Nucleotides in Shrimp Feeds
October 15, 2010
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. They play a central role in metabolism, where they serve as a source of chemical energy, participate in cellular signaling, and are incorporated into important cofactors of enzymatic reactions.
Juan Aguirre (firstname.lastname@example.org): Does anybody have first hand experience on how nucleotides affect shrimp growth and survival?
Neil Gervais (email@example.com): Fernando Grando in Machala, Ecuador, has done some very important work on nucleotides. Contact him for information on their commercial benefits.
Billy Setio (firstname.lastname@example.org): I tried nucleotides three years ago. They were packaged in a product called “Vannagen” from Switzerland. I asked a feed company to mix them for me at one gram per metric ton. In ponds with very bad water conditions, they helped with survival, but not growth. In ponds with good water quality, survival and growth were better than in a pond without nucleotides, but the results were not significant. Survivals were only 3 to 5% better, and growth was 22 grams in 120 days, with Vannagen, compared to 20 grams in 120 days without Vannagen.
I stopped using them because of the cost, up to 10% of feed costs. Later in the year when I began using bioflocs, the water quality improved and I got good results without using nucleotides. It’s not practical to add nucleotides at the farm level; it just too much work.
Udaya Ram Jothy (email@example.com): We have been using a commercial nucleotide for the past five years as a top dressing on Penaeus monodon feed. It works as a feed attractant and promotes higher survivals rates and disease resistance.
In ponds with no disease, the top dressing was done at the rate of 5 to 10 grams per kilogram of feed (once or twice a day), and in ponds with disease, it was applied at 20 grams per kilogram of feed.
If you can manage to do the top dressing, you will see benefits.
Job Madrona (firstname.lastname@example.org): Dietary nucleotides when used as a feed premix really improve shrimp growth and survival. They help improve shrimp appetite especially during cold months. Some shrimp growers have their feed company incorporate nucleotides in their feed. When used as top dressing on feed, nucleotides require proper preparation to avoid leaching and waste.
I tested nucleotides in two growout modules. Each module consisted of ten ponds with the same stocking density, the same postlarvae, and the same stocking date. We used two feed brands, one with nucleotides and one without nucleotides. The results were amazing! Nucleotides work.
Hervé Lucien-Brun (email@example.com): I uploaded a presentation on nucleotides to the Shrimp List Website about a product called “NUCLEO 20”. The presentation includes result of field trials done with Penaeus vannamei and tilapia. The base of this product is a nucleotide produced by the Canadian company: Lallemand. You can download the presentation titled “Mazatlan a 2006.pdf” at http://groups.yahoo.com/group/shrimp/files/Presentation NUCLEO. You will need your Yahoo Shrimp Group ID and password to download the file. [Editor: I found Lucien-Brun’s presentation at the Shrimp List Website, but when I clicked on its link, I got a “page-not-found” message, so I recommend that you contact Lucien-Brun at the email address above for a copy of the presentation.]
Mark Rottmann (firstname.lastname@example.org): Nucleotides work, but many are produced using a fermentation process that limits the production of natural RNA/DNA “strings”. To reproduce all the nucleotide fractions that occur in nature during normal decomposition or digestion is impossible. The same is true with amino acids—this is why only the “limiting” amino acids are produced by fermentation (like lysine, for example). Why is fishmeal still 20 to 30 percent, or more, of the aquafeed market? Even with fishmeal at $1,600 a ton, we can’t produce a full array of complex proteins to cost effectively replace the fishmeal.
When properly managed, nucleotides and peptides can be extracted from seafood processing waste materials, and the resulting product has more than just a few of the nucleotide strings, it has all of them. And unlike fishmeal, the entire complex can be kept bioactive so that the proteins and nucleotides are not denatured. Fishmeal has less than 0.1% nucleotides and only a few peptides—all of which are denatured during processing.
To maximize peptide and nucleotide additions to aquafeeds, the most economical method to date is the addition of concentrated and purified hydrolysate streams (ground up fish carcasses, after the usable portions have been removed for human consumption). The companies in Ecuador using our PefectDigest peptide/nucleotide mix vary the inclusion of nucleotides from 1% to 3%. The best results are always achieved when they are applied as a top-dressing! When added at the feed mill, they pass through an extruder and some denaturing occurs. Spraying pellets with nucleotides is fine, but it can result in molds and fungi. A 1% peptide addition plus a nucleotide solution results in a 2-4% improvement in feed conversion ratios. The economic benefit seems to plateau at 2-3% inclusion.
I find it interesting that “small farms” are much more likely to use top-dressing, while larger farms seem to avoid this as “too much work”. Actually, the return on investment for top dressing is better for big farms, but they shy away from using it because of the amount of work.
Information: Mark Rothman, Bluewave Marine Ingredients, Av. La Encalada 1388, Office #1101, Lima 33, Peru (Skype phone Mark.Rottmann Peru, cell phone +51-98-750-3929, email email@example.com, webpage http://www.bluewaveperu.com).
Sources: 1. The Shrimp List (a mailing list for shrimp farmers). Subject: Nucleotides. September 26 to 29, 2010. 2. Wikipedia. Nucleotides. Website visit on October 7, 2010. 3. Aquaculture Research. Preliminary Evaluation of a Purified Nucleotide Mixture as a Dietary Supplement for Pacific White Shrimp Litopenaeus Vannamei (Boone). Peng Li, Addison Lawrence, Frank Castille and Delbert Gatlin III (firstname.lastname@example.org, Department of Wildlife and Fisheries Sciences, Faculty of Nutrition, Texas A&M University System, College Station, Texas 77843, USA). Volume 38, Issue 8, Page 887. Published online on May 30, 2007. 4. Bob Rosenberry, Shrimp News International, October 15, 2010.
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