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Mean Dry Weight (mean + dry_weight)

Distribution by Scientific Domains

Earth and Environmental Science	100%

Selected Abstracts

Forage potential of semi-leafless grain peas

GRASS & FORAGE SCIENCE, Issue 2 2003
J. M. Koivisto
Abstract Individually sown plants of a forage-type pea (Pisum sativum L.), cv. Magnus, and a grain-type pea cv. Eiffel, were harvested several times over the growing season to determine how the quantity of plant components changed with time from sowing. There was no difference between the pea types in the mean dry weight per plant. The leaf-to-stem ratio of the two types was also not different. An appropriate grain-type pea cultivar could be a suitable substitute for forage-type cultivar in some forage production systems. [source]

The effect of body size on food consumption, absorption efficiency, respiration, and ammonia excretion by the inland silverside, Menidia beryllina (Cope) (Osteichthyes: Atherinidae)

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2003
M. A. Peck
Summary The inland silverside, Menidia beryllina (Cope), is an annual zooplanktivore that occurs in estuarine and freshwater habitats along the Atlantic and Gulf of Mexico coasts and drainages of the United States. Experiments were conducted at 25 ± 1°C to quantify the relationship between mean dry weight (WD) and rates of energy gain from food consumption (C), and energy losses as a result of respiration (R) and ammonia excretion (E) during routine activity and feeding by groups of fish. The absorption efficiency of ingested food energy (A) was also quantified. Rates of C, E, and R increased with WD by factors (b in the equation y = aWDb) equal to 0.462, 0.667, and 0.784, respectively. Mean (±SE) rates of energy loss during feeding were 1.6 ± 0.1 (R) and 3.4 ± 0.6 (E) times greater than those for unfed fish. Absorption efficiency was independent of WD and estimated to be 89% of C. From these measurements, the surplus energy available for growth and activity (G) and growth efficiency (K1) were estimated. Over the range in sizes of juveniles and adults (5,500 mg WD), predicted G and K1 values decreased from 7.42 to 0.20 J mg fish,1 day,1 and 63 to 21%, respectively. Measured and predicted bioenergetic parameters are discussed within an ecological context for a northern population of this species. [source]

Assessment of dietary lecithin and cholesterol requirements of mud crab, Scylla serrata, megalopa using semi-purified microbound diets

AQUACULTURE NUTRITION, Issue 6 2007
M.-H. HOLME
Abstract The effects of varying dietary lecithin and cholesterol levels on growth, development and survival of mud crab, Scylla serrata, megalopa were evaluated using six semi-purified, microbound diets formulated to be iso-energetic and containing three levels of supplemental lecithin (0, 20 and 40 g kg,1 diet dry weight) and two levels of supplemental cholesterol (0 and 7 g kg,1 diet dry weight). Fifteen megalopa were reared individually in each treatment and the nutritional value of diets was assessed on basis of mean dry weight and mean carapace width of newly settled first crab stage, as well as development time to the first crab stage and overall survival. A significant interaction between supplemental dietary lecithin and supplemental dietary cholesterol was found for final mean dry weight of newly settled crabs, and highest survival (60%) was recorded for megalopa fed diets containing the highest levels of dietary lecithin (39.7,44.1 g kg,1) (diet 5 and 6) regardless of whether diets were supplemented with cholesterol; this rate of survival was identical to that of megalopa fed live Artemia nauplii. The results indicate that supplemental dietary cholesterol may not be essential for mud crab megalopa when fed diets containing sufficient levels of supplemental dietary phospholipids. [source]