One of the more common problems that farmers face is one that seems somewhat basic. “How much forage is enough?” is a question asked by more producers each year. Knowing when fields and pastures have enough grass for animals, or when to switch to hay is not only an important issue, but one with definite complexities. Poor management of pastures and fields can lead to several problems such as weed growth and poor grazing habits by the livestock.
Brie Menjoulet, an agronomist with the University of Missouri Extension, explained that the time to put out hay is as simple as just knowing “when there is not enough available, quality forage for animals to maintain or gain weight.” However, it’s understanding the ‘when’ that things become a bit more complicated.
Menjoulet stated that there are several factors that contribute to this understanding, such as plant species, plant height and plant density, which all impact the total forage mass, and therefore the stocking rate/days on the field. Menjoulet goes on to state that, “several states have calibrated tables that, based on the plant height and density, can be used to figure the pounds of available forage per acre.” This information tells the farmer how much is in the field, and then they can “use estimates on cattle intake to figure out how long he/she has before feeding hay,” Menjoulet suggested.
“Farmers need to take into consideration the weed population when figuring the available forage because cattle will readily eat certain species of weeds when the weeds are very young.” She further explained that the cattle will pick the weeds over good forages – clover, orchardgrass – usually in spring and early summer. “As weeds mature, they become unpalatable to the animal and should not be used to calculate total available forage.” Her suggestion is to start by estimating a percentage of how much of the pasture is mature weeds that the cattle won’t eat and subtract that amount out of total available forage.
She said producers should always scout for poisonous plants when quality forages are running slim. “When animals can’t be picky about what they want to eat in the field, intake of poisonous plants tends to occur more often.” She added that this time of year Perilla mint can be problematic in resting areas, particularly under shade trees and that due to how dry we have been, many of our pastures are getting a little thin.
Ultimately, the problem of knowing if you have enough grass for your animals, or when to switch to hay is a common issue among farmers. Paying attention to the plants in fields and considering their height and density, as well as being aware of any poisonous plants, will enable farmers to be able to have a better idea of how much sustainable forage is in their pastures, and in turn, will ensure healthy and productive animals.
