Corn has been a go-to crop for many dairymen when it comes to silage production, but it isn’t always the best option. Drought conditions that have spread across the country in recent years have underscored the need for productive forage crops with high water-use efficiency.
Sorghum, which has a much lower water requirement than corn, provides high tonnage, digestibility and palatability. This is why more and more dairies are discovering the benefits of adding sorghum to a forage rotation.
Forage sorghum, sorghum-sudangrass and sudangrass hybrids fit very well in the forage plans of many dairymen because they provide valuable, high-quality tonnage during the summer months.
Each type has its own set of strengths and growth characteristics that should be evaluated before making a planting decision. It’s best to consider adaptation, yield potential and the needs of the operation when selecting which type will work best for each farm.
Sorghum for forage offers several advantages over other types of forage crops and provides a diversity of management options. It makes an excellent choice for dry-land farming, limited and full irrigation situations and dairy operations needing forage during the summer months.
Sorghum works well in double-cropping plans and can also be planted as an emergency forage option. There are a variety of ways the crop can be used, including grazing, hay production, greenchop and silage. Regardless of the production system, sorghum’s adaptive nature and diverse uses make it a valuable component of forage rotations.
Production cost of forage sorghum vs. corn silage
Sorghum can provide dairies with an appealing combination of high yield and excellent nutritive value at a cost-effective price. Independent studies have shown forage sorghum saves producers an average of more than $200 per acre in total production costs compared to corn silage. The production cost savings of sorghum show it has tremendous potential to benefit growers as an alternative to corn silage.
Water-sipping efficiency
Sorghum has excellent water-use efficiency compared to corn. According to data from Texas A&M University, irrigated forage sorghums will yield 1.75 to 2.5 tons of biomass per inch of irrigation water, while corn produces 0.84 tons per inch of water applied. In other words, sorghum is nearly twice as efficient with water as corn silage.
Sorghum can help most producers in areas with water concerns reduce production costs without sacrificing tonnage or forage nutritional quality. Sorghums tolerate significant moisture stress and will resume vegetative growth after drought-induced dormancy.
Sorghums have a large and extensive root system capable of reaching soil profile depths of more than 5 feet. The size and efficiency of its root system enables sorghum to find water when other crops cannot.
Nutritional value
High-quality forage is an important tool dairy producers have to get the most milk from their herd. There is a direct relationship between daily milk production and forage digestibility that producers should be aware of and capitalize on. As digestibility increases, animal production increases and feed costs decrease. It’s a win-win situation.
Sorghum can be a dependable feedstuff if growers select the proper types. Sorghums with the brown midrib-6 (BMR-6) trait offer a feeding value similar to corn on a per-ton basis. BMR-6 genetics reduce the lignin content of sorghum stalks and leaves, which equates to a higher percent digestibility and increased palatability, supporting more increased milk production.
Lignin is the primary non-digestible component of forages – the higher the lignin percentage, the lower the digestibility and quality.
BMR-6 sorghums have 40 to 60 percent less lignin compared to conventional sorghums, and BMR-6 sorghum silage has similar, and oftentimes better, nutritive value than corn silage. According to Texas AgriLife Extension Services, BMR-6 forage sorghums are 81.3 percent digestible and contain crude protein that is equal to or higher than corn.
Variety and hybrid selection
Selecting the right variety or hybrid is an important decision. It has direct impact on the potential yield and forage quality achieved. Not all sorghums are created equal when it comes to tonnage and quality.
Sorghums used for hay production need to be selected based upon yield potential, rapid regrowth ability, stalk size – smaller stalks promote rapid curing – and harvest-time flexibility. BMR-6 sorghum-sudangrass hybrids are an excellent choice for haying and grazing uses.
The brachytic dwarf trait is relatively new in sorghum but has proven valuable to growers. Brachytic forages have reduced internode length without affecting other agronomic plant characteristics, such as leaf number, leaf size, maturity or yield/biomass production.
Brachytic dwarf forages typically grow to about 6 feet tall and produce comparable tonnage to taller hybrids by producing more leaves and more tillers. Sorghum with this trait has very high leaf-to-stalk ratios, prolific tillering, superior standability and comparable tonnage to normal-height sorghums with little to no lodging.
Hybrids with the brachytic dwarf and BMR-6 genetics provide growers with a powerful combination of traits. The shortened internodes of brachytic forages results in a more compact plant that has excellent standability.
The increased standability of hybrids with the brachytic trait alleviates lodging concerns from having reduced lignin because of the BMR-6 trait. Thus, dairymen receive the highly valuable nutritional benefits of BMR-6 genetics in a hybrid that stands well.
Another important trait to consider when selecting sorghum hybrids is the dry-stalk trait. Varieties and hybrids with the dry-stalk characteristic reduce crop moisture in sorghum and sudangrass. Forage sorghum hybrids with this trait allow growers to ensile the harvested crop at reduced moisture levels with less opportunity for spoilage.
When harvested at the soft dough stage, forage sorghums with the dry-stalk characteristic have approximately 64 to 69 percent moisture content. Dry-stalk sudangrass hybrids can be stored much sooner as baleage or haylage than non-dry-stalk types and can also be harvested as dry hay when needed.
See for yourself
The sorghum forage genetics of today have improved greatly over recent years. This is an excellent time to consider adding sorghum to your forage ration. It is an economical choice with lower input costs than corn silage that is competitive in tonnage and quality. Sorghum will produce a dependable crop in even the harshest conditions thanks to its outstanding water-use efficiency and drought tolerance.
Dairymen should ask their local agronomists and nutritionists about adding sorghum to the rotation. Review the available varieties or hybrids for your area and test them to see how they perform. Dairymen who are willing to experiment and try new things will find sorghum is a valuable option in crop rotation plans. PD
Travis Kidd
Technical Development Manager
Advanta and Alta Seeds
