Control of residual nitrogen in shrimps
During the aging of the shrimps, a notable amount of organic remains is produced with high content, 50 to 60 kg, of nitrogen per mt of shrimp...
(1) During the aging of the shrimps, a notable amount of organic remains is produced with high content, 50 to 60 kg, of nitrogen per mt of shrimp.
(2) The most of these nitrogen waste comes from uneaten feed and shrimp excreta.
(3) Residual nitrogen is presented in the form of ammonium nitrogen, nitrates and nitrites whose presence in pond water affects the welfare, growth, gills, nervous system and hepatopancreas of shrimps.
(4) Although there are established maximum standard levels of contamination, it is known that, at much lower doses, ammonium nitrogen at 0.1mg/liter of water and nitrites at 0.45mg/liter of water have adverse effects, in percentages that range between 10 and 40%, on the growth of shrimps. Ionized ammonia nitrogen (NH⁴+) is considered to be the most toxic form.
(5) Many specialists in aquaculture consider that the only technique to reduce these nitrogen contaminations is changing the water, of the ponds, on a continuous way or within limited times.
However, the relationship between the cost/benefit of this practice is questioned by other specialists for various reasons:
5.1 The cost of the machinery necessary to perform this operation in the appropriate time
5.2 The cost of the filters
5.3 The stress caused to the shrimp by the mechanical drag.
(6) For these reasons, the industry has developed mixed procedures that combine the physical reduction of nitrogen with the fixation of nitrogen by flocculating bacteria and in botanical molecules incorporated in water or feed.
(7) When using botanical molecules in feed, it has been discovered that these allow the design of products with a quadruple purpose:
7.1 Reduce ammoniacal nitrogen
7.2 Reduce microorganisms that transform ammoniacal nitrogen into other nitrogen components.
7.3 Balance the digestive microbiome of the shrimp, improving the intestinal well-being 7.4 Reduce those microorganisms capable of acting, as occasional saprophytes, during times of immune weakness during molting cycles and ocular manipulations to stimulate reproduction.
(8) Biovet’s research has been carried out, since 2001, in collaboration with farms in Baja California del Sur and Sonora (in Mexico) farms in Veraguas (in Panama), and on farms and the University of Hanoi (in Vietnam).
(9) As the fruit of these investigations, Biovet has developed two products:
9.1 One of them in liquid form based on saponins and glycosides of botanical origin
9.2 Another in premix form based on saponins, glycosides and cimenol of botanical origin.
Both are marketed under the name ALQUERNAT YUCCA SHRIMP™.