The Significance of Breeding on Corn Hybrids

When it comes to a dairy operation’s bottom line, the importance of a high-quality forage as the basis of the total mixed ration (TMR) cannot be underestimated. In light of this fact, it is important to always keep in mind the effect breeding has on a corn hybrid.

In general, grain and silage hybrids have opposite characteristics. This should come as no surprise since they are bred for different purposes. Corn silage hybrids are bred for total plant silage characteristics while dual purpose hybrids are bred for total grain characteristics. In other words, if you want to grow corn for grain choose a grain hybrid. For silage, a hybrid specifically bred for silage.

The majority of corn acres are used to grow grain. Therefore, a grain hybrid for this purpose must have durable kernels that do not break apart easily, especially during combining, elevating and shipping. They also must dry quickly, or the cost of mechanical drying will make them cost-prohibitive.

The most successful breeders choose grain hybrids that have stiff stalks that last late into the season and a high ear placement to make combining easier. Since kernel integrity is the name of the game, these characteristics will be the difference between profit and loss.

Since dual purpose hybrids are bred for grain, they do not make great silage. This comes down to two factors: fiber and starch. The ideal grain hybrid is bred to stand up to the elements until late into the harvest season. This means its stalks must be stiff and extremely solid and the position of its ear must be high on the stalk-both of which reduce fiber digestibility.

When it comes to starch, keep in mind that when a grain hybrid reaches silage maturity, its kernels dry fast and become extremely tough. This results in a narrow window for it to be harvested as silage. This is further complicated by the fact that when its kernels reach the appropriate moisture level for silage, the plants are too green and wet for the bunker. If the plant is harvested at that time, the kernels will be hard and dry. And while they may contain high starch levels, they will likely remain intact or break into large pieces when eaten by cows. This makes the starch useless in the rumen for milk production.

Breeding for silage involves a much different process than breeding for grain. The ultimate goal of a corn silage hybrid is to produce a hearty, digestible crop that promotes rumination and produces high quality milk when mixed into a TMR and fed to a lactating cow.

Unlike grain hybrids, the ideal silage will have a high total plant yield of digestible fiber and starch and an extended harvest window that allows it to dry to the correct moisture level and stay there. It also will have adequate sugars to promote fermentation and a relatively short storage period to save space and reduce dry matter loss.