Energy Level of 2000 Grain Corn

By Ron Lackey, Feed Ingredients and Byproducts Feeding Specialist, OMAFRA

Lower energy levels in 2000 grain corn may be contributing to lackluster performance of your livestock.

During harvest in November, OMAFRA and Agricorp randomly collected twenty-five samples of 2000 Ontario grain corn, which were then analyzed to determine the nutrient content. NIRA analysis was used to establish the poultry metabolizable energy levels of the corn. An average of 2960 kcal/kg for these twenty-five samples would suggest that this year’s corn is 10% lower than what is considered standard (3300 kcal/kg) and may be on average 13% lower than the reported energy levels of 1999 corn. The fact that the energy levels in the samples were quite variable (ranging from 2360 kcal/kg to 3270 kcal/kg) may also result in a wide range of livestock performances, depending on the energy level of the corn being fed.

The 2000 corn growing season was less than ideal with abundant moisture, cool nights, cloudy days and various root rot problems, similar to the situation in 1992. That year, ninety samples of Ontario corn were collected and analyzed . The following table compares some of the nutritional values from 1992 with those from 2000.

These figures suggest that the 2000 corn is lower in energy but higher in protein and starch levels than the corn of 1992.

Vomitoxin levels were also checked on twenty-four of the twenty-five 2000 corn samples. Levels of vomitoxin varied from .2 parts per million to 4 parts per million. The majority of the samples showed relatively low levels, with only three samples testing over 1 ppm.

Based on industry comments, a fairly high percentage of the 2000 grain crop had the test weights and quality to be marketed as grade 2 and 3 corn despite the poor season. Moisture levels at harvest were considerably better in general than in 1992. However, there were some regional exceptions to this. Parts of eastern Ontario in particular harvested a higher percentage of grades 4, 5 and sample grade corn.

However, energy levels were found to be similar across all test weights and grades of the corn sampled. This data supports what was determined from the samples taken in 1992. Test weights alone are not a good indicator of corn energy levels.

Feeding trials conducted in 1992 with poultry in Guelph and pigs in Ridgetown showed that the feeding of low test weight corn did not significantly affect the average daily gain or feed efficiency. More information on this can be obtained from the info sheet Feed Value of Low Test Weight Corn for Pigs published by Janice Murphy, OMAFRA’s Swine Nutritionist.

This info sheet can be found at: www.gov.on.ca/OMAFRA/english /livestock/swine/facts/info_n_testweight.htm.

Recommendations for Feeding 2000 Corn

1. Have Your Corn Analyzed - energy appears to be on average10% lower than standard levels, but is also quite variable. Know what energy levels you are working with, and make adjustments accordingly.

2. Adjust Rations to Compensate for Lower Energy - this will be simpler for some than others. If, for instance, you normally have 800 kg of corn in a1000 kg mix, and you assume the standard energy level of 3300 kcal/kg for corn, the corn would be contributing 2,640,000 kcal to the total mix. Assuming your 2000 corn’s energy at 2960 kcal/kg, then in order for your 2000 corn to make a similar energy contributio

	1992	2000
Moisture (at harvest)	25-60%	19.8-47.2%
Test Wts. (lbs/bu)	37-58	9-55
Avg. Energy Level (poultry AMEn (kcal/kg)	3160	2960
Range of Energy	2904-3300	2360-3270
Avg. Protein	8.3%	8.82%
Range of Protein	7-10.4%	8.01-10.9%
Starch Levels	57%	63.5%

n to the mix, you would have to add 892 kg of corn. But the question is what are you displacing from that 1000 kg mix by adding an additional 92 kg of corn? It may mean that you have cut back on your protein supplement and are lowering the protein content of the mix. It may be better to replace some of the corn with a higher energy source such as fat, oil or even high oil corn. You need to work with your nutritionist on this.

3. Know the Test Weight of Your Corn - low test weight corn is less dense: it takes up more space. It need not mean less animal performance, provided allowances are made for the lower density. That means that metering and mixing equipment that are set on volume may need to be recalibrated. Ruminants can and will adjust their intake to accommodate larger volumes easier than monogastrics (pigs & poultry). Feed the higher test weight corn to monogastrics, to young stock in particular.

4. Don’t Ignore Lower Test Corn - test weight is not a reliable indicator of energy values. If you are in a position to buy or use low test weight corn, don’t assume it has low energy - have it analyzed and base your decision on these results as well as on palatability.

5. Monitor your Livestock’s Performance - this will also be easier for some than others. If your animal’s performance is satisfactory, no changes are in order. If, on the other hand, performance is dismal, it’s best to recognize this and make adjustments sooner rather than later.

6. Monitor Feed Stocks - lower energy and lower test weights mean that inventories will likely be used up faster. More grain may need to be purchased - plan ahead to secure quality supplies.