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2004, Number 3

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Vet Mex 2004; 35 (3)

Comparison of equations to estimate lactation curves using different sampling strategies in Angus and Brown Swiss cattle and their crosses

Ramírez VR, García-Muñiz JG, Núñez DR, Ruiz FA, Meraz AMR

Language: English/Spanish
References: 27
Page: -201
PDF size: 490.42 Kb.


ABSTRACT

The objectives of this study were to compare four equations to estimate lactation curves in Angus and European Brown Swiss cattle, as well as in their reciprocal-crosses, based on four sampling frequencies of milk production, and to determine the minimum number of samples to adequately predict lactation curves. Milk yield (MY) data (297 lactations) were collected weekly by the weigh-suckle-weigh technique up to 180 days after calving. Equations evaluated for each lactation were: 1) Yt = a exp(bt+ct2); 2) = atbexp(-ct); 3) = t/(a+bt+ct2); and 4) Yt = a+bt+ct2. The sampling strategies were 26, 13, 7, and 4 measure-ments of daily MY during lactation. Friedman’s test was used as the main criterion to compare the rank of the equations in each sampling frequency. The criterion to determine the minimum number of samples to properly fi t lactation curves was the standard error of the estimated parameters on weekly sampling as compared to the other sampling strategies. The equation of best fi t depended on cow’s genotype and sampling strategy. However, equations 1 and 2 consistently showed the best performance regardless of sampling frequency and genotype studied. The similar values of standard errors for the parameters esti-mated when MY was registered weekly or every other week, suggest that either equation 1 or 2 is a good choice to fi t lactation curves when daily MY is recorded every other week in the studied genotypes.


REFERENCES

  1. Montaño-Bermudez M, Nielsen MK. Biological efficiency to weaning and to slaughter of crossbred beef cattle with different genetic potential for milk. J Anim Sci 1990;68:2297-2309.

  2. Meyer K, Carrick MJ, Donnelly BJP. Genetic parame-ters for milk production of Australian beef cows and weaning weight of their calves. J Anim Sci 1994;72:1155-1159.

  3. Myers SE, Faulkner DB, Ireland FA, Parrett DF. Comparison of three weaning ages on cow-calf performance and steer carcass traits. J Anim Sci 1999;77:323-329.

  4. García PMJ. Tiempo óptimo de secado en ganado mestizo Pardo Suizo-Brahman. Gaceta Cienc Vet 1997;2:5-22.

  5. Akers RM. Selection for milk production from a lactation biology viewpoint. J Dairy Sci 2000;83:1151-1158.

  6. Brown MA, Brown Jr AH, Jackson WG, Miesner JR. Genotype × environment interactions in milk yield and quality in Angus, Brahman, and reciprocal-cross cows on different forage systems. J Anim Sci 2001;79:1643-1649.

  7. Varona L, Moreno C, García LA, Altarriba J. Bayesian analysis of Wood’s lactation curve for Spanish dairy cows. J Dairy Sci 1998;81:1469-1478.

  8. Ruiz R, Oregui LM, Herrero M. Comparison of models for describing the lactation curve of Latxa sheep and an analysis of factors affecting milk yield. J Dairy Sci 2000;83:2709-2719.

  9. Vargas B, Koops WJ, Herrero M, Van Arendonk JAM. Modeling extended lactations of dairy cows. J Dairy Sci 2000;83:1371-1380.

  10. Olori VE, Brotherstone S, Hill WG, McGuirk BJ. Fit of standard models of the lactation curve to weekly records of milk production of cows in a single herd. Livest Prod Sci 1999;58:55-63.

  11. White IMS, Thompson R, Brotherstone S. Genetic and environmental smoothing of lactation curves with cubic splines. J Dairy Sci 1999;82:632-638.

  12. Wood PDP. Algebraic model of the lactation curve in cattle. Nature 1967;216:164-165.

  13. Ramírez VR, Ramírez VG, Núñez DR, Tewolde MA. Curvas de lactancia en vacas Angus, Suizo Pardo y sus cruzas. II. Comparación de ecuaciones. Agrociencia 1998;32:325-330.

  14. Sikka LC. A study of lactation as affected by heredity and environment. J Dairy Res 1950;17:231-252.

  15. Nelder JA. Inverse polynomials, a useful group of multi factor response functions. Biometrics 1966;22;128- 141.

  16. Gaskins TC, Anderson DC. Comparison of lactation curves in Angus-Hereford, Jersey-Angus and Simmental-Angus cows. J Anim Sci 1980;50:828-832.

  17. SAS®. User’s Guide. Statistics. 8th ed. Cary (NC): SAS Institute Inc., 2001.

  18. Myles H, Wolfe DA. Non-parametric statistical methods. New York (NY): John Willey & Sons, 1973.

  19. Papajcsik IA, Bodero J. Modelling lactation curves of Friesian cows in a subtropical climate. Anim Prod 1988;47:201-207.

  20. Landete-Castillejos T, Gallego L. Technical note: The ability of mathematical models to describe the shape of lactation curves. J Anim Sci 2000;78:3010-3013.

  21. Sherchand L, McNew RW, Kellogg DW, Johnson ZB. Selection of a mathematical model to generate lactation curves using daily milk yields of Holstein cows. J Dairy Sci 1995;78:2507-2513.

  22. Singh B, Bhat PN. Models of lactation curves for Hariana Cattle. Indian J Anim Sci 1978;48:791-797.

  23. Bhat PN, Kumar R, Garg RC. Note on comparative efficiency of various lactation curve functions in Hariana cattle. Indian J Anim Sci 1981;51:102.

  24. Hohenboken WD, Dudley A, Moody DE. A comparison among equations to characterize lactation curves in beef cows. Anim Prod 1992;55:23-28.

  25. Grossman M, Koops WJ. Multiphasic analysis of lactation curves in dairy cattle. J Dairy Sci 1988;71:1598- 1608.

  26. Schneeberger M. Inheritance of lactation curve in Brown Swiss cattle. J Dairy Sci 1981;64:475-483.

  27. Ferris TA, Mao IL, Anderson CR. Selecting for lactation curve and milk yield in dairy cattle. J Dairy Sci 1985;68:1438-1448.




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