Between 2000 and 2003, 99 cattle with limb fractures were treated. Over 50 per cent were tibial fractures, with the femur and os calcis being the second and third most frequently affected bones. Eight of the cattle were slaughtered because of their poor prognosis, 10 were treated by stall confinement, 76 were treated by external coaptation with a Thomas splint-cast combination and three were treated with a simple or reinforced half limb cast; these 79 cattle were usually discharged immediately. One calf was treated with internal fixation, and another by amputation. Follow-up information was obtained by telephone, and the treatments were classified as either completely successful (return to previous production level), partially successful (return to lower production level) or failure. Forty (52.6 per cent) of the cattle treated with the Thomas splint-cast combination were classified as a complete success and 14 (18.4 per cent) as a partial success; the treatment failed in 19 of the cattle and three were lost to follow-up. The animals' bodyweight, age and sex, and whether the fracture was open or closed, had no significant influence on the outcome. Among the 10 cattle treated for proximal fractures by stall confinement, there were five survivors, four non-survivors and one was lost to follow-up.

The effects of temperature and exposure time to vitrification solutions on In vitro survival of mouse blastocysts were investigated. Blastocysts were first exposed for 10 min to vitrification Solution 1 (VS1) containing 10% glycerol-20% 1,2 propanediol in phosphate buffered saline (PBS), then to vitrification Solution 2 (VS2) with 25 % glycerol-25% 1,2 propanediol for various periods either at room temperature or at 4 degrees C. At room temperature survival dropped quickly, while at 4 degrees C an increase in survival was observed. It is concluded that the viability of mouse blastocyts after vitrification is dependent on the temperature and duration of equilibration in vitrification solutions.

Concentrations of bovine placental lactogen (bPL) were determined in fetal plasma samples by twelve double-antibody competitive radioimmunoassay systems (RIA I-XII) based on either recombinant bPL (non-glycosylated) or native bPL (glycosylated). Both preparations were used as standard and tracer, and for primary antisera production. The minimum detection limit measured by these RIA varied from 0.02 to 0.6 ng bPL mL(-1). The coefficients of correlation of different bPL RIA systems were up to 90% (P < 0.0001) when each RIA was tested against the average values of all twelve RIA systems. All developed RIA were used to investigate the incidence of different bPL isoforms in bovine fetal serum samples (n = 71). Fetal concentrations ranged from 11.8 to 35.7 ng mL(-1) at the third month and from 1.1 to 13.5 ng mL(-1) at the ninth month of gestation. They tended to decrease with advancing gestation. In general, those RIA systems that used recombinant bPL as the standard measured higher values than those using the native bPL preparation. These differences decreased toward the end of gestation (P < 0.05), suggesting a lower rate of glycosylation. Our results provide evidence of different glycosylated isoforms of bPL in fetal serum at different gestation periods.

We described an exclusively in vitro procedure for cloning and recloning bovine embryos. Embryos obtained by IVM/IVF/IVC developed to the morula stage were used as blastomere donors in cunjunction with IVM recipient oocytes. Reconstructed embryos were developed in vitro in co-culture using bovine oviductal epithelial cells. The resulting morulae were used as donors for recloning under the same experimental conditions. No significant difference was observed between cloning and recloning in terms of development (rates of blastocysts: 12.9 versus 14.9%), in the number of nuclei per blastocyst (63.8 versus 49.1), or in pregnancy rates (35.7 versus 33.3%). The high variability observed between replicates and the correlation between results in first and second cycle nuclear transfer may suggest an inherant potential of individual donor embryos to support development by cloning.

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