[Deep intrauterine insemination in cattle].
BACKGROUND
Most of the artificial inseminations in cattle nowadays are being performed in the uterine body with a rigid insemination device. Uterotubal junction insemination can only be performed in cattle with a device which is rigid enough to pass the cervix and flexible enough to follow the curvature of the uterine horns. At the Faculty of Veterinary Medicine in Ghent, a new insemination device has been developed for semen deposition near the utero-tubal junction in cattle and other animals.


METHODS
In a first field trial the feasibility of the newly developed Ghent device was evaluated. Four thousand sixty-four dairy cows were inseminated by 12 inseminators with a standard insemination dose (10-15 million of frozen-thawed spermatozoa). Three insemination methods were compared; group 1: insemination in the uterine body with the conventional insemination device, group 2: insemination in the uterine body with the Ghent device, and group 3: insemination in the tip of both uterine horns with the Ghent device. In a second field trial insemination of dairy cows with the Ghent device was compared with the conventional insemination technique to evaluate the effect on pregnancy rates. The insemination dose was lowered to eight million (trial 1), four million (trial 2), and finally to two million frozen-thawed spermatozoa (trial 3). In each field trial, cows were divided into three groups: the first group was inseminated with a full insemination dose (12 x 10(6)) in the uterine body with the conventional insemination device, the second group with a lowered insemination dose in the uterine body with the conventional insemination device, and the third group with a lowered insemination dose in the tip of both uterine horns with the Ghent device. It can be concluded that decreasing the insemination dose from 12 to four million frozen-thawed spermatozoa had no effect on pregnancy rate in our experiments, neither with the conventional insemination device, nor with the Ghent device. The device is made of disposable materials and has been tested to be non-toxic for bovine spermatozoa, can be used by one person and is adapted for application in the field.


CONCLUSIONS
In the near future, similar field trials will be performed with even lower doses of semen. It is only in these cases that we truly hope to show a positive effect of uterotubal junction insemination by using low quality semen or by using sexed semen.
Van Soom
A
A
Département de reproduction, obstétrique et clinique ambulatoire, faculté de médecine vétérinaire, université de Gand, Salisburylaan 133, B-9820 Merelbeke, Belgique.
Verberckmoes
S
S
D000818:Animals; D002417:Cattle; D005260:Female; D007315:Insemination, Artificial / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D011897:Random Allocation; D012661:Semen / Q000502:physiology*; D013076:Sperm Count / Q000662:veterinary*