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Our corn grazing in 2013

Kevin Elmy’s been experimenting with varieties for corn grazing

Like the last few years, our 2013 corn year started behind the eight ball. The winter of 2012 posed some seed logistics challenges. Some varieties had seed supply issues, seed size options were limited, new varieties were available but without local trials. These issues added to seasonal stress. Then, for us, snow and rain delayed our projected seeding date.

By the time one of our Kinze planters came back from a customer seeding corn, it was June 14.

In 2012, the field had six acres of corn and 34 acres of three cover crops that we grazed off. We had pre-worked the field three times during the spring of 2013, trying to dry it out.

We seeded 21 varieties from Hyland, Thunder, and Canamaize Seeds. Varieties included TH 3388, TH 3381, TH 3382, TH 8781, TH 3383, TH 2146, BAXXOS, HL SR35, HL SR22, HL S4120, HL 3093, HL 3085, HL R219, X 12002 XR, X 29013, LF 755R, LF 728R, MZ 1677R, LF 815R, MZ 1440R, and CM 533R. All varieties, except the Canamaize 533R, were seeded on 36-inch centers at 26,666 seeds per acre (three acres per bag).

On the farm, there was just under 14 inches (356 mm) of rain from May 1 to the end of September. From seeding to the end of September, there were 1842 Corn Heat Units (CHU) and from May 1 to the end of September, there were 2142 CHU.

This was the first year we did not seed soybeans in between the corn rows because of the late seeding date. In past years we have seeded RoundUp Ready soybeans to help compete with weeds, increase production, increase protein availability to the cattle and potentially fix some extra nitrogen. The Kinze planter we use has finger units, so once we are done seeding corn, we load up with soybeans and seed the soybeans at the same rate as the corn. The soybeans are pre-inoculated with liquid inoculant. It ended up adding 0.5 dry tonnes per acre.

From the Canadian Cattlemen website: Feed the rumen first: Part 2

With the open fall, the corn ranged from late milk to early dent. We have always recommended that one third of the corn field be seeded to a variety that needs the amount of corn heat units you would normally get. For our area, the Yorkton area, we use a 2250 to 2300 CHU variety. For the rest of the field, we add 200 to 400 CHU requirements, so for us that’s 2400 to 2600 CHU varieties. This will vary with the animal type we are feeding, seeding date and local conditions. This helps manage grain overload and variations in climate and maximizes tonnage produced and clean up.

corn grazing chart

In-depth tests of BAXXOS and HL SR35 varieties gave us the following results. * RFV = Relative feed values Click on image to view at full size

Results

We sampled the field November 9, measuring 1/1000 of an acre of each variety — weighing, chipping and sampling for feed tests. We took a close look at two plants from two varieties, BAXXOS and HL SR35. We took the plants apart, weighing each of the cob, leaves, upper stalk and lower stalk, and then had feed tests done at SGS Agrifood Laboratories in Guelph, Ont. We considered the cob being the divide between the upper and lower stalk. Our observations:

  •  By November 9, BAXXOS was in late dough stage, where HL SR35 was in late milk.
  •  Moisture was around 50 per cent for the BAXXOS; the HL SR35 was just over 60 per cent.
  •  BAXXOS had 57 per cent of its dry weight in the cob; HL SR35 was at 28 per cent.
  •  Cob protein was over three per cent higher in the HL SR35 cob.
  •  Leaves’ dry weight and protein were similar.
  •  Upper stalk weight was higher on the HL SR35, as was the lower stalk, as well as the protein, Relative Feed Value (RFV).
  •  Lignin of the upper stalk of the BAXXOS was higher than the HL SR335.
  •  Energy was exactly the same for the leaves, and all stalks.
  •  Percent starch was in most cases under one per cent.
  •  Milk production per acre was significantly higher with the BAXXOS cob, but the rest of the plant was higher in the HL SR35 and more evenly balanced through the HL SR35.
  •  Total grazing days were similar, slightly higher in BAXXOS due to the more mature cob that contributed to an extra 64 grazing days per acre. Once again, the grazing days per acre attributed to plant parts was more consistent in the HL SR35.

For our variety trial, dry tonnes per acre averaged 2.80. Not bad, considering the late seeding and cool end of July and early August.

For dry tonnes, Canamaize 533R, TH 3388 and TH3382 were the top performers.

Protein averaged 9.73 per cent, ranging from 8.48 to 10.89 per cent.

Relative feed values (RFV) averaged 135, ranging from 94 to 180.

Net energy for maintenance averaged 1.63 megacalories per kilogram, ranging from 1.42 to 1.78, while total digestible nutrients averaged 66.88 per cent, ranging from 61.56 to 70.62 per cent.

Forage quality was down this year, once again due to late seeding and cool silking period. Calculated kilograms milk produced per acre averaged 3437, where last year was almost triple that. Grazing days, assuming 35 pounds of dry matter per cow per day, averaged 173, ranging from 86 to 220.

We’ll post the final results on our website (www.friendlyacres.sk.ca) and on our Facebook page.

Grazing just started mid-December so there is no comments yet on variety clean up. Overall stand is below normal, due to excess moisture through June and cool conditions. Grazing cost per day will be higher than average, but still cheaper than feeding bales in corrals. Seed supplies are better than last year, but not great for most varieties.

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