Research Briefs
Aquaculture Volume 426-427
Evaluation of the performance of pyrethroids on different life stages of Caligus rogercresseyi in southern Chile
GA ARRIAGADA, H STRYHN, JL CAMPISTÓ, EE REES, J SANCHEZ, R IBARRA, M MEDINA AND S ST-HILAIRE
Control of sea lice in Chile is largely based on antipara- Zeolites good for rainbow trout Results
show better preservation and greater freshness of seabream fed diets containing rosemary extract
sitic treatments, synthetic pyrethroids being the most used drugs. In recent years, farmers in Chile have reported decreased performance of pyrethroid-based treatments. The aim of this study was to assess the performance of two deltamethrin-based (Alphamax® and a generic prod- uct) and one cypermethrin-based (Betamax®) product on the different life stages of Caligus rogercresseyi, while controlling potential confounders. We found that both deltamethrin products and the cypermethrin product had a signifi cant effect on the reduction of juvenile, mobile adult, and gravid female lice, compared with untreated pens; however, the effect on juvenile lice was less than on mobile stages. There was no evidence that pyrethroids performed better on certain mobile life stages, such as gravid females. When the three products were compared, no signifi cant differences were observed in the numbers of juvenile, adult male, and non-gravid female lice after we controlled for potential confounders; however, cypermeth- rin exhibited a small, yet signifi cantly greater effect on the gravid female group when compared with one of the del- tamethrin-based products. We also confi rmed that other factors besides the product choice, such as the pre-treat- ment sea lice abundance, water temperature and salinity, and time elapsed to the post-treatment sample, affect the post-treatment sea lice level as well, and therefore, they should be taken into consideration when assessing the effect of immersion treatments.
Improved conservation of gilthead seabream (Sparus aurata) in ice storage. The infl uence of doses of rosemary extract added to feed
A HERNÁNDEZ, B GARCÍA GARCÍA, MJ JORDÁN AND MD HERNÁNDEZ This study focused on the effects of the dose of rose-
mary extract (Rosmarinus offi cinalis) on the quality of gilthead seabream. A control diet (basal diet) and four experimental diets (R600, R1200, R1800 and R2400) with 600, 1200, 1800 and 2400 mg kg–1
1 of rosemary
extract were administered, respectively. The fi sh were sacrifi ced and stored on ice at 4°C for 0, 7, 14 and 21 days. Physical–chemical, microbiological and sensory tests were conducted at each sampling point to determine the degree of deterioration suffered by the gilthead seabream. The differences in water-holding capacity (WHC) and the trends in TBARS, TVBN and TMA observed suggest better preservation with the 600 mg kg–1
Aquaculture Society
Volume 45, Issue 1 Essential Oregano Oil as a Growth Promoter for the Yellowtail Tetra, Astyanax altiparanae
POLLYANNA DE MORAES FRANÇA FERREIRA, LIDIANE DA SILVA NASCIMENTO, DEVLYNN COELHO DIAS, DIOGO MAGALHÃES DA VEIGA MOREIRA, ANA LÚCIA SALARO, MARIELLA BONTEMPO DUCA DE FREITAS, ANTONIO POLICARPO SOUZA CARNEIRO AND JENER ALEXANDRE SAMPAIO ZUANON
This study aimed to evaluate the potential of oregano
oil as a growth promoter for the yellowtail tetra, Astyanax altiparanae. The fi sh (1.46 ± 0.09 g) were distributed into twenty-four 60-L aquaria at a stocking density of 0.5 fi sh/L. Six isonitrogenous (350 g crude protein/kg) and isocaloric (4272 kcal gross energy/kg) diets containing 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 g/kg of oregano oil were evaluated. At the end of 90 d there was a quadratic effect of oregano oil levels for weight gain, specifi c growth rate, protein effi ciency ratio and carcass weight, and the estimated values to maximize these variables were between 0.2 and 0.6 g/kg. There was also a quadratic effect on the feed conversion ratio, and the estimated value to improve this variable was 0.62 g/kg. A positive linear effect of the treat- ments was observed for muscle glycogen. With increased levels of oregano oil in the diet, there was a reduction in dry matter and ether extract and an increase in the protein content of the carcass. Thus, it can be concluded that oregano oil, at the level of 0.5 g/kg, acts as a growth promoter for A. altiparanae by improving growth perform- ance and carcass composition.
Journal of Aquaculture Research & Development
The Infl uence of Chankanay Zeolites as Feed Addi- tives on the Chemical, Biochemical and Histologi- cal Profi le of the Rainbow Trout (Oncorhynchus mykiss)
ASSEL PARITOVA, NURZHAN SARSEMBAYEVA, BOZENA ŁOZOWICKA, AMANGELDY MAULANOV, GULNUR KUZEMBEKOVA AND PIOTR KACZYNSKI
This article presents the results of the infl uence of dose. In addition,
the Quality Index showed greater freshness in fi sh fed diets containing rosemary extract, regardless of the dose; shelf-life also increased by one day with all tested doses, as compared to the control group.
Journal of the World 36
zeolites as feed additives on the chemical, biochemical and histological profi le of fi sh. Research was conducted for 63 days using a rainbow trout from Turgen village (Kaza- khstan). The studied material was zeolitic tuff from the Chankanay deposit as an additive to RGM-2M feed. The fi sh were fed with a normal diet, and the diet supplement- ed with 1%, 2%, 3% and 4% of natural zeolites. Pathomor- phological and histological examinations of muscle tissues and internal organs of the rainbow trout were carried out. Additionally, lipid contents, FAs compositions and amino acid compositions were studied. The content of essential amino acids and proportion of essential amino acids to non-essential amino acids in the experimental group was higher than in the control group. Zeolite supplementation at the 4% inclusion level showed a high content of the amino acids. The results of this study confi rmed that zeo- lites had a positive effect on the chemical, amino acid and fatty acid composition. The addition of natural zeolites to
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