Artificial insemination in the dog

Extract

Little could the Abbe Spallanzani have known the extent to which artificial insemination would develop when in 1780 he successfully inseminated a bitch with semen siphoned from the vagina of a second bitch. Three live puppies were reported to have been born to this insemination after a 62-day gestation. A long period elapsed before the possibilities of this technique were refined to their present state and it is only during this century that the full potential of the method as a means of animal breeding is being realized. Although the initial success utilized the dog as the experimental subject developments have been more restricted in this than in other common domestic species and critical research reports are still relatively few. It is the purpose of this paper to summarize progress achieved to date and to raise questions to which we still await unequivocal answers.     

Artificial insemination and the field veterinarian

Extract

The development of the commercial operation of artificial insemination (A.I.) in New Zealand has in the main been associated with the New Zealand Dairy Board and the affiliated Herd Improvement Associations with a relatively minor contribution from the practising profession.     

Artificial insemination of Bobwhite quail

The purpose of this study was to determine whether fertilisation of Bobwhite quail could be secured by artificial insemination. After this proved to be feasible, the period between insemination and the onset of laying fertile eggs, the time during which fertile eggs were laid and levels of fertility and hatchability of eggs obtained from hens inseminated at weekly intervals over an extended period of time were determined.

Semen was collected from Bobwhite quail males by simultaneously applying pressure to both the left and right sides of the vent without prior stimulation. Upon collection, the semen was diluted with 0.9 per cent saline solution to prevent dehydration. Semen volume measurements were made with a tuberculin syringe to which was attached a piece of graduated, fine‐bore plastic tubing. Females were artificially inseminated by placing the diluted semen in the posterior opening of the everted oviduct.

Mean duration of fertility of the eggs from six trials, two of which utilised only a single insemination, one of which was the final insemination of a series of weekly inseminations and three of which utilised two inseminations within a period of 24 hr, was 9.3 days. Percentage fertility of eggs improved considerably after the first trial probably due to improvement of technique and gain in experience. Average fertility of eggs for the six trials was 64–9 per cent.

The average time interval between insemination and the appearance of the first fertile egg was 3.4 days. Peak fertility was reached by the fourth day following insemination.

Fertility of eggs averaged 62.2 ±3.5 per cent and their hatchability averaged 77.2 ±1.4 per cent over a period of 31 weekly inseminations. These values were comparable to 60.2 per cent fertility and 78.9 per cent hatchability which were obtained from natural matings.     

种鸡人工授精技术

一 种鸡的选择 1 种公鸡的选择和调教 对拟留种的公鸡要进行五次选留。一周龄时,选留健壮、头大、眼睛明亮有神、鸣声响亮的公雏。四周龄时,选留生长良好的、体况健康的、毛色符合本品种特征公鸡。     

Artificial insemination in swine.

This article analyses the advantages and disadvantages of artificial insemination with semen purchased from a center as well as from the herd boars on the farm. Intensive swine production could benefit greatly by adapting artificial insemination with herd boars, particularly from savings in labor and boar numbers. The techniques for semen collection, extension, and insemination are described, and sources for equipment given. Expected results of artificial insemination are quoted from experiments and international field experience.     

浅谈绵羊人工授精技术

绵羊人工授精是指利用器械以人工方法采集公羊的精液,经检查、稀释、保存等特定方法处理后,用器械输入到发情母羊生殖道的特定部位,使其妊娠的一种家畜繁殖技术。人工授精在当前仍然是先进的繁殖技术之一,在绵羊的杂交改良、新品种育成方面发挥着重要作用。     

Artificial insemination and fertility in turkeys

Large‐type White turkey hens from a flock with a record of low “fertility” (live embryos at 7 to 10 days’ incubation) were distributed randomly into four groups of 50 hens each and were given treatments involving antibiotic and inseminations on a weekly or fortnightly schedule. During the first 5 weeks of the experiment, semen was introduced, via a plastic tube, at least 5 cm. into the oviduct of all birds in each group. Irrespective of the type of treatment, there was a significant rise in “fertility” in all groups. This was sustained for a 4‐week period, with the highest “fertility” occurring in the group inseminated weekly. When shallow insemination was used with two groups, “fertility” over a second 4‐week period was lowest in these two groups. Since percentage infertile eggs could account for the major share of the decline in percentage live embryos, it is postulated that the low live embryo percentage existing previously in the flock resulted from insufficient numbers of spermatozoa being inseminated rather than from a reaction to an unidentified pathogenic agent, as frequently suspected.     

Artificial insemination and preservation of semen.

Artificial insemination is an effective technique for improving utilization of stallions in breeding programs. When proper semen handling and insemination procedures are used, optimal pregnancy rates are attainable. When AI techniques are employed for mares and stallions with marginal fertility, pregnancy rates may be improved in comparison with natural mating. Preservation of stallion semen in the liquid or frozen state reduces the costs and potential health hazards incurred by transporting mares and provides easier access to genetic material that may otherwise be unavailable. Acceptable pregnancy rates are consistently obtained with cooled semen. Conversely, techniques for cryopreservation of stallion semen will require more refinement before the procedure can be considered commercially viable on a wide scale.