A critical study of the failure of a long-term calcium and phosphorus balance experiment with laying hens

1960 ◽  
Vol 54 (1) ◽  
pp. 131-139 ◽  
Author(s):  
N. K. Jenkins ◽  
C. Tyler
Keyword(s):  
Laying Hens ◽  
Systematic Errors ◽  
Critical Study ◽  
Short Term ◽  
Phosphorus Balance ◽  
Long Term Experiments ◽  
Calcium And Phosphorus

A long-term calcium and phosphorus balance experiment with laying hens is described.The cumulative balances of calcium and phosphorus over a whole year were seen to be physiologically impossible.Results from other workers using short term balances could be equally impossible and a similar situation has recently been noted in balance experiments with ruminants.The techniques employed in the experiment were, therefore, investigated in detail.Only systematic errors could be responsible and it was found that the most likely source of such errors was (a) the spilling of food on to the floor or into the water bowl, and (b) failure to collect all the droppings.These errors only become apparent in long-term experiments and are more pronounced when diets containing high levels of calcium and/or phosphorus are fed.

scholarly journals Can Long-Term Experiments Predict Real Field N and P Balance and System Sustainability? Results from Maize, Winter Wheat, and Soybean Trials Using Mineral and Organic Fertilisers

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1472
Author(s):  
Ilaria Piccoli ◽  
Felice Sartori ◽  
Riccardo Polese ◽  
Maurizio Borin ◽  
Antonio Berti
Keyword(s):  
Winter Wheat ◽  
Nutrient Balance ◽  
Environmental Indicators ◽  
Nutrient Loss ◽  
Real Field ◽  
Short Term ◽  
Organic Fertiliser ◽  
Long Term Experiments ◽  
P Balance

Agri-environmental indicators such as nutrient balance may play a key role in soil and water quality monitoring, although short-term experiments might be unable to capture the sustainability of cropping systems. Therefore, the objectives of this study are: (i) to evaluate the reliability of long-term experimental N and P balance estimates to predict real field (RF) (i.e., short-term transitory) conditions; and (ii) to compare the sustainability of short- and long-term experiments. The LTE-based predictions showed that crops are generally over-fertilised in RF conditions, particularly maize. Nutrient balance predictions based on the LTE data tended to be more optimistic than those observed under RF conditions, which are often characterised by lower outputs; in particular, 13, 44, and 47% lower yields were observed for winter wheat, maize, and soybean, respectively, under organic management. The graphical evaluation of N and P use efficiency demonstrated the benefit of adopting crop rotation practices and the risk of nutrient loss when liquid organic fertiliser was applied on a long-term basis. In conclusion, LTE predictions may depend upon specific RF conditions, representing potential N and P use efficiencies that, in RF, may be reduced by crop yield-limiting factors and the specific implemented crop sequence.

The effect of phosphate and potash fertilizers on cut and grazed grassland

1970 ◽  
Vol 74 (2) ◽  
pp. 397-407 ◽  
Author(s):  
J. S. Brockman ◽  
P. G. Shaw ◽  
K. M. Wolton
Keyword(s):  
Short Term ◽  
Long Term Experiments ◽  
K Fertilizer ◽  
P Fertilizer ◽  
Cutting Management ◽  
Experimental Management ◽  
Almost All ◽  
Grazed Swards ◽  
Grazed Grassland

SUMMARYAn experiment was carried out over a 5-year period on a grass/clover sward at North Wyke to compare three methods of experimental management—individually grazed plots, communally grazed plots and cutting with removal of herbage. Responses to phosphate and potash fertilizers under each management were measured.P fertilizer increased grass yields in the first 4 years and decreased clover yields in the last 2. In almost all respects cut and grazed sward responded similarly to P. Fertilizer K had no effect on grass yield but markedly increased clover yield and raised herbage K content. Grazed swards developed a higher herbage K content than cut swards, and K fertilizer increased it more in the fourth and fifth years on the individually grazed than on the communally grazed plots. Thus communal grazing resulted in appreciable transfer of K from plot to plot in animal returns.It is concluded that whilst cutting management may be used for short-term experiments, its use in long-term experiments gives different results from grazing. Communal grazing can lead to the transfer of N and K effects from plot to plot, so that plots must be grazed individually except perhaps where P is the only variable nutrient.

MONOCLONAL ANTIBODY-MEDIATED ENHANCEMENT OF GROWTH HORMONE ACTIVITY IN VIVO

1985 ◽  
Vol 107 (3) ◽  
pp. R9-R12 ◽  
Author(s):  
A. T. Holder ◽  
R. Aston ◽  
M.A. Preece ◽  
J. Ivanyi
Keyword(s):  
Monoclonal Antibody ◽  
Hormone Activity ◽  
Short Term ◽  
Long Term Experiments ◽  
Snell Dwarf ◽  
New Perspective ◽  
Dwarf Mice ◽  
Dose Dependent

ABSTRACT This work demonstrates that complexing hGH with monoclonal antibody EBl (MAB-EBl) can produce a striking potentiation of the somatogenic actions of hGH in vivo in Snell dwarf mice. In short-term experiments significant increases in cartilage metabolism and body weight were noted; these responses were dose-dependent for both MAB-EBl and hGH concentration. Increased growth was also observed in long-term experiments. In marmosets where MAB-EBl cross-reacts with endogenous GH, MAB-EBl alone enhanced the actions of endogenous GH. A new perspective may be necessary to incorporate these results into the current concept of antibody action.

scholarly journals Systematic Errors in Service Speed

1972 ◽  
Vol 25 (2) ◽  
pp. 261-263
Author(s):  
J. M. Irvine
Keyword(s):  
Surface Condition ◽  
Systematic Errors ◽  
Short Term ◽  
Average Speed ◽  
Accurate Knowledge

An accurate knowledge of the service speed of a merchant vessel is becoming increasingly important. Service speed and average speed (the former traditionally implying a long-term average, the latter a short-term average) are both derived by dividing the sum of a number of observed distances by the relevant time elapsed. In this way fluctuations in observed distances arising from random fix errors and the effects of change of draught, weather and variable currents are smoothed. Service speed may be used as a basis for determining log errors, engine efficiencies, hull surface condition, liner schedules and charter party speeds. It is therefore relevant to consider possible systematic errors which may be introduced in the calculation of these speeds.

scholarly journals Long-term field experiment on the impacts of the neonicotinoid dinotefuran and the organophosphate fenitrothion on a honeybee colony

2015 ◽  
Author(s):  
Toshiro Yamada ◽  
Yasuhiro Yamada ◽  
Kazuko Yamada
Keyword(s):  
Field Experiment ◽  
Lethal Dose ◽  
Short Term ◽  
Long Period ◽  
Sugar Syrup ◽  
The World ◽  
Long Term Experiments ◽  
Honeybee Colony ◽  
Term Field

Neonicotinoides are persistent and highly toxic pesticides that have become popular instead of organophosphates, being suspected to be a trigger of massive disappearance of bees that raises concern in the world. The evaluation of the long-term influence for a whole colony in the natural environment is, however, not established yet. In this paper, we conducted a long-term field experiment and found different impacts on honeybee colonies (Apis mellifera) in an apiary between the neonicotinoid dinotefuran and the organophosphate fenitrothion even though whose concentrations in sugar syrup provided for bees were adjusted to have nearly equal short-term effects on a honeybee based on the median lethal dose (LD50) as well as the insecticidal activity to exterminate stinkbugs. The colony with administration of dinotefran (dinotefuran colony) became extinct in 26 days, while the colony with administration of fenitrothion (fenitrothion colony) survived the administration for the same period. Furthermore, the fenitrothion colony succeeded to be alive for more than 293 days after administration, and also succeeded an overwintering, which indicates that colonies exposed to fenitrothion can recover after the exposure. Meanwhile, the dinotefuran colony became extinct even though the intake of dinotefuran was estimated to be comparable with that of fenitrothion in terms of the LD50 of a honeybee. Moreover, the colonies in our previous long-term experiments where dinotefuran with higher concentration were administered only for first few days (Yamada et al., 2012) became extinct in 104 days and 162 days, respectively. From these results, we speculate that colonies exposed to dinotefuran hardly recover from the damage because dinotefuran is much more persistent than fenitrothion and toxic foods stored in cells can affect a colony in a long period.

scholarly journals Serum clinical biochemical markers of Hy-Line W-36 laying hens under the influence of increased stocking densities in cages of multilevel batteries

2021 ◽  
Vol 12 (3) ◽  
pp. 425-429
Author(s):  
Y. V. Osadcha ◽  
M. I. Sakhatsky ◽  
R. O. Kulibaba
Keyword(s):  
Lactate Dehydrogenase ◽  
Chronic Stress ◽  
Aspartate Aminotransferase ◽  
High Performance ◽  
Laying Hens ◽  
Stocking Density ◽  
The Body ◽  
Gamma Glutamyltransferase ◽  
Calcium And Phosphorus

Today, the organism of hens is constantly exposed to numerous technological stressors in the conditions of industrial poultry farming, the least studied of which are long-term, which can cause the development of chronic stress. One of such stressors is the increased stocking density of hens, which is also a way of saving resources in egg poultry and is often used by producers to obtain more eggs per 1 m2 of poultry area. The aim of this study was to examine the effect of overcrowding, as a factor of chronic stress development, on the body of hens of a modern high-performance cross, which is necessary to select the best ways to keep them. Four groups of hens were formed for this purpose, which were kept at different stocking densities, according to European standards, Ukrainian standards and with increasing overcrowding. In this way, the gradually increasing intensity of the technological stressor was modeled. Long-term keeping of laying hens at high stocking density did not affect the content in the serum of total protein, albumin, urea and cholesterol, which were within the physiological norm. It was found that the increase in the stocking density of hens to Ukrainian standards, compared to the European, was accompanied by an increase in the activity of lactate dehydrogenase in the serum of their blood. With an increase in stocking density above European and Ukrainian standards, namely to 25.3 birds/m2, there was an increase in the activity of three enzymes – lactate dehydrogenase, aspartate aminotransferase and gamma-glutamyltransferase. It is proved that further overcompaction of hens to 26.7 birds/m2 is accompanied by an increase in serum glucose, creatinine, as well as a decrease in the ratio of calcium and phosphorus, which was confirmed by an increase in alkaline phosphatase activity. Also, increased activity of aspartate aminotransferase, lactate dehydrogenase and gamma-glutamyltransferase was observed. Thus, the main effects of chronic stress caused by prolonged keeping of hens at high stocking densities are reflected in the biochemical parameters of their serum, namely in the increase of glucose, creatinine, enzyme activity, as well as the violation of the ratio of calcium and phosphorus.

scholarly journals On the Correspondence between Mean Forecast Errors and Climate Errors in CMIP5 Models

2014 ◽  
Vol 27 (4) ◽  
pp. 1781-1798 ◽  
Author(s):  
H.-Y. Ma ◽  
S. Xie ◽  
S. A. Klein ◽  
K. D. Williams ◽  
J. S. Boyle ◽  
...  
Keyword(s):  
Large Scale ◽  
Climate Models ◽  
Systematic Errors ◽  
Cmip5 Models ◽  
Model Intercomparison ◽  
Short Term ◽  
Climate Simulations ◽  
Intercomparison Project ◽  
Short And Long Term

Abstract The present study examines the correspondence between short- and long-term systematic errors in five atmospheric models by comparing the 16 five-day hindcast ensembles from the Transpose Atmospheric Model Intercomparison Project II (Transpose-AMIP II) for July–August 2009 (short term) to the climate simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5) and AMIP for the June–August mean conditions of the years of 1979–2008 (long term). Because the short-term hindcasts were conducted with identical climate models used in the CMIP5/AMIP simulations, one can diagnose over what time scale systematic errors in these climate simulations develop, thus yielding insights into their origin through a seamless modeling approach. The analysis suggests that most systematic errors of precipitation, clouds, and radiation processes in the long-term climate runs are present by day 5 in ensemble average hindcasts in all models. Errors typically saturate after few days of hindcasts with amplitudes comparable to the climate errors, and the impacts of initial conditions on the simulated ensemble mean errors are relatively small. This robust bias correspondence suggests that these systematic errors across different models likely are initiated by model parameterizations since the atmospheric large-scale states remain close to observations in the first 2–3 days. However, biases associated with model physics can have impacts on the large-scale states by day 5, such as zonal winds, 2-m temperature, and sea level pressure, and the analysis further indicates a good correspondence between short- and long-term biases for these large-scale states. Therefore, improving individual model parameterizations in the hindcast mode could lead to the improvement of most climate models in simulating their climate mean state and potentially their future projections.

A modified Munger cell for testing long-term effects of predator-induced stress on prey: an example using Tyrophagus putrescentiae (Acaridae) and its predator Neoseiulus cucumeris (Phytoseiidae)

2019 ◽  
Vol 24 (10) ◽  
pp. 2285-2289
Author(s):  
XIAOYING WEI ◽  
ZHI-QIANG ZHANG
Keyword(s):  
New Method ◽  
Tyrophagus Putrescentiae ◽  
Long Term Effects ◽  
Short Term ◽  
Neoseiulus Cucumeris ◽  
Induced Stress ◽  
Long Term Experiments

Predators can influence prey directly by consuming them, or indirectly by inducing stress to them. In previous studies, the exposure of leaves or containers to predators is short term and the replacement of such predator-exposed units for any long-term experiments is laborious. This study aims to establish a new method to enable continuous predator-induced stress to prey by using a modified Munger cell, with Tyrophagus putrescentiae and its predator predator Neoseiulus cucumeris as an example.

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