Grassland Evaluation Contest Study Guide	Fifth Edition: October 2005
Grassland Evaluation Contest Rules - Matching Livestock and Forage
Does the given system's growth cycle match the seasonal peak nutritional needs of this livestock herd under present management? Yes No Now that you know some basic concepts of forage production and changes in livestock nutritional needs you still face the challenge of matching these production schedules together. A good manager relies on his ability to combine the production of forage and livestock along with the environment into an economically and biologically sound program. Spring time is the period when forage is abundant and the weather is favorable for calf survival and rapid growth. Most pastures in Missouri are made up of cool season forage species. A spring calving program matches the cool-season grass seasonal growth pattern rather well. The cow's greatest nutritional needs are between calving and re-breeding. The growth and quality of a cool season grass is also high at this time (Figure 2). Forage production and quality drop off in summer along with a slight drop in nutritional requirement by the cow. Adding a warm season grass or other summer forage to a cool season grass program fills the summer forage deficit and maintains livestock production until the cool season grass begins growing again in fall. Summer calving is not recommended in Missouri. The reason for this is not entirely related to forage production since warm season forages are available and of high enough quality to maintain adequate nutrition. The primary reason not to have a summer calving season is due to weather. In summer, high temperatures and humidity reduce breeding activity and conception rates. Research has shown much lower conception rates in cattle breeding during hot weather because of higher embryonic mortality. The number of calves weaned per cow exposed to the bull has much greater impact on profitability than any other single factor. If a calf is never conceived it cannot be weaned. Fall calving works well in Missouri since the combination of forage quality and cooler temperatures are again favorable for high conception rates in cows. Cool season grasses produce about one third of yearly production in fall. The quality of this fall growth is very good. Cows calving in September will have adequate nutrition on properly managed fall pastures. Re-breeding will take place after the cows have been flushed with high quality fall pasture. Warm season pastures (warm season grass, annual lespedeza, alfalfa) can improve a fall calving program by increasing the nutrition level of the cows during STAGE 4, which occurs during July and August for a fall calving herd. This improves milk production, calf vigor, and re-breeding success. Warm season pastures also work well if fall born calves are kept till they are yearlings before they are sold. The calves are weaned in spring and put on high quality spring pasture. In early summer the calves are rotated to warm season pastures to maintain good weight gains until they are sold later that summer or in fall. Winter calving is not recommended in Missouri. The reason for this is due to adverse weather conditions for calving and not matching forage production with peak nutritional demands. Management of forage resources through the wintertime may be the most cost-effective practice a producer can use. Stock piling forages particularly tall fescue, grazing crop residues, and planting winter annual forages can drastically reduce a producers winter-feed cost when compared to hay and/or supplements. Research has shown that with proper management and utilization the quality of stockpiled tall fescue and winter annual forages can meet the needs of most beef animals including lactating cows. NOTE: Transparencies of Figures 2 and 3 can be overlain to illustrate how to match livestock nutritional needs with seasonal growth of cool-season grasses. Return to Grassland Evaluation Contest Study Guide