scholarly journals THE RATE OF GROWTH OF THE DOMESTIC FOWL

1921 ◽  
Vol 3 (6) ◽  
pp. 765-770 ◽  
Author(s):  
Samuel Brody
Keyword(s):  
Guinea Pig ◽  
Domestic Fowl ◽  
Growth Period ◽  
Rate Of Growth ◽  
Monomolecular Reaction

This paper points out the fact that the growth period of the domestic fowl is analogous to that of the mammal, being composed of three, or perhaps four, cycles; two of these cycles are postembryonic with maxima at about 8 and 18 weeks varying somewhat with the breed and two or at least one, are embryonic with maxima at 11 to 12 and 15 to 16 days of age. Hatching occurs during the first part of the second or third cycle resembling in this respect the guinea pig rather than the mouse. The velocity curves of each of these cycles are similar to and can be represented by the equation of an autocatalytic monomolecular reaction.

scholarly journals THE RATE OF GROWTH OF THE DAIRY COW

1921 ◽  
Vol 3 (5) ◽  
pp. 623-633 ◽  
Author(s):  
Samuel Brody ◽  
Arthur C. Ragsdale
Keyword(s):  
Dairy Cow ◽  
Growth Period ◽  
Holstein Cows ◽  
Rate Of Growth ◽  
Retarding Effect ◽  
Monomolecular Reaction ◽  
Pregnancy And Lactation

The growth period of the Jersey and Holstein cows is made up of at least three cycles, two extrauterine cycles with maxima at about 5 and 20 months of age, and one intrauterine cycle, the maximum of which has not yet been determined. The equation of an autocatalytic monomolecular reaction was found to give very good results when applied to the cycle having its maximum at about 5 months of age. The values obtained from this equation when applied to the cycle having the maximum at about 20 months of age were higher than the observed values probably due to the retarding effect of pregnancy and lactation on growth.

scholarly journals Effects of Subsurface Drip Irrigation on Water Consumption and Yields of Alfalfa under Different Water and Fertilizer Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xuesong Cao ◽  
Yayang Feng ◽  
Heping Li ◽  
Hexiang Zheng ◽  
Jun Wang ◽  
...  
Keyword(s):  
Water Consumption ◽  
Nitrogen Fertilizer ◽  
Drip Irrigation ◽  
Growth Period ◽  
High Water ◽  
Subsurface Drip Irrigation ◽  
Rate Of Growth ◽  
Maximum Water ◽  
Use Efficiency ◽  
Subsurface Drip

A field experiment was conducted for the purpose of examining the effects of different combinations of water and fertilizer applications on the water consumption and yields of alfalfa under subsurface drip irrigation (SDI). The results showed that the jointing and branching stages were the key stages for alfalfa water requirement. The water consumption had varied greatly (from 130 to 170 mm) during the growth period of each alfalfa crop. The water consumption during the whole growth period was approximately 500 mm, and the maximum water consumption intensity was 3.64 mm·d-1. The overall changes in water consumption and yields during the growth period of the alfalfa displayed trends of first increasing and then decreasing. The sensitivities of the yields to water changes were much higher than that of fertilizer. The water use efficiency (WUE) of the alfalfa was determined to range from 1.68 to 3.20 kg·m-3, and the rate of growth had ranged from 4.85% to 51.77%. The WUE and rate of growth of the alfalfa indicated the following trend: second crop > third crop > first crop. The results of frequency analysis based on the water-nitrogen-yield regression equation are the following: irrigation amounts of 142~165 mm and nitrogen application of 61~80 kg·hm-2 have a 95% probability of obtaining a hay yield of alfalfa of more than 11903 kg·hm-2. These results suggest that SDI is a promising irrigation method, which can increase the WUE and hay yield of alfalfa under the condition of SDI within an appropriate amount of water and nitrogen fertilizer, and too low or too high water and nitrogen fertilizer will adversely affect the WUE and hay yield of alfalfa.

scholarly journals THE GROWTH AND DURATION OF LIFE OF CELOSIA CRISTATA SEEDLINGS AT DIFFERENT TEMPERATURES

1934 ◽  
Vol 17 (6) ◽  
pp. 763-781 ◽  
Author(s):  
Thomas I. Edwards ◽  
Raymond Pearl ◽  
Sophia A. Gould
Keyword(s):  
Growth Rate ◽  
Maximum Yield ◽  
Total Duration ◽  
Growth Curves ◽  
Growth Period ◽  
Hypocotyl Length ◽  
Rate Of Growth ◽  
Life Duration ◽  
Celosia Cristata ◽  
The Mean

Daily measurements of hypocotyl length were made on Celosia cristata seedlings cultured in darkness under aseptic conditions at six constant temperatures between 14.5° and 40.5°C. At 40.5° roots did not penetrate the agar and only the hypocotyls that were supported by the wall of the test tube could be measured. The growth curves were of the generalized logistic type, but of different degrees of skewness. The degree of symmetry of the growth curves was influenced by temperature. At the lower temperatures the maximal growth rate came relatively late in the grand period of growth; at successively higher temperatures it came progressively earlier. The mean total time rate of growth (millimeter per diem) was found to be a parabolic function of the temperature. The maximum rate of growth was found from the curve to be at 30.48°C. The maximum observed rate of growth, and the maximum yield, were found to be at 30°C. At all temperatures above 14.5° the maximum growth activity fell in the second quarter of the whole growth period. At all temperatures tested other than 30°, and at all parts of the growth cycle, the growth yield as measured by height of hypocotyl at any given equivalent point was less than at 30°. The total duration of life of the seedlings, and the duration of life after the end of the growth period (intermediate period) were inversely proportional to the mean total growth rate. The observations on Celosia cristata seedlings are thus in accord with the "rate of living" theory of life duration. The optimal temperature for life duration is the minimum temperature, within the range of these observations.

Growth and Phosphate Absorption in Lettuce and Cabbage Plants in Dilute Solution Culture

1977 ◽  
Vol 4 (4) ◽  
pp. 505 ◽  
Author(s):  
MG Temple-Smith ◽  
RC Menary
Keyword(s):  
Dry Matter ◽  
Maximum Yield ◽  
Growth Period ◽  
Solution Culture ◽  
Lower Solution ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Phosphate Absorption ◽  
Rate Of Growth ◽  
Total Plant

Growth and phosphate absorption of lettuce and cabbage plants were compared at seven solution phosphate concentrations in the range 0.06-8.0 �M. Phosphate levels were maintained constant throughout the 35-day growth period by the use of large volume (450 litres per 24 plants) continuous- flow solution culture units. Both lettuce and cabbage achieved maximum relative growth rates of approximately 14 g dry matter per 100 g dry matter per day. For cabbage this rate of growth was achieved at a solution phosphate concentration of 0.5 �M. However, to attain the same rate of growth, lettuce required a solution phosphate level at least fourfold greater (between 2.0 and 4.0 �M) . These phosphate concentrations are many times lower than those previously reported for maximum yield of these species. The ability of cabbage to achieve maximum dry matter yield at lower solution phosphate concentrations than that required by lettuce appears to be due to a combination of its greater rate of phosphate absorption per unit of root at low phosphate concentrations, its higher proportion of total plant phosphorus and dry matter contained in the shoot, and its higher phosphate utilization quotient at maximum yield.

scholarly journals Variation in Susceptibility of Guinea-pigs to Diphtheria Toxin

1909 ◽  
Vol 9 (4) ◽  
pp. 399-408 ◽  
Author(s):  
H. J. Sudmersen ◽  
A. T. Glenny
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Diphtheria Toxin ◽  
Rate Of Growth ◽  
Lethal Doses

1. A larger dose of toxin is necessary to kill a guinea-pig of the same weight in summer than in winter.2. The rate of growth of guinea-pigs is more rapid in the summer months.3. The weights of guinea-pigs are least affected by lethal doses in summer.4. For guinea-pigs of the same weight the fatal dose increases with the age.

scholarly journals THE RATE OF OVULATION IN THE DOMESTIC FOWL DURING THE PULLET YEAR

1921 ◽  
Vol 3 (4) ◽  
pp. 431-437 ◽  
Author(s):  
Samuel Brody
Keyword(s):  
Chemical Reaction ◽  
Domestic Fowl ◽  
Autocatalytic Reaction ◽  
Limiting Factor ◽  
Rate Of Growth

The rate of ovulation of the domestic fowl may be expressed by the equation of an autocatalytic chemical reaction. This is not surprising in view of the fact that the rate of growth may also be expressed by such an equation, and that the rate of ovulation is probably an index of the growth of the eggs. This brings the phenomenon of ovulation in the hen under the general subject of growth, and substantiates the generality and the probability of the hypothesis that growth, or at any rate the limiting factor of growth, is an autocatalytic reaction.

Innervation of domestic fowl and guinea-pig ventricles

1966 ◽  
Vol 18 (3) ◽  
pp. 192-193 ◽  
Author(s):  
T. B. Bolton ◽  
C. Raper
Keyword(s):  
Guinea Pig ◽  
Domestic Fowl

scholarly journals THE EFFECTS OF X-RAYS AND BETA RAYS (TRITIUM) ON THE GROWTH OF RICKETTSIA MOOSERI AND RICKETTSIA AKARI IN EMBRYONATE EGGS

1960 ◽  
Vol 111 (6) ◽  
pp. 841-849 ◽  
Author(s):  
Donald Greiff ◽  
E. L. Powers ◽  
Walter E. Kisieleski ◽  
Henry Pinkerton
Keyword(s):  
Growth Period ◽  
The Other ◽  
Control Group ◽  
X Rays ◽  
Partial Inhibition ◽  
Rate Of Growth ◽  
Other Hand

The growth of Rickettsia mooseri was accelerated and quantitatively increased in embryonate eggs containing tritium oxide at levels of 180, 90, and 45 mc./egg during the growth period. The eggs of a group containing 22.5 mc./egg showed only a slight increase in the rate of growth of organisms; the infections in the eggs of a group given 11.2 mc./egg did not differ significantly from those of the control group. On the other hand, growth of R. akari was inhibited in embryonate eggs containing tritium oxide at levels of 180, 90, and 45 mc./egg, and partially inhibited in groups containing 22.5 and 11.2 mc./egg. The patterns of growth of R. mooseri and of R. akari exposed to tritium oxide for 6 hours prior to inoculation into embryonate eggs did not differ significantly from that of the control group. Single and divided doses of x-rays to the host resulted in partial inhibition of the growth of R. akari.

scholarly journals Inheritance of Rate of Growth in Domestic Fowl

1934 ◽  
Vol 13 (6) ◽  
pp. 348-352 ◽  
Author(s):  
V.S. Asmundson ◽  
I. Michael Lerner
Keyword(s):  
Domestic Fowl ◽  
Rate Of Growth
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