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Adjustment of birth weight for weighing age and relationship of standardized birth weight with early mortality in N'Dama calves under traditional husbandry systems in The Gambia

  • K. Agyemang (a1) (a2)


Birth-weight data recorded between 1986 and 1991 on 3453 N'Dama calves from the village production systems of The Gambia were analysed to identify major factors influencing this trait and to quantify the relationship between birth weight and early calf mortality. Birth weights were measured over a range of time, from a few hours to 14 days after birth. Least-squares analysis of the fixed effects of site, year and season of birth, parity of dam, sex, age in days at which birth weight was recorded and random effects of herd and cow nested within site showed that all these factors significantly influenced this trait.

A subset of these data (no. = 2452) was used to derive adjustment factors which were applied to the larger data set to standardize birth weights to a common age measurement. Results from these adjustments showed that birth weights recorded between the 7th and 14th day after birth should be decreased by proportionately 0·12 to 0·14 to be comparable with those measured on day of birth.

Maximum likelihood analyis of cumulative calf mortality to 30, 60, 90 and 120 days of age using age-standardized data (no. = 3156), which excluded deaths of traumatic origin, showed that mortality was highly influenced by birth weight. Calves were grouped into three classes, namely below-average, average and above-average of sitemates' values. Mortality rates among the three groups during the first 30 days of life were 3·6, 0·9 and 0·3%. The corresponding values at day 120 were 13·8, 6·3 and 5·0%. The average age at death during the first 120 days in the three groups were 51, 58 and 73 days. Mortality rates among calves born in the wet season were higher than those born in the dry season (e.g. 9·9 v. 5·9% for mortality to day 120).

Examination of data on calving distribution and milk production patterns of the dams of the calves used in this study as well as the causes of deaths among the calves indicated that although dam effect was an important determinant of calf survival other factors such as the vigour of the calf at birth, weather conditions and disease environment at the tethering and grazing areas were important as well.



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Agyemang, K. 1983. Multiple trait sire evaluation on parts of lactation milk yield of Holstein cows using best linear unbiased prediction procedures. Ph.D. thesis, Cornell University, Ithaca, New York.
Agyemang, K., Dwinger, R. H., Grieve, A. S. and Bah, M. L. 1991. Milk production characteristics and productivity of N'Dama cattle kept under village management in The Gambia. Journal of Dairy Science 74: 15991608.
Agyemang, K., Jeannin, P., Grieve, A. S. and Dwinger, R. H. 1988. Milk extraction for human consumption from N'Dama cattle under village management conditions in The Gambia. In Livestock production in tsetse affected areas of Africa. Proceedings of International Livestock Centre for Africa/International Laboratory for Research on Animal Diseases meeting, Nairobi, Kenya, 1987, pp. 231245.
Alexander, G. and Peterson, J. E. 1961. Neonatal mortality in lambs: intensive observations during lambing in a flock of maiden Merino ewes. Australian Veterinary Journal, 10, pp. 371381.
Bonsma, J. C. and Skinner, J. D. 1961. Factors influencing birth date, birthweight and preweaning growth rate of Afrikaner, Bonsmara and Hereford cattle in the subtropics. Proceedings of the South Africa Society of Animal Production, pp. 161163.
Brumby, P. J. and Trail, J. C. M. 1986. Animal breeding and productivity studies in Africa. ILCA Bulletin 23: 2327.
Dennis, S. M. 1971. Perinatal lamb mortality. Cornell Veterinarian 62: 253263.
Dunsmore, J. R., Blair Rains, A., Lowe, G. D. N., Moffat, D. J., Anderson, I. P. and Williams, J. B. 1976. The agricultural development of The Gambia: an agricultural, environmental and socio-economic analysis. Land resource study 22, Ministry of Overseas Development, Great Britain, pp. 224235.
Dwinger, R. H., Agyemang, K., Kaufmann, J. and Grieve, A. S. 1992. Effects of trypanosome infections and helminth infestations in health and production parameters of village cattle in The Gambia. Veterinary Parasitology In press.
El-Barbary, A. S. A., Ahmed, I. A. and Ibrahim, M. A. R. 1987. Mortality rate in Friesian calves. Proceedings of the first conference of agricultural development research. Vol. 1. Animal production, Cairo, Egypt, pp. 216–214.
Findlay, C. F. 1973. Serum immune globulin levels in lambs under a week old. Veterinary Record 92: 530532.
Holness, J. A. Y. 1982. Genetic, environmental parameters and predicted sire values for Jamaica Red Poll beef cattle. M.S. thesis, Cornell University, Ithaca, New York.
Mwandotto, B. A. J., Carles, A. B. and Cartwright, T. C. 1988. Weaning and 18-month weights of Boran, East African Shorthorn Zebu and Sahiwal breeds or crosses in Kenya. Tropical Agriculture, Trinidad 65: 257264.
Njie, A. and Agyemang, K. 1991. Performance of a station-managed N'Dama herd in The Gambia. Tropical Animal Health and Production 23: 4554.
Sadek, R. R., Nigm, A. A. and Barghout, A. A. 1989. Mortality in new-born calves in relation to thermal reactions. In Ruminant production in the dry subtropics: constraints and potentials (ed. Galal, E. S. E., Aboul-Elfa, M. B. and Shafie, M. M.), proceedings of the international symposium on the constraints and possibilities of ruminant production in the dry tropics, Cairo, Egypt, 1988, pp. 7881. Netherlands Centre for Agricultural Publishing and Documentation, Pudoc, Wageningen.
Statistical Analysis Systems Institute. 1987. SAS/STAT guide for personal SAS computers, 6th ed. Cary, NC.
Varma, A. K., Sastry, N. S. R. and Kar, D. 1988. Mortality trends in female Murrah buffalo calves. Indian Journal of Animal Production and Management 4: (1), 1821.
Zrelli, M. and Ben-Younes, A. 1989. Inquiry on calf mortality in herds in Tunisia; factors during perinatal and postnatal periods. Maghreb-Veterinaire 4: (16), 1416.



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