| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Iowa State University, Ames, Iowa 50010
Abstract
The goal for milk production in the commercial cow herd depends on the reflection of this milk in the performance of the calf, both pre and post weaning, and on the reproductive performance of the cow. Evidence suggests that the composition of the steer at a particular weight is not drastically dependent on the nutritional environment up to weaning. This means that the lean tissue growth can be had when the gain is most economical. The efficiency of utilizing gross energy through the cow in milk to the calf probably is competitive with the energy utilization by the calf itself. If low quality roughage, that can be harvested only by the cow, is considered, a good case for milk efficiency can be built. Milk production in excess of growth demands by the calf seems of little economic value since this results in less efficiency in the feedlot and lower prices per pound at weaning. The ceiling to milk production in the commercial cow herd is natural selection for reproductive performance. With a fixed calving season in a particular feed environment, an excessive level of milk production can result in a reduced calf crop. This level varies from extensive systems, utilizing natural ecologies where the cow herd must be adapted to the conditions, to intensive systems that utilize stored feed and an attempt to increase unit output rather than volume for improved net returns. As the cow-calf operation invades the more traditional farming areas where the capability for forage and grain production are great, a need will exist first for more rapid early growth and next for more maternal performance to exploit the potential, provided this is more economical than artificial feed environments. Vertical integration will allow exploitation of the most economical portions of the growth curve be they either pre- or post-weaning in a given circumstance. Several courses are open to improve maternal performance. Selection for weaning weight results in more accurate selection for pre-weaning growth than for maternal performance. Thus, the potential to utilize the maternal performance is there before it is available. Production of milk can be introduced quickly by using dairy breeding. Optimum levels need to be quickly established either by decreasing milk production or by improving the management system. Crossbreeding systems can both introduce milk and produce heterosis for the reproductive complex. The more extensive opertions are more dependent on maternal ability for increased calf weights yet are tied to a level commensurate with the feed resources to maintain reproductive performance. The more intensive operations are less dependent on maternal ability because of creep feeding, harvested feeds, and the possibilities of vertical integration; but they can utilize a higher level of maternal performance and still maintain reproductive performance should such prove to be the most economic segment of the growth curve in their particular system. Although maximizing milk production as a goal seems improper, this is not to say that the British beef breeds do not need both the growth potential to utilize it and some more maternal ability to exploit even under many conventional systems of beef production.
1 Presented at the Beef Cattle Session of the 63rd Annual Meeting of the American Society of Animal Science, the University of California, Davis, August 1971.
2 Journal Paper No. J-7020 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 1704.
This article has been cited by other articles:
|
|
 |
|
  R. L. Sapp, R. Rekaya, and J. K. Bertrand Teat scores in first-parity Gelbvieh cows: Relationship with suspensory score and calf growth traits J Anim Sci, August 1, 2004; 82(8): 2277 - 2284. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
