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The effect of the dry period on the subsequent lactation in three half-sib groups of British Friesians

Published online by Cambridge University Press:  27 March 2009

P. D. P. Wood
Affiliation:
Milk Marketing Board, Thames Ditton, Surrey

Summary

Reserve energy accumulated before calving may make a contribution to total lactation yield. Random samples of cows which produced their first two lactations in the same herds were drawn from the progeny groups of three British Friesian sires whose milk yield proofs differed by a very significant amount. Regression of second lactation yield on first lactation, intervening dry period and length of lactation showed that the effect of the dry period was different in the three groups. Daughters of sire A with a contemporary comparison of + 374 ± 20 kgshowed a regression of 21·6 ± 7·8kg/day of dry period; sire B+174 ± 24 kg, 9·0 ± 5·2 kg/day; and sire C -174 ± 87 kg, 5·5 ±3·0 kg/day. If the dry period can be regarded as an opportunity for the cow to accumulate body reserves, a standard 60-day dry period could have made a contribution to total yield in group A of 25·5%, in group B of 12·2% and in group C of 8·1%. The argument for regarding these figures as approximate measures of the relative response to steaming up of the cows in the three groups is developed.

Type
Short Notes
Copyright
Copyright © Cambridge University Press 1977

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References

REFERENCES

Broster, W. H. (1971). The effect on milk yield of the cow of the level of feeding before calving. Dairy Science Abstracts 33, 253–70.Google Scholar
Keown, F. J. (1973). Comparison of mixed model methods of sire evaluation. Journal of Dairy Science 57, 245–50.CrossRefGoogle Scholar
Maff, (1975). Energy Allowances and Feeding Systems for Ruminants. Technical Bulletin 33 Her Majesty's Stationery Office.Google Scholar
Preston, T. R. & Wilms, M. B. (1970). Intensive Beef Production. Pergamon Press.Google Scholar
Schmidt, G. H. & Van Vleok, L. D. (1973). Principles of Dairy Science. San Francisco: W. H. Freeman & Co.Google Scholar
Wood, P. D. P. (1977). The biometry of lactation. Journal of Agricultural Science, Cambridge 88, 333–9.CrossRefGoogle Scholar
Wood, P. D. P. & Hodges, John (1976). Comparative methods of testing Hereford × British Friesian progeny groups for growth and carcass characters. Animal Production 22, 257–97.Google Scholar