I quote the following summary from a paper on feeding algae to cattle. The paper is well worth reading in its entirety because they discuss feeding protocols to cattle. The results were very positive and even suggestive.
The possibility of using unicellular algae (Chlorella and Scenedesmus) as feed for cattle has been studied. Mixed algal culture was grown in a shallow polythene-lined pond and gave a recorded daily yield of 95 tonnes of algal suspension (packed cell volume 5-10 ml/litre) or 247 kg dry substances per hectare. The cost was about $1.25 (Tk. 50) per tonne of algal suspension production. Dried algal cells contained 613 g crude protein (N x 6.25) and 155 g fibre per kg DM. In a 120 d feeding trial 8 growing cattle (7 females and 1 male), of indigenous breed with mean initial live weight kg 146"9 kg, were fed ad libitum urea- molasses-straw and 2 kg/d wheat bran as basal diet. The treatments were 0.5 kg/d Til (sesame) oil cake per head in group I and ad libitum algal suspension in group II. The suspension was drunk at 10% of animal live weight. These animals received no other liquid (water).
This is actually along way down the road in the road in the mastering of algae husbandry. Dry weight algae is a prime animal feedstock on its own. If we successfully select an algae blend that also maximizes the production of biodiesel, we have a very economic protocol for the production of both feed and oil.
At present the best oil production is around ten times the oil production from oilseeds. The potential is ten times that. Of course at the present time I am mixing apples and oranges as these two applications must have some level of conflict which we need to overcome.
What I am reaching for, though is a least effort protocol for the algae production stream. A system that produces oil and feed through a one step process is very attractive to farm operation. You are continuously shipping oil at the farm gate and consuming the pressed algae as cattle feed. The indicated efficiency of the feed aspect means that any oil production is a bonus to the feed lot.
A conversion of the global cattle industry over to algae feed has the additional benefit of releasing huge amounts of acreage from feed grain production.
In fact this revelation will create a huge demand for an algae production protocol on the part of the agricultural industry. The oil aspect and the release of land will be a bonus.
It was also noted that the production rate approached 100 tons of dry product per hectare compared to a previously reported 10 tons per hectare. Comparing either figure to grain production of perhaps a ton per acre is very compelling. A lower oil yield may even be acceptable in this type of regime.
Of course, this requires a nitrogen fertilizer input that is significant but obviously vastly superior to cropland fertilization in which the bulk of the fertilizer is currently lost. and never used.
The idea of having a one acre algae field replacing as much as fifty acres of grain production is very compelling.