Strategic re-use of intravaginal progesterone devices increases conception rate in primiparous Nellore cows / Reutilização estratégica de dispositivo intravaginal de progesterona aumenta a taxa de concepção em vacas Nelore primíparas

In the present study, we investigate the effect of the presence or absence of corpus luteum (CL) at the beginning of a fixed-time artificial insemination (FTAI) protocol and to evaluate the impact of one-time use of intravaginal progesterone device (P4 device) in cows with or without CL. A total of 776 primiparous Nellore cows were subjected to FTAI approximately 45 days postpartum. In Experiment 1, 476 cows were divided into two experimental groups: with (CL-present, n=113) or without (CL-absent, n=363) CL, after ultrasound evaluation. On day 0 (D0), all cows received a new P4 device (1.0 g) and 2.0 mg estradiol benzoate (EB). Eight days later (D8), the P4 devices were withdrawn, and prostaglandin (15 mg), estradiol cypionate (0.5 mg), and eCG (300 IU) were administered i.m. All cows were inseminated 48 h after P4 device withdrawal (D10). In Experiment 2, the cows (n= 300) received (at D0) P4 devices that were previously used once in other cows with (n=109) or without CL (n=191) and 2 mg of EB. The same protocol as that used in Experiment 1 was performed from D8 onwards. In Experiment 1, the overall conception rate after FTAI was 55% (262/476). No difference was found in the conception rate between CL-present and CL-absent cows (52.2 vs. 55.5%). In Experiment 2, the conception rate obtained with P4 devices previously used in cows with CL (58.7%) was greater (P<0.05) than that obtained with P4 devices previously used in cows without CL (42.9%). Thus, this strategy resulted in a 15.8% increase in conception rate. In conclusion, the presence or absence of CL at the beginning of the FTAI protocol did not affect the conception rate in cows synchronized with the new P4 device, but the insertion of P4 devices previously used in cows with CL enhanced the conception rates in cows without CL.

No presente estudo, investigamos o efeito da presença ou ausência de corpo lúteo (CL) no início de um protocolo de inseminação artificial em tempo fixo (IATF) e avaliamos o impacto do uso único de dispositivo intravaginal de progesterona (dispositivo P4) em vacas com ou sem CL. Um total de 776 vacas Nelore primíparas, aproximadamente 45 dias pós-parto foram submetidas à IATF. No Experimento 1, após avaliação ultrassonográfica, 476 vacas foram divididas em dois grupos experimentais: com (CL-presente, n=113) ou sem (CL-ausente, n=363) CL. No dia 0 (D0), todas as vacas receberam um novo dispositivo de P4 (1,0 g) e 2.0 mg de benzoato de estradiol (BE). Após 8 dias (D8), os dispositivos P4 foram retirados e prostaglandina (15 mg), cipionato de estradiol (0,5 mg) e eCG (300 UI) foram administrados i.m. Todas as vacas foram inseminadas 48 horas após a retirada do dispositivo de P4 (D10). No Experimento 2, as vacas (n= 300) receberam (no D0) um dispositivo de P4 previamente utilizado uma única vez em outras vacas com (n=109) ou sem CL (n=191) e 2 mg de BE. O mesmo protocolo utilizado no Experimento 1 foi realizado a partir do D8. No experimento 1, a taxa geral de concepção após IATF foi de 55% (262/476). Não foi encontrada diferença na taxa de concepção entre as vacas com CL presente e CL ausente (52,2 vs. 55,5%). No Experimento 2, a taxa de concepção obtida com dispositivos P4 previamente utilizados em vacas com CL-presente (58,7%) foi maior (P<0,05) quando comparada aos dispositivos P4 previamente utilizados em vacas com CL-ausente (42,9%). Essa estratégia resultou em aumento de 15,8% na taxa de concepção. Em conclusão, a presença ou ausência de CL no início do protocolo de IATF não afetou a taxa de concepção em vacas sincronizadas com dispositivo novo de P4; e a eficácia dos dispositivos de P4 previamente utilizados em vacas com CL é maior durante seu segundo uso em vacas sem CL.

Synchronization of follicular wave emergence does not improve embryonic yield in superovulated ewes

Abstract The present study aimed to investigate the effects of a combination of progesterone with different doses of E-17β on following end points: (1) ovarian follicular dynamics and emergence of a new follicular wave, and (2) superovulatory response and embryo yield. In Experiment 1, 28 ewes were randomly divided into four groups (n = 7) to receive either 2.0 mg, 1.0 mg, 0.5 mg or none E-17β one day after insertion of a progesterone device. The different doses of estradiol similarly delayed the moment of follicular emergence (overall mean = 3.1 ± 1.0 days vs. control group = 0.86 ± 1.0 days; P < 0.01), but the emergence of the new wave showed greater synchronization with the 0.5 mg dosage of E-17β. In Experiment 2, sixty-two donor ewes received an internal progesterone release device (day -1) for 7 d and 1 d after the insertion of this device (day 0) were allocated randomly to receive 0.5 mg of E-17β or only the vehicle (control group). Superstimulation was initiated on day 3 with the administration of 133 mg of pFSH in eight decreasing doses. Contrary to expectations, the protocol with the administration of 0.5 mg E-17β did not improve the percentage of donors with > 2 CL, the number of CL and the production of embryos (P > 0.05). It was concluded that the combination of progesterone and 0.5 mg E-17β was more efficient in synchronizing the emergence of the new follicular wave, however this approach seems to be unnecessary in ewe's superovulation programs.

Synchronization of follicular wave emergence does not improve embryonic yield in superovulated ewes

The present study aimed to investigate the effects of a combination of progesterone with different doses of E-17β on following end points: (1) ovarian follicular dynamics and emergence of a new follicular wave, and (2) superovulatory response and embryo yield. In Experiment 1, 28 ewes were randomly divided into four groups (n = 7) to receive either 2.0 mg, 1.0 mg, 0.5 mg or none E-17β one day after insertion of a progesterone device. The different doses of estradiol similarly delayed the moment of follicular emergence (overall mean = 3.1 ± 1.0 days vs. control group = 0.86 ± 1.0 days; P < 0.01), but the emergence of the new wave showed greater synchronization with the 0.5 mg dosage of E-17β. In Experiment 2, sixty-two donor ewes received an internal progesterone release device (day -1) for 7 d and 1 d after the insertion of this device (day 0) were allocated randomly to receive 0.5 mg of E-17β or only the vehicle (control group). Superstimulation was initiated on day 3 with the administration of 133 mg of pFSH in eight decreasing doses. Contrary to expectations, the protocol with the administration of 0.5 mg E-17β did not improve the percentage of donors with > 2 CL, the number of CL and the production of embryos (P > 0.05). It was concluded that the combination of progesterone and 0.5 mg E-17β was more efficient in synchronizing the emergence of the new follicular wave, however this approach seems to be unnecessary in ewes superovulation programs.(AU)

Comparative analysis of the hormone production and gene expression profiles in ovine uterus tissue during oestrus cycle synchronized using medroxyprogesterone acetate plus eCG and prostaglandin analogue / Análise comparativa da produção de hormônios e perfis de expressão gênica em tecido uterino ovino durante o ciclo estral sincronizado usando acetato de medroxiprogesterona mais eCG e análogo de prostaglandina

The combination of medroxyprogesterone acetate (MPA) and gonadotropin chorionic (eCG) has been widely used to synchronize oestrus cycle in sheep, but their effects on the gene expression in uterine tissue are yet to be elucidated. To evaluate the effect of MPA + eCG or prostaglandin analogue (PA) treatments on the rate of oestrus cycle synchronization, as well as further hormone production and gene expression profiles in uterine tissue, 14 Santa Inês ewes were randomly selected. The MPA + eCG group (n=7) received intravaginal insertion of MPA-impregnated sponges for 14 days and was administered 350 IU eCG on the day of sponge withdrawal. The PA group (n=7) was administered two doses of 100 µg of PA separated by 12 days. The ewes were assessed for the rate of oestrus cycle synchronization and the serum concentrations of progesterone (P4) and estradiol (E2). Additionally, the expression of estrogen receptor (ERα), progesterone receptor (P4R), and immunolocalization of interferon receptor (IFNAR1) in the uterine tissue samples collected 15th day post-mating were examined. The rate of oestrus cycle synchronization was 100% (n=7/7) and 57.14% (n=4/7) in the MPA + eCG and PA groups, respectively. Moreover, the MPA + eCG group exhibited higher serum concentration of P4 than the PA group (p < 0.05). However, the E2 serum concentration did not differ between the two groups (p > 0.05). The relative expression of P4R and ERα mRNA analyzed using real-time PCR and immunodetection of IFNAR1 were similar between the two groups tested (p > 0.05). Conclusively, MPA + eCG treatment improved the rate of oestrus cycle synchronization and endogenous P4 production; however, it did not affect the expression of sex steroid receptors and IFNAR1 in uterine ovine tissue.(AU)

A combinação de acetato de medroxiprogesterona (MPA) com gonadotrofina coriônica (eCG) é amplamente utilizada para sincronizar o estro de ovelhas, mas seus possíveis efeitos sobre a expressão gênica em tecido uterino não foram elucidados. Para avaliar o efeito dos protocolos MPA + eCG ou análogo de prostaglandina (PA) sobre a taxa de sincronização do estro, bem como na futura produção hormonal e expressão gênica em tecido uterino, 14 ovelhas Santa Inês foram selecionadas. O grupo MPA + eCG (n=7) recebeu a inserção de esponjas impregnadas de MPA por via intravaginal por 14 dias e 350 UI de eCG no dia da retirada da esponja. O grupo PA recebeu duas doses de 100 µg de PA administradas com 12 dias de intervalo. As ovelhas foram avaliadas quanto à taxa de sincronização do estro, concentração sérica de progesterona (P4) e estradiol (E2). Além disso, foram examinadas a expressão do receptor de estradiol (ERα), receptor de progesterona (P4R) e localização do receptor de interferon (IFNAR1), a partir de amostras de tecido uterino coletadas 15 dias após o acasalamento. A taxa de sincronização do estro foi 100% (n = 7/7) e 57,14% (n = 4/7) nos grupos MPA + eCG e PA, respectivamente. Além disso, o grupo MPA + eCG apresentou maior concentração sérica de P4 em comparação com o grupo PA (P < 0,05). No entanto, a concentração sérica de E2 não diferiu entre os grupos testados (P > 0,05). A expressão relativa de RNAm para P4R e ERα analisado por PCR em tempo real e imunodetecção de IFNAR1 foi semelhante entre os grupos testados (P > 0,05). Em conclusão, o tratamento com MPA + eCG melhora a taxa de sincronização do estro e a produção de progesterona endógena; contudo, não afeta a regulação da expressão de receptores de esteroides sexuais e IFNAR1 no tecido uterino de ovinos.(AU)

Milk production in Saanen goats treated with repeated low doses of intermediate-release insulin during early lactation / Produção de leite em cabras Saanen tratadas com repetidas doses baixas de insulina de liberação intermediária durante a lactação inicial

The effect of insulin administration on the productive responses of Saanen goats during early lactation was investigated. Ten of 20 adult females were subjected to subcutaneous administration of intermediate-acting insulin (0.14UI/kg body weight) at 2, 9, and 14 days postpartum. Milk yield was measured twice daily for 13 weeks and milk samples were collected to measure protein and fat contents. Plasma levels of progesterone, insulin, non-esterifies fatty acids, glucose and other metabolites were measured. Results showed a significantly increased effect of insulin treatment on the content of milk fat and protein; moreover, milk production in the first and second postpartum weeks were higher than control group. The peak of lactation in the insulin group was achieved one week earlier in comparison to the control group. In addition, the milk production rate showed lower persistency (milk yield 13 week/milk yield at peak) in the same group. During the first four weeks of postpartum, treated animals showed greater weight loss and higher non-esterified fatty acid concentration, whereas no effect was observed on the concentration of progesterone and other metabolites. The above results indicated that repeated administration of insulin in dairy goats during early lactation increase yield and qualitative components of milk, but has substantial consequences on animal productive rate and metabolic response.(AU)

O objetivo do estudo foi avaliar o efeito da administração de insulina sobre a resposta produtiva de cabras Saanen durante a lactação inicial. Dez de vinte fêmeas adultas foram sujeitas à administração subcutânea de repetidas e baixas doses de insulina de liberação intermediária aos 2, 9 e 14 dias pós-parto. A produção de leite foi mensurada duas vezes ao dia, por 13 semanas, e amostras de leite foram coletadas para mensurar teores de proteína e gordura. Os níveis plasmáticos de progesterona, insulina, ácidos graxos não-esterificados (AGNE), glicose e outros metabólitos foram mensurados. Os resultados mostraram um efeito significativamente maior nos animais tratados com insulina sobre o teor de gordura e proteína no leite. Além disso, a produção de leite na primeira e segunda semana pós-parto foi maior no grupo tratado do que no grupo controle. O pico de lactação no grupo insulina foi alcançado uma semana antes em comparação ao grupo controle. Além disso, a taxa de produção de leite nos animais tratados mostrou uma menor persistência de produção de leite durante o período analisado. Durante as primeiras quatro semanas pós-parto, os animais tratados com insulina mostraram maior perda de peso e maior concentração de AGNE, enquanto não se observou nenhum efeito sobre a concentração de progesterona ou outros metabólitos. Os resultados acima indicam que repetidas doses de insulina em cabras leiteiras durante a lactação inicial aumenta o rendimento de produção e concentração de componentes qualitativos do leite, mas apresenta consequências consideráveis sobre taxa de produção animal e resposta metabólica.(AU)

Impact of body condition on postpartum features in morada nova sheep / Impacto da condição corporal sobre o pós-parto em ovelhas morada nova

This study evaluated the impact of nutritional status of Morada Nova sheep at lambing on the reproductive and productive performance and on the survival of lambs in early weaning system. Nineteen, Morada Nova sheep were assigned to two groups according to body condition score (BCS) at lambing: low BCS (n = 11) and high BCS (n=8) with body condition respectively of (mean ± SD) 2.0 ± 0.3 e 2.9 ± 0.1. From birth until lamb weaning (45 days), sheep were weighed weekly and checked the BCS, loin subcutaneous fat thickness, loin depth, hematological profile, milk composition and production, and every three days, we measured the uterine diameter. Lamb weightings were performed up to one week after weaning (52 days). The lower availability of muscle and fat reserves in the low BCS group negatively affected milk production and consequently performance of suckling lambs. However, the results indicated that the uterine involution process, the reproductive parameters including prolificacy, rate of multiple births, number of white blood cells, milk quality, body weight of lambs at birth and mortality rates were not affected by the body condition. The results allowed to describe the responsiveness to opposite nutritional status of Morada Nova sheep, showing their characteristics of adaptation...(AU)

O objetivo do trabalho foi verificar o impacto do estado nutricional de ovelhas Morada Nova ao parto sobre o seu desempenho reprodutivo e produtivo e sobre a sobrevivência de cordeiros em sistema de desmame precoce. Foram utilizadas 19 ovelhas Morada Nova, divididas em dois grupos de acordo com o escore da condição corporal ECC ao parto: grupo ECC baixo (n = 11) e ECC alto (n = 8) com escore médio (± DP) respectivamente de 2.0 ± 0.3 e 2.9 ± 0.1. A partir do parto até o desmame dos cordeiros (45 dias), as mães foram pesadas semanalmente e verificado o ECC, espessura da gordura subcutânea lombar, profundidade do lombo, perfil hematológico, composição e produção leiteira e a cada três dias mensurado o diâmetro uterino. Os cordeiros foram pesados até uma semana após o desmame (52 dias). A menor disponibilidade de reservas muscular e adiposa no grupo ECC baixo refletiu negativamente na produção de leite e consequentemente no desempenho dos cordeiros na fase de aleitamento. Todavia os resultados indicaram como o processo de involução uterina, os parâmetros reprodutivos como prolificidade, taxa de partos múltiplos, o número de células brancas, a qualidade do leite, o peso vivo dos cordeiros ao nascer e as taxas de mortalidade não foram afetados pela condição corporal. Em conclusão o conjunto de dados obtidos pelo presente estudo permitiu descrever a capacidade de resposta as condições...(AU)

Impact of body condition on postpartum features in morada nova sheep / Impacto da condição corporal sobre o pós-parto em ovelhas morada nova

This study evaluated the impact of nutritional status of Morada Nova sheep at lambing on the reproductive and productive performance and on the survival of lambs in early weaning system. Nineteen, Morada Nova sheep were assigned to two groups according to body condition score (BCS) at lambing: low BCS (n = 11) and high BCS (n=8) with body condition respectively of (mean ± SD) 2.0 ± 0.3 e 2.9 ± 0.1. From birth until lamb weaning (45 days), sheep were weighed weekly and checked the BCS, loin subcutaneous fat thickness, loin depth, hematological profile, milk composition and production, and every three days, we measured the uterine diameter. Lamb weightings were performed up to one week after weaning (52 days). The lower availability of muscle and fat reserves in the low BCS group negatively affected milk production and consequently performance of suckling lambs. However, the results indicated that the uterine involution process, the reproductive parameters including prolificacy, rate of multiple births, number of white blood cells, milk quality, body weight of lambs at birth and mortality rates were not affected by the body condition. The results allowed to describe the responsiveness to opposite nutritional status of Morada Nova sheep, showing their characteristics of adaptation...

O objetivo do trabalho foi verificar o impacto do estado nutricional de ovelhas Morada Nova ao parto sobre o seu desempenho reprodutivo e produtivo e sobre a sobrevivência de cordeiros em sistema de desmame precoce. Foram utilizadas 19 ovelhas Morada Nova, divididas em dois grupos de acordo com o escore da condição corporal ECC ao parto: grupo ECC baixo (n = 11) e ECC alto (n = 8) com escore médio (± DP) respectivamente de 2.0 ± 0.3 e 2.9 ± 0.1. A partir do parto até o desmame dos cordeiros (45 dias), as mães foram pesadas semanalmente e verificado o ECC, espessura da gordura subcutânea lombar, profundidade do lombo, perfil hematológico, composição e produção leiteira e a cada três dias mensurado o diâmetro uterino. Os cordeiros foram pesados até uma semana após o desmame (52 dias). A menor disponibilidade de reservas muscular e adiposa no grupo ECC baixo refletiu negativamente na produção de leite e consequentemente no desempenho dos cordeiros na fase de aleitamento. Todavia os resultados indicaram como o processo de involução uterina, os parâmetros reprodutivos como prolificidade, taxa de partos múltiplos, o número de células brancas, a qualidade do leite, o peso vivo dos cordeiros ao nascer e as taxas de mortalidade não foram afetados pela condição corporal. Em conclusão o conjunto de dados obtidos pelo presente estudo permitiu descrever a capacidade de resposta as condições...

REPRODUCTIVE AND METABOLIC RESPONSES IN EWES TO DIETARY PROTEIN SUPPLEMENT DURING MATING PERIOD IN DRY SEASON OF NORTHEAST BRAZIL

This study evaluated the effect of food supplements with different levels of protein on reproductive and metabolic response of ewes during the mating period. Forty-one ewes were supplemented during 43 days with amount protein to meet 1.0 (diet I; n = 14), 1.7 (diet II; n = 13) and 2.1 (diet III; n = 14) times the maintenance requirements. Dry matter (DM) intake was higher (P 0.01) in diet III when compared to diets I and II. Orts were lesser in diets II and III (P 0.05) when compared to diet I. Intake of organic matter (OM), crude protein (CP) and ether extract (EE) was higher in diet III (P 0.05), but NDF and ADF intake was superior in diet I (P 0.05). In diet III, a higher frequency of female mated was observed (P 0.05). The prolificity and twinning rate was higher in ewes of diet II (P 0.05). Greater birth weight of lambs (P 0.05) was verified in diet III. The progesterone levels were affected by diets II and III (P 0.05). In conclusion, the supplementation of ewes with intermediate level of protein improves their reproductive response.

Este estudo avaliou o efeito de suplementos alimentares com diferentes níveis de proteína sobre a resposta reprodutiva e metabólica de ovelhas durante o período de monta. Quarenta e uma ovelhas foram suplementadas durante 43 dias com proteína em quantidade para satisfazer 1,0 (dieta I; n = 14), 1,7 (dieta II; n = 13) e 2,1 (dieta III; n = 14) vezes as exigências de manutenção. O consumo de matéria seca (MS) foi superior (P 0,01) na dieta III quando comparada com as dietas I e II. As sobras foram menores nas dietas II e III (P 0,05) quando comparada à dieta I. O consumo de matéria orgânica (MO), proteína bruta (PB) e extrato estéreo (EE) foram superiores na dieta III, porém a ingestão de NDF e ADF foi maior na dieta I (P 0,05). Na dieta III foi observada uma maior frequência de fêmeas montadas (P 0,05). A taxa de prolificidade e gemelaridade foi maior em ovelhas da dieta II (P 0,05). Verificou-se um maior peso ao nascimento de cordeiros (P 0,05) na dieta III. Os níveis de progesterona medidos após o acasalamento foram afetados pelas dietas II e III (P 0,05). Em conclusão, a suplementação de ovelhas com nível intermediário de proteína melhora sua resposta reprodutiva.

Uso de farelo de mamona (Ricinus communis L.) como fonte de proteína na dieta de caprinos durante o período de monta: impacto sobre a resposta reprodutiva e metabólica / Use of castor meal (Ricinus communis L. ) as a source of dietary protein in goats during the mating period: impact on reproductive and metabolic responses

O objetivo do presente estudo foi avaliar o efeito da substituição total do farelo de soja por farelo de mamona detoxificado ou não sobre a resposta à sincronização do estro, taxa de concepção, desenvolvimento fetal inicial, presença de IgG e resposta metabólica-hormonal. Sessenta cabras mestiças foram alimentadas sem farelo de mamona (SFM), com farelo de mamona detoxificado (FMD) e com farelo de mamona (FM) durante a gestação inicial. Todos os animais tiveram o estro sincronizado e depois foram acasaladas por monta natural. A partir do 25º dia após a monta, foi determinado o número de fetos e realizado o acompanhado do desenvolvimento dos mesmos por ultrassonografia até os 60 dias de gestação. Foi avaliado o perfil de progesterona (P4), os níveis de metabólitos e a resposta imunológica. A partir do 15º dia de alimentação a imunoglobulina G (IgG) foi marcada através da técnica de Western Blotting, apenas em animais que receberam farelo de mamona não detoxificado. Não houve efeito (p>0,05) do tipo de dieta sobre a resposta à sincronização do estro, níveis plasmáticos de P4, taxa de gestação e desenvolvimento embrionário/fetal. Em cabras gestantes, observou-se um efeito da dieta (p 0,001) sobre os níveis plasmáticos de uréia em animais de gestação múltipla, de gama-glutamil transferase (GGT) em gestação simples e de lactato desidrogenase (LDH) em ambos os tipos de gestação.(AU)

The aim of the present study was to evaluate the effects of the total substitution of soybean meal with castor meal, detoxified or non-detoxified, on the response to estrous synchronization, conception rate, early fetal development, presence of IgG, and metabolic-hormonal response. Sixty mixed goats were fed diets without castor meal (WCM), with detoxified castor meal (DCM), and with castor meal (CM) during early pregnancy. The goats had their estrous synchronized and were then submitted to the mating season. The number of fetuses was determined by ultrasonography after 25 days of mating and their development was followed until 60 days of gestation. Plasma levels of progesterone (P4), liver enzymes, and urea were determined along with the evaluation of the immunological response. After 15 days of experimental feeding, immunoglobulin G (IgG) was detected by western blotting only in goats that received non-detoxified castor meal. There was no effect (p > 0.05) of type of diet on response to estrous synchronization, plasma P4 levels, conception rate, or embryonic/fetal development. In pregnant goats, there was an effect of diet (p 0.001) on plasma urea levels in multiple-birth pregnancy, gamma-glutamyltransferase (GGT) in single-birth pregnancy, and lactate dehydrogenase (LDH) in both types of pregnancy. In non-pregnant goats, there were increased urea levels in all types of diet were higher in non-pregnant goats than pregnant goats. In conclusion, it can be inferred that the inclusion of 15% castor meal, whether or not it is detoxified, to the diet of goats does not affect the reproductive performance, embryonic and early fetal development, or blood metabolites.(AU)

Post-partum reproductive activity and estrus synchronization responsiveness in anglonubian x sprd fed with dried carnauba wax palm fruit (Copernicia prunifera) long term / Atividade reprodutiva e resposta à sincronização de estro no pós-parto em cabras mestiças de anglonubiana x sprd alimentadas com o fruto desidratado da carnaubeira (Copercinia prunifera) por longo tempo

The present study evaluates the use of dried carnauba wax palm fruit in 28 postpartum goats fed diets containing Bermudagrass hay and either corn (WCWP) or carnauba-based (CWP) concentrated feed. Estrus synchronization was performed 90 days postpartum, and the goats were mated. In the CWP group, compared to the WCWP group, the daily dry matter intake was significantly reduced (646.48 ± 11.03 g vs. 739.29 ± 3.24 g, respectively; P 0.01). The time to the first functional corpus luteum was similar between the groups, occurring a mean 66 days postpartum. During estrus synchronization, the CWP group had a decreased sternal subcutaneous adipose tissue thickness when compared to the WCWP group (11.93 ± 0.45 mm vs. 13.69 ± 0.57 mm, respectively; P 0.05) and a lower pregnancy rate (86.67% vs. 46.15%, respectively; P 0.02). The embryonic vesicle and crown-rump length growth rates, and the biparietal, thoracic, and abdominal diameters at 45 days of pregnancy were within normal range for goats in both groups. Litter size at birth was similar between the groups at a mean 1.39 ± 0.11. In conclusion, the substitution of corn with dehydrated carnauba wax palm fruit in concentrated feed for postpartum goats showed no positive effects. Reduced feed intake in the does consuming the carnauba diet caused decreased body reserves, which probably resulted in a decreased pregnancy rate...(AU)

O presente estudo avaliou o uso do fruto da carnaubeira desidratado em 28 cabras no período pós-parto alimentadas com dieta contendo feno de Tifton e concentrado comercial a base de milho (WCWP) ou com o fruto da carnaubeira (CWP). A sincronização de estro foi realizada aos 90 dias pós-parto e todas as fêmeas foram cobertas. No grupo CWP, em relação ao grupo WCWP, o consumo de matéria seca foi significativamente menor (646.48 ± 11.03 g vs. 739.29 ± 3.24 g, respectivamente; P 0.01). O tempo para o aparecimento do primeiro corpo lúteo funcional foi semelhante entre os grupos, ocorrendo em média aos 66 dias pós-parto. No momento da sincronização do estro, o grupo CWP apresentou uma menor espessura do tecido adiposo subcutâneo esternal quando comparado ao grupo WCWP (13,69 ± 0,57 mm vs. 11,93 ± 0,45 mm, respectivamente; P 0,05) e uma menor taxa de gestação (86,67% vs. 46,15%, respectivamente; P 0.02). A taxa de crescimento da vesícula embrionária e do comprimento crânio-caudal, assim como no diâmetro biparietal, torácico e abdominal aos 45 dias de gestação estavam em ambos os grupos dentro do esperado para a espécie em questão. Ao parto a prolificidade não diferiu entre os grupos, com média de 1,39 ± 0,11. Em conclusão, a substituição total do milho pelo fruto da carnaubeira no concentrado fornecido às fêmeas caprinas no período pós-parto não apresentou efeitos...(AU)

Tissue thickness may influence the outcome of vitrification of goat ovarian cortex

Background: The main advantage of the cryopreservation of ovarian fragments is a thinner tissue, which facilitates the penetration of cryoprotective agents, but the size of tissue may not be a limiting factor in achieving a successful cryopreservation of the ovarian tissue. This information is highly significant considering that the cryopreservation of hemi-ovary or whole ovary may preserve the entire or major part of the contingent of primordial follicles of ovarian fragments. Therefore, the aim of this study was to evaluate the vitrification of different dimensions goat ovarian tissue on the follicular morphology, viability, diameter, and the stromal cell density. Materials, Methods & Results: The ovarian tissue was vitrified as fragment, hemi-ovary, or whole ovary, and after warming, the preantral follicles were examined by trypan blue dye exclusion test and histological analysis. Preantral follicles incubated with trypan blue were considered viable if the oocyte and granulosa cells remained unstained. Preantral follicles were classified as morphologically normal only when they contained intact oocyte and granulosa cells. The follicular diameter was measured considering the major and minor axes of each follicle; the average of these 2 measurements was used to determine the diameter of each follicle. Ovarian stroma cells density was evaluated by calculating the number of stromal cell in an area of 100 × 100 µm. There was no difference in the percentage of morphologically normal and viable follicles after vitrification compared to the control (fresh tissue), regardless of the dimension of the vitrified ovarian tissue (P > 0.05). In addition, there were no differences in the follicular diameter after ovarian tissue vitrification, independent of the dimension (P > 0.05). However, after vitrifi cation, a decrease in the ovarian stromal cells density was observed (P < 0.05). This reduction was more intense after the vitrification of the hemi-ovary and whole ovary, compared to the ovarian fragment vitrification (P < 0.05). Discussion: No differences were observed in the percentages of morphologically normal and viable follicles from fresh or vitrified ovarian tissue (fragment, hemi-ovary, and whole ovary). These results are in agreement with other reports which no showed morphological changes after cryopreservation of the whole ovary, and the ovarian fragments. With respect to follicular diameter, only the diameter of the preantral follicles in ovarian tissue vitrified as hemi-ovary was similar to that observed in the fresh control, in the present study. The results demonstrate that fragments and whole ovary vitrification had greater cell dehydration (exposure to VS) and/or less cell rehydration (VS removal), showing that minor adjustments are needed in the protocols of cryoprotectants addition or removal from the fragments and the whole ovary. However, this reduction in follicular diameter did not appear to have affected the follicular architecture or cellular viability, which were maintained in all dimensions of ovarian tissue undergoing vitrifi cation. A reduction in the stromal cell density was observed, especially in the hemi-ovary and whole ovary as compared to the ovarian fragment. Previous reports have shown that ovarian stromal cells are responsible for the production of essential substances for follicular development and these substances are fundamental for follicles development and these cells tend to be more sensitive to cryopreservation procedure than ovarian follicles. In conclusion, the maintenance of follicular morphology and viability demonstrated that vitrification of goat ovarian tissue under the conditions applied in this study can be performed in any dimension of ovarian tissue (fragment, hemi-ovary, and whole ovary).

Criopreservação de tecido ovariano: limitações e perspectivas para a preservação da fertilidade de fêmeas / Ovarian tissue cryopreservation: limitations and perspectives for female pertility preservation

Background: The ovarian tissue cryopreservation has been achieved a great notoriety in the Reproductive Biology area, due to its potential in preserving female fertility through the protection of exocrine and endocrine functions of the ovary. The association of this technique with in vitro culture and/or transplant in adult or young individuals who has not initiated its reproductive activities represents not only the conservation and perpetuation of the genetic material of economic valuable animals, but also the preservation of female gametes from endangered species, or even from young women who may have ovarian dysfunctions caused by gonadotoxic treatments. Studies with some species (human, mice and ovine) have demonstrated the recovery of the ovarian function and the birth of healthy offspring after transplant of ovarian tissue which has been previously cryopreserved. However, most studies have shown that ovarian cryopreservation process offer risks to different structures (follicle and stroma ) as well as to the different cell types (oocyte, granulosa, thecal and stromal cells), which constitute this tissue. Review: Extreme cold, intracellular ice crystallization, osmotic shock and the toxicity of the cryoprotectant agents are factors that are usually associated with the injuries caused by the cryopreservation process. As a direct or indirect consequence, those factors limit the success of the cryopreservation of ovarian tissue, since they affect the survival or alter the tissue functionality or cellular structure, like the ovarian follicles, for example, after the thawing/warming procedure. Among the injuries that may take place as a consequence of those factors, we can mention: cell death by the necrotic or apoptotic pathways; alterations in normal levels of genic expression; ischemia and changes of communication and interaction between the oocyte and follicular cells. As a result, many authors have studied and developed protocols of cryopreservation that may prevent or minimize the cryoinjuries, since the cryopreservation per si or combined to other techniques (in vitro culture and/or transplant) can compromise the ovarian integrity, leading consequently to a significant loss of follicles. In this regard, the present review seeks to app roach the advantages of the cryopreservation of ovarian tissue; indicating the difficulties and challenges that encompass this procedure, with purpose of pointing out solutions to overcome the damages of ovarian tissue cryopreservation, through of convenient cryopreservation protocols that avoid those follicular losses. For this purpose, it is necessary the preservation of the follicular viability as well as the preservation of the tissue integrity and the contact between reproductive (oocytes) or somatic cells, which are essentials to the follicle development, and, consequently, to the embryo production. Conclusion: The use of cryopreserved ovarian tissue is an important strategy to the preservation of female fertility. This tool has being pointed as an alternative way to the cryopreservation of mature oocytes and embryos. However, additional studies are necessary to diminishing the cellular damages inherent to this procedure, especially those related to the comprehension of the obstacles and mechanisms associated to the exposition to extreme cold.

Criopreservação de tecido ovariano: limitações e perspectivas para a preservação da fertilidade de fêmeas / Ovarian tissue cryopreservation: limitations and perspectives for female pertility preservation

Background: The ovarian tissue cryopreservation has been achieved a great notoriety in the Reproductive Biology area, due to its potential in preserving female fertility through the protection of exocrine and endocrine functions of the ovary. The association of this technique with in vitro culture and/or transplant in adult or young individuals who has not initiated its reproductive activities represents not only the conservation and perpetuation of the genetic material of economic valuable animals, but also the preservation of female gametes from endangered species, or even from young women who may have ovarian dysfunctions caused by gonadotoxic treatments. Studies with some species (human, mice and ovine) have demonstrated the recovery of the ovarian function and the birth of healthy offspring after transplant of ovarian tissue which has been previously cryopreserved. However, most studies have shown that ovarian cryopreservation process offer risks to different structures (follicle and stroma ) as well as to the different cell types (oocyte, granulosa, thecal and stromal cells), which constitute this tissue. Review: Extreme cold, intracellular ice crystallization, osmotic shock and the toxicity of the cryoprotectant agents are factors that are usually associated with the injuries caused by the cryopreservation process. As a direct or indirect consequence, those factors limit the success of the cryopreservation of ovarian tissue, since they affect the survival or alter the tissue functionality or cellular structure, like the ovarian follicles, for example, after the thawing/warming procedure. Among the injuries that may take place as a consequence of those factors, we can mention: cell death by the necrotic or apoptotic pathways; alterations in normal levels of genic expression; ischemia and changes of communication and interaction between the oocyte and follicular cells. As a result, many authors have studied and developed protocols of cryopreservation that may prevent or minimize the cryoinjuries, since the cryopreservation per si or combined to other techniques (in vitro culture and/or transplant) can compromise the ovarian integrity, leading consequently to a significant loss of follicles. In this regard, the present review seeks to app roach the advantages of the cryopreservation of ovarian tissue; indicating the difficulties and challenges that encompass this procedure, with purpose of pointing out solutions to overcome the damages of ovarian tissue cryopreservation, through of convenient cryopreservation protocols that avoid those follicular losses. For this purpose, it is necessary the preservation of the follicular viability as well as the preservation of the tissue integrity and the contact between reproductive (oocytes) or somatic cells, which are essentials to the follicle development, and, consequently, to the embryo production. Conclusion: The use of cryopreserved ovarian tissue is an important strategy to the preservation of female fertility. This tool has being pointed as an alternative way to the cryopreservation of mature oocytes and embryos. However, additional studies are necessary to diminishing the cellular damages inherent to this procedure, especially those related to the comprehension of the obstacles and mechanisms associated to the exposition to extreme cold.(AU)

Ativina intraovariana: uma atualização sobre estrutura, regulação e função / Intraovarian activin: an update on structure, regulation and function

Background: Important advances have been made recently that clarify our understanding of the structural basis, signaling and regulation, as well as the biological role of activin in ovaries. During folliculogenesis various growth factors are produced locally in the mammalian ovary. Among these factors, activin has been a focal point in research as it has emerged as a crucial substance capable of inducing follicular development. The important actions indicate that activin has many relevant homeostatic functions in the reproduction of several species. Therefore, this review discusses the ligand protein structure, activin receptors, mechanisms of action and regulation, as well as the importance of activin on in vitro culture of preantral follicles. Review: Activin belongs to the transforming growth factor β (TGF - β) super family. It is a homodimer or heterodimer of two similar but distinct subunits (βA and βB). The dimerisation of activin subunits gives rise to three forms of activin, which are classified as, activin A (βA - βA), activin B (βB - βB) and activin AB (βA - βB). The biological activity of activin occurs through its connection with two types of cell surface receptors designated type I and type II. These receptors are represented by two isoforms, activin receptor types IA (ActR - IA), IB (ActR - IB), IIA (ActR - IIA) and IIB (ActR - IIB). Activin receptors are transmembrane proteins, composed of a ligand-binding extracellular domain, a transmembrane domain and a cytoplasmic domain with serine/threonine kinase activity. The transient activation of the receptor induces phosphorylation of protein mediators called Smads. Activation of Smad 2/3 by phosphorylation causes trimerization and hetero-oligomerization with the common Smad, Smad 4. This complex translocates to the nucleus to activating and regulating transcription of target genes. Members of another class of Smads act as negative regulators of the signal transduction pathway. Inhibitory Smad 7 can bind to type I receptors, preventing receptor–Smad 2/3 association, or by competitively binding of Smad 4, which blocks Smad intracellular translocation. In addition, within the extracellular environment, binding proteins such as follistatin and inhibin can modulate the biological activity of activin. In the ovaries of mammals specifically, activin participates in several cellular events, including cellular proliferation, differentiation, and survival, as well as assisting steroidal hormones during follicular development. Activin has been localized in the oocytes and granulosa cells of rodent, porcine, caprine and bovine follicles. Activin is also within the granulosa cells of human follicles and in the thecal layers of porcine and human. In addition, activin stimulates follicle growth in-vitro, is used in pre-antral ovine and caprine follicles and enhances growth and survival of human pre-antral follicles in vitro. Conclusion: Activin is controlled by competitive substances and a dynamic interaction between the various regulatory proteins responsible for coordinating several signaling pathways. The balance between the actions of these proteins is critical for regulation of gene expression in different structures, including pre-antral follicles. However, the nature of physiological effects of activin in the ovary is still equivocal and awaits clarification.(AU)

Papel de agentes antioxidantes na criopreservação de células germinativas e embriões / Role of Antioxidants Agents in Germ Cells and Embryos Cryopreservation

Background: Antioxidants are molecules or substances able to convert the reactive oxygen species (ROS) in water, preventing its overproduction. In an attempt to reduce or eliminate oxidative stress during cryopreservation, antioxidants, especially catalase and trolox®, have been added to the freezing medium to maximize cell survival after the process of freezing / thawing. These substances have been used mainly in the cryopreservation of semen, embryos and oocytes. Given the importance of adding these agents in cryopreservation of mammal germ cells, this review aims to describe issues related to the addition of catalase and trolox® for maintaining the viability of these cells in the cryopreservation process. Review: Numerous protocols for germ cells cryopreservation have achieved satisfactory results in different species, although some points of these protocols still require adjustments in order to succeed in the repeatability of results. Cryopreservation can affect negativelly cell and / or tissues viability by several factors, including the formation of intracellular ice crystals, solution effect and toxicity caused by the inappropriate use of cryoprotective agents. Currently, several studies have emphasized the damage caused by the formation of ROS during cryopreservation processes, leading to oxidative stress. ROS formed during the cryopreservation process can degrade essential molecules to cells, including the polyunsaturated lipids present in the cell membrane (lipid peroxidation), leading them to death. In order to prevent oxidative stress that occurs during cryopreservation, some researchers have tested the addition of antioxidants to the freezing medium in order to achieve higher rates of cell survival after the thawing process. Antioxidants are substances that can neutralize ROS, thus reducing its power of chemical reaction.[...]

Agentes crioprotetores intracelulares: características e utilização na criopreservação de tecido ovariano e oócitos / Intracellular Cryoprotectant Agents: Characteristics and Use of Ovarian Tissue and Oocyte Cryopreservation

Background: The application of cryopreservation in human and animal reproductive medicine has stimulated several studies about the effects of low temperatures and freezing processes on cells and tissues, in order to develop efficient protocols for gamete and embryo preservation. Moreover, cryopreservation is a fundamental tool for the establishment of animal germplasm banks, allowing the preservation of genetic material from several species and breeds or for further study and/or recovery of desirable characteristics. For the success of cryopreservation, the addition of an intracellular cryoprotectant agent in the freezing solution is indispensable. However, issues related to intracellular cryoprotectant agents used, e.g., their metabolism and potential toxicity, must be examined carefully so we can choose the cryoprotectant most suitable for a specific structure. Review: In this regard, this review introduces several aspects of cryopreservation, such as basic principles and methods used (slow freezing and vitrification), describing the fundamental steps of cryoprotectant agent’s exposure, cooling, storage, thawing or warming and removal of the cryoprotectant agent. The addition of an intracellular cryoprotectant to the freezing solution is essential, but does not guarantee the success of the cryopreservation protocol, due to its toxic effect, which requires a perfect balance between cryoprotectant concentration, temperature and exposure time to the structure which will be cryopreserved. Some studies attribute the toxicity of these agents mainly to the secondary metabolites formed when the cell resumes its activi ty and gradually begins to metabolize the cryoprotectant agent.[...]

Ativina intraovariana: uma atualização sobre estrutura, regulação e função / Intraovarian activin: an update on structure, regulation and function

Background: Important advances have been made recently that clarify our understanding of the structural basis, signaling and regulation, as well as the biological role of activin in ovaries. During folliculogenesis various growth factors are produced locally in the mammalian ovary. Among these factors, activin has been a focal point in research as it has emerged as a crucial substance capable of inducing follicular development. The important actions indicate that activin has many relevant homeostatic functions in the reproduction of several species. Therefore, this review discusses the ligand protein structure, activin receptors, mechanisms of action and regulation, as well as the importance of activin on in vitro culture of preantral follicles. Review: Activin belongs to the transforming growth factor β (TGF - β) super family. It is a homodimer or heterodimer of two similar but distinct subunits (βA and βB). The dimerisation of activin subunits gives rise to three forms of activin, which are classified as, activin A (βA - βA), activin B (βB - βB) and activin AB (βA - βB). The biological activity of activin occurs through its connection with two types of cell surface receptors designated type I and type II. These receptors are represented by two isoforms, activin receptor types IA (ActR - IA), IB (ActR - IB), IIA (ActR - IIA) and IIB (ActR - IIB). Activin receptors are transmembrane proteins, composed of a ligand-binding extracellular domain, a transmembrane domain and a cytoplasmic domain with serine/threonine kinase activity. The transient activation of the receptor induces phosphorylation of protein mediators called Smads. Activation of Smad 2/3 by phosphorylation causes trimerization and hetero-oligomerization with the common Smad, Smad 4. This complex translocates to the nucleus to activating and regulating transcription of target genes. Members of another class of Smads act as negative regulators of the signal transduction pathway. Inhibitory Smad 7 can bind to type I receptors, preventing receptor–Smad 2/3 association, or by competitively binding of Smad 4, which blocks Smad intracellular translocation. In addition, within the extracellular environment, binding proteins such as follistatin and inhibin can modulate the biological activity of activin. In the ovaries of mammals specifically, activin participates in several cellular events, including cellular proliferation, differentiation, and survival, as well as assisting steroidal hormones during follicular development. Activin has been localized in the oocytes and granulosa cells of rodent, porcine, caprine and bovine follicles. Activin is also within the granulosa cells of human follicles and in the thecal layers of porcine and human. In addition, activin stimulates follicle growth in-vitro, is used in pre-antral ovine and caprine follicles and enhances growth and survival of human pre-antral follicles in vitro. Conclusion: Activin is controlled by competitive substances and a dynamic interaction between the various regulatory proteins responsible for coordinating several signaling pathways. The balance between the actions of these proteins is critical for regulation of gene expression in different structures, including pre-antral follicles. However, the nature of physiological effects of activin in the ovary is still equivocal and awaits clarification.

Agentes crioprotetores intracelulares: características e utilização na criopreservação de tecido ovariano e oócitos / Intracellular Cryoprotectant Agents: Characteristics and Use of Ovarian Tissue and Oocyte Cryopreservation

Background: The application of cryopreservation in human and animal reproductive medicine has stimulated several studies about the effects of low temperatures and freezing processes on cells and tissues, in order to develop efficient protocols for gamete and embryo preservation. Moreover, cryopreservation is a fundamental tool for the establishment of animal germplasm banks, allowing the preservation of genetic material from several species and breeds or for further study and/or recovery of desirable characteristics. For the success of cryopreservation, the addition of an intracellular cryoprotectant agent in the freezing solution is indispensable. However, issues related to intracellular cryoprotectant agents used, e.g., their metabolism and potential toxicity, must be examined carefully so we can choose the cryoprotectant most suitable for a specific structure. Review: In this regard, this review introduces several aspects of cryopreservation, such as basic principles and methods used (slow freezing and vitrification), describing the fundamental steps of cryoprotectant agents exposure, cooling, storage, thawing or warming and removal of the cryoprotectant agent. The addition of an intracellular cryoprotectant to the freezing solution is essential, but does not guarantee the success of the cryopreservation protocol, due to its toxic effect, which requires a perfect balance between cryoprotectant concentration, temperature and exposure time to the structure which will be cryopreserved. Some studies attribute the toxicity of these agents mainly to the secondary metabolites formed when the cell resumes its activi ty and gradually begins to metabolize the cryoprotectant agent.[...](AU)

Papel de agentes antioxidantes na criopreservação de células germinativas e embriões / Role of Antioxidants Agents in Germ Cells and Embryos Cryopreservation

Background: Antioxidants are molecules or substances able to convert the reactive oxygen species (ROS) in water, preventing its overproduction. In an attempt to reduce or eliminate oxidative stress during cryopreservation, antioxidants, especially catalase and trolox®, have been added to the freezing medium to maximize cell survival after the process of freezing / thawing. These substances have been used mainly in the cryopreservation of semen, embryos and oocytes. Given the importance of adding these agents in cryopreservation of mammal germ cells, this review aims to describe issues related to the addition of catalase and trolox® for maintaining the viability of these cells in the cryopreservation process. Review: Numerous protocols for germ cells cryopreservation have achieved satisfactory results in different species, although some points of these protocols still require adjustments in order to succeed in the repeatability of results. Cryopreservation can affect negativelly cell and / or tissues viability by several factors, including the formation of intracellular ice crystals, solution effect and toxicity caused by the inappropriate use of cryoprotective agents. Currently, several studies have emphasized the damage caused by the formation of ROS during cryopreservation processes, leading to oxidative stress. ROS formed during the cryopreservation process can degrade essential molecules to cells, including the polyunsaturated lipids present in the cell membrane (lipid peroxidation), leading them to death. In order to prevent oxidative stress that occurs during cryopreservation, some researchers have tested the addition of antioxidants to the freezing medium in order to achieve higher rates of cell survival after the thawing process. Antioxidants are substances that can neutralize ROS, thus reducing its power of chemical reaction.[...](AU)

Suplementação proteica no meio de cultivo in vitro de folículos pré-antrais / Protein supplementation on In Vitro Preantral Follicle Medium Culture

The in vitro culture of preantral follicles is an important tool to elucidate the mechanisms involved in controlling early folliculogenesis as well as to improve reproductive efficiency by providing a large number of oocytes for in vitro production of embryos. To this end, improvements in the performance of current culture systems are needed, including changes in the composition of the medium. Supplementation of culture medium with proteins is a great strategy to improve survival and in vitro development of preantral follicles. This review highlights the importance of in vitro culture of preantral follicles with emphasis on the main protein sources used to supplement the culture media.