A couple of weeks ago, I started discussing the ‘why’ behind alternative forages. No answer as to ‘why’ would be complete without at least a bit of conversation around the financial aspect of alternative forages. Are they cheaper to grow? More expensive? Do they increase the income over feed cost? Do they increase the cost of the ration? Dr. Ferriera also touched on this during his talk at the Tri-State Dairy Nutrition Conference.
When it comes to selecting alternative forages, or any management change for that matter, the numbers have to pencil out for it to make sense. Let’s look at sorghum silage versus corn silage. Chances are, sorghum seed is going to cost about half of that of corn seed per acre. Seems like a benefit. Further, nitrogen requirements are also likely going to be less. For grain sorghum, you can estimate the crop will need 1.12 lb of N per bushel of grain produced. On average, sorghum will produce about 80-100 bu/A, so it’ll need about 112 lb of N on the top end. Forage sorghum will need about 120 lb N per acre given the soil is testing in an adequate range (Penn State). Now, switch over to corn, and we’re looking at about 170 lb N per acre AT LEAST for corn with yield potential of 200 bu/A. So, if you plant 1 acre of sorghum, it’ll cost $164, and if you plant 1 acre of corn, it’ll cost you $282. In just looking at these numbers, growing sorghum is the clear way to go. Or is it?
Let’s fast forward to harvest. Corn still trumps sorghum in tonnage harvest by about 0.7 tons per acre (7.5 vs 6.8 for corn and sorghum, respectively). Additionally, corn still has the lowest neutral detergent fiber (NDF) digestibility compared to sorghum. Corn silage also has a greater starch content, meaning that less additives would need to be fed to a sorghum silage-based diet that only has about 14% starch. This brings us to the final point on cost – sorghum diets will cost more. The inferior quality of the sorghum silage in comparison to the corn silage means that there will need to be additional starches or sugars added to a sorghum diet to make it equally nutrient dense as that of a corn silage diet. Yes, the sorghum was cheaper per acre to grow, but it may cost upwards of $1 more per cow per day to feed (Ferreira, 2022). What kind of cost savings is that really? Even if it was only 50 cents more per cow per day, for a 180-cow herd, it still amounts to about $33K more in feed costs.
Now, let’s look at mixed grass hay as our alternative to alfalfa hay. Cows fed the grass hay produced 4 lbs less milk and ate about 6 lbs less dry matter per day compared to cows fed alfalfa hay. However, the income over feed cost per cow per day actually increased by 71 cents from $7.68 with alfalfa to $8.39 with grass hay. But how so, with less milk? The mixed grass hay is a less expensive feed ingredient and increased milk fat production by 0.3 percentage points, a real game changer in a component-driven market.
So to wrap up alternative forages – what are your thoughts on them now? Why might your operation decide to grow them or feed them? While the sorghum looks like it may not be the number one choice over corn, droughty areas may find it to be a beneficial crop. As far as nutrition goes, corn silage is still king, and while alfalfa is queen, she also has ladies in waiting.
There will be an equine-focused pasture walk on June 7 from 6 to 8 PM at the ATI Equine Facility. Topics include poisonous plants and toxicities, pasture evaluation, and rotational grazing. Please call 330-264-8722 to register by June 1. Cost to attend is $15. Walk-in or late registrations will be $20. Forages for Horses course participants may use their pasture walk coupon for 1 free attendance. Dinner and materials will be provided.
Haley Zynda is an Extension Educator, Agriculture and Natural Resources for Ohio State University Extension. She can be reached at 330-264-8722 or firstname.lastname@example.org.
CFAES provides research and related educational programs to clientele on a nondiscriminatory basis. For more information, visit cfaesdiversity.osu.edu.