Some Aspects of Infertility in the British Highland Cattle

Ng, In Hooi (1992) Some Aspects of Infertility in the British Highland Cattle. Master of Veterinary Medicine thesis, University of Glasgow.

Abstract

This study investigated some aspects of infertility in British Highland Cattle on two farms in Scotland. In farm 1, the study involved 48 head of post-partum cows which were examined, monitored for fertility and recorded in a computer spread sheet using a commercial spreadsheet "Microsoft Excel". This investigation also involved the study of chromosomal defects and examination of reproductive tracts using rectal palpation, plasma progesterone concentrations and ultrasonography. A second herd of animals, on farm number 2 near Oban, Argyll, which had reproductive problems in growing heifers was also examined for other aspects of fertility. Examination of abattoir specimens of the reproductive tracts from culled unproductive animals was carried out. Chromosomal analysis was undertaken on both of these farms when the initial blood culture revealed the existence of Robertsonian translocation in farm 1. On the whole, the reproductive parameters in farm 1 showed a slight decline in fertility compared with accepted standards. The results implicated certain individual cows which had contributed to this reduction in fertility. This could be seen in the wide variations of the results obtained. Thus, in order to improve the fertility of the herd, it was necessary to identify these problem cows and consider culling them as culling due to infertility was almost negligible on the farm. The causes of infertility were complex as no simple cause was identified. This study could only rule out likely causes through the process of elimination and to concentrate on the potential areas that could be the contributing source of this infertility problem. Specific disease screening of the bulls was recommended, especially when natural mating was practiced. Further studies in this area could elucidate, and may help to identify, the cause of infertility. As there was no simple cause of the infertility in herd 1, various ways of improving the fertility through good management, nutrition and introduction of superior genetic materials by the use of AI or even ET is recommended. Thus, computerisation of the breeding records would enable fertility analysis to be carried out promptly and action lists produced to assist in the management decision. On farm 2, the majority (92%) of the uterine cultures of the reproductive tract from the abattoir specimens harboured no bacteria. About 67% of these tracts showed some form of gross morphological abnormality involving the tubular genitalia. However, histological sections of the endometrium revealed no obvious abnormalities. Detailed chromosomal investigation was carried out on 69 animals. This showed that 11.36% and 12% of cattle on farms 1 and 2 respectively were found to be heterozygous for a Robertsonian translocation, identified as involving numbers 1 and 29. Studies of the pedigrees of the last 5 generations of the positive cases were carried out to identify the source of inheritance. It is suggested that de novo production of the genetical aberration could have occurred some generations ago in the breed. It was found that the defect did not have any apparent affect on fertility in the present study. This was the first time that the 1/29 Robertsonian translocation has been found in this breed.

• Item Type: Thesis (Master of Veterinary Medicine)
• Qualification Level: Masters
• Additional Information: Adviser: Neil Gorman
• Keywords: Veterinary science, Animal sciences
• Date of Award: 1992
• Depositing User: Enlighten Team
• Unique ID: glathesis:1992-75259
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 Nov 2019 21:26
• Last Modified: 19 Nov 2019 21:26
• URI: https://theses.gla.ac.uk/id/eprint/75259