Effect of growth rate of the food alga on the growth/ingestion efficiency of a marine herbivore

1980 ◽  
Vol 60 (3) ◽  
pp. 681-702 ◽  
Author(s):  
J. M. Scott
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Biochemical Composition ◽  
Brachionus Plicatilis ◽  
Calorific Value ◽  
Growth Efficiency ◽  
Food Alga ◽  
Marine Herbivore

The chlorophycean alga, Brachiomonas submarina var. pulsifera Droop, was grown in two bacteria-free chemostats, differing only in the amount of light each received. Investigations were made into the changes in biochemical composition and calorific value of the cells when they were grown at different growth rates. This information was used to help to explain changes in the growth efficiency of the rotifer Brachionus plicatilis Miiller, grown in a bacteria-free chemostat which was linked to one of the algal chemostats, the algae being supplied as the source of food.

scholarly journals In Pursuit of a Better Broiler: Growth, Efficiency and Mortality of 16 Strains of Broiler Chickens

2020 ◽  
Author(s):  
Stephanie Torrey ◽  
Mohsen Mohammadigheisar ◽  
Midian Nascimento dos Santos ◽  
Daniel Rothschild ◽  
Lauren Dawson ◽  
...  
Keyword(s):  
Growth Rate ◽  
Feed Intake ◽  
Growth Rates ◽  
Broiler Chickens ◽  
Growth Efficiency ◽  
Small Scale ◽  
Phenotypic Traits ◽  
Feed Conversion ◽  
Wide Range ◽  
Body Weights

ABSTRACTTo meet the growing consumer demand for chicken meat, the poultry industry has selected broiler chickens for increasing efficiency and breast yield. While this high productivity means affordable and consistent product, it has come at a cost to broiler welfare. There has been increasing advocacy and consumer pressure on primary breeders, producers, processors and retailers to improve the welfare of the billions of chickens processed annually. Several small-scale studies have reported better welfare outcomes for slower growing strains compared to fast growing, conventional strains. However, these studies often housed birds with range access or used strains with vastly different growth rates. Additionally, there may be traits other than growth, such as body conformation, that influence welfare. As the global poultry industries consider the implications of using slower growing strains, there was a need for a comprehensive, multidisciplinary examination of broiler chickens with a wide range of genotypes differing in growth rate and other phenotypic traits. To meet this need, our team designed a study to benchmark data on conventional and slower growing strains of broiler chickens reared in standardized laboratory conditions. Over a two-year period, we studied 7,528 broilers from 16 different genetic strains. In this paper, we compare the growth, efficiency and mortality of broilers to one of two target weights (TW): 2.1 kg (TW1) and 3.2 kg (TW2). We categorized strains by their growth rate to TW2 as conventional (CONV), fastest slow strains (FAST), moderate slow strains (MOD) and slowest slow strains (SLOW). When incubated, hatched, housed, managed and fed the same, the categories of strains differed in body weights, growth rates, feed intake and feed efficiency. At 48 days of age, strains in the CONV category were 835-1264 g heavier than strains in the other categories. By TW2, differences in body weights and feed intake resulted in a 22 to 43-point difference in feed conversion ratios. Categories of strains did not differ in their overall mortality rates.

The effect on bacon pig backfat iodine number and calorific value of feeding barley or maize based diets to give different growth rates

1974 ◽  
Vol 82 (1) ◽  
pp. 177-179 ◽  
Author(s):  
T. L. J. Lawrence
Keyword(s):  
Growth Rate ◽  
Iodine Number ◽  
Growth Rates ◽  
Live Weight ◽  
Calorific Value ◽  
Large White ◽  
The Mean ◽  
Ad Libitum ◽  
Main Effects ◽  
Feeding Interactions

SUMMARYIn an experiment involving sixty Large White pigs fed maize or barley based diets either ad libitum (AL) or to one of two restricted scales (R1 and R2), between 55 and 86 kg live weight, there were no significant cereal × feeding interactions for growth rate and the mean growth rates for the main effects were 0·62, 0·63, 0·81, 0·73 and 0·35 kg/day for the maize, barley, AL, R1 and R2 treatments respectively. There were no significant cereal × feeding treatment interactions for iodine number or calorific value of carcass backfat and the only significant differences between the main effects were those of lower iodine numbers for the barley (cf. maize) and the AT. (cf. R1) treatments.

Effects of the biochemical composition of three microalgae on the life history of the rotifer Brachionus plicatilis (Alvarado strain): an assessment

2018 ◽  
Vol 54 ◽  
pp. 20 ◽  
Author(s):  
Ignacio Alejandro Pérez-Legaspi ◽  
Brenda Marina Guzmán-Fermán ◽  
Jesús David Moha-León ◽  
Luis Alfredo Ortega-Clemente ◽  
Verónica Valadez-Rocha
Keyword(s):  
Growth Rate ◽  
Life Table ◽  
Biochemical Composition ◽  
Production Systems ◽  
Brachionus Plicatilis ◽  
Dry Weight ◽  
Reproductive Rate ◽  
Toxicity Tests ◽  
Net Reproductive Rate ◽  
Table Analysis

The biochemical composition of microalgae used as food is essential for aquatic species in commercial production systems, such as rotifers and microcrustaceans. Life table bioassays with the rotifer Brachionus sp. “Alvarado” strain were performed using three microalgae (Nannochloropsis oculata, Dunaliella salina and Isochrysis sp.) as food. Microalgae growth rate, dry weight and biochemical composition (protein, lipid, carbohydrate) and pigments (chlorophyll and carotenoid) were determined. The microalgae showed significant differences in their biochemical composition. N. oculata showed the highest growth rate, while D. salina showed the slowest growth rate, but instead, it displayed a higher content of proteins, lipids, carbohydrates, chlorophyll, and carotenoids per cell. Rotifer life table analysis showed no significant differences among any of the microalgae as food bioassays. However, Isochrysis sp. had a higher effect on the net reproductive rate of the rotifer Brachionus sp. “Alvarado” followed by D. salina, while N. oculata showed a higher effect on life expectancy and generation time. In conclusion, the three microalgae are found to be useful to support rotifer cultures; however, both, D. salina and Isochrysis sp., might improve the rotifer culture due to better growth and reproduction in short time. This information is useful to implement the culture of this tropical strain of Brachionus plicatilis complex in order to obtain high population densities, making rotifers available for several applications such as the establishment of larviculture in hatcheries, bioassays for ecological studies or to assess its sensitivity through toxicity tests.

Comparison of copper sulphate pentahydrate growth rates determined by different methods

1990 ◽  
Vol 55 (7) ◽  
pp. 1691-1707 ◽  
Author(s):  
Miloslav Karel ◽  
Jiří Hostomský ◽  
Jaroslav Nývlt ◽  
Axel König
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Fluidized Bed ◽  
Growth Rates ◽  
Copper Sulphate ◽  
Crystal Growth Rate ◽  
Effect Of Temperature ◽  
Rotating Disc ◽  
Shape Factors ◽  
Data Treatment

Crystal growth rates of copper sulphate pentahydrate (CuSO4.5 H2O) determined by different authors and methods are compared. The methods included in this comparison are: (i) Measurement on a fixed crystal suspended in a streaming solution, (ii) measurement on a rotating disc, (iii) measurement in a fluidized bed, (iv) measurement in an agitated suspension. The comparison involves critical estimation of the supersaturation used in measurements, of shape factors used for data treatment and a correction for the effect of temperature. Conclusions are drawn for the choice of values to be specified when data of crystal growth rate measurements are published.

Measurement of growth rates for single crystals and pressed tablets of CuSO4.5 H2O on a rotating disc

1989 ◽  
Vol 54 (11) ◽  
pp. 2951-2961 ◽  
Author(s):  
Miloslav Karel ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Single Crystals ◽  
Growth Rates ◽  
Diffusion Coefficients ◽  
Preferred Orientation ◽  
Rotating Disc ◽  
Dissolution Rates ◽  
Rates Of Growth ◽  
Good Agreement

Measured growth and dissolution rates of single crystals and tablets were used to calculate the overall linear rates of growth and dissolution of CuSO4.5 H2O crystals. The growth rate for the tablet is by 20% higher than that calculated for the single crystal. It has been concluded that this difference is due to a preferred orientation of crystal faces on the tablet surface. Calculated diffusion coefficients and thicknesses of the diffusion and hydrodynamic layers in the vicinity of the growing or dissolving crystal are in good agreement with published values.

scholarly journals Accuracy of State-Level Surveillance during Emerging Outbreaks of Respiratory Viruses: A Model-Based Assessment

2021 ◽  
pp. 0272989X2110222
Author(s):  
Yuwen Gu ◽  
Elise DeDoncker ◽  
Richard VanEnk ◽  
Rajib Paul ◽  
Susan Peters ◽  
...  
Keyword(s):  
Growth Rate ◽  
Data Collection ◽  
Disease Progression ◽  
Health Care Providers ◽  
Growth Rates ◽  
State Level ◽  
Future Research ◽  
Care Providers ◽  
State Surveillance ◽  
First Come First Serve

It is long perceived that the more data collection, the more knowledge emerges about the real disease progression. During emergencies like the H1N1 and the severe acute respiratory syndrome coronavirus 2 pandemics, public health surveillance requested increased testing to address the exacerbated demand. However, it is currently unknown how accurately surveillance portrays disease progression through incidence and confirmed case trends. State surveillance, unlike commercial testing, can process specimens based on the upcoming demand (e.g., with testing restrictions). Hence, proper assessment of accuracy may lead to improvements for a robust infrastructure. Using the H1N1 pandemic experience, we developed a simulation that models the true unobserved influenza incidence trend in the State of Michigan, as well as trends observed at different data collection points of the surveillance system. We calculated the growth rate, or speed at which each trend increases during the pandemic growth phase, and we performed statistical experiments to assess the biases (or differences) between growth rates of unobserved and observed trends. We highlight the following results: 1) emergency-driven high-risk perception increases reporting, which leads to reduction of biases in the growth rates; 2) the best predicted growth rates are those estimated from the trend of specimens submitted to the surveillance point that receives reports from a variety of health care providers; and 3) under several criteria to queue specimens for viral subtyping with limited capacity, the best-performing criterion was to queue first-come, first-serve restricted to specimens with higher hospitalization risk. Under this criterion, the lab released capacity to subtype specimens for each day in the trend, which reduced the growth rate bias the most compared to other queuing criteria. Future research should investigate additional restrictions to the queue.

scholarly journals Biological Impact of Photoperiod on Fairy Shrimp (Branchinecta orientalis): Life History and Biochemical Composition

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 695
Author(s):  
Sara Farhadi ◽  
Behrooz Atashbar Kangarloei ◽  
Ahmad Imani ◽  
Kourosh Sarvi Moghanlou
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Protein Content ◽  
Biochemical Composition ◽  
Digestive Enzyme ◽  
Total Body Length ◽  
Constant Darkness ◽  
Fairy Shrimp ◽  
Daily Growth ◽  
Isoleucine Leucine

B. orientalis, fairy shrimp, is often among the most conspicuous invertebrates inhabiting temporary aquatic habitats with a typical variation in environmental conditions. Its life history characteristics and biochemical composition were studied under four different photoperiodic regimes (24L:0D, 0L:24D, 16L:8D, and 12L:12D). The significantly highest cumulative and initial hatching rates (48 h) were obtained at 24L:0D (p < 0.05). Cultivating the larvae under different photoperiods did not significantly affect specific growth rate (SGR) (p > 0.05). However, higher final total body length and daily growth rate were recorded under constant darkness. Higher lipid content was found at 24L:0D to the extent that it was more than two times higher than that at 16L:8D and 12L:12D (p < 0.05). There was also a remarkable increase in body crude protein content at 24L:0D (p < 0.05). Body fatty-acid profiles of the fairy shrimps were also affected by culture condition (p < 0.05). Extension of lighting period resulted in a subtle increase in body contents of arginine, lysine, histidine, isoleucine, leucine, valine, methionine, and phenylalanine, especially in the group kept under a 16L:8D regime. The highest and lowest digestive enzyme activity was observed at 0L:24D and 24L:0D, respectively (p < 0.05). In contrast, the highest and lowest soluble protein content was recorded at 24L:0D and 0L:24D, respectively (p < 0.05). Similarly, antioxidant status was significantly higher at 0L:24D (p < 0.05). In conclusion, a 16L:8D light–dark cycle might be an optimal condition in terms of growth performance and physio-biochemical characteristics. These findings could be helpful in optimizing the rearing conditions for upscaling B. orientalis production.

scholarly journals StalGrowth—A Program to Estimate Speleothem Growth Rates and Seasonal Growth Variations

Geosciences ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 187
Author(s):  
Rolf Vieten ◽  
Francisco Hernandez
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Environmental Parameters ◽  
Ion Concentration ◽  
Radiometric Dating ◽  
Seasonal Growth ◽  
Climate Signal ◽  
Show Evidence ◽  
Cave Monitoring ◽  
Calcium Ion Concentration

Speleothems are one of the few archives which allow us to reconstruct the terrestrial paleoclimate and help us to understand the important climate dynamics in inhabited regions of our planet. Their time of growth can be precisely dated by radiometric techniques, but unfortunately seasonal radiometric dating resolution is so far not feasible. Numerous cave environmental monitoring studies show evidence for significant seasonal variations in parameters influencing carbonate deposition (calcium-ion concentration, cave air pCO2, drip rate and temperature). Variations in speleothem deposition rates need to be known in order to correctly decipher the climate signal stored in the speleothem archive. StalGrowth is the first software to quantify growth rates based on cave monitoring results, detect growth seasonality and estimate the seasonal growth bias. It quickly plots the predicted speleothem growth rate together with the influencing cave environmental parameters to identify which parameter(s) cause changes in speleothem growth rate, and it can also identify periods of no growth. This new program has been applied to multiannual cave monitoring studies in Austria, Gibraltar, Puerto Rico and Texas, and it has identified two cases of seasonal varying speleothem growth.

scholarly journals Effect of Light Intensity and Quality on Growth Rate and Composition of Chlorella vulgaris

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 31 ◽  
Author(s):  
Maria N. Metsoviti ◽  
George Papapolymerou ◽  
Ioannis T. Karapanagiotidis ◽  
Nikolaos Katsoulas
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Chlorella Vulgaris ◽  
Lipid Content ◽  
Growth Rates ◽  
Solar Irradiance ◽  
White Led ◽  
Microalgal Biomass ◽  
Nm Range ◽  
Effect Of Light

In this research, the effect of solar irradiance on Chlorella vulgaris cultivated in open bioreactors under greenhouse conditions was investigated, as well as of ratio of light intensity in the 420–520 nm range to light in the 580–680 nm range (I420–520/I580–680) and of artificial irradiation provided by red and white LED lamps in a closed flat plate laboratory bioreactor on the growth rate and composition. The increase in solar irradiance led to faster growth rates (μexp) of C. vulgaris under both environmental conditions studied in the greenhouse (in June up to 0.33 d−1 and in September up to 0.29 d−1) and higher lipid content in microalgal biomass (in June up to 25.6% and in September up to 24.7%). In the experiments conducted in the closed bioreactor, as the ratio I420–520/I580–680 increased, the specific growth rate and the biomass, protein and lipid productivities increased as well. Additionally, the increase in light intensity with red and white LED lamps resulted in faster growth rates (the μexp increased up to 0.36 d−1) and higher lipid content (up to 22.2%), while the protein, fiber, ash and moisture content remained relatively constant. Overall, the trend in biomass, lipid, and protein productivities as a function of light intensity was similar in the two systems (greenhouse and bioreactor).

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