BACKGROUND Focus on the hatching process has so far been in the field of fresh embryos. Cryopreserved-thawed embryos have a lower rate of pregnancy than fresh embryos, which might be due to hardening of the zona pellucida. METHODS During a 2 year period, a prospective randomized study enrolling 253 cryopreserved-thawed cycles was performed on day 2 embryos. Pseudorandomization to assisted hat...

This study was designed to gain insight into the influence of spraying and cooling, during artificial incubation, on the embryo metabolic rate and hatching ability of Muscovy duck eggs. Three times a week 93 incubated eggs were sprayed and cooled for 0.5 h at room temperature. Daily embryo metabolic rate was measured in 30 eggs with a water vapor conductance ranging from 1.15 to 2.07 mg/day-kPa...

In this study, fertilization, hatching and deformation rate of the eggs, and larvae obtained from hormone injected (HI) and non-injected broodstock (NHI), were determined. In the experiment, no differences were observed in the groups’ fertilization rates (p>0.05). Hatching rate was found higher in the HI group (p < 0.05). During the experiment, malformations such as spinal fluid accumulation, s...

In this study, fertilization, hatching and deformation rate of the eggs, and larvae obtained from hormone injected (HI) and non-injected broodstock (NHI), were determined. In the experiment, no differences were observed in the groups’ fertilization rates (p>0.05). Hatching rate was found higher in the HI group (p<0.05). During the experiment, malformations such as spinal fluid accumulation, sad...

The effect of dormancy in zooplankton populations is still unknown, largely because of the lack of methods to estimate hatching and production of the dormant stages. This study aimed to compare the production and hatching rates of ephippia of Daphnia laevis between thermal stratification and mixing periods in Jacaré Lake (Middle Rio Doce, Minas Gerais, Brazil). For this, we collected ephippia o...

The role of actin filaments and contractions in hatching was determined in mouse blastocysts whose actin filament bundling abilities had been suppressed by H-89, an inhibitor of protein kinase A. The hatching rate of blastocysts developed from morulae in a medium containing H-89 at a concentration of 4.0 microM was 17.2%, which was significantly lower than the 76.7% of the control blastocysts d...

Twenty-five pesticides used in the production of rice and soybeans in Texas were tested in the laboratory to determine their toxicity to the eggs of Psorophora columbiae. A reduction in hatching rate occurred when eggs were treated with a herbicide formulation containing thiobencarb and with one containing a tank mixture of propanil and molinate. A carbaryl formulation induced hatching of eggs ...

the aim of the peresent study was to find the optimum weaning time to shift pikeperch larvae feeding from live food to the artificial feed. in this experiment, pikeperch larvae were fed with seived pond zooplankton (mainly rotifers) and artemia nauplii from the first feeding day to day 16 of post-hatching. then three weaning times were used on day 16 (w16), day 22 (w22), and day 28 (w28) of pos...