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Biomedical subjects

W R Ward

Publications and source records attributed to W R Ward.

At least 55 records · Page 3Linked to original sources
PubMed1989

Associations between types of lameness and fertility.

Four hundred and twenty-seven cases of first-reported foot lameness were recorded in 17 dairy herds in Somerset during the winter housing period. Lameness was classified into three categories: sole ulceration, digital disease (white line abscess, foreign bodies in the sole and pricked or punctured sole), and interdigital disease (lesions of the skin between claws and heel including foul in the foot, interdigital fibroma and dermatitis). In addition, a 'clinical effect score' was calculated to take account of the severity of lameness, the structures involved and the time for which the cows were clinically affected. The fertility records of lame cows were compared with those of the healthy cows nearest in parity and stage of lactation. In the lame cows the interval from calving to first service was four days longer, and the interval from calving to conception was 14 days longer than in the control cows, the pregnancy rate to first service was 46 per cent (controls 56 per cent), 2.14 services were required per conception (controls 1.72) and 16 per cent of lame cows were culled (controls 5 per cent). Lameness, first reported in the period 36 to 70 days after calving, was associated with a significant (P less than 0.01) increase in the interval from calving to first service of eight days; and sole ulceration, in the period 71 to 120 days after calving, was associated with an increase of 11 days (P less than 0.05). Lameness in all periods up to 120 days after calving was associated with significantly increased intervals from calving to conception (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Development of a microcomputer system for recording veterinary visits, preparing accounts, and as an aid to herd fertility and herd health schemes.

A computerised method of recording clinical information from farm animal practice visits and using it for herd fertility visits, herd health schemes, the investigation of disease outbreaks and as a source of data for epidemiological studies was developed in the University of Liverpool farm animal practice. The system stores clinical and reproductive information in a data base from which data can be readily extracted and analysed, and monthly bills produced.

Data Collection↗
PubMed1989

Development of a coding system for recording clinical findings in farm animal practice.

A coding system was developed for recording veterinary information in the University of Liverpool farm animal practice. Existing coding systems were found to be unsuitable for use on a microcomputer in a veterinary practice. A number of new coding formats were developed and tried. The need to record varying detail, to analyse data and to enter data quickly resulted in biaxial hierarchical codes. These are used in an automated coding system to record all veterinary and reproduction information in the practice.

Animals↗
PubMed1989

Opioid modulation of tonic luteinizing hormone release in ovariectomized dairy cows.

A possible role of endogenous opioid peptides (EOP) in regulating the release of luteinizing hormone (LH) in the absence of ovarian influence was investigated. Experiments were conducted on three lactating Holstein-Friesian dairy cows, 20-27 days after ovariectomy. The cows were bled before and after a single intravenous (i.v.) injection of either 250 mg of naloxone (EOP antagonist) or 300 mg of morphine (EOP agonist) or a combination of the two in Experiments 1, 2 and 3, respectively. The mean and basal LH concentrations and the LH pulse frequency and amplitude were compared before and after each treatment in each cow. Naloxone induced an immediate rise in LH concentration by 60-300% above the preceding baseline values. This rise lasted for 15-30 min in each cow, after which the normal rhythmic LH release continued. One cow (A) suffered discomfort and respiratory distress 15-25 min after naloxone administration and the mean and basal LH concentration dropped significantly. Morphine significantly reduced the mean LH concentration by decreasing the number and amplitude of LH pulses and the basal LH values in two cows, although the decrease in one was not significant. The mean LH concentration in each cow remained unaffected by the combined treatment of morphine and naloxone. In conclusion, the elevation of LH concentration by naloxone, the suppression of LH release by morphine and the reversal by morphine and naloxone of each other's effects suggest that EOP could be involved in the control of LH release in cows in the absence of ovarian influence.

Animals↗
PubMed1989

Effects of naloxone on the oestradiol-induced LH surge and cortisol release in transported cows.

Four control cows released a normal LH surge in response to 1 mg oestradiol benzoate i.m. Compared to controls, 30 min transport of 5 cows 16-18 h after oestradiol significantly delayed the onset (P less than 0.05), suppressed the amplitude (P less than 0.01) and reduced the total LH release (P less than 0.001) in 4 cows and totally blocked the surge in the 5th cow. Just before the onset of transport, 5 cows were given 250 mg naloxone i.v. In 3 cows, the LH surge was delayed and reduced in amplitude and duration and was totally blocked in the other two, i.e. naloxone did not avert the detrimental effects of transport. Transport stimulated cortisol release in cows. Cows given naloxone + transport released significantly more (P less than 0.001) cortisol than did those subjected to transport alone. In conclusion, naloxone appeared to have further stimulated the hypothalamopituitary-adrenal axis of cows under stress.

Animals↗
PubMed1988

Retrospective analysis of the efficacy of different hormone treatments of cystic ovarian disease in cattle.

Cystic ovarian disease in cows was treated either with a single intramuscular injection of 500 micrograms cloprostenol, a prostaglandin F2 alpha analogue, in 77 cases of luteal cysts or with 500 micrograms gonadorelin or 20 micrograms buserelin, gonadotrophin releasing hormone or its analogue (GnRH), in 116 cases of follicular cysts. Recovery was defined as the absence of cysts and the formation of a corpus luteum either with or without observed oestrus within 10 days after treatment with cloprostenol and 15 days after treatment with GnRH. Recovery occurred in 65 per cent and 52.6 per cent of cases, respectively, in average times of 4.9 and 19 days. Fifteen days after treatment with GnRH, 20 cows with luteinised cysts were treated with cloprostenol and 15 recovered in a mean of 20.4 days, while 10 which still had follicular cysts, were given GnRH and one recovered 31 days after the beginning of treatment. Another 27 cows, in which cysts became luteinised, were treated with cloprostenol seven days after treatment with GnRH to give quicker (average 11.5 days) but poor (48 per cent) recovery and with a higher rate (33 per cent) of recurrence of cysts. A progesterone releasing intrauterine device was used in 25 cases of cystic ovarian disease, some of which had been previously treated. Sixty-eight per cent recovered in an average of 15 days. The proportions of cows becoming pregnant to one to three inseminations after the different methods of treatment were similar (77 to 94 per cent).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Effect of endogenous and exogenous progesterone on the oestradiol-induced LH surge in dairy cows.

Four cows released an LH surge after 1.0 mg oestradiol benzoate administered i.m. during the post-partum anoestrous period with continuing low plasma progesterone. A similar response occurred in the early follicular phase when plasma progesterone concentration at the time of injection was less than 0.5 ng/ml. Cows treated with a progesterone-releasing intravaginal device (PRID) for 8 days were injected with cloprostenol on the 5th day to remove any endogenous source of progesterone. Oestradiol was injected on the 7th day when the plasma progesterone concentration from the PRID was between 0.7 and 1.5 ng/ml. No LH surge occurred. Similarly, oestradiol benzoate injected in the luteal phase of 3 cows (0.9-2.1 ng progesterone/ml plasma) did not provoke an LH surge. An oestradiol challenge given to 3 cows 6 days after ovariectomy induced a normal LH surge in each cow. However, when oestradiol treatment was repeated on the 7th day of PRID treatment, none released LH. It is concluded that ovaries are not necessary for progesterone to inhibit the release of LH, and cows with plasma progesterone concentrations greater than 0.5 ng/ml, whether endogenous or exogenous, did not release LH in response to oestradiol.

Anestrus↗
PubMed1985

Specialisation.

Explore the source record for details and available documents.

Curriculum↗
PubMed1978

Effect of fetal hypophysectomy on the initiation of parturition in the goat.

Fetal hypophysectomy performed between 97 and 130 days of gestation caused a significant (P is less than 0.005) prolongation of pregnancy in 5 goats in which every fetus was treated. Three of these goats gave birth spontaneously. Sham surgery or hypophysectomy of one fetus of twins had no effect on gestation length. Hypophysectomized kids, delivered after prolonged pregnancy, were significantly heavier than normal term kids (P is less than 0.005) and had lighter adrenals (P is less than 0.025). Measurements of maternal peripheral plasma concentrations of progesterone and total unconjugated oestrogens showed that the changes in goats carrying hypophysectomized fetuses were similar to those of normal pregnancy except that the prepartum oestrogen peak was absent, whether or not parturition occurred spontaneously.

Adrenal Glands↗
PubMed1978

Effect of active immunization against oestrogens on plasma gonadotrophins in the ewe and the response to synthetic oestrogen or LH.

Immunization against oestrogen resulted in elevated LH concentrations, in the form of a pulsatile release, which rose from 3 to as much as 41 ng/ml approximately every 1.5 h, even in the presence of high plasma progesterone concentrations. Elevated FSH concentrations showed only minor oscillations without consistent synchrony to the LH pulses. Injection of 250 microgram stilboestrol did not abolish the LH pulses but in 2 out of 8 ewes FSH was initially lowered. Injection of 1 mg stilboestrol abolished the LH pulses within 11 h and decreased FSH values in 2 out of 4 ewes. Between 16 and 35 h after injection there was a large increase in LH and FSH concentrations. Thus, in the ewe, the tonic secretion of LH and FSH is controlled by a negative feedback action of oestrogen, and diethylstilboestrol will exert both dose. Infusion of LH was unable to alter the frequency or height of the LH pulses, thereby excluding regulation of the LH pulses by a short feedback mechanism.

Animals↗
PubMed1978

Correlations of maternal and fetal endocrine events with uterine pressure changes around parturition in the ewe.

In 4 Clun Forest ewes maternal peripheral plasma concentrations of progesterone were still elevated at the onset of parturient uterine activity. Fetal and maternal plasma concentrations of oestrogen started to rise before parturition and concentrations in maternal plasma were positively correlated with parturient uterine activity (P less than 0.05; r = +0.42). Fetal plasma concentrations of corticosteroids were positively correlated with fetal plasma concentrations of oestrogen (P less than 0.01; r = +0.65), but negatively correlated with maternal peripheral plasma progesterone concentrations (P less than 0.05; r = -0.50). Before parturition plasma concentrations of PGF rose but stayed high only in maternal peripheral plasma. Maternal peripheral plasma concentrations of PGF were positively correlated with uterine activity (P less than 0.05; r = +0.79) and plasma concentrations of oestrogen (P less than 0.05; r = +0.79), but negatively correlated with plasma concentrations of progesterone (P less than 0.01; r = -0.54).

Animals↗
PubMed1978

The effect of passive immunization against oestrogens on the onset of parturition in the ewe.

Six ewes were treated twice daily with intravenous injections of antiserum to oestrogens and 3 ewes received normal sheep serum from Day 140 of gestation until parturition. All 9 ewes experienced normal parturitions and produced healthy active lambs after similar gestation lengths. Progesterone and prostaglandin F concentrations in maternal jugular venous plasma were similar in the immunized and control ewes, but total unconjugated oestrogen concentrations were significantly higher in the immunized ewes (P less than 0.005). It is concluded that immunization of the ewe against total unconjugated oestrogens did not affect the normal occurrence of parturition.

Animals↗
PubMed1977

Bovine cystic ovarian disease: plasma hormone concentrations and treatment.

Ovarian function in 91 dairy cows with cystic ovarian disease was assessed by rectal palpation and by plasma hormone analysis before and after treatment. Plasma analysis showed that 84% of the cysts were correctly classified clinically and only these cows are considered further. Luteinised cysts occurred in 59 cows whereas only 18 had non-luteinised cysts. The mean plasma concentrations of luteinising hormone (LH), follicular stimulating hormone (FSH), progesterone, oestradiol and testosterone were not significantly different when compared with values at relevant stages of the oestrous cycle in normal cows. Success of treatment with progesterone, a synthetic prostaglandin, human gonadotrophin (HCG), or gonadotrophin releasing hormone (GnRH) was not dependent upon prior hormone concentrations, except for the prostaglandin which required active luteal tissue. LH and FSH concentrations in cows with luteinised cysts were not significantly different before and after successful treatment with GnRH or progesterone. Normal luteal function was not always established after treatment of non-luteinised cysts with GnRH.

Animals↗
PubMed1977

Alterations in plasma gonadotrophin patterns caused by sodium pentobarbitone in ewes at oestrus and in anoestrous ewes after infusion of oestradiol.

A radioimmunoassay system for the measurement of ovine follicle-stimulating hormone (FSH) was established. After the onset of normal oestrus, there were simultaneous surges of luteinizing hormone (LH) and FSH, and 24 h later, a surge of FSH alone. Administration of sodium pentobarbitone when the dual surge of LH and FSH was expected inhibited the release of LH, but prolonged that of FSH. Development of corpora lutea that took place immediately was normal in ewes treated with sodium pentobarbitone, but after the subsequent oestrus, the life-time of corpora lutea was abnormally short. When sodium pentobarbitone was administered at the time when the second surge of FSH was expected, no effect was observed on the level of LH or FSH. Subsequent development of corpora lutea was similar to that in the non-treated group. Administration of sodium pentobarbitone at the expected time of the dual surges of LH and FSH after infusion of oestradiol to anoestrous ewes blocked the release of both LH and FSH. Administration of sodium pentobarbitone at the expected time of the second surge of FSH after infusion of oestradiol delayed the increase in the level of FSH. In a pilot experiment after combined infusion of androstenedione and oestradiol, sodium pentobarbitone did not completely inhibit the release of FSH, but the release of LH was totally prevented.

Androstenedione↗