A study of the fertility status of a commercial dairy herd in Zambia
Date
2012-09-17
Authors
Schneebeli, Markus.
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Abstract
The dairy industry in Zambia is a vital sector of the food industry and it has not been given the attention it deserves. Aspects such as level of production and factors affecting production have not been examined in the recent past.The reproductive performance of dairy animals is a field of major importance in veterinary medicine and subject to an enormous amount of dynamic research. Knowledge about the events determining reproduction and methods of influencing and improving the same has increased significantly over the past years, but the benefit of this to developing countries has so far been unsatisfactory. Milk production of dairy animals is largely dependent on the reproductive performance of individual animals. No recent studies on this subject are available in Zambia and it was therefore felt that a detailed study of the reproductive performance of dairy animals under local Zambian conditions was required. A study of the reproductive performance and fertility problems encountered on a commercial dairy farm near Lusaka was performed, covering a period of four years. The records of reproductive performance over three years were analysed and cull cows and heifers examined over a one year period. The hypothesis which was followed during this study was to confirm the assumption that there were no significant problems present in the culled cows and heifers from this particular dairy, but that the reproductive performance was poor due to managerial problems. The examination of cull cows and heifers included record analysis, gross post-mortem examination, bacteriological examination of uterine swabs and microscopic examination of histopathological sections of uterine tissue.
The results revealed a high incidence of disposal of dairy cows and heifers for reproductive reasons. The examination of herd records, which included the reproductive history of 1108 cows after calving, suggests that this disposal was largely due to management problems such as heat detection rate and timing of insemination in this herd where artificial insemination was in use. The examination of slaughtered animals, which involved 92 animals did not reveal any significant findings which would be responsible for the reproductive failure of the majority of disposed animals. A seasonal pattern of slightly improved reproductive performance with regards to conception to first service has been observed, and this should be taken into consideration when deciding on future breeding policies in dairy herds in Zambia, This period occurs during the early winter, when environmental factors such as ambient temperature and humidity drop, reducing stress on the animal and improving conception rates. The main reason for the reproductive failure of the examined animals is attributed to poor heat detection and timing of insemination.It was concluded that the reproductive performance of dairy animals in Zambia can meet targets set for developed countries, provided the level of management is improved and knowledge of the control of the reproductive cycle of the dairy cow is implemented.
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Keywords
Dairying Research , Dairy Cattle ---Breeding