The inclusion of biological silage from chicken intestines and blood in the feed for Nilotic tilapia Oreochromis niloticus, substituting 80% of the protein content of fishmeal, was evaluated. The silages were made with 70% waste, 15% energy source (14% molasses and 1% sugar) and 15% yogurt (lactic acid bacteria). The pH and acidity were determined for 180 days, and the chemical analysis was done using standard methods. The base diet was formulated with the minimum cost equation, and considering the nutritional requirements for tilapia, inclusion levels and cost of inputs. A control diet and two with silages were used. The fingerlings (n=270) with an initial weight of 5.17 ± 0.18 g were randomly distributed in nine aquariums (3 per diet). The fish were fed three times a day and evaluated monthly. A significant difference (p<0.05) was found in the final weight and biomass averages betw...

El objetivo del trabajo fue desarrollar un modelo matemático que haga la predicción del comportamiento epidemiológico causado por SARS-CoV2 (COVID-19) en la República Popular de China. El modelo de basó en determinar la relación entre la variación del número de casos reportados (dN) y la variación del tiempo transcurrido (dt), denominado velocidad con que el fenómeno de casos reportados en China. La velocidad del fenómeno se determinó por diferenciación gráfica, con el propósito de encontrar una Ecuación Diferencial Ordinaria de Primer Orden (EDOPO), tipo lineal. Esta ecuación fue resuelta entre las condiciones iniciales de los datos reportados (t=1 día, N=278 casos reportados), llegando a obtener el modelo predictivo correspondiente. El modelo predictivo (Ecuación 15) fue validado estadísticamente, evaluando su coeficiente de correlación r de Pearson, cuyo valor es ...

Albino fish have greater economic value than fish that have coloration both at the ornamental level and at the consumption level for their meat. Th e slc45a2 gene is associated with the induction of an albinism phenotype initially reported in Zebrafish (Danio rerio Hamilton, 1822) and Medaka fish (Oryzias latipes Temminck & Schlegel, 1846). With the information registered in the Genbank of the slc45a2 gene of the Tilapia fish (Oerochromis niloticus Linnaeus, 1758) and the Gamitana (Colossoma macropomum Bleeker, 1869), specific primers were designed in silico to identify this gene in these two freshwater species. Both sets of primers were used fi rst on these two species (Tilapia and Gamitana). And then tested in the fi sh Paco (Piaractus brachypomus Cuvier, 1818) and Oscar (Astronotus ocellatus Agassiz, 1831) whose slc45a2 gene sequences are currently unknown. With the set of primers...

Obtaining viable Argopecten purpuratus seeds faces challenges, especiallyci the unpredictability of the marine environment and high production costs in hatcheries. However, improving the method of "Broodstock Conditioning In Hatcheries" is key to ensure permanent seed supplies by minimizing the dependence on marine conditions and by maximizing economic viability in hatcheries. In an effort to overcome these barriers, broodstock were conditioned into two different environments: (a) Natural Environment: Natural marine conditions located in Bahía Inglesa, Atacama Region, Chile. (b) Hatchery: Laboratory conditions to achieve gonadal maturation, spawning induction, fertilization and larval development. The purpose of this research was to evaluate how the type of reproductive conditioning affects the reproductive potential and nutritional quality of the progeny. Both methods were successful a...

Obtaining viable Argopecten purpuratus seeds faces challenges, especiallyci the unpredictability of the marine environment and high production costs in hatcheries. However, improving the method of "Broodstock Conditioning In Hatcheries" is key to ensure permanent seed supplies by minimizing the dependence on marine conditions and by maximizing economic viability in hatcheries. In an effort to overcome these barriers, broodstock were conditioned into two different environments: (a) Natural Environment: Natural marine conditions located in Bahía Inglesa, Atacama Region, Chile. (b) Hatchery: Laboratory conditions to achieve gonadal maturation, spawning induction, fertilization and larval development. The purpose of this research was to evaluate how the type of reproductive conditioning affects the reproductive potential and nutritional quality of the progeny. Both methods were successful a...

NITROGEN-FIXING CYANOBACTERIAL CONSORTIA ARE AN ALTERNATIVE TO THE INDISCRIMINATE USE OF CHEMICAL FERTILIZERS THAT AFFECT THE ENVIRONMENT, FIX ATMOSPHERIC NITROGEN, AND CAN THEREFORE BE USED AS PLANT GROWTH PROMOTERS, SYNTHESIZE VARIOUS SUBSTANCES SUCH AS AUXINS, VITAMINS, AND TOTAL PROTEINS, AND FIX ATMOSPHERIC BIOFERTILIZERS AND SOIL CONDITIONERS. THE PRESENT STUDY AIMED TO OBTAIN AND DEVELOP, BY BIOTECHNOLOGICAL MEANS, TWO CONSORTIA OF CYANOBACTERIA ISOLATED FROM THE ROOT AND RHIZOSPHERE OF CARICA PAPAYA GROWN IN SANDY LOAM SOIL. THE CULTURE WAS CARRIED OUT IN BLUE GREEN MEDIUM WITHOUT MODIFIED NITROGEN (BG110), WITH AERATION OF 0.32 L MIN−1, AT A LIGHT INTENSITY OF 48.83 ΜEM−2S−1, AND A TEMPERATURE OF 22 ± 2 °C. TWO CONSORTIA CONSISTING OF NOSTOC COMMUNE, APHANOTHECE MINUTISSIMA, PLANKTOTHRIX SP. (C1), NOSTOC COMMUNE, CALOTHRIX SP., AND APHANOTHECE MINUTISSIMA (C2) WERE ISOL...