Effects ofYucca shidigeraExtract on Water Quality and Fish Growth in Recirculating-Water Aquaculture Systems

Abstract

In livestock industries such as poultry and swine, an extract of the Yucca shidigera plant has shown promise in controlling ammonia buildup in production facilities. In three trials, effects of Y. shidigera extract on ammonia levels and fish growth in recirculating‐water aquaculture systems were evaluated. When added to in vitro ammonia solutions, extract concentrations of 0.043% and 0.43% caused a significant (P < 0.05) reduction in ammonia levels after 24 h. The 0.43% concentration also caused significantly (P < 0.05) lower levels of nitrite and higher levels of nitrate. Both concentrations were subsequently found to be toxic to juvenile channel catfish (Ictalurus punctatus). In a feeding trial, fish fed diets containing 1.1‐g/kg concentrations of Y. shidigera extract had decreased (P < 0.10) weight gain and increased feed conversion (P < 0.05) compared with fish fed control diet, but there were no significant differences (P > 0.05) in ammonia, nitrite, and dissolved oxygen levels. These results suggest that Y. shidigera could be evaluated as a preconditioning agent for water‐recirculating systems and biofillers but should not be used in direct contact with fish.

Effect of dietaryYucca schidigeraextract on growth, total ammonia-nitrogen excretion and haematological parameters of juvenile striped catfishPangasianodon hypophthalmus

“…Consistent with Tidwell et al . (), and in contrast with Gaber () and Sarkar (), Yucca schidigera inclusion in the diet did not affect FCR. The effect of Yucca schidigera on feed utilization in fish may vary among finfish species, age, environmental conditions, inclusion level of Yucca Schidigera and saponin contents.…”

“…In contrast, Tidwell et al . () found no effect on TAN excretion in catfish when Yucca schidigera were included at levels ranging from 0.011 to 1.100 g/kg diet. It must be noted, however, that during the last years, production technologies of feed additive and aquafeed have advanced and the present Yucca schidigera extract most likely have different properties compared with that used by Tidwell et al .…”

“…It must be noted, however, that during the last years, production technologies of feed additive and aquafeed have advanced and the present Yucca schidigera extract most likely have different properties compared with that used by Tidwell et al . ().…”

Phytoplankton Preferences of Young Silver Carp,Hypophthalmichthys molitrix, in Hypereutrophic Mesocosms during a Warm Season

“…The results showed a highly significant relationship between the abundance and IU values of each phytoplankter in all the enclosures, without regard to the presence or density of fish. In general, cyanobacteria may be ingested unselectively when occurring abundantly (Kajak et al 1977, Tidwell et al 1992), but they are not-at all preferred and are even avoided by silver carp (Sirenko et al 1976). The feeding behavior of silver carp in cyanobacteria-rich lakes is not hlly understood due to complex relationships among algal growth and mortality and feeding preferences of fish (Siege1 1998).…”

Ammonia reduction in seawater byYucca schidigeraextract: efficacy analysis and empirical modelling

“…Although yucca extract can be potentially used in aquaculture for the same purposes as in livestock husbandry, few studies have been conducted. Yucca extract was used as a fish feed additive to enhance the protein metabolism and reduce ammonia excretion (Tidwell, Webster, Clark & Yancey 1992; Francis 2001; Kelly & Kohler 2003; El‐Saidy & Gaber 2004; Gaber 2006). Yucca extract was also used to reduce ammonia in aquaculture culture water (Tidwell et al 1992; Sarkar 1999a, b).…”