Pregnancy-specific protein B and progesterone in monitoring viability of the embryo in early pregnancy in the cow after experimental infection with Actinomyces pyogenes

Actinomyces pyogenes can cause embryonic death and abortion during the early stages of pregnancy in cows. Bovine pregnancy-specific protein B (PSPB) is produced in response to a viable embryo and as such it could be a potential marker for embryronic survival. The plasma concentration of PSPB was monitored in cows following an intrauterine infection with A. pyogenes and during the subsequent abortion and recovery from infection. Plasma progesterone concentrations were also monitored, and the results were compared withthose for animals in which abortion had been induced by prostaglandin F2alpha treatment. In abortions induced both by infection and by cloprostenol, the plasma concentration of PSPB fell steadily from the day of treatment, with a half-life of 7 days. In the cloprostenol-induced abortions, progesterone levels fell dramatically to <0.5ng/ml within 24 hours of treatment, while following inoculation with A. pyogenes , progesterone concentration remained elevated for 20 to 40 days and fell to <0.5ng/ml after evacuation of pus from the uterus. Sequential monitoring of PSPB, which identifies embryonic death when a continuing fall in plasma concentration is demonstrated, is a better indicator of embryonic death following bacterial infection with A. pyogenes than plasma progesterone concentration, which falls only when infection is resolved.

Comparison of production systems and selection criteria of Ankole cattle by breeders in Burundi, Rwanda, Tanzania and Uganda

A survey in Burundi, Rwanda, Tanzania and Uganda was conducted in order to determine the different production systems under which Ankole cattle are currently kept. Additionally, selection criteria of livestock keepers were documented. In Burundi, Rwanda and parts of Uganda, livestock keepers are sedentary and herds are small, whereas in the other areas Ankole cattle are kept in large herds, some of them still under a (semi-)nomadic system. Milk is the main product in all areas, and is partly for home consumption and partly for sale. Although the production systems vary in many aspects, the selection criteria for cows are similar. Productive traits such as milk yield, fertility and body size were ranked highly. For bulls, the trait 'growth' was ranked highly in all study areas. Phenotypic features (coat colour, horn shape and size) and ancestral information are more important in bulls than in cows. The only adaptive trait mentioned by livestock keepers was disease resistance. In areas of land scarcity (Burundi, Rwanda, western Uganda), a clear trend from pure Ankole cattle towards cross-bred animals can be observed.

Ultrasonographic study of early embryonic loss induced by Actinomyces pyogenes in cattle

Four cows were inoculated into the uterus with Actinomyces pyogenes between 30 and 41 days of gestation. Gross morphological changes were monitored by rectal palpation and with a realtime B-mode two-dimensional scanner with a 7.5 MHz transrectal linear transducer, shortly before infection and afterwards at three to 12 hours intervals. Two control groups of cows 27 to 50 days pregnant were used: two cows were inoculated with 6 ml of sterile saline into the uterine lumen and four cows were treated with cloprostenol (prostaglandin F2 alpha analogue). There was a change in the uterine fluid from a black, non-echogenic image before infection to a grey or cloudy echogenic image as early as 21 hours after infection. There was an increase in the thickness of the endometrium of the horns and body of the uterus. The embryonic membranes thickened and separated from the endometrium as early as four hours after infection, followed by cessation of the embryonic heart beat, opening of the cervix and abortion. Abortion was followed by an increase in the amount of echogenic intrauterine fluid leading to an increase in the size of the uterus, and the cervix remained open for at least eight days. The area of the corpus luteum remained greater than 2 cm2 throughout the whole period. Intrauterine inoculation with sterile saline had no effects, but the administration of cloprostenol was followed by the death of the embryo and abortion within 72 hours, and the regression of the corpus luteum from greater than 2 cm2 at treatment to 0.4 cm2, 24 hours after abortion.(ABSTRACT TRUNCATED AT 250 WORDS)

Early abortion in cattle induced by experimental intrauterine infection with pure cultures of Actinomyces pyogenes

Actinomyces pyogenes from a case of endometritis was used to study the effects of infection of the bovine embryo between days 27 and 41 of pregnancy. From 10(9) to 10(10) washed organisms were introduced into the uterine lumen of four pregnant cows. Two pregnant cows were inoculated with sterile saline and four pregnant cows were treated with cloprostenol. Embryonic death and abortion followed 29 to 144 hours after the inoculation of the live bacteria. The aborted embryos were macerated or clearly degenerating and yielded profuse pure cultures of A pyogenes. Abortion was accompanied by a sustained increase in uterine tone, opening of the cervix, presence of vaginal pus and a vulval discharge and the persistence of the corpus luteum for at least eight days after abortion. Intrauterine inoculation with saline did not affect pregnancy, but embryonic death, abortion and regression of the corpus luteum occurred 66 to 72 hours after the treatment with cloprostenol. The results suggest that A pyogenes is a primary pathogen and is capable of causing embryonic death and abortion.