Effect on Field Fertility of Addition of Gelatine,Different Dilution Rates and Storage Times of Cooled Ram Semen After Vaginal Insemination

In a field trial, 633 ewes from 24 farms were inseminated vaginally using liquid semen (150 × 10⁶ per dose) collected from 15 rams. The semen was either diluted with a milk‐based extender (M), filled in 0.2 ml straws and stored for 12 or 24 h (M12, M24) or diluted with M but with the addition of gelatine, filled in 0.5 ml straws and stored for 12 or 24 h (G12, G24). The hypothesis was that a larger volume and the addition of gelatine would prolong the survival of the spermatozoa. The ewes, aged between 6 months and 5.5 years, were allocated into four groups and inseminated after natural oestrus by the farmers themselves with a dose of 150 × 10⁶ spermatozoa. Inseminations in the groups (M12, M24, G12, G24) resulted in lambing rates of 69.6%, 63.6%, 69.4% and 58.3% (overall 65.2%), respectively. Farmer (p < .0002) had a significant effect on the lambing rate, while ram, age of the ewe and dilution rate/addition of gelatine/storage time had not. A pair‐wise comparison of the lambing rates between the four groups showed that significant lower results were only achieved for G24 compared with M12. None of the other comparisons showed significant differences. In conclusion, a higher dilution rate of the AI‐dose together with the addition of gelatine to the semen extender did not lead to improved fertility results after storage for 24 h when compared with standard AI‐doses used in Norway.     

Post-Death Cloning of Endangered Jeju Black Cattle (Korean Native Cattle): Fertility and Serum Chemistry in a Cloned Bull and Cow and Their Offspring

To preserve Jeju black cattle (JBC; endangered native Korean cattle), a pair of cattle, namely a post-death cloned JBC bull and cow, were produced by somatic cell nuclear transfer (SCNT) in a previous study. In the present study, we examined the in vitro fertilization and reproductive potentials of these post-death cloned animals. Sperm motility, in vitro fertilization and developmental capacity were examined in a post-death cloned bull (Heuk Oll Dolee) and an extinct nuclear donor bull (BK94-13). We assessed reproductive ability in another post-death cloned cow (Heuk Woo Sunee) using cloned sperm for artificial insemination (AI). There were no differences in sperm motility or developmental potential of in vitro fertilized embryos between the post-death cloned bull and its extinct nuclear donor bull; however, the embryo development ratio was slightly higher in the cloned sperm group than in the nuclear donor sperm group. After one attempt at AI, the post-death cloned JBC cow became pregnant, and gestation proceeded normally until day 287. From this post-death cloned sire and dam, a JBC male calf (Heuk Woo Dolee) was delivered naturally (weight, 25 kg). The genetic paternity/maternity of the cloned JBC bull and cow with regard to their offspring was confirmed using International Society for Animal Genetics standard microsatellite markers. Presently, Heuk Woo Dolee is 5 months of age and growing normally. In addition, there were no significant differences in blood chemistry among the post-death cloned JBC bull, the cow, their offspring and cattle bred by AI. This is the first report showing that a pair of cattle, namely, a post-death cloned JBC bull and cow, had normal fertility. Therefore, SCNT can be used effectively to increase the population of endangered JBC.     

Utilization of dissolved organic phosphorus by the two toxic dinoflagellates, Alexandrium tamarense and Gymnodinium catenatum (Dinophyceae)

ABSTRACT: The utilization of dissolved organic phosphorus (DOP) by the two toxic dinoflagellates Alexandrium tamarense (Lebour) Balech and Gymnodinium catenatum Grahamm which were isolated from Hiroshima Bay, Japan, was studied. Alexandrium tamarense grew poorly on fructose-6-phophate, glucose-1-phosphate, glycerophosphate, and ribose-5-phosphate with a phosphomonoester bond, although it grew well on the nucleotides adenosine-5-diphosphate (ADP) and adenosine triphosphate (ATP), as well as on dissolved inorganic phosphorus (DIP; as metaphosphate, pyrophosphate, tripolyposphate and orthophosphate). The results imply that A. tamarense was able to utilize DOP and DIP from ambient water using nucleotidase, pyrophosphatase and poly-phosphatase, which hydrolyze phosphodiesters. In contrast, G. catenatum was able to utilize DOP compounds of various molecular weights and structures as well as DIP. In time-course experiments, alkaline phosphatase activity (APA) was induced at orthophosphate concentrations of 0.43 mmol/L and 3.3 mmol/L for A. tamarense and G. catenatum , respectively, and APA increased with orthophosphate depletion. The experiments also demonstrated that APA was maximum at the optimum temperatures for the growth of A. tamarense and G. catenatum ; that is, 15°C and 25°C, respectively. These results suggest that the DIP-depleted conditions in Hiroshima Bay might have led to the outbreaks of noxious dinoflagellates in recent years.