Using Body Condition Score to Manage the Nutritional Program (Continued)
Resource: Dr. Rick Rasby, University of Nebraska–Lincoln.
Table 4 lists some common feedstuffs and their respective Net Energy for maintenance.
|Table 4. NEm for Some Common Feedstuffs|
|Corn silage/40% grain||.69|
|Alfalfa hay, early bloom||.60|
|Prairie hay, early bloom||.59|
|Dried Distillers Grains||1.22|
Feedstuffs listed other than the grains have less energy and would require larger amounts to be fed in order to affect a change of one BCS. Alfalfa hay, for example, fed at 5 pounds per day beyond daily maintenance needs, would require 69 days of feeding to change the cow mentioned above from a BCS 4 to a BCS 5. Thus, energy density of the feed used is a factor in feeding cows to change body condition. Energy dense feeds such as grains or grain by-products will usually be required fewer days to change BCS and less energy dense feeds will need more days to change BCS so plan accordingly. Your ability to change body condition in a short period (50 to 60 days) using forage may be a challenge because the animal can consume a certain amount of feed daily. It would be a challenge for a 1,200 to consume 40 lb dry matter of a diet of average quality grass hay and alfalfa.
Time Of Calving and Time Of Weaning
The choice of calving season in relation to peak forage production for a given location is critical to the cost of maintaining adequate body condition on mature cows. Calving too soon before peak forage production leads to the use of more harvest forage and drives up total feed cost. Calving about two weeks ahead of available grass up to four weeks after first grass growth would substantially reduce harvested feeds fed to cows and also substantially reduce labor at calving and early calfhood health problems. Such systems can result in lighter calves at weaning and to optimize profit, calves ownership needs to be retained for some time after weaning. The advantage of a late-spring or early-summer calving program is to force the cow to graze for most, if not all of her needs and avoid harvested feeds being fed to the cow. A Nebraska study, using four years of data, indicates March calving cows were fed 3,182 pounds of hay per year while June calving cows were fed 30 pounds of hay per year.
June calving cows were fed on average 23 pounds more of a protein supplement than March calving cows to maintain body condition. Strategic planning of the nutritional program for young cows when the calving season is moved to a later date is essential.
Adjusting the weaning date, particularly for first-calf two-year-olds, can be used to allow for lactating two-year-olds to graze their way back to a higher body condition prior to winter. Weaning calves at 120-150 days can give these females a real opportunity to recover body condition so they won't be so thin as three-year-olds.
Take time to record body condition scores well ahead of calving with particular attention to age groups of your cows. Plan a sound nutritional program with an eye toward optimizing profit. Keep an open mind for ideas such as early weaning or calving season adjustments, but ask lots of questions and get documentation before implementing. Body Condition Scores are simply a tool that help you or your customer do a better job of producing beef.
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