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The aims of this study were to determine if the protein source of the medium influences zebu embryo development and if developmental kinetics, developmental block and programmed cell death are related. The culture medium was supplemented with either fetal calf serum or bovine serum albumin. The embryos were classified as Fast (n = 1,235) or Slow (n = 485) based on the time required to reach the fourth cell cycle (48 h and 90 h post insemination - hpi -, respectively). The Slow group was further separated into two groups: those presenting exactly 4 cells at 48 hpi (Slow/4 cells) and those that reached the fourth cell cycle at 90 hpi (Slow). Blastocyst quality, DNA fragmentation, mitochondrial membrane potential and signs of apoptosis or necrosis were evaluated. The Slow group had higher incidence of developmental block than the Fast group. The embryos supplemented with fetal calf serum had lower quality. DNA fragmentation and mitochondrial membrane potential were absent in embryos at 48 hpi but present at 90 hpi. Early signs of apoptosis were more frequent in the Slow and Slow/4 cell groups than in the Fast group. We concluded that fetal calf serum reduces blastocyst development and quality, but the mechanism appears to be independent of DNA fragmentation. The apoptotic cells detected at 48 hpi reveal a possible mechanism of programmed cell death activation prior to genome activation. The apoptotic cells observed in the slow-developing embryos suggested a relationship between programmed cell death and embryonic developmental kinetics in zebu in vitro-produced embryos.

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This study aimed to evaluate the potential of Girolando (Bos taurus × Bos indicus) cows with high and low antral follicle counts (AFC) for the in vitro production of bovine embryos (IVEP), as well as the pregnancy rates of the recipients of these embryos. Girolando cows (Bos taurus × Bos indicus) were classified as high and low AFC when they had 35-52 (n = 13) and 11-17 follicles (n = 15), respectively. All animals were subjected to repeated follicular aspiration [Ovum pick-up (OPU)] and subsequent IVEP sessions. The synchronization protocol of the recipients was performed on a random day of the estrous cycle (Day 0) with the implantation of progesterone, estradiol benzoate, and prostaglandin. The high AFC group had higher aspirated oocyte/OPU (42.6 ± 5.2 vs. 14.6 ± 1.9; p < 0.01) and cultured oocyte/OPU (38.1 ± 6.6 vs. 12.3 ± 2.8; p < 0.01) averages as well as a higher blastocyst percentage on D7 (23.0 ± 1.0% vs. 18.4 ± 1.5%; p < 0.05) and higher pregnancy rate (42.7 ± 2.7% vs. 39.7 ± 4.6%; p < 0.05) than the low AFC group. Thus, we can conclude that animals with high AFC had better IVEP success rates than animals with low AFC.

From the moment of laying, eggs come into contact with microorganisms that adhere to the shelland disinfection is the process that reduces contamination by preventing them from penetrating the shell and invading the egg's internal content, however, different active principles can result in effects several. The objective was to evaluate the efficiency of different active principles in the disinfection of ostrich eggs on contamination andthe productive indexes of incubation. 16 eggs were used, distributed in two disinfectant active ingredients (quaternary ammonia and formaldehyde) in a completely randomized design with 8 replications. Contamination of the eggshell was evaluated by microbiological analysis on the surface of the eggshell after disinfection. The productive indexes of the incubation were evaluated by means of the index of weight loss of the egg (%), mortality rate (%), embryology (%) and hatchability (%). There was no significant difference (p> 0.05) between the active ingredients used in terms of disinfection capacity and productive indexes of incubation. It is concluded that bothactive ingredients are efficient in the disinfection of eggs, ensuring the control of contamination on the surface of the egg shell during the storage and incubation processes, in addition to not affecting the parameters of the incubation.

RESUMOO objetivo do experimento foi avaliar se o tempo de permanência dos ovos no ninho afeta a qualidade do ovo a ser incubado interferindo na taxa de eclosão. Utilizaram-se 34 ovos divididos em blocos inteiramente casualizados. A coleta dos ovos foi realizada em dois períodos, manhã (tratamento 1) e madrugada (tratamento 2). Os parâmetros de qualidade dos ovos foram avaliados por meio do peso dos ovos nos dias 0 e 39 de incubação (g), índice de perda de peso do ovo (%), taxa de fertilidade (%), eclodibilidade (%) e mortalidade (%). Os resultados obtidos mostram que não houve diferença significativa em nenhuma das variáveis analisadas. Dessa forma, pode-se concluir que o tempo de permanência no ninho não influência na taxa de eclosão dos ovos, uma vez que o baixo índice de eclodibilidade possa estar relacionado a problemas durante o manejo de incubação, genéticos ou nutricionais. Palavras-chave: incubação; qualidade do ovo; eclodibilidade; ninho; avestruz.

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