ANOXIA IN THE BOVINE FOETUS

SUMMARY Laparohysterotomies were performed, under local analgesia, on 18 plurigravid Hereford cattle and the response of their foetuses to anoxia was examined. All control and 4 of 6 foetuses subjected to 4 minutes of anoxia survived whereas all others died when the umbilical cord was clamped for 6 or 8 minutes. Death mostly occurred just before or soon after delivery, which was undertaken immediately following release of the umbilical clamp. In 2 cases, however, the calves survived for at least 2 days before being slaughtered when death appeared imminent. During the intervening period both animals failed to suck although one was able to stand temporarily following the oral administration of glucose and milk.     

THE EFFECT OF BOVINE EPHEMERAL FEVER VIRUS ON THE BOVINE FOETUS

Six pregnant heifers that were experimentally infected with bovine ephemeral fever virus produced normal calves. Foetuses of 8 heifers that were immune to bovine ephemeral fever were inoculated with bovine ephemeral fever virus. One was aborted after 36 days, but the cause of abortion could not be determined. One was sacrificed after 28 days. The foetus and its membranes were normal and neither virus nor antibody was demonstrated. The other 6 heifers produced normal calves. One calf, 501, inoculated after 160 days gestation, contained high levels of neutralising antibody in serum before ingestion of colostrum. The others, inoculated at gestational ages of 52 days to 157 days showed no evidence of neutralising antibody in blood samples collected at birth.     

HISTOLOGICAL AGEING OF BRUISES IN LAMBS AND CALVES

SUMMARY Groups of 10-day-old calves and 5-month-old lambs were bruised 48 hours, 24 hours, 8 hours, or the instant before slaughter. By gross examination, 48-hour-old calf bruises had a characteristic red-yellow colouration, but other bruises could not be differentiated reliably. By microscopic examination, bruises of all ages could be differentiated by cellular criteria common to both species. Unlike fresh lesions, 8 hour bruises contained numerous neutrophils. Twenty-four hour old bruises contained equal numbers of macrophages and neutrophils and at 48 hours macrophages, fusiform cells and new capillaries were present in the damaged muscle. The criteria established in this study could be used to determine the ages of spontaneous bruises in abattoir carcases and so provide a basis for an investigation aimed at detection of the traumatic episode from which they result.