PubMed Health⌕ Search

Biomedical subjects

W J McCaughey

Publications and source records attributed to W J McCaughey.

At least 55 records · Page 3Linked to original sources
PubMed1988

Detection of zeranol in the blood of ram lambs by a radioimmunoassay technique.

Plasma separated from jugular blood samples from six weaned ram lambs was examined for zeranol after the lambs had been implanted, behind the left ear, with a 12 mg pellet. The results showed that the ipsilateral vein contained significantly more zeranol for up to 100 days after implantation; by 145 to 175 days the difference between the ipsi- and contralateral veins was no longer significant. Massage of the implant site did not increase the rate of release of zeranol from the residual mass.

Animals↗
PubMed1986

Investigation into the inhibitory effect of flurofamide on animal ureaplasmas and its use in the treatment of ureaplasma-infected sheep.

In vitro tests with the urease inhibitor flurofamide demonstrated that the final inhibitory concentration of 0.5-4 microM on the growth of nine ureaplasma strains was largely ureaplasmastatic, requiring prolonged incubation to have a ureaplasmacidal effect. Intramuscular injection of flurofamide successfully eliminated genital infections of ureaplasma in sheep only when the treatment was repeated on two consecutive days. A dose rate of 5-20 mg/kg body weight eliminated the organism from naturally infected sheep, but 15-25 mg/kg body weight was required to eliminate the infection from eleven of fourteen experimentally, newly infected sheep. Administration of the flurofamide orally in the drinking water failed to eliminate ureaplasmas from any of twenty newly infected sheep.

Administration, Oral↗
PubMed1985

Experimental intrauterine inoculation of pregnant ewes with ureaplasmas.

The pregnancies of 13 ewes which were inoculated intrauterine with one of two strains of ovine ureaplasmas resulted in 9 normal and 3 abnormal births, and one ewe was found to be no longer pregnant on postmortem examination. Vaginal ureaplasma infection was detected in the majority of ewes only after lambing. Of the 12 ewes examined at postmortem, ureaplasmas were isolated from the uterus of 5 out of the 6 necropsied up to 21 days post-partum. The vulvar/preputial areas of the majority of lambs that survived were infected with ureaplasmas for the duration of the experiment, but infections of the nasal cavity and eye areas, detected at birth in 4 lambs, were resolved within 8 days post-partum. The only pathological effects detected that could possibly be attributed to ureaplasma infection were a placentitis in an ewe that aborted, and the resorption of the foetus in another.

Animals↗
PubMed1985

The physical appearance of the vulva in ureaplasma infected ewes.

The vulvar labia of ewes naturally infected with ureaplasma were significantly more swollen and red than those of uninfected ewes. Similar changes were observed following experimental infection of previously uninfected ewes. These differences, although statistically significant, were not sufficiently marked to be useful in diagnosing infection by clinical examination.

Animals↗
PubMed1984

Tail painting technique as an aid to oestrus detection in cattle.

The value of heat detection by tail painting was assessed by simultaneous visual observation and regular plasma progesterone assay in grazing animals; 88.1 per cent of all heats were accompanied by a positive tail paint record and 30.1 per cent of positive tail paint records occurred in dioestrous animals. Conception rates to the first insemination were 57.6 per cent and 57.9 per cent for heifers and cows, respectively. Of seven animals which showed behavioural oestrus but had intact tail paint, three conceived following insemination. These results suggest that tail paint may be a useful aid in heat detection.

Animals↗
PubMed1981

Vaginal electrical resistance in cows: 2. Relationship to milk progesterone concentrations during the reproductive cycle.

When the vaginal electrical resistance (VER) was measured in the anterior vagina in 4 cows during a total of 12 oestrous cycles, there was a close correlation between VER, milk progesterone levels and visual observations of oestrus. The cyclic changes in both VER and milk progesterone ceased in 2 cows which became pregnant during the study. In a pregnant cow, the VER was found to be constant both pre-partum and immediately post-partum. These results show that measurement of VER can be a useful aid in the confirmation of oestrus and suggest that the technique may also be applicable to the early diagnosis of pregnancy.

Animals↗
PubMed1981

Pregnancy diagnosis in cattle by measuring vaginal electrical resistance.

The results of early pregnancy diagnosis using a milk progesterone assay and a measurement of electrical resistance of the vaginal mucosa made on 135 dairy cows in two herds are compared. The tests were carried out on the day of insemination and 21 days later. Ninety-eight cows were diagnosed as pregnant by both tests. Of these, 92 calved and there were 6 cases of suspected embryonic mortality. Thirty animals were diagnosed as non-pregnant by both tests and none calved. One cow, diagnosed as non-pregnant by the vaginal electrical resistance method, calved later. Of the remaining 6 cows, 4 had extended post-parturition anoestrus, one had cystic ovarian disease and another had a long oestrus cycle. The results of this study suggest that measurements of the electrical resistance of the vaginal mucosa in dairy cows may have a part to play in on-farm pregnancy diagnosis.

Animals↗
PubMed1980

An assessment by progesterone assay of the accuracy of oestrus detection in dairy cows.

The use of a milk progesterone assay in determining the extent to which dairy cows are presented for insemination at the wrong time is reported. Milk samples were taken from cows at the time of insemination and were subjected to plasma progesterone assay. In a preliminary study samples were obtained from 96 cows in an experimental herd at insemination. The calving rate of these cows was compared with the milk progesterone level at insemination. Eight cows which had levels of progesterone much above the normal oestrus level 9 more than 0.3 ng per ml) failed to conceive. As the progesterone level at insemination rose, calving rate declined. A further 1177 milk samples taken from cows being inseminated in commercial dairy herds were also examined. Ninety-one animals (7.7%) had levels of milk progesterone in excess of those observed at normal oestrus. A negative correlation was confirmed between non-return rate and milk progesterone level at insemination. These investigations show that the proportion of cows from the national herd which have high progesterone levels when presented for insemination is similar to that found under experimental conditions and suggests that the problem of heat detection may be a relatively constant factor in reduced conception to artificial insemination.

Animals↗