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Biomedical subjects

R I Coubrough

Publications and source records attributed to R I Coubrough.

14 recordsLinked to original sources
PubMed1988

The integration of the transfer of frozen embryos with artificial insemination in a commercial beef herd.

This trial was designed to examine the integration of the transfer of frozen embryos and artificial insemination (A.I.) in a commercial herd of beef cows. Embryos were collected nonsurgically from 15 superovulated cows and all embryos judged viable (n = 69) were frozen in 0.25 ml plastic A.I. straws. Glycerol was used as a cryoprotectant and the embryos were frozen with omission of the traditional "seeding" step. On three consecutive days immediately preceding the onset of a 60-day breeding season, 54 embryos were transferred to multiparous cows with calves at foot. The remaining 82 cows in the same herd were used as controls. Cows receiving embryos were maintained under observation, but not inseminated for 21 days, after which cows exhibiting signs of estrus were inseminated up to Day 60. Cows in the control group were inseminated at observed estrus throughout the 60-day period. The overall pregnancy rate for the experimental and control groups did not differ (77.8 % and 73.2 % respectively). Of the experimental cows, 24.1 % conceived to the embryo transfer, and 53.7 % to A.I. The mean calving to conception interval for the experimental cows was 96.3 days (median 101 days) and for the control cows it was 92.3 days (median 88 days). The calving pattern in the experimental cows was biphasic, calvings resulting from embryo transfer of A.I. accounting for the two peaks. Reconception rates in the following breeding season were not different between the embryo transfer or A.I. groups or between experimental and control herds. Weaning masses of calves born of embryo transfer were significantly higher than the other groups, but calves resulting from A.I. in the experimental herd were not different from calves in the control herd. It was concluded that the transfer of frozen embryos could be successfully integrated into an A.I. program with a limited breeding season without detrimentally affecting the overall reproductive performance of the recipient herd.

Journal Article↗
PubMed1987

The transmission of bluetongue virus by embryo transfer in sheep.

The susceptibility of sheep to intrauterine infection with bluetongue virus (BTV) was established by introducing 10(4) plaque-forming units of BTV type 10 into the uterine lumen of two seronegative ewes in a simulated embryo transfer operation. Both ewes became viraemic and underwent seroconversion to BTV. Embryos recovered from seronegative superovulated donor ewes were incubated in vitro for 8 h with BTV type 10. After incubation the embryos were thoroughly rinsed by repeated transfer to sterile culture medium, and 12 of these embryos were then transferred to the uterus or oviduct of seronegative, synchronized recipients. Viraemia and seroconversion were detected in nine recipient ewes. Embryos recovered from eight viraemic ewes were transferred to 15 seronegative, synchronized recipients. Viraemia and seroconversion were detected in 2 of the recipients, both of which also became pregnant. A lamb born to a ewe becoming infected at the time of embryo transfer was clinically normal, and no evidence of BTV infection was obtained at postmortem examination of the lamb after slaughter.

Journal Article↗
PubMed1986

[Planned dairy herd health II. An integrated gynecological program].

Integrated gynaecological programmes play an extremely important role in total herd health control by ensuring the maintenance of optimal reproduction and production. The economic implications of reduced breeding efficiency manifest in, and are reflected by total lifetime milk production, the size of the calf drop, the availability of replacement animals and increased involuntary culling rate. Measured against production costs (feed, labour and veterinary expenses), lowered reproductive efficiency erodes the margin of profitability of the farming enterprise. Herd health programmes must be well planned, stringently implemented and regularly evaluated to ensure their effectiveness. To this end they must be based on simple and practical guidelines which can be adapted as required to cope with varied farming and management conditions. This paper outlines the setting of clear objectives, factors to consider during the introductory phasing in of an integrated gynaecological programme and details of each subsequent routine visit. Ideal objectives are presented and discussed in terms of the individual animal as well as the herd. Suggested figures for each parameter are given. The significance of oestrus observation is stressed as cardinal to the attainment of many of the set objectives. The significance of calf management as the nucleus of the production of a healthy heifer replacement herd is discussed. During the introductory phase, which can be a protracted period, the foundation for routine visits is laid. Herd structure is defined, facilities are evaluated, record systems are set up and the farmer is groomed as to his role in the successful implementation of the planned programme. The value of a control questionnaire is highlighted, and factors considered are set out. The method of the routine gynaecological programme is discussed in detail. The necessity for a standard examination list is set out and the various categories of cows to be examined on each routine visit is clearly outlined, with important factors relating to each being highlighted. Examples of the various forms used are given. Evaluation of the acquired data should be done immediately, and discussed with the farmer during the current visit. Findings can be compared with those of previous visits, analysed, and recommendations may be considered immediately in consultation with the farmer. Dairy farming is a highly complex farming enterprise involving large capital outlays, intensification of labour and astute management for optimal and economic production.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Husbandry↗
PubMed1985

Successful transfer of embryos recovered from a cow with chronic cervicitis of mixed aerobic and anaerobic bacterial aetiology a case report.

An imported 13-year-old Simmentaler cow was presented with severe purulent cervicitis and endometritis from which Corynebacterium pyogenes , Fusobacterium necrophorum , Bacteroides melaninogenicus and an untyped Clostridium perfringens were isolated. The endometritis responded to treatment but the cervix did not and remained fibrous, continuously patent and purulent. Natural pregnancy was considered unlikely and the cow was prepared as an embryo transfer donor. Eight embryos were recovered and six transferred, resulting in five confirmed pregnancies and four live births.

Journal Article↗
PubMed1985

Stress and fertility. A review.

The effect of both environmental and management related stressors on fertility is discussed. While environmental heat as a stressor is significant in disrupting normal reproductive cyclicity, management induced stress is becoming more important when related to the requirements of modern production methods. Deviations in hormonal patterns are noted, and the clinical manifestations brought about by these changes are described. Since reproduction is the ultimate measure of an animal's ability to adapt to an ever changing external milieu, as well as forming the basis of life-time productivity, research should be aimed at obtaining greater clarity of the hormonal interactions involved. The role of neurotransmitters in these physiological mechanisms should not be overlooked. Psychobiological studies must be extended so as to provide a positive input into management procedures that should be used in intensive production units for optimal fertility and productivity.

Adaptation, Physiological↗
PubMed1985

A pregnant heifer with a congenital incompletely developed vulva.

A 2 year old Friesland heifer was presented in an advanced stage of pregnancy with a vulva showing only 2 small openings of 1,5 and 0,5 cm in diameter in the dorsal and ventral vulvar commissures, respectively. Normal vulvar skin covered a thick band of fibrous tissue between the two openings. From the vestibulum forward, the rest of the genital tract was normal. At calving, the fibrous tissue was resected under epidural anaesthesia, and the calf delivered with ease. The vulva was reconstructed by stitching the vestibular mucosa to the vulvar skin using simple interrupted sutures.

Animals↗
PubMed1985

[Planned dairy herd health. I: General philosophy].

A dairy herd health programme may be defined as a planned and co-ordinated approach which aims at achieving and maintaining optimal herd health, production and reproduction, the implementation of which is governed by sound economic principles. The object of this article is to present and discuss some facets of the background philosophy of the concept of herd health, and look at some of the pitfalls and shortcomings of their application in practice. In terms of production levels achieved in other developed countries, South Africa lags behind. While factors such as climate, environment, feed quality, and basic livestock potential may play a role in this difference, the single most important factor is undoubtedly the managemental approach. Modern livestock production requires a shift in emphasis of veterinary involvement towards a herd approach which promotes increased cost-effective production. The veterinarian forms part of a production team which, apart from himself, includes the farmer, farm labour and the animal scientist. The veterinarian has a key role in this endeavour. Through his basic training he is well equipped to serve as a co-ordinator of the massive flow of information being generated. To do this effectively he must be able to work with, advise and communicate with people at various levels of management as well as with the labour force. While optimal co-operation of each team member is cardinal to the success of such a programme, no progress will be made unless the farmer is convinced of the viability of the undertaking, and indeed has the managerial skills to implement any directive or recommendation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Husbandry↗
PubMed1978

The South African Veterinary Association: glimpses from 75 years of service to veterinary science.

The South African Veterinary Association originated with the formation of the Transvaal Veterinary Medical Association in 1903. The amalgamation of the three existing provincial associations under a joint constitution in 1920 formed a body representing the veterinary profession in the whole of South Africa. Throughout the past 75 years the SAVA has served as representative for the diversity of interests of the profession. The aims and major contributions of the Association, past and present, as well as the challenges of the future, are outlined.

History, 20th Century↗
PubMed1976

The "herd approach" to bovine reproductive disorders. Part I: The diagnosis and management of infectious infertility.

The authors describe the methods employed by the Artificial Insemination Section of the Division of Veterinary Services in collaboration with the Reproduction and Bacteriology Section of the Veterinary Research Institute, Onderstepoort when herds are examined for infertility. A "herd" rather than an "individual animal" approach is advocated and certain infectious causes of infertility are discussed.

Animals↗