The Cow/Calf Manager

Livestock Update, November 2000

John Hall, Extension Animal Scientist, Beef, Virginia Tech

Body Condition Scoring and Forage Testing -- Keys to Nutritional Management

Body condition scoring (BCS) is easy to learn and really easy to do. Cows are given a score from 1 to 9 with 1 = emaciated, weak and 9 = obese. You can learn from your extension agent or a producer that's already doing BCS. Using the chart below will help you learn how to body condition score.

Cows that are in BCS 4 or below at calving will have trouble breeding back. Thin cows could be delayed by 30 to 60 days or more in breeding back. In addition, pregnancy rates will be reduced by 20-40% in thin cows. Calves born to thin cows are more likely to die at calving or be more susceptible to illness like scours or pneumonia. These nutrition-based reproductive problems can be avoided if cows are in BCS 5 or 6 from 60 days before calving through the breeding season.

Over-conditioned cows (BCS 8 & 9) indicate either over supplementation of grain or lack of production. If producers examine records on their cows, they will usually find that these cows are failing to conceive or are weaning extremely light calves. These unproductive or under-productive cows are not earning their keep.

Body condition scoring should be performed three times during the year -- weaning, 60 to 90 days before calving and at calving. By condition scoring at weaning, producers can identify thin cows and poor producers. Thin cows can then be sorted off for supplemental feeding to increase BCS. Condition scoring 60 to 90 days before calving allows producers to assess their winter feeding program and make any necessary changes so cows calve in BCS 5 or 6. Finally, assessing BCS at calving will allow for "emergency" feeding of cows that still calved below BCS 5.

Certainly, we don't need to test everything our cattle eat, but there are some critical times to test forage. Research from Virginia Tech and Extension Agents in Virginia indicates that for a majority of the year well-managed pasture or properly stockpiled fescue will meet all the nutritional needs of the cow/calf herd except minerals. The most critical forage that needs tested is hay, especially hay that you will feed in late gestation and after calving. The next most critical forage is pasture in July and August as well as stockpiled fescue in January or February.

Forage not only varies from month to month but from year to year. Dr. Stallings and his staff at the Virginia Tech Forage Testing Laboratory compared forage samples from '98-'99 and '99-'00 (Table 2). As you can see, 2000 was a great year for forages.

Hay samples we have seen over the past two years have varied in energy content from 45 to 60 % TDN and protein content of 6 to 14 % Crude Protein. Basically, this means that the hay either meets the needs of the cow or is way below her needs. Energy needs supplementing more often than protein. But you can't tell by looking. That nice looking hay may be green, but if it was under-fertilized or over-mature it can still lack enough nutrients to meet the cows needs.

Table 2. Differences in Hay Quality Among Types and Year (Virginia Samples)

Hay type and year	Number of samples	Crude Protein (CP) %	Total Digestible Nutrients (TDN) %
Grass - '98-'99	250	10.5	55.5
Grass - '99-'00	360	10.8	57.9
Grass/legume - '98-'99	232	12.9	59.1
Grass/Legume - '99-'00	148	12.3	58.7

Adapted from Stallings, 2000

Note that the average grass hay tested in '98-'99 did not meet the energy needs of beef cows in most stages of production. Also, remember that these are averages that means that half of the samples tested were worse than what is listed in the table. Table 3 also reminds us that it is energy that is usually the nutrient that needs supplementing in beef cow diets.

The other advantage to forage testing is you can reduce your feed costs by supplementing only those nutrients that are lacking. For example, the hays often lacked sufficient energy for lactating cows, but usually had enough protein. Supplementing protein like soybean meal would be a waste of money because you would be feeding (and paying for) unneeded protein when corn may be a cheaper alternative.

Table 3. Comparison of Cow Nutrient Requirement to Forage Analysis

	Cow Nutrient Requirements by Stage of Production
	Pre-calving		Calving to Breeding		Post-breeding to weaning		Weaning to 60 days before calving
Hay Type	%CP	%TDN	%CP	%TDN	%CP	%TDN	%CP	%TDN
	8.6	54.6	10.5	59.2	8.7	55.1	6.6	47.4
Grass - '98-'99	M	Boarder-line	M	F	M	Boarder-line	M	M
Grass - '99-'00	M	M	M	F	M	M	M	M
Grass/legume '98-'99	M	M	M	M	M	M	M	M
Grass/Legume '99-'00	M	M	M	M	M	M	M	M

M = meets requirements; F = fails to meet requirement

Since we are having nice Autumn days, now is the time to get out and body condition score cows (both fall and spring calvers) and take hay samples. Get those hay samples analyzed and I'll have more on nutritional management next month.

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