To evaluate the effect of pFSH dose on the in vivo embryo production of Dorper ewes in the semi-arid northeast of Brazil, 40 sheep females were distributed into two groups of 20 animals that received intravaginal CIDR for 14 days, and two days before device removal, they received one of the following treatments: in the FSH200 group, the ewes received 200 mg of pFSH; and in the FSH128 group, the ewes received a total of 128 mg in decreasing doses every 12 h. Beginning 12 h after the conclusion of the treatments, estrus detection was performed every four hours using two Dorper rams of proven fertility. The ewes were mated at estrus onset and 24 hours later. Seven days after intravaginal device removal, the superovulatory response was evaluated, and embryo collection was performed using the laparotomy method. The recovered flushings were subjected to embryo searches under a stereomicroscope and classified according to their qualities. Analyses of variance (ANOVAs) and LSD tests were used to compare the different parameters. The data expressed as percentages were analysed by chi-square test. The ovulation rate was higher in the FSH200 group, which had 16.3 ± 0.3 corpora lutea (CL), than in the FSH128 group, which had 11.3 ± 0.3 CL (P<0.05). However, higher fertilization rate (83.6% vs. 62.4%) and higher transferable (86.0% vs. 71.6%) and freezable (67.9% vs. 40.8%) embryo rates were observed in the FSH 128 group compared with the group that received 200 mg. Furthermore, no significant differences in the remaining parameters were observed between the experimental groups (P>0.05), demonstrating that pFSH dose reduction promoted a greater production of freezable and transferable embryos in Dorper ewes subjected to MOET. ResumoCom o objetivo de avaliar o efeito da redução de pFSH na produção in vivo de embriões de ovelhas da raça Dorper exploradas no semiárido do Nordeste do Brasil, 40 fêmeas ovinas foram distribuídas em dois grupos com 20 animais, os quais receberam um CIDR intravaginal por 14 dias e dois dias antes da remoção do dispositivo receberam um tratamento superovulatório proposto: grupo FSH200 onde as ovelhas receberam 200 mg de pFSH, enquanto o grupo FSH128 totalizou 128 mg em doses decrescentes intervaladas por 12 horas. Doze horas após o final do tratamento, foi realizada a detecção de estro, a cada quatro horas, utilizando dois carneiros Dorper, de fertilidade comprovada. As ovelhas foram cobertas no início do estro e 24 horas depois. Sete dias após a retirada do dispositivo intravaginal, foi realizada a avaliação da resposta superovulatória e a colheita de embriões pelo método de laparotomia. O lavado recuperado foi submetido à procura de embriões em estereomicroscópio e classificados de acordo com sua qualidade. Para comparação dos diversos parâmetros, foi utilizada a Análise de Variância (ANOVA), seguida da realização do teste LSD. Os dados expressos em porcentagem foram submetidos ao Teste de Qui-quadrado. A taxa de ovulação foi superior no grupo FSH200 com 16,3 ± 0,3 corpos lúteos (CL) quand...

To evaluate the effect of pFSH dose on the in vivo embryo production of Dorper ewes in the semi-arid northeast of Brazil, 40 sheep females were distributed into two groups of 20 animals that received intravaginal CIDR for 14 days, and two days before device removal, they received one of the following treatments: in the FSH200 group, the ewes received 200 mg of pFSH; and in the FSH128 group, the ewes received a total of 128 mg in decreasing doses every 12 h. Beginning 12 h after the conclusion of the treatments, estrus detection was performed every four hours using two Dorper rams of proven fertility. The ewes were mated at estrus onset and 24 hours later. Seven days after intravaginal device removal, the superovulatory response was evaluated, and embryo collection was performed using the laparotomy method. The recovered flushings were subjected to embryo searches under a stereomicroscope and classified according to their qualities. Analyses of variance (ANOVAs) and LSD tests were used to compare the different parameters. The data expressed as percentages were analysed by chi-square test. The ovulation rate was higher in the FSH200 group, which had 16.3 ± 0.3 corpora lutea (CL), than in the FSH128 group, which had 11.3 ± 0.3 CL (P<0.05). However, higher fertilization rate (83.6% vs. 62.4%) and higher transferable (86.0% vs. 71.6%) and freezable (67.9% vs. 40.8%) embryo rates were observed in the FSH 128 group compared with the group that received 200 mg. Furthermore, no significant differences in the remaining parameters were observed between the experimental groups (P>0.05), demonstrating that pFSH dose reduction promoted a greater production of freezable and transferable embryos in Dorper ewes subjected to MOET. ResumoCom o objetivo de avaliar o efeito da redução de pFSH na produção in vivo de embriões de ovelhas da raça Dorper exploradas no semiárido do Nordeste do Brasil, 40 fêmeas ovinas foram distribuídas em dois grupos com 20 animais, os quais receberam um CIDR intravaginal por 14 dias e dois dias antes da remoção do dispositivo receberam um tratamento superovulatório proposto: grupo FSH200 onde as ovelhas receberam 200 mg de pFSH, enquanto o grupo FSH128 totalizou 128 mg em doses decrescentes intervaladas por 12 horas. Doze horas após o final do tratamento, foi realizada a detecção de estro, a cada quatro horas, utilizando dois carneiros Dorper, de fertilidade comprovada. As ovelhas foram cobertas no início do estro e 24 horas depois. Sete dias após a retirada do dispositivo intravaginal, foi realizada a avaliação da resposta superovulatória e a colheita de embriões pelo método de laparotomia. O lavado recuperado foi submetido à procura de embriões em estereomicroscópio e classificados de acordo com sua qualidade. Para comparação dos diversos parâmetros, foi utilizada a Análise de Variância (ANOVA), seguida da realização do teste LSD. Os dados expressos em porcentagem foram submetidos ao Teste de Qui-quadrado. A taxa de ovulação foi superior no grupo FSH200 com 16,3 ± 0,3 corpos lúteos (CL) quand...

No abstract

There have been few studies on the use of diets and strategies to reduce the length of postpartum anoestrus in dairy goats, especially in tropical semi-arid regions. This review discusses the factors influencing the return of postpartum ovarian activity in goats. During the postpartum period, goats are in puerperal anoestrus and their reproductive tract is being prepared for a new conception. Anoestrus is necessary for tissue renewal in the uterus (uterine involution) associated with the return of cyclic ovarian activity, and is influenced by factors such as suckling of the offspring, social interactions, body condition score (BCS) before and after birth, intensity of negative energy balance (NEB) and stress from adverse climatic conditions. The anoestrus period can be extended by delays in the resumption of reproductive activity of females in puerperium. The duration of puerperal anoestrus in goats directly affects the productivity of the herd and is mainly influenced by nutrition, lactation period and heat stress. To minimize the negative effects of postpartum anoestrus on productivity, we recommend a mating season and a plan for the kidding period, as well as a program to monitor the body condition score during pregnancy so that the animals will have a better BCS at parturition. To minimize the effects of a negative energy balance, we suggest nutritional supplementation with levels of energy above the requirements for maintenance. Highlights The duration of postpartum anoestrus in goats is influenced by nutrition and body condition score. Heat stress can intensify the negative energy balance, consequently increased the period of anoestrus. Puerperal anoestrus occurs as a result of tissue renewal in the uterus. Suckling of the offspring associated with the period of lactation and social interactions can modified the puerperal anoestrus period. Use of diets and strategies to reduce the postpartum anoestrus in goats.

This study aimed to evaluate the efficacy of adding sucrose in vitrification solution of ovine embryos produced in vivo. Forty Dorper ewes were selected and superovulated. Immediately prior to the embryo collection by laparotomy, a laparoscopy was performed to verify the superovulatory response. The recovered flushing was followed by embryo evaluation and embryos were divided in two experimental groups where embryos from Control group were submitted to a traditional vitrification protocol and embryos from Sucrose group to a modified vitrification protocol with sucrose. After warming, embryos were again divided regarding cryoprotectant removal (Indirect) or not (Direct). The embryo quality was classified as embryos of degrees I (excellent or good), II (regular), III (poor) and IV (dead or degenerate). It was also verified the homogeneity of mass, occurrence of embryonic mass retraction and rupture of pellucid zone. The results were expressed as percentages and were subjected to Chi-square test with P < 0.05. The embryos vitrified in the presence of sucrose had lower proportions of lower-quality embryos after warming (22.20 vs. 44.50%), higher percentages of homogeneous embryos after warming (63.89 vs. 38.89 %) while concerning other parameters there was no difference between these groups. It can be concluded that the addition of 0.4 M sucrose during vitrification improves the embryo quality. Key words: Cryopreservation, embryo, ewe, multiple ovulation, sugar ResumoEste estudo objetivou avaliar a eficácia da adição de sacarose na solução de vitrificação de embriões ovinos produzidos in vivo. Foram selecionadas 40 ovelhas da raça Dorper as quais foram superovuladas. Imediatamente antes da colheita de embriões por laparotomia, uma laparoscopia foi realizada para verificar a resposta superovulatória. O lavado recuperado foi submetido à procura e avaliação de embriões e estes foram divididos em dois grupos experimentais, onde os embriões do Grupo Controle foram submetidos ao protocolo tradicional de vitrificação e os embriões do Grupo Sacarose a um protocolo modificado de vitrificação com sacarose. Após a descongelação, os embriões foram novamente divididos considerando a remoção (Indireto) ou não (Direto) do crioprotetor. A qualidade embrionária foi classificada como embriões de graus I (excelente ou bom), II (regular), III (pobre) e IV (morto ou degenerado). Foi também verificada a homogeneidade da massa, ocorrência de retração da massa e ruptura de zona pelúcida. Os resultados foram expressos em porcentagem e foram submetidos ao teste do Qui-quadrado com P < 0.05. Os embriões vitrificados na presença de sacarose apresentaram menores proporções de embriões de menor qualidade após a descongelação (22,20 vs. 44,50%), e maiores percentuais de embriões homogêneos após a descongelação (63,89 vs. 38,89%) enquanto com relação aos demais parâmetros não existiram diferenças entre grupos. Pode-se concluir que a adição de 0,4 M de sacarose durante os procedimentos de vitrificação e descongelação beneficia a qualidade ...

This study aimed to evaluate the efficacy of adding sucrose in vitrification solution of ovine embryos produced in vivo. Forty Dorper ewes were selected and superovulated. Immediately prior to the embryo collection by laparotomy, a laparoscopy was performed to verify the superovulatory response. The recovered flushing was followed by embryo evaluation and embryos were divided in two experimental groups where embryos from Control group were submitted to a traditional vitrification protocol and embryos from Sucrose group to a modified vitrification protocol with sucrose. After warming, embryos were again divided regarding cryoprotectant removal (Indirect) or not (Direct). The embryo quality was classified as embryos of degrees I (excellent or good), II (regular), III (poor) and IV (dead or degenerate). It was also verified the homogeneity of mass, occurrence of embryonic mass retraction and rupture of pellucid zone. The results were expressed as percentages and were subjected to Chi-square test with P < 0.05. The embryos vitrified in the presence of sucrose had lower proportions of lower-quality embryos after warming (22.20 vs. 44.50%), higher percentages of homogeneous embryos after warming (63.89 vs. 38.89 %) while concerning other parameters there was no difference between these groups. It can be concluded that the addition of 0.4 M sucrose during vitrification improves the embryo quality. Key words: Cryopreservation, embryo, ewe, multiple ovulation, sugar ResumoEste estudo objetivou avaliar a eficácia da adição de sacarose na solução de vitrificação de embriões ovinos produzidos in vivo. Foram selecionadas 40 ovelhas da raça Dorper as quais foram superovuladas. Imediatamente antes da colheita de embriões por laparotomia, uma laparoscopia foi realizada para verificar a resposta superovulatória. O lavado recuperado foi submetido à procura e avaliação de embriões e estes foram divididos em dois grupos experimentais, onde os embriões do Grupo Controle foram submetidos ao protocolo tradicional de vitrificação e os embriões do Grupo Sacarose a um protocolo modificado de vitrificação com sacarose. Após a descongelação, os embriões foram novamente divididos considerando a remoção (Indireto) ou não (Direto) do crioprotetor. A qualidade embrionária foi classificada como embriões de graus I (excelente ou bom), II (regular), III (pobre) e IV (morto ou degenerado). Foi também verificada a homogeneidade da massa, ocorrência de retração da massa e ruptura de zona pelúcida. Os resultados foram expressos em porcentagem e foram submetidos ao teste do Qui-quadrado com P < 0.05. Os embriões vitrificados na presença de sacarose apresentaram menores proporções de embriões de menor qualidade após a descongelação (22,20 vs. 44,50%), e maiores percentuais de embriões homogêneos após a descongelação (63,89 vs. 38,89%) enquanto com relação aos demais parâmetros não existiram diferenças entre grupos. Pode-se concluir que a adição de 0,4 M de sacarose durante os procedimentos de vitrificação e descongelação beneficia a qualidade ...

This study was carried out to compare Day 0 and traditional protocols for in vivo embryo production. Twenty-two crossbred ewes were used as embryo donors and assigned to two groups. Ewes from Traditional protocol were submitted to estrus synchronization with CIDR for 14 days and superovulation treatment was induced 60 h before the withdrawal of CIDR with 240 mg pFSH. Donors from Day 0 protocol were subjected to a short-term protocol of estrus synchronization (6 days) and superovulation treatment was the same to the other group, but it started 84 h after CIDR withdrawal. Embryo recoveries were performed using the transcervical method. All embryo donors (100%) presented estrus regardless of the hormone protocol used. The treatments did not affect the ovarian response, as well as quality and viability of embryos (P > 0.05). Treatments had a small dispersion of estrus, 81.81% (9/11) animals from the Traditional protocol group presented estrus 20 h after CIDR withdrawal and 90.9% (10/11) of the Day 0 protocol group presented estrus 24 h. Regarding embryo production, there was no significant difference between hormonal treatments for the different parameters evaluated (P > 0.05). It can be concluded that the Day 0 protocol was not different from the Traditional protocol in crossbred ewes.