Experimental reproduction of necrotic enteritis in the chicken. 2. Further mono- and polyinfections with CL. perfringens and coccidia with special reference to ground-kept chickens]

Coccidial oocysts and/or vegetative germs, spores, and toxins of Cl. perfringens Type A were used in mono-infection and poly-infection experiments on SPF chicken aged seven and 56 days and kept under different conditions. Necrotic enteritis was regularly reproduced in all experimental groups with polyinfections. In chicken aged seven days necrotic enteritis was reproduced even after repeated mono-infections with 4 X 10(9) gerus and toxin of Cl. perfringens. The loss figures recorded from ground-kept infected groups were higher than those established from the cage-kept animals. The pathologica-anatomic findings recorded from the dead chicken included necrotic, ulcerative, and catarrhal to haemorrhagic intestinal inflammations, with necrotic enteritis being most strongly pronounced in the ileum and jejunum. All infected groups lost not only animals but weight as well. Their average weight on the 21 st day from the onset of infection was up to 26.4 per cent lower than that of the control groups.     

Experimental infection in man and monkey (Cercopithecus callitrichus) by sarcosporidian cysts of cattle and swine]

Reported in this paper is experimental sarcosporidial infection of man and lower primates (grass monkey). The courses of infection were followed up by coprological and serological tests. Oral-alimentary administration of 100 Sarcocystis (S.)-fusiformis cysts obtained from cattle muscle caused patent infection in man. Gastro-intestinal symptoms developed in one of the probands, between five and seven days after infection. No sporocysts were detectable from the stools of seven probands who had consumed 200 g each of commercially available minced pork which contained small amounts of Sarcocystis miescherania villi. Rise in antibody to Sarcocystes following infection was detected however, by means of indirect fluorescence antibody reaction (IFAR). Gastrointestinal complaints were reported by one of the probands, one day after infection. No sporocysts were detectable from the stools of four grass monkeys, following oral-alimentary administration of 50 or 25 S. miescherania cysts, but rise in antibody to S. miescherania was recorded in these cases. Those grass monkeys which had received 50 cysts responded by exhibiting, after infection, severe clinical phenomena with intestinal signs and symptoms of the central nervous sytem.     

Changes in urinary and plasma oestrone sulphate concentrations after induction of foetal death in mares at 45 days of gestation

Foetal death was induced in 10 Standardbred mares at day 45 of gestation by injecting 20 to 45 ml of hypertonic (24% W/V) saline into the conceptus at surgery. Ten mares underwent sham treatment and acted as controls. Blood and urine samples were collected every other day between days 30 and 45 post ovulation and at 0, 3 and 6 h relative to the infusion of saline in the treated mares, or sham treatment in control mares. Blood and urine samples were then collected daily between days 46 and 55 post ovulation. Urine oestrone sulphate (E1S) concentrations, measured by radioimmunoassay, increased between day 34 and day 36 of gestation in treated and control groups. In mares in which foetal death was induced, urine E1S concentrations declined post-operatively and were significantly (p less than .05) lower than controls by day 50. In plasma, E1S concentrations showed a major increase between days 36 and 40 in both groups. This was followed by a rapid decline after treatment in saline-injected mares, so that by day 48 plasma E1S concentrations in treated mares were significantly (P less than .05) lower than the controls. The results show that urinary and plasma E1S concentrations rise rapidly during early pregnancy, and are associated with a viable foetus after day 45 of pregnancy.     

Reproductive performance of Thoroughbred mares on six commercial stud farms

The records of 1630 mare years from 6 Thoroughbred stud farms in south eastern Australia were analysed for the years 1981 to 1986. Overall pregnancy and foaling rates were 83.9% and 69.3%, respectively. When calculated per served oestrous cycle, pregnancy and foaling rates were 54.7% and 43.1%, respectively. Pregnancy and foaling rates were higher (P < 0.001) for mares 3 to 10 years of age than for older mares. There was no difference in the pregnancy rates of maiden, barren and foaling mares. The foaling rate was significantly higher (P < 0.001) in mares that became pregnant during the first served oestrous cycle (77.8%) than in mares that needed two served oestrous cycles to become pregnant (65.4%). Of all diagnosed pregnancies, 19.5% were not completed. Pregnancy loss was lower (P < 0.05) in maiden (12.4%) than in barren (19.7%) or foaling (20.9%) mares. Twins were diagnosed in 7.8% of all pregnancies. If one conceptus was lost without external interference, 84.1% of pregnancies went to term. If one conceptus was manually crushed, 55.9% of pregnancies were maintained. If prostaglandin was used to terminate twin pregnancies, 60% of mares so treated produced foals the following year.