Artificial insemination of the ewe

Extract

Having imported a 15-month-old Clun Forest ram from England with the intention of grading-up the small-bodied native ewe indigenous to the Kenya Highlands it was something of a shock to find the weight of the ram when loaded aboard the Mombasa-bound ship was no less than 250 lb. On arrival, he appeared to have lost little if any weight during the three weeks spent upon the journey, and it was very apparent that to let him loose in a flock of ewes, the average weight of which was little more than 50 lb, was asking for serious trouble, with probably few lambs to show for it at the end of the season. In any case, if the grading-up process was to be of any real value, this ram would have to sire far more ewes than he was physically capable of, even in normal circumstances of weight and size. As a result of this, artificial breeding was developed as a flock policy.     

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.     

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 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.     

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。     

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 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.     

Artificial intravaginal insemination using fresh semen in cats

To clarify the sperm count required for fertilization by artificial intravaginal insemination (AIVI), twenty-nine female cats were examined. Six male cats aged 2-12 years with normal semen quality, copulation capability, and fertility were used. In AIVI, animals received administration of 250 iu hCG once or 100 iu twice on days 2-4 of estrus to induce ovulation, and were inseminated 15, 20, or 30 hr after the initial hCG administration. The success of ovulation was judged by elevation of the peripheral progesterone level after hCG administration. AIVI was investigated at three sperm counts, 20 x 10(6) (Experiment 1), 40 x 10(6) (Experiment 2), and 80 x 10(6) (Experiment 3), with semen collected by the artificial vagina method. Semen was infused in the vagina under general anesthesia by advancing a 9 cm-long nylon probe with 1.5 mm diameter connected to a 1 ml syringe in the vagina for 3-4 cm. Ovulation was induced in 43 of 45 animals (95.6%). One of 16 animals was fertilized (conception rate: 6.6%) by AIVI in Experiment 1. In Experiments 2 and 3, conception was obtained in six of 18 animals (33.3%) and seven of nine animals (77.8%), respectively, and the mean numbers of kits were 4.0 +/- 0.4 and 3.3 +/- 0.5, respectively, and the mean numbers of kits were 4.0 +/- 0.4 (SE) and 3.3 +/- 0.5, respectively, showing no significant difference. There were no differences in the time of insemination after hCG administration and the conception rate among these groups. Our findings showed that the number of sperm required for fertilization by AIVI of fresh semen in cats was 80 x 10(6).