivo utilizando implante auricular de progesterona

This study was carried out to evaluate the influence of a synthetic progesterone ear implant onweight gain and meat quality of Nellore heifers. Twenty-eight Nellore heifers with an average initial weight of 240.9 kg were used in this experiment. All heifers received the same dietary management, in an intensive rearing system, with mineral salt and water ad libitum. Heifers were distributed, in a completely randomized design, into two treatments (with and without progesterone ear implant) with seven replications, in 14 stalls. Analysis of variance was performed, and, for non-parametric variables, the Kruskal-Wallis test was applied. Parameters referring to the meat quantitative and qualitative characteristics, represented by the weight and yield of the carcass, conformation, marbling, color, meat texture, carcass morphometric measurements, longissimus dorsi muscle area, and fat thickness, were not affected by the progesterone hormone. The use of the progesterone ear implant did not change the carcass physical characteristics or the meat quality characteristics.

Este trabalho foi realizado para avaliar a influência do implante auricular de progesterona sintética sobre ganho de peso e na qualidade de carne de novilhas Nelore. Foram utilizadas 28 novilhas Nelore com peso inicial médio de 240,9 kg. Todas as novilhas receberam o mesmo manejo alimentar, em sistema intensivo de criação, com sal mineral e água ad libitum. Foram distribuídas em delineamento inteiramente casualizado, com dois tratamentos (com e sem implante auricular de progesterona) e sete repetições, em 14 baias, com a realização de análise de variância e para as variáveis não paramétricas foi realizado o teste de Kruskal-Wallis. Os parâmetros referentes às características quantitativas e qualitativas da carcaça e da carne, representados pelo peso e rendimento da carcaça, conformação, marmoreio, coloração, textura da carne, medidas morfométricas da carcaça, área do músculo Longissimus dorsi e espessura de gordura não foram afetados pelo hormônio progesterona. A utilização do implante auricular de progesterona, não alterou as características físicas da carcaça e a qualidade da carne.