EVALUATION OF GRAIN CORN GROWN IN NEW BRUNSWICK FED TO DAIRY CATTLE
Research initiated by Milk 2020 & Atlantic Dairy and Forage Institute - December 2010
Corn is the primary grain used in animal feed in North America. Corn supplies greater density of energy than small grains such as wheat, barley and oats, which increases its desirability for feed applications. With continued genetic improvement of the corn crop and a warmer climate, newer earlier maturing hybrids can be grown in New Brunswick and other Maritime provinces, reducing the need to import corn from the United States and Central Canada.
Grain corn acreage in New Brunswick has seen a stunning expansion, quadrupling in the past four years from approximately 3,000 acres to more than 12,000 acres. Total corn production in New Brunswick in 2008 was 36,800 tonnes and was the second largest grain crop commodity, behind barley at 38,200 tonnes. Non-livestock farmers in the St. John River Valley have shown the greatest increase in production and are interested in selling either high moisture corn or dry corn to dairy farmers in all regions of the province.
This research was conducted to provide answers to dairy and corn producers and feed suppliers who want to know which harvesting and storage procedures would allow them to best take advantage of this valuable crop. There was also considerable debate whether the newer hybrids have energy densities equal to those hybrids from more traditional corn growing areas of central Canada and US.
The first step in the study was to gather samples from around the province and to determine complete chemical analyses for the samples. As the table below shows, the average composition of the New Brunswick shelled corn was very close to the Ontario shelled corn.
After that, samples were incubated in the rumen, in order to determine how the cow digested them. Again, the results suggested that the New Brunswick corn was quite comparable to the Ontario corn. With this information, the next step was to formulate diets for the cows using a sophisticated diet formulation program. Diets were formulated so that corn was the main source of energy and were balanced for ADF, NDF, starch, amino acids and minerals. Actual results, based on weekly analyses of the TMR over the 16 weeks of the study are shown below:
Results of the feeding trial are provided in the following table. Results were excellent with all diets, but milk production was highest with the locally produced dry shelled corn.
Milk/feed and milk energy/feed energy was determined to be the same for all of the diets. The local corn and local high moisture corn replaced the imported corn in the diets. The High Moisture Corn Cob Meal replaced the imported corn as well as approximately half of the corn silage in the diet. Using a price of $105/tonne for corn silage, savings were determined to be approximately 14 cents/cow/day with the local shelled corn and 20 cents/cow /day with the ensiled forms of the corn studied. The economics clearly indicate a savings through the use of locally produced corn products.
The price of imported corn was $ 281.00, the price of local corn was determined by subtracting $25.00 per tonne for trucking and high moisture corn was reduced a further $15.00 per tonne. The grade on the corn was No 3 CE or better.
It is important to consider that High Moisture Corn Cob Meal is a method of producing corn on dairy farms without much additional equipment. (Combines, drying equipment and dry storage)
The conclusion of this corn nutrition trial is that New Brunswick grown corn is equal to or better than imported corn and that all methods of corn harvest are equal providing rations are balanced.
Author; Dr Essi Evans, with contributions from David Walker
Funding for the project provided by the Canada/New Brunswick Growing Forward Enabling Agriculture Research and Innovation Program