Allan LeBlanc, VP of market development at Calysta, said the study is further evidence that FeedKind protein can be used as successfully in carnivorous marine species common to Asian markets as it has been in salmonids and shrimp.
Lead author on the paper, Dr Amal Biswas of Japan’s Kindai University, details two trials, one of 1,500 yellowtail fish, the second of 800. Both were analyzed over an eight-week period. In both cases, a control diet was used, alongside increasing concentrations of FeedKind.
Fish survivability was 100% across all tests, with no significant difference between the control diets and the 25% inclusion rate across both trial groups, according to the paper, which was published in Aquaculture.
The study, said the authors, further indicated that the alternative protein can effectively replace 30% of fishmeal protein in the diet of yellowtail without any impact on growth rate, digestibility, daily feeding rate or feed efficiency.
FeedKind is produced by fermenting natural gas with a naturally occurring bacteria, producing a single cell protein. Calysta outlined how the meal has been shown to be an effective feed for salmon, trout, and shrimp, as well as pets and terrestrial livestock. The non-GMO protein is approved for commercial use in feeds throughout the EU, Japan, and Thailand, among other countries.
Two trials were carried out to determine the optimal replacement level of fish meal (FM) protein by the bacterial protein meal, FeedKind (FK), in the diet of juvenile Japanese yellowtail, Seriola quinqueradiata.
In Trial 1, six diets were formulated: control diet (C) with FM as protein source; four experimental diets in which the FM of diet C was replaced at 25 (FK25), 50 (FK50), 75 (FK75) and 100% (FK100) by FK; and a final experimental diet in which 3% of FK in diet FK100 was replaced by enzyme-treated FM (EFK).
In Trial 2, seven diets were prepared: control diet C similar to Trial 1; three experimental diets in which the FM of diet C was replaced at 20 (FK20), 25 (FK25) and 30% (FK30) by FK; two experimental diets in which FK from diet FK25 was replaced either by further grinding FK (FK25J) or lower digestible FK (FK25L); and experimental diet EFK in which 3% of the FK in diet FK25 was replaced by enzyme-treated FM.
Fifteen (ca. 126g) or ten fish (ca. 80 g) were stocked into each of 18 500 L tanks in triplicates in Trial 1 and 2, respectively, fed two times daily until apparent satiation, and cultured for eight weeks.
At the end of both trials, feces were collected after feeding with chromic oxide (Cr2O3) mixed diets.
In Trial 1, all growth parameters and nutrients retention efficiencies showed similar patterns and no significant differences were observed between diets C and FK25, though feed efficiency (FE) was reduced by 10% in the latter diet, said the researchers.
However, other diets showed significantly lower growth performance compared to diet C.
When different lots of FK was used and feed formula was slightly adjusted in Trial 2, there were no significant differences in the growth performance, nutrients digestibility and retention efficiency, among the treatments even up to 30% FM protein replacement, said the authors.
FE was also either equal to or higher in all FK-based diets compared with control group.
“Overall, results indicated that the FK can comprise up to 20% of total diet, replacing 30% of the FM protein in diet for yellowtail, without compromising growth performance or feed efficiency,” said the researchers.
Calysta, in its 50/50 joint venture with Adisseo, is building the world’s first commercial FeedKind production facility in China for supply to Asia. That facility in Chongqing, China, is progressing as planned and on time, said the companies. So 20,000 tons of the SCP ingredient should be available from next year.