Some things are attractive at first look but fall apart upon analysis – maybe like that “cream puff” car that broke down three weeks after you drove it off the lot.
Hydroponic fodder systems may fall into that category. We looked into them recently when a local friend brought us some sprouted barley he grew hydroponically. We analyzed it in several batches.
What is hydroponic forage? The sprouted forage is produced under artificial conditions (greenhouse or lighted systems in a closed box) with regular watering. A “crop” of sprouted barley, wheat or other grain is produced within six to seven days (see photo). One website indicated that 2 lbs of seed will make 9-12 lbs of fodder from either barley (30¢/lb) or wheat (20¢/lb).
Wow! Twelve pounds of feed from 2 lbs of seed after seven days. That’s a sixfold increase in a week. Furthermore, Web videos show cattle and horses gobbling up sprouted grain like a vegetarian at a salad bar! Sounds pretty good – until you think about it more carefully.
Be sure to correct for dry matter. In all animal rations, feeds are considered as dry matter (DM) equivalents, since water is provided separately and all of the other nutrients required by the animals to live, grow and lactate are in the dry matter portion. Thus, a feed with 90% water has considerably less “feed value” than something with only 5% water on a pound-for-pound basis.
In the samples we analyzed, we found that, after six or seven days of growth, 2 lbs of seed indeed resulted in about 13 lbs of sprouts, similar to the website claims (see table). The forage quality appeared good – with 14.7% crude protein and low fiber. However, the story doesn’t stop there. After correcting for DM, we found the sprouts had an average of 89.2% moisture, and the seeds averaged 5.7% moisture. Thus, the 1.9 lbs DM seed resulted in 1.4 lbs DM of sprouts, a net loss of 25% of the weight of the seed. That means there appears to be a loss of DM when sprouting seeds for seven days.
Why do seedlings lose dry matter the first week of growth? Plants utilize starch stored in their seeds during the first week or so of growth, before photosynthesis and root uptake of minerals begin to cause dramatic increases in growth, plant physiologists tell us. So it’s not surprising that the total dry weight of the plant (seed, root and shoot) actually goesdown during that time rather than increases – because the plant is using up stored carbohydrates from the seed. Later, the plant is quite capable of producing its own food from sunlight, minerals and CO2.
Can hydroponic fodder be profitable? If you have animals, you can: 1) graze or pasture; 2) grow your own hay or silage crops; 3) purchase hay, other forages or grains; or 4) feed hydroponically. So which makes most sense? We calculate that one “pod” or tray starting with 104 lbs seed (52 weeks x 2 lbs/pod/week) would produce about 60-80 lbs DM per year (1.4 lbs/week, or 73 lbs DM/year in our study). That is approximately two-thirds the DM of a 125-lb bale of hay (alfalfa, small grain or grass) per pod per year, which, these days, goes for $10-18/bale retail in our neighborhood ($160-300/ton depending upon quality/volume). So a hydroponic system at a minimum must be cheaper – including infrastructure, seed and labor – than two-thirds the cost of a bale.
Another way to look at it is, if seed cost was 18¢/lb, the hydroponic cost of production would be equal to $462/ton of 90% DM hay using data from our study. This considers only seed cost – not the greenhouse infrastructure, energy, trays or labor, which would significantly increase that cost. During the past 10 years, California top-quality alfalfa hay has only occasionally topped $300/ton delivered, and, in 2011-2013, generally ranged between $220 and $320/ton (90% DM hay). Cheaper grain would make hydroponics a little more favorable, but it’s clear that the economics of hydroponic production are quite questionable.
Additionally, consider that significant DM is lost each week in a hydroponic system compared to feeding barley grain directly, and “feed-grade” barley is considerably cheaper than “sprout-grade” quality grains.
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But isn’t the nutritional quality better? There is little doubt that sprouts of nutritious grains like barley are highly palatable to livestock. Witness, in Web photos and videos, the relish with which animals consume them. However, we do not have data to suggest that barley “forage” is superior to other forages with similar analyses, or even better than feeding barley directly.
Actually, the feeding value of the shoot-seed-root mixture (typically 15-17% shoots in our study) may not be better than the barley seeds themselves. Fazaeli et al. (2012) found decreases in true protein; non-fiber carbohydrate, metabolic energy (ME); and in-vitro gas production in sprouted barley compared with the raw seed, and there were losses in DM yield. The lack of improvement in either quantity or quality led them to recommend against feeding sprouted seed vs. raw seed. Since stored starches have been used to grow the seedlings (loss of DM), the crop is likely to lose available energy (also known as TDN or NEL), and have a lower feeding value compared with the seeds themselves on a DM basis.
Where might hydroponic forage fit? For small-animal producers (goats, rabbits, etc.), this may offer a ready source of palatable feed, and may be of interest to those who simply want to be self-sufficient in feed. Hydroponic-sprouted grain may also provide palatable variety in diets for animals fed only hay and grains, although we should caution that the high costs must be considered.
Summary. Although hydroponic forage has great appeal, the yield, quality and costs of this system appear not to be favorable. Its main problem is that sprouted seeds exhibit a net loss in DM yield after six to seven days of growth. Additionally, there is likely to be a net loss in feeding value of sprouted grain compared with raw grain on a DM basis, and the costs per pound or ton produced are likely to be significantly higher compared with purchased hay or feed-grain equivalent.
See the UC Forage Blog for references and comments.
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