Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-18T05:59:10.415Z Has data issue: false hasContentIssue false

Individual performance and production per unit area of grazing steers of different potential growth rates

Published online by Cambridge University Press:  02 September 2010

H. A. Molinuevo
Affiliation:
Institute National de Tecnologia Agropecuaria (INTA), 7620 Balcarce (BA), Argentina
Get access

Abstract

The purpose of this work was to investigate the relationship between individual animal performance and production per unit area of land of steers of different potential growth rate under different grazing stocking rates (SR). The analysis involved 160 steers divided equally between two breeds, over 2 years at four SRfor each breed and two replicates for each SR. Thus there werefive steers per replicate. The breeds were purebred Aberdeen Angus (Angus) and 4 Limousin (Limousin). After weaning steers were grazed for 251 days on a pasture dominated by Festuca arundinacea. Given that equal SR does not equate to equal treament for breeds characterized to be of different size and rate of growth at a given age, the analysis was undertaken on the basis of three categories of metabolic body size per ha (S). The variables analysed were individual live-weight gain (final minus initial weight, kg), relative individual live-weight gain (logefinal weight - loge initial weight) and production (kg/ha). A mixed model was used to examine effects of breed, S, year and the interactions between these variables. In general significant (P < 0·05) differences were found for all factors of classification and interactions. Independent linear regressions were calculated for each breed between absolute live-weight gain, relative live-weight gain, and production on S. It was concluded that there was a genotype × environment interaction, with the Angus breed tending to show a higher production per unit area than the Limousin, especially at high levels of S when scarcity of forage was apparent. Nevertheless Limousin steers had higher absolute individual performance than the Angus. The higher production of the smaller breed may be explained by a higher SR at a given S level and also by its higher relative individual live-weight gain in relation to that of the larger breed. The data were coded to use Mott's model to study the relationship between absolute performance (kg) and production (kg/ha). However this model ignores the existing interaction involving breeds.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1997

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

Brody, S. 1945. Bioenergeties and growth. Chapter 15. Hafner, New York.Google Scholar
Cundiff, L. V. 1970. Experimental results on crossbreeding cattle for beef production. journal of Animal Science 40: 421432.Google Scholar
Fitzhugh, H. A. and Taylor, St C. S. 1971. Genetic analysis of degree of maturity. journal of Animal Science 33: 715725.CrossRefGoogle ScholarPubMed
Joandet, G. E. and Molinuevo, H. A. 1975. [Mating systems and conclusions. Technical meeting.] INTA Balcarce, Dpto. de Produccion Animal, pp. 4961 (mimeograph).Google Scholar
Jones, R. J. and Sandland, R. L. 1974. Relation between animal gain and stocking rate: derivation of the relation from the results of grazing trials. journal of Agricultural Science, Cambridge 83: 335342.CrossRefGoogle Scholar
McCall, D. G. and Marshall, P. R. 1991. Factors affecting beef finishing efficiency on pasture. Proceedings of the New Zealand Society of Animal Production 51:453457.Google Scholar
Mezzadra, C., Escuder, J. and Miquel, M. C. 1992. Effects of genotype and stocking density on post-weaning daily gain and meat production per hectare in cattle. Animal Production 55: 6572.Google Scholar
Miquel, M. C., Molinuevo, H. A., Joandet, G. E., López Saubidet, C. A. and Bidart, J. B. 1977. [Evaluation of growth rate of fattening steers from non-traditional breeds crossed with Aberdeen Angus cows under grazing systems.] Produccion Animal, Argentina 5:160.Google Scholar
Molinuevo, H. A., Melucci, L. M., Bustamante, J. L. and Miquel, M. C. 1982. Genetic × environmental interaction of growth on pasture condition of cross-bred beef steers. Proceedings of the second world congress of genetics applied to livestock production, Madrid, volume 8, pp. 286289.Google Scholar
Molinuevo, H. A. and Miquel, M. C. 1978. [Absolute and relative growth rate of different beef cattle breeds and crosses. Correlations among parameters.] Produccion Animal, Argentina 6:244249.Google Scholar
Mott, G. O. 1960. Grazing pressure and the measurement of pasture production. Proceedings of the eighth international grassland congress, pp. 606611.Google Scholar
Statistical Analysis Systems Institute. 1988. SAS/STAT user's guide, release 6.03. SAS Institute Inc., Cary, NC.Google Scholar
Taylor, St C. S. 1971. The effect of body size on production efficiency in cattle. Anales de Genetique et de Selection Animate 3: 8598.Google Scholar
Villarreal, E. 1995. [Carcass traits.] In [Beef cattle breeding] (ed. Molinuevo, H. A.), pp. 107167. EEA Balcarce, INTA, ArgentinaGoogle Scholar
Webster, A. J. F. 1989. Bioenergetics, bioengineering and growth. Animal Production 48: 249269.Google Scholar