The seaweeds Sargassum spp. and Macrocystis pyrifera: An alternative for cattle forage in the Baja California peninsula?

The nutritional quality of dried seaweed Macrocystis pyrifera and a group of Sargassum species were compared with desert plants, cereals and animal meals commonly used as a feed for livestock in the Baja California peninsula during the dry season. The associated digestive enzymatic activity and the presence of digestive enzymatic inhibitors and lectins were evaluated and their general chemical analysis was also considered. The protein concentration of seaweeds was low, compared to other plants. The presence of lectins and enzyme inhibitors was negligible, compared to desert legumes. The use of seaweeds as a supplementary forage for herded cattle is apparently a good strategy, despite their low protein concentration. High carbohydrate, mineral and lipid concentrations can help meet maintenance requirements, especially when grasses are not available

A review of digestive enzyme activity in penaeid shrimps

The purpose of this article is to present an overview of the digestive enzymes of penaeid shrimp. The review also covers the effects of circadian rhythms and variations according to moulting cycles on the activities of the various digestive enzymes. © 2007 Brill Academic Publishers

Biology and culture of Macrobrachium tenellum: State of the art [Biología y cultivo de Macrobrachium tenellum: Estado del arte]

This research aims to collect and classify information on the biology and culture of the prawn Macrobrachium tenellum, in a clear and sequential manner, which would integrate the knowledge to develop new ways in research and sustainable exploitation of this resource. It covers various topics including taxonomy and systematics, geographic distribution, ecology, reproduction, development, pathology, fisheries and aquaculture of this species, taking into account all the information generated by different authors, from four decades to today. We conclude that there are significant knowledge gaps of basic and applied aspects of the biology of the species and this requires a great deal of research for the correct understanding of this native organism to allow for its protection and proper utilization. It is recommended to take special interest in studies to fully know its distribution, the effects of pollution and the loss of its natural habitats. It is necessary to review the regulations for the use and conservation, and to develop and improve aquacultural management techniques

Biology and culture of Macrobrachium tenellum: State of the art [Biología y cultivo de Macrobrachium tenellum: Estado del arte]

This research aims to collect and classify information on the biology and culture of the prawn Macrobrachium tenellum, in a clear and sequential manner, which would integrate the knowledge to develop new ways in research and sustainable exploitation of this resource. It covers various topics including taxonomy and systematics, geographic distribution, ecology, reproduction, development, pathology, fisheries and aquaculture of this species, taking into account all the information generated by different authors, from four decades to today. We conclude that there are significant knowledge gaps of basic and applied aspects of the biology of the species and this requires a great deal of research for the correct understanding of this native organism to allow for its protection and proper utilization. It is recommended to take special interest in studies to fully know its distribution, the effects of pollution and the loss of its natural habitats. It is necessary to review the regulations for the use and conservation, and to develop and improve aquacultural management techniques

Muscle amino acid profile of Macrobrachium tenellum and chemical score of used protein in its feeding [Perfil de aminoácidos del músculo de Macrobrachium tenellum y cómputo químico de proteínas usadas en su alimentación]

Freshwater prawns Macrobrachium tenellum were used to determine the content of amino acids (aa) of the muscle, and the chemical score of the main ingredients used in feeds for the species was determined. The separation and identification of aa is carried out by high performance liquid chromatography (HPLC) with fluorescence detection. The calculation of chemical score was obtained by dividing the value of essential aa between aa of the reference protein. The most abundant aa in muscle were glutamic acid (16.14%), lysine (9.60%) and aspartic acid (9.06%) and the lowest were methionine (2.88%), histidine (2.52%) and the tryptophan (0.47%). The first limiting amino acid for fishmeal was threonine and histidine for squid meal; and as a second limiting aa arginine and threonine, respectively. In wheat flour first and second limiting amino acids were lysine and threonine, in soybean meal, methionine and lysine, respectively. For feed formulation for M. tenellum intends to use a combination of plant and animal proteins that approximates the amino acid profile of the species

Muscle amino acid profile of Macrobrachium tenellum and chemical score of used protein in its feeding [Perfil de aminoácidos del másculo de Macrobrachium tenellum y cZapotitlánmputo químico de proteínas usadas en su alimentación]

Freshwater prawns Macrobrachium tenellum were used to determine the content of amino acids (aa) of the muscle, and the chemical score of the main ingredients used in feeds for the species was determined. The separation and identification of aa is carried out by high performance liquid chromatography (HPLC) with fluorescence detection. The calculation of chemical score was obtained by dividing the value of essential aa between aa of the reference protein. The most abundant aa in muscle were glutamic acid (16.14%), lysine (9.60%) and aspartic acid (9.06%) and the lowest were methionine (2.88%), histidine (2.52%) and the tryptophan (0.47%). The first limiting amino acid for fishmeal was threonine and histidine for squid meal; and as a second limiting aa arginine and threonine, respectively. In wheat flour first and second limiting amino acids were lysine and threonine, in soybean meal, methionine and lysine, respectively. For feed formulation for M. tenellum intends to use a combination of plant and animal proteins that approximates the amino acid profile of the species

Effect of three diets on growth of hatchlings of American crocodile Crocodylus acutus [Efecto de tres dietas en el crecimiento de crías de cocodrilo Americano Crocodylus acutus]

The effect of three diets with replacement of marine fish (20 and 40%) for beef liver in the growth and survival, and the effect of temperature on feed intake of young Crocodylus acutus was studied. Crocodiles fed the 40% of liver had the highest growth and 100% survival, with potential for greater tolerance to winter conditions

Effect of three diets on growth of hatchlings of American crocodile Crocodylus acutus [Efecto de tres dietas en el crecimiento de crías de cocodrilo Americano Crocodylus acutus]

The effect of three diets with replacement of marine fish (20 and 40%) for beef liver in the growth and survival, and the effect of temperature on feed intake of young Crocodylus acutus was studied. Crocodiles fed the 40% of liver had the highest growth and 100% survival, with potential for greater tolerance to winter conditions