ABSTRACT A feeding trial was performed to assess dietary protein:lipid ratios for the grow-out phase of the bullfrog (Lithobates catesbeianus). Nine balanced isoenergetic diets were formulated, combining three different protein levels (300, 400, and 500 g kg−1) with three different lipid levels (50, 100, and 200 g kg−1), designated as P300/50L, P300/100L, P300/200L, P400/50L, P400/100L, P400/200L, P500/50L, P500/100L, and P500/200L. Additionally, a commercial fish feed, commonly used in Mexico to feed bullfrogs, was also tested during the experiment. Growth performance, animal performance parameters, carcass composition, and fatty acid profiles in muscle and liver were evaluated. The feeding trial results showed that all the experimental diets enhanced growth, feed conversion ratio, and frog-leg weight compared with the commercial diet. Bullfrogs had higher growth with 400 and 500 g kg−1 of dietary protein regardless of dietary lipid content. It was also notable that with the P500/200L diet, frogs doubled the weight of those fed the commercial diet. DHA, EPA, and total omega-3 fatty acids were double in muscle and two to eight times higher in the liver compared with the commercial diet. In all cases, the final proximal composition of carcass reflected the diet composition. It is suggested that a diet containing 400 g kg−1 of protein and 50 g kg−1 lipids (protein/lipid ratio: 7.4; gross energy: 18.2 MJ kg−1) is adequate for bullfrog performance during the grow-out phase to achieve market size in a shorter period, thus, reducing farming risks and production costs. proteinlipid growout grow out Lithobates catesbeianus. catesbeianus . catesbeianus) formulated 300, 300 (300 kg1 kg 1 50, (50 100 20 kg−1, , P30050L PL P300 50L P L P300/50L P300100L 100L P300/100L P300200L 200L P300/200L P40050L P400 P400/50L P400100L P400/100L P400200L P400/200L P50050L P500 P500/50L P500100L P500/100L P500200L Additionally bullfrogs experiment parameters evaluated ratio frogleg frog leg 40 kg− content DHA EPA omega3 omega 3 omega- cases 5 protein/lipid 7.4 74 7 4 energy 182 18 2 18. period thus costs 30 (30 (5 10 P30 P40 P50 7. (3 ( P3 P4 P5

The nutritional value of four meals made from animal by-products of squid (SBM), tuna (TBM), poultry (PBM) and pork (POBM), and their potential use in diets for Octopus maya were evaluated. Lyophilized crab-meat meal (CRM) (Callinectes sapidus) was used as a reference for the nutritional requirements of the octopus. CRM had the highest crude protein (CP) content (847.2 g kg-1) and the lowest lipid content (27.5 g kg-1). SBM and PBM had more than 700 g kg-1 CP content, while TBM and POBM had less than 600 g kg-1. Lipid content varied between 75.3 (SBM) and 127.2 (PBM) g kg-1. Energy content of CRM was 17.5 MJ kg-1, and the maximum difference with respect to the by-product meals did not exceed 3 MJ kg-1. Amino acid analysis showed that SBM and PBM had high content of Thr, Ser and Ala, which are the most important amino acids for the metabolism of O. maya. Fatty acid analysis showed that they also had a high content of PUFA. PBM showed deficiencies in EPA and DHA content, but had a high content of linoleic acid, which can be a precursor of C:20 and C:22. Based on this, SBM and PBM have nutritional qualities which could be adequate for use as primary protein sources in artificial diets for O. maya.

Se evaluó el valor nutricional de cuatro harinas de subproductos de calamar (HSCA), atún (HSAT), ave (HSAV) y cerdo (HSCE), así como su uso potencial en dietas para Octopus maya. Como referencia de los requerimientos nutricionales del pulpo se usó harina de carne de jaiba (Callinectes sapidus) liofilizada (HCJA). HCJA tuvo el mayor contenido de proteína cruda (PC) (847.2 g kg-1) y el menor contenido de lípidos (27.5 g kg-1). HSCA y HSAV tuvieron un contenido de PC de más de 700 g kg-1, mientras que HSAT y HSCE tuvieron menos de 600 g kg-1. El contenido de lípidos varió entre 75.3 (HSCA) y 127.2 (HSAV) g kg-1. El contenido de energía de HCJA fue de 17.5 MJ kg-1, y la diferencia máxima con respecto a las harinas de subproductos no fue mayor de 3 MJ kg-1. El análisis de aminoácidos mostró que HSCA y HS-AV tuvieron un alto contenido de Thr, Ser y Ala, los cuales son los aminoácidos más importantes para el metabolismo de O. maya. El análisis de ácidos grasos mostró que tales harinas tuvieron también un alto contenido de PUFA. HSAV mostró deficiencias en EPA y DHA; sin embargo, tuvo un alto contenido de ácido linoleico, el cual puede actuar como un precursor de C:20 y C:22. De acuerdo a esto, HSCA y HSAV tienen un perfil nutricional adecuado para su uso como fuentes primarias de proteína en dietas artificiales para O. maya.