Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-24T10:34:15.788Z Has data issue: false hasContentIssue false

Prediction of gross energy content of ewe milk

Published online by Cambridge University Press:  02 September 2010

L. B. J. Šebek
Affiliation:
Research Institute for Livestock Feeding and Nutrition (IVVO-DLO), PO Box 160, NL 8200 AD Lelystad, Netherlands
H. Everts
Affiliation:
Research Institute for Livestock Feeding and Nutrition (IVVO-DLO), PO Box 160, NL 8200 AD Lelystad, Netherlands
Get access

Abstract

The interpretation of the results of feeding trials with lactating ewes and their sucking lambs can be improved considerably when milk energy production is known. The determination of gross energy (GE) however is time consuming and expensive. Therefore an equation to predict GE from milk constituents would be helpful.

Using multiple regression analysis a GE-prediction equation was derived with milk samples mainly from crossbred ewes. The concentrations of milk constituents were determined by infrared spectrometry (calibrated with cow milk). Fat concentration ranged between 43·8 and 125·0 g/kg, protein concentration between 32·4 and 53·1 g/kg and lactose concentration between 38·9 and 52·9 g/kg. GE (adiabatic bomb calorimetry) of the samples under consideration ranged between 3500 to 6800 kj/kg.

The following equation, including fat (f), protein (p) and lactose (I), is recommended and predicts GE as kj/kg fresh milk using constituents in g/kg fresh milk:

GE = 41·94 × f + 15·85 × p + 21·41 ×l (residual s.d. = 92, adj.R2 = 0·98).

This equation has, in the GE range 4500 kj to 6000 kj, an almost constant confidence interval with an average of ±25 kJ and an almost constant prediction interval, with an average of ±87 kJ. In the period until weaning it would appear justified to use the derived equation regardless of stage of lactation. The equation is valid for milk samples from sheep breeds with relatively high fat and low protein contents and where milk constituents have been determined by cow milk calibrated infrared spectrometry.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alvarez, P. J., Ovejero, F. J. and Guada, J. A. 1985. [Prediction of the energy value of ewe's milk from composition data.] Anales del Instituto Nacional de Investigaciones Agrarias 22: (1), 3950.Google Scholar
Alvarez, P. J., Ovejero, F. J., Guada, J. A. and Gonzalez, J. S. 1980. Commission on sheep and goat production; prediction of the energy value of ewe's milk. Jahrestagung der Europäischen Vereinigung für Tierzucht, 31, pp. 15.Google Scholar
Brett, D. J., Corbett, J. L. and Inskip, M. W. 1972. Estimation of the energy value of ewe milk. Proceedings of the Australian Society of Animal Production 9: 286291.Google Scholar
Economides, S. 1986. Comparative studies of sheep and goats: milk yield and composition and growth rate of lambs and kids. Journal of Agricultural Science, Cambridge 106: 477484.CrossRefGoogle Scholar
Harris, W. M. 1986. Automated determination of fat, crude protein and lactose in ewe milk by infrared spectrometry. Analyst, London 111: 3739.CrossRefGoogle ScholarPubMed
Hernández de Tejada, E., Gomez, A., Torres, A. and de Bias, C. 1975. [Estimation of the energy value of milk of Merino ewes from its chemical composition.] Anales del Instituto Nacional de Investigaciones Agrarias, Producción Animal 6: 6975.Google Scholar
Mavrogenis, A. P. and Papachristoforou, Chr. 1998. Estimation of the energy value of milk and prediction of fat-corrected milk yield in sheep and goats. Small Ruminant Research 1: 229236.CrossRefGoogle Scholar
Montgomery, D. C. and Peck, E. A. 1982. Introduction to linear regression analysis. John Wiley, New York.Google Scholar
Payne, R. W., Lane, P. W., Ainsley, A. E., Bicknell, K. E., Digby, P. G. N., Harding, S. A., Leech, P. K., Simpson, H. R., Todd, A. D., Verrier, P. J. and White, R. P. 1987. Genstat 5 reference manual. Oxford University Press, Oxford.Google Scholar
Perrin, D. R. 1958. The calorific value of milk of different species. Journal of Dairy Research 25: 215220.CrossRefGoogle Scholar
Ramos, M. and Juarez, M. 1981. The composition of ewe's and goat's milk. Bulletin of the International Dairy Federation, document 140.Google Scholar
Šebek, L. B. J. and Everts, H. 1991. [Regression equations to predict gross energy content in sheep milk.] Instituut voor veevoedings onderzoek (IVVO) rapport no. 225, Lelystad.Google Scholar
Varela-Alvarez, H., Wilson, L. L., Rugh, M. C., GraciaGarza, E. and Simpson, M. J. 1970. Prediction of the energy value of ewe milk from amount and composition characters. Journal of Dairy Science 53: 17831786.CrossRefGoogle Scholar