scholarly journals Seasonal Changes in Reproductive Productivity, Growth Rate, and Food Intake in Mice Exposed to Different Regimes of day Length and Environmental Temperature

1972 ◽  
Vol 25 (3) ◽  
pp. 627 ◽  
Author(s):  
Pamela R Pennycuik
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Constant Temperature ◽  
Productivity Growth ◽  
Seasonal Changes ◽  
Environmental Temperature ◽  
Day Length ◽  
Seasonal Fluctuations

Groups of mice were maintained in three different environments: (1) constant day length and constant temperature; (2) seasonal fluctuations in day length and constant temperature; (3) seasonal fluctuations in day length and seasonal fluctua-tions in temperature.

The effect of supplementary light during winter on the growth, body composition and behaviour of steers and heifers

1997 ◽  
Vol 65 (2) ◽  
pp. 173-181 ◽  
Author(s):  
C. J. C. Phillips ◽  
P. N. Johnson ◽  
T. M. Arab
Keyword(s):  
Growth Rate ◽  
Body Composition ◽  
Food Intake ◽  
Day Treatment ◽  
Day Length ◽  
Fatty Tissue ◽  
Reduced Body ◽  
Entire Experiment ◽  
Female Cattle ◽  
Autumn And Winter

AbstractIn two experiments the growth, body composition and behaviour of steers and heifers kept in a building with natural day length only (average 9·7 h/day, treatment N) were compared with similar groups of animals kept in identical housing with the day length artificially extended to 16 h/day, (treatment L). The effects were recorded for 126 days in steers and 180 days in heifers, with both groups of animals being slaughtered in March when the two experiments ended. There were no effects over the entire experiment on the growth rate or food intake of either steers or heifers. The growth of the steers was reduced in the first 2 weeks after the lights were switched on but they gained more weight to compensate over the next 8 weeks. Over the whole experiment there was no treatment effect on food conversion ratio for either steers or heifers but it was reduced for steers on treatment L over the first 10 weeks. Steers in treatment N produced fatter carcasses than those on treatment L. Ultrasonic scanning of the heifers showed that those on treatment N deposited more fatty tissue between autumn and winter and less between winter and spring compared with those on treatment L.The behaviour of steers on treatment L did not vary over the experiment but steers on treatment N changed their behaviour with season. They slept for more time in winter and less in spring. Over the whole experiment steers on treatment L slept less and spent more time lying ruminating than those on treatment N but the total time spent lying was not affected by treatment. In contrast, the heifers on treatment L lay down for longer than those on treatment N, suggesting that the effect of supplementary light on lying time, which has been observed previously with dairy cows, is confined to female cattle. Heifers on treatment L started mounting each other earlier than heifers on treatment N and, like the steers, they spent less time sleeping It is concluded that extending the photoperiod for cattle in winter reduced body fatness in both steers and heifers and increased the time heifers spend lying down but that there were no major effects on growth rate or food intake.

The effect of daily photoperiod on the wool growth of Merino rams subjected to unrestricted and restricted feeding regimes

1964 ◽  
Vol 4 (13) ◽  
pp. 124 ◽  
Author(s):  
AJ Williams
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Seasonal Changes ◽  
Period Variation ◽  
Day Length ◽  
Growth Responses ◽  
Significant Treatment ◽  
Significant Period ◽  
Wool Growth ◽  
Daily Food

Twelve adult Merino rams were divided into two groups matched for body weight and previous fleece weights. One group was subjected to a reversed and accentuated rhythm of seasonal changes in day length. The second group received normal seasonal changes in day length (latitude 32�s). There was no temperature control for either group. For eighteen months, these rams were fed a constant ration ad lib. Daily food intakes and wool growth from a tattooed mid-side patch were recorded. Although the periodic differences in wool growth were very highly significant (P<0.001), no well defined rhythm of wool growth was expressed. There was a highly significant treatment x period interaction (P<0.001). Examination of daily food intake values revealed very highly significant period interaction ; due to a positive relation between day length and food intake during part of the eighteen months. In each treatment group, 75 per cent of the period variation in wool growth could be accounted for by variations in food intake. During a further period of fifteen months, when all rams received the same quantity of a constant diet, there was a progressive loss of body weight which amounted to 18 per cent of the initial weight in each group. The wool growth responses of the two groups were similar, and there was no significant interaction term. The very highly significant period variation in wool growth was confined largely to the first three months following the decreased intake. It appears that temperature and day length have little direct effort on wool growth of Merino sheep. However, day length may influence wool growth indirectly through its effect on voluntary food intake.

Growth and adaptation to sea water in 'underyearling' sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon subjected to regimes of constant or changing temperature and day length

1978 ◽  
Vol 56 (11) ◽  
pp. 2413-2421 ◽  
Author(s):  
W. C. Clarke ◽  
J. E. Shelbourn ◽  
J. R. Brett
Keyword(s):  
Growth Rate ◽  
Environmental Factors ◽  
Constant Temperature ◽  
Sea Water ◽  
Rate Of Change ◽  
Day Length ◽  
Artificial Photoperiod ◽  
Final Length ◽  
Temperature Controlled ◽  
Rate Of Response

Growth and hypoosmoregulatory ability of 'underyearling' sockeye and coho were studied in relation to the influence of constant as well as changing temperature and day length. Both environmental factors influenced growth and osmoregulatory performance. Temperature controlled the rate of response to photoperiod so that changes in growth rate caused by photoperiod treatments were apparent sooner at higher temperatures than at lower ones. Changing temperatures did not alter the final length or weight achieved in comparison with a constant temperature of the same mean.The sensitivity of the fry to photoperiod varied seasonally. The characteristics of photoperiod which formed the most important cues were direction of change and rate of change of day length.It is concluded that artificial photoperiod treatments are not required to produce 'underyearling' sockeye smolts in spring, provided that water temperatures are sufficient to allow growth to a weight of 3–4 g. However, coho smoltify at a larger size and thus would require a substantially greater thermal input to produce 'underyearling' smolts in spring.

Forming Sources of Long-run Growth: How to Understand Them?

2014 ◽  
pp. 4-20 ◽  
Author(s):  
G. Idrisov ◽  
S. Sinelnikov-Murylev
Keyword(s):  
Economic Growth ◽  
Growth Rate ◽  
Economic Policy ◽  
Business Cycle ◽  
Capital Markets ◽  
Productivity Growth ◽  
Government Spending ◽  
Long Run ◽  
Accelerate Growth ◽  
Budget Institutions

The paper analyzes the inconsequence and problems of Russian economic policy to accelerate economic growth. The authors consider three components of growth rate (potential, Russian business cycle and world business cycle components) and conclude that in order to pursue an effective economic policy to accelerate growth, it has to be addressed to the potential (long-run) growth component. The main ingredients of this policy are government spending restructuring and budget institutions reform, labor and capital markets reforms, productivity growth.

scholarly journals Evolutionary economics: Crisis, transformation and metamorphosis

2021 ◽  
pp. 1-8
Author(s):  
Milan Zeleny
Keyword(s):  
Growth Rate ◽  
Productivity Growth ◽  
Driving Force ◽  
Evolutionary Economics ◽  
Regional Economies ◽  
Economic Evolution ◽  
Economic Sectors ◽  
Advanced Economies ◽  
First Time

Most world economies are undergoing fundamental transformations of economic sectors, shifting their employed workforce through the secular sequence of (1. Agriculture⟶2. Industry⟶3. Services⟶4. Government). The productivity growth rate is the driving force. Most advanced economies have reached the final stages of the sequence. Assorted recessions, crises and stagnations are simply cofluent, accompanying phenomena. Crises might be cyclical, but economic evolution is unidirectional. Traditional economics can hardly distinguish phenomena of crisis from those of the transformation. Because there is no “fifth sector”, some economies are entering the phase of metamorphosis, for the first time in history. Metamorphosis is manifested through deglobalization, relocalization and autonomization of local and regional economies. We are entering the Age of Entrepreneurship.

Exergy Analysis of Thermal Energy Storage With Specific Remarks on the Variation of the Environmental Temperature

1996 ◽  
Vol 118 (2) ◽  
pp. 81-88 ◽  
Author(s):  
G. Bisio
Keyword(s):  
Energy Storage ◽  
Constant Temperature ◽  
Exergy Analysis ◽  
Environmental Temperature ◽  
Variable Temperature ◽  
Thermal Storage ◽  
Exergy Efficiency ◽  
Basic Question ◽  
Storage Devices ◽  
Temperature Environment

Energy storage is a key technology for many purposes and in particular for air conditioning plants and a successful exploitation of solar energy. Thermal storage devices are usually classified as either variable temperature (“sensible heat”) or constant temperature (“latent heat”) devices. For both models a basic question is to determine the efficiency suitably: Only exergy efficiency appears a proper way. The aim of this paper is to examine exergy efficiency in both variable and constant temperature systems. From a general statement of exergy efficiency by the present author, two types of actual definitions are proposed, depending on the fact that the exergy of the fluid leaving the thermal storage during the charge phase can be either totally lost or utilized elsewhere. In addition, specific remarks are made about the exergy of a system in a periodically varying temperature environment.

scholarly journals INDUCTION OF METASTASIS OF FROG CARCINOMA BY INCREASE OF ENVIRONMENTAL TEMPERATURE

1949 ◽  
Vol 89 (3) ◽  
pp. 269-278 ◽  
Author(s):  
Balduin Lucké ◽  
Hans Schlumberger
Keyword(s):  
Tissue Culture ◽  
Elevated Temperature ◽  
Constant Temperature ◽  
Rana Pipiens ◽  
Environmental Temperature ◽  
Kidney Tumors ◽  
Primary Tumors ◽  
Metastatic Dissemination ◽  
Leopard Frogs ◽  
Tumor Bearing

Metastasis of the kidney carcinoma of leopard frogs (Rana pipiens) has been induced by exposing tumor-bearing animals for approximately 50 days to a constant temperature of 28°C. Under these conditions 54 per cent of the frogs developed secondary growths, whereas in groups kept at 18° or at 7° metastatic dissemination was found in only 6 per cent. Moreover, at the elevated temperature the metastases were usually more numerous and more widely disseminated; they were also fairly uniform in size, suggesting that they had developed at nearly the same time. Dissemination of the kidney tumors was influenced by the nutritional state of the frogs, occurring more readily in well nourished than in poorly nourished animals. Periodic Roentgen ray examinations showed that the size of the primary tumors was not significantly or uniformly affected during the course of the experiments. No correlation was found between change in size of the kidney tumors and the incidence of their metastasis. Although the mechanism by which temperature induces metastasis of frog carcinoma cannot as yet be elucidated, previous experiments with this tumor indicate that certain factors at least may be involved: Elevation of temperature has been found to cause more ready detachment of cells of frog carcinoma in tissue culture; to bring about increased velocity of locomotion of the detached cells; to lead more promptly and efficiently to vascularization of transplants; and to effect their greater invasiveness.

A comparison of the effects of infection with Eimeria maxima and dietary restriction on weight gain, plasma metabolites and liver glycogen in the immature fowl, Gallus domesticus

Parasitology ◽  
1982 ◽  
Vol 84 (2) ◽  
pp. 205-213 ◽  
Author(s):  
H. D. Chapman ◽  
D. L. Fernandes ◽  
T. F. Davison
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Uric Acid ◽  
Weight Gain ◽  
Food Intake ◽  
Acute Phase ◽  
Plasma Glucose ◽  
Liver Glycogen ◽  
Plasma Metabolites ◽  
Eimeria Maxima

SUMMARYThe effects of Eimeria maxima or restricted pair-feeding on weight gain, plasma concentrations of protein, glucose, free fatty acids (FFA) and uric acid and liver glycogen were compared in immature fowl. Food intake/kg body weight and weight gain decreased during the acute phase of infection (days 5–7) while weight loss was prolonged for an extra day compared with pair-fed birds. During recovery, food intake/kg body weight of infected birds was greater than that of non-infected controls but there was no evidence for an increase in growth rate compared with controls when body weight was considered. Growth rate of pair-fed birds was greater than that of infected birds during recovery, indicating their better use of ingested food. Liver glycogen and plasma protein concentration were decreased during the acute phase of infection but the concentrations of plasma glucose, free fatty acid (FFA) and uric acid were not affected. In pair-fed birds liver glycogen was depleted, concentrations of plasma glucose and uric acid decreased and FFA increased, and these changes persisted for the remainder of the experiment. The findings are similar to those in birds whose food has been withheld and were probably due to the pattern of food intake imposed by the experimental protocol. It is concluded that the metabolic differences between infected and pair-fed birds are of doubtful significance.

Temperature/light interactions and the effect of seed source on germination of annual ryegrass (Lolium rigidum Gaud.) seeds

1976 ◽  
Vol 27 (6) ◽  
pp. 779 ◽  
Author(s):  
D Gramshaw
Keyword(s):  
Constant Temperature ◽  
Day Length ◽  
Maximum Temperature ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Average Temperature ◽  
Seed Sources ◽  
Alternating Temperature ◽  
Germinating Seeds ◽  
Temperature Optima

Germination of Lolium rigidum seeds, in the light (12 hr day length) and in the dark, was studied at constant and alternating (12/12 hr) temperatures in the range 8–35°C. Seeds had after-ripened for 22 weeks. Different constant temperature optima for germinability were found: 27° in light and 11° in dark. Germinability at alternating temperatures in darkness was determined solely by the minimum temperature of the alternation, and there was no response to thermoperiodicity per se. In contrast, light and alternating temperature appeared to interact to increase germinability, although the highest germinability occurred only when the maximum temperature was close to the optimum constant temperature, i.e. about 27°. Germination in both light and dark was most rapid where either the constant or the average temperature of an alternating regime was between 18 and 29°. Below 18° germination rates decreased markedly, and at 8°, rates were one-third of those at 18°. Seeds germinated more slowly in light than in darkness at all temperatures, but the differences were small relative to the effects of low temperatures.In another study, seeds collected from plants naturalized in eight different localities in the cereal belt of Western Australia and subsequently planted together in two contrasting environments were examined for germinability at 24/12°C in light and dark 18 weeks after harvest. Dark germinability differed between seed sources but not between planting sites, and ranged between 78 and 93%. Exposure of germinating seeds to light substantially alleviated dormancy in seeds from all sources.

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