Potential Benefits of Plant Modification of Alfalfa and Corn Silage to Dairy Diets

Summary Corn silage and alfalfa are the main forages fed to dairy cattle in the United States. Determining the attributes of ideal corn for silage and alfalfa for silage or hay should be done via a holistic approach encompassing the entire dairy enterprise. Attributes of ideal forage may be different for individual dairy farms depending on factors such as production level of the dairy herd; what crops if any are produced as part of the enterprise; cost, availability and quality of feed ingredients; feed storage; equipment; and management capabilities. Ideal attributes for plant modification may include those that increase milk potential per acre and/or per ton, enhance digestible NDF, improve starch quality and content, improve protein content and amino acid balance, improve agronomic traits for insect protection (safer forage supply), herbicide tolerance, virus resistance, drought tolerance, cold tolerance, improved mineral availability and enhanced yield. Progress in attaining these attributes has been slow using traditional plant breeding but will accelerate with the use of biotechnology. Dairy enterprises will benefit through forages that are less prone to contain mycotoxins or toxic weeds, or to induce bloat; have improved nutrient utilization for milk and meat production; and produce less animal wastes resulting in improved efficiency, profitability, and a better environment.