Text Box: Introduction

Little animal performance information is available on immature or low test weight, high-moisture corn. Mature high-moisture corn is generally perceived to have more energy than dry-rolled corn as it is digested more thoroughly in the ruminant animal. As the corn kernel dries down, the starch becomes more compact. This compaction and other physiological developments make the kernel less digestible (Pritchard, 2005). Dry rolling or grinding increases digestibility of dry corn, but optimum digestibility is not achieved. High-moisture corn ferments more rapidly in the rumen compared to dry-rolled corn, and most of the starch is removed in the rumen. Immature corn, however, with a higher proportion of fiber from the bran and germ, should not produce the same acidosis potential as mature corn. This study was conducted to compare dry-rolled mature corn with immature high-moisture corn from the harvest of 2004 in finishing feedlot diets.

Procedure

Ninety-eight crossbred steers (765.4 22.4 lbs.) were allotted by source and weight to a dry-rolled or high-moisture corn-based diet (6 pens per treatment, 8 to 9 head per pen) to determine the effect of corn type on performance and carcass quality. Diets were formulated to contain 12.3% CP and 64.7 MCal NEg/cwt. Bushel test weight varied with the many different loads of immature corn delivered to the feeder. The range was estimated at 37 to 48 pounds per bushel with an average of 42 to 44 pounds. Moisture content of the corn was taken as it was removed from the feedyard pile (two loads per week). The wet corn averaged 72% dry matter over the trial. Dry, mature corn averaged 54 pounds per bushel and was 14% moisture. Ten out of 12 of the pens were slaughtered at Tyson Foods (Dakota City, NE) after 118 days on trial. The performance trial ended after 118 days on feed. Hot carcass weight, fat thickness, percentage kidney, pelvic and heart fat, longissimus muscle area, and USDA quality and yield grades were determined by qualified personnel 48 hours after slaughter.

 

Results

Cattle fed mature dry-rolled or immature high-moisture corn gained similarly (3.79 vs. 3.91 lbs. /d, respectively; P > 0.44), and consumed a similar amount of dry matter (22.4 vs. 21.8 lbs. /d, respectively; P > 0.24) over the entire trial. Some period to period variation was observed but overall, cattle fed the immature wet corn exceeded the performance expectations. No differences were observed for hot carcass weight, dressing percent, ribeye area, fat thickness, yield grade, marbling score, or percentage of carcasses grading choice (P > 0.24). Percent kidney, pelvic, and heart fat was greater for cattle fed dry-rolled corn (2.43 vs. 2.23%, P < 0.04).

 

Discussion

Considering the similarity in animal performance in this study, feeders may have an economic advantage if they can purchase immature corn grain at a discount from corn farmers with no cattle. At a minimum, feeders can save corn growers the drying costs and negotiate an advantage in price. Corn growers, on the other hand, may want to consider feeding cattle to capture more value from their grain production. The net result could be more pounds of beef per acre and increased profits to the feeding enterprise. The positive outcome of this study is another reason to consider the opportunities for cattle and feedlots in North Dakota. n