Showing papers in "Animal Reproduction Science in 1986"

TL;DR: The increase in PR and the altered distribution in return to service intervals produced by an injection of 10 μg Bus during days 11–13 PFI appeared to be dose related and was probably associated with delayed luteolysis previously reported in unmated cycling dairy cows treated with this GnRH analogue.

TL;DR: Sperm motility did not correlate well with acrosome integrity and most acrosomal damage appeared to occur during the freeze/thaw processes.

TL;DR: A sensitive, simple and direct enzyme immunoassay system for the measurement of progesterone in bovine milk and blood plasma and application of the milk-progesterone EIA to pregnancy testing gave an accuracy of 79.6% for positive diagnoses and 100% for negative diagnoses.

TL;DR: The results of this study indicate that development of the preovulatory follicle starts in the cow at the onset of luteolysis, about 2.5 days before thePreovulatory LH surge, and that oestradiol secretion by this follicle is possibly inhibited by the LH surge.

TL;DR: The hormonal asynchronism starts before or early in oestrus, which presumably leads to a sequence of improper hormonal changes responsible for the elevated embryonic loss in repeat breeder animals.

TL;DR: Ewes lambing and lambs born per ewe inseminated increased with time of insemination at 48, 60 and 72 h (linear, P) and egg fertilisation rates were not different between ewes irrespective of time of onset of oestrus or whether or not eWes were marked.

TL;DR: It is concluded that body condition affected the size of the large follicle (⪖ 4 mm diameter) population through changes in FSH and possibly pulsatile LH secretion and prolactin secretion during the luteal and follicular phases of the cycle and that the number of follicles that were potentially ovulatory was probably determined during theLuteal phase of the cycles.

TL;DR: Although site of insemination did not affect the percentage of ewes lambing, thepercent of lambs born per ewe inseminated was higher afterInsemination in the middle of the uterine horn than at the other sites (P < 0.001).

TL;DR: It is demonstrated that ultrasonography was useful in examining the normal uterus, being particularly helpful in differentiating questionable palpation results when uterine pathology was present.

TL;DR: In this article, the role of the sense of smell in the ovarian and oestrous responses of anovular goats to the introduction of bucks was investigated and two experiments were conducted in order to determine the role and role of smell.

TL;DR: The volume of the ejaculates obtained was slightly lower than that obtained using an artificial vagina, but the sperm count was considerably higher, and other parameters including pH, percentage of live sperm and sperm dimensions were comparable to those of ejaculates collected by the artificial vagina.

TL;DR: Although cost, delicacy of the equipment, and time required for an examination currently preclude the complete replacement of bovine rectal palpation by ultrasound, the ultrasound machine is easy to use and can augment palpation in individual animals that present diagnostic problems.

TL;DR: Replicate experiments were conducted using ovariectomized ewes to evaluate four progesterone-releasing devices and progesterone levels were similar in replicate experiments but differed significantly between treatments and days.

TL;DR: It was found that near 100% reliable results could be obtained for positive diagnosis from 45 days onwards and that the ultrasonographic results were 100% reliability for negative diagnosis from 40 days onwards.

TL;DR: The causes of lamb mortality in two highly prolific flocks and a flock of medium prolificacy and the effects of year, ewe age, and litter size on the distribution of mortality between these groups were examined.

TL;DR: The study has confirmed the minimal progesterone levels determined earlier for maintenance of pregnancy in swine and indicates that in the etiology of an abortion at day 60 of pregnancy, any possible fetopathic effect of the tested LPS would be secondary to its luteolytic effect.

TL;DR: Spermatogenesis in the camel was generally similar to that of most mammalian species, although some features specific for the camel were observed.

TL;DR: The effect of supramaintenance feeding on ovulation rate was reflected in subsequent lamb and kid production, and in neither species was the incidence of oestrus affected by level of nutrition.

TL;DR: Addition of detergents to sperm immediately reduced motility, respiration and calcium uptake of control and cold-shocked sperm to zero and subsequent cold shock increased the sperm calcium.

TL;DR: Success rates when transferring embryos collected surgically or from reproductive tracts of slaughtered animals do not differ significantly, provided tracts are removed and flushed immediately after slaughter.

TL;DR: The data suggest that for normal expulsion of fetal membranes a rise in oestradiol-17β prepartum must be accompanied by a fall in progesterone, and that this shift should occur in a gradual and sustained manner.

TL;DR: It is suggested that the mechanism for protection of the corpus luteum is based on the uptake of uterine-origin PGF 2α by the mesometrium which is then transferred to the uterus in arterial blood by the counter current system.

TL;DR: It is concluded that an ejaculation frequency of five successive ejaculations for 17 consecutive days does not affect the fertility of Finn cross rams, irrespective of the season of semen collection.

TL;DR: In this paper, changes in plasma concentrations of luteinizing hormone (LH), progesterone and oestradiol-17β were analysed in relation to the chronology of behavioural oestrus and ovulation in six cyclic swamp buffaloes.

TL;DR: It is suggested that the efficiency of reproduction in dairy herds may be improved by the use of hormone-treated steers, and their advantages are discussed.

TL;DR: A comparison of the theoretical possibilities of the twisting mechanism with the data of the present study, and with developmental and clinical facts indicates that the fetal movements themselves perform the principal role in the twisting process.

TL;DR: Neither treatments nor bulls had any significant effect on PIA and PIHA after 0 and 3 h incubation, and thaw rate of 37°C for 30 s was comparatively superior to other rates studied.

TL;DR: Nubian goats seem to provide better quality semen than other breeds of goats, and in some traits their semen was superior to that of Desert sheep.

TL;DR: Crossbred ewes lambed during the breeding season were performed to determine whether the interval to first postpartum ovulation could be reduced by weaning or mastectomy, and GnRH-induced corpora lutea from postpartums were lighter in weight, paler in color, had lower LH receptor concentrations and had a more regressed histological appearance.

TL;DR: Post-partum anovulation was the primary cause of conception failure within 100 days of calving in Afrikaner cows and a reduction in the suckling stimulus had no significant effect on any parameter of luteal function measured in this study.