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8 results on '"Magalhães, Vitalina"'

7. Use of biofloc technology during the pre-maturation period of Litopenaeus vannamei males: effect of feeds with different protein levels on the spermatophore and sperm quality.

Author

Braga, André, Lopes, Diogo LA, Magalhães, Vitalina, Poersch, Luís H, and Wasielesky, Wilson

Subjects
WHITELEG shrimp, SPERMATOZOA, ANIMAL feeding, PROTEINS, SHRIMP fisheries
Abstract

The objectives of this study were: (1) Compare two systems for pre-maturation of Litopenaeus vannamei in terms of spermatophore and sperm quality, (2) Compare the effect of feeds with different protein levels on reproductive quality of males reared in a biofloc-dominated system. Animals (36.40 ± 3.13 g) reared under biofloc technology ( BFT) were used in the 30-day experiment, which involved four treatments: one in a clear water system ( CW) and other three in a BFT system. The BFT treatments were differentiated by feed: mix of fish, squid and crab ( BFT+ FF) composed of 68.48% dietary protein ( DP); broodstock feed ( BFT+ BF) composed of 52.51% DP; and juvenile feed ( BFT+ JF) composed of 39.91% DP. Feed in the CW was also the mix of fresh food. Spermatophore and sperm quality were analyzed at the beginning and end of the experiment. Higher normal sperm rate was recorded in the CW compared with the BFT+ FF. Among the BFT treatments, the BFT+ FF had the lowest normal sperm rate. Thus, the use of BFT for pre-maturation of L. vannamei allowed the reduction in dietary protein levels from 68.48% ( BFT+ FF) to 39.91% ( BFT+ JF) and the maintenance of spermatophore and sperm quality compared to the system based on high daily exchange rate. [ABSTRACT FROM AUTHOR]

Published
2015
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8. The effects of feeding commercial feed formulated for semi-intensive systems on Litopenaeus vannameiproduction and its profitability in a hyper-intensive biofloc-dominated system

Author

Braga, André, Magalhães, Vitalina, Hanson, Terry, Morris, Timothy C., and Samocha, Tzachi M.

Abstract

•Turbidity, total and volatile suspended solids were higher in the treatment with feed designed for semi-intensive system, whereas alkalinity was lower.•Semi-intensive feed treatment required more solids removal, oxygen and bicarbonate supplementation.•Weekly growth, yield and biomass were lower in semi-intensive feed treatment, whereas FCR was higher.•The feed designed for semi-intensive systems (low-cost feed) financially underperformed the feed formulated for hyper-intensive (more-expensive feed).

Published
2016
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