Ingestion rate and body size in phagotrophic organisms

1990 ◽  
Vol 68 (2) ◽  
pp. 313-317 ◽  
Author(s):  
Gerard M. Capriulo ◽  
David Lints ◽  
Martin Lewinter

A general functional relationship between body weight (10−11 to 108 g) and ingestion rate has been found to exist throughout the protistan and metazoan kingdoms. Results, based on a mathematical interpretation of standardized, quantitative data, indicate that ingestion rate is a log–log linear function (i.e., power function) of body weight (I = a W0.829 for cold-blooded forms and I = a W0.778 for warm-blooded forms, where I = ingestion rate and W = body weight). The slopes of the cold-blooded and warm-blooded regression lines are not significantly different from each other (i.e., they are parallel). This allows one to use the difference between the respective curves to estimate the weight-specific cost of warm-bloodedness. Such an analysis of the data indicates that a warm-blooded organism must ingest about ten times more food per unit body weight than cold-blooded forms. This functional relationship may be a manifestation of the physiological constraints placed on organisms by surface area to volume ratio phenomena, related to absorptive surfaces, mouth areas, and body volumes. The present analysis suggests that flexibility in functional design is limited by physical phenomena which affect phenotypic plasticity.

1969 ◽  
Vol 20 (3) ◽  
pp. 561 ◽  
Author(s):  
LR Piper ◽  
CHS Dolling

An experiment is described in which ewes from a flock selected for a number of years for high clean wool weight per head (S) are compared with ewes from a random control flock (C) under ad libitum feeding of three diets differing in crude protein content but not in gross energy. Differences between the S and C groups were significant for clean wool weight (W), efficiency of conversion of gross energy to wool (W/I), fibre number per unit area of skin (N), and mean body weight (B), the S group having higher values for W, W/I, and N but being lighter in B. Differences between the means of ewes fed on the high and medium protein diets (H and M groups) and the means of those fed on the low protein diet (L group) were highly significant for Wand each of its physical and physiological components. The H and M groups had higher values for W, W/I, B, intake per unit body weight (I/B), fibre cross-sectional area (A), staple length (L), and smooth body surface area (S) but lower values for N. The mechanisms of these differences are discussed in relation to other published work. Differences between ewes fed on the H and M diets were significant for Wand W/I, the H groups having the higher value in each case. These responses are contrasted with those reported by other workers and the possible mechanisms are outlined. When differences between the S and C groups on the H and M diets were averaged and contrasted with the differences between them on the L diet, there were significant group x diet interactions in W and W/I and appreciable but not significant interactions in N, A, and L. Taking the value for the C group as 100 in each case, the values for the S group on the L, M, and H diets respectively were: W, 97, 125, 129;W/I, 92,129,132; N,129,110,111; A, 74,114,110; L, 92,109,110. The possible mechanisms for these changes in the differences between the S and C groups are discussed. The group x diet interaction was not significant for any character when the difference between S and C groups on the H diet was contrasted with the difference between them on the M diet, though there were slight increases in the differences in Wand W/I on the H diet.


1957 ◽  
Vol 48 (2) ◽  
pp. 317-322 ◽  
Author(s):  
C. Potter ◽  
E. M. Gillham

SummaryBy means of a laboratory spraying technique, ten comparisons were made of the resistance to rotenone of samples of adult apterous viviparous parthenogenetic females of the Pea Aphid, Acyrthosiphon pisum (Harris), reared on broad bean and on clover, respectively. In nine of the tests, the Aphids from clover were more resistant than those from broad bean, the ratios ranging from 1·1 to 2·5. These differences were not all significant. In the remaining test the Aphids. from broan bean showed a very small increase in resistance over the Aphids from clover which was not significant.The Aphids from the clover were generally smaller than those from broad bean. Figures are given to show that while the total amount of poison retained by the larger individuals from broad bean was more than that retained by the smaller individuals from clover, the amount of poison retained per unit body weight was greater with the smaller individuals. It appears, therefore, that while the results obtained might be due, at least partially, to the greater total weight of poison retained by the larger individuals from broad bean, the difference in resistance between the insects from broad bean and clover, respectively, might be even greater if the poison were applied on the basis of equal weight of poison per unit of body weight. Since the difference in resistance between the Aphids from the two host-plants did not appear to depend primarily on difference in size, the assumption might be made that it is due to difference in nutrition. It was found that Aphids reared on clover had a significantly higher proportion of dry matter in their composition than those reared on broad bean, which may be taken as evidence that differences due to nutrition are being produced. These may lead to differences in resistance.


1960 ◽  
Vol 11 (1) ◽  
pp. 75 ◽  
Author(s):  
M Wodzicka

The monthly wool growth of three groups of rams was studied at Beltsville, Maryland. Group I received natural daylight (at 38° 53' N.) and was shorn monthly. Group II had a 7:17 hours of daylight to hours of darkness rhythm and was shorn every 6 months, once in winter and once in summer. Group III received natural daylight and was likewise shorn every 6 months. The rams of all groups produced more wool in summer than in winter. This difference was significant (P<0.001). The mean body weight and food intake were both greater in the winter months, which indicated that the seasonal rhythm of wool growth was not a consequence of poorer feeding in winter. The rams which were shorn monthly (group I) grew considerably more wool than the other two groups, but the difference was not statistically significant. The short-day treatment of group II did not increase the annual wool production nor decrease the seasonal rhythm of wool growth. The balance of evidence from this and other experiments indicates that temperature rather than light controls the seasonal rhythm of wool growth.


2021 ◽  
Author(s):  
Mahyar Pourghasemi ◽  
Nima Fathi

Abstract 3-D numerical simulations are performed to investigate liquid sodium (Na) flow and the heat transfer within miniature heat sinks with different geometries and hydraulic diameters of less than 5 mm. Two different straight small-scale heat sinks with rectangular and triangular cross-sections are studied in the laminar flow with the Reynolds number up to 1900. The local and average Nusselt numbers are obtained and compared against eachother. At the same surface area to volume ratio, rectangular minichannel heat sink leads to almost 280% higher convective heat transfer rate in comparison with triangular heat sink. It is observed that the difference between thermal efficiencies of rectangular and triangular minichannel heat sinks was independent of flow Reynolds number.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Enerst C. Ohanu ◽  
Paul C. Inyang-Etoh

Amebiasis caused by <em>Entamoeba histolytica</em> is a major public health problem in tropical and subtropical countries. Treatment failure with specific chemotherapy has been reported suggesting the possibility of drug resistance. This study investigated the anti-amoebic effects of four plant extracts on cecal amebiasis in rats. The cecal amebiasis was induced by the injection of 3.0×105 troph/mL of <em>E. histolytica</em> parasite directly into the rat’s caecum. A total of 137 rats were used for these studies; five rats in each group for both positive and negative control, 15 rats in each group to test the four plant extracts and metronidazole. The infected rats were treated for cecal amebiasis using each of the four plant extracts at graded doses of 100 mg/kg, 200 mg/kg and 400 mg/kg and with metronidzole at a dose of 62.5 mg/kg,100 mg/kg and 125 mg/kg for five consecutive days. The efficacy of the four plant extracts were evaluated based on Neal’s, 1951 method. The plant extracts of Garlic, <em>Guava</em>, Pawpaw and Pumpkin at 400 mg/kg and 200 mg/kg body-weight gave a cure rate of 80%, 100%, 60%, 40% and 40%, 80%, 40%, 0%, respectively. The mean parasite count in the cecal contents of the treated rats at a dose 400 mg/kg were 18.5±1.6, 0.0±0.0, 33.3±1.8 and 49.5±4.0, respectively. The difference was statistically significant (P&lt;0.05). This study has revealed that Guava at a high dosing level (400 mg/kg body weight) is as good as the standard drug in reducing the both parasite load (probably with limited side effect).


2020 ◽  
Vol 21 (7) ◽  
Author(s):  
Edy Riwidiharso ◽  
Darsono Darsono ◽  
Endang ariyani Setyowati ◽  
Hery Pratiknyo ◽  
EMING SUDIANA ◽  
...  

Abstract. Riwidiharso E, Darsono, Setyowati EA, Pratiknyo H, Sudiana E, Santoso S, Yani E, Widhiono I. 2020. Prevalence and diversity of ectoparasites in scavenging chickens (Gallus domesticus) and their association to body weight. Biodiversitas 21: 3163-3169. Domestic chickens (Gallus domesticus) which are traditionally fed by scavenging on farms predispose them to ectoparasites infestation. In this study, a preliminary survey was conducted on the common ectoparasites on G. domesticus in the rural areas of Banyumas. The purposes of this study were to determine the diversity of ectoparasites, their prevalence, and their relationship to the chickens body weight. This research was conducted by the survey method from December 2019 to April 2020 in five villages around the city of Purwokerto, Banyumas District, Central Java, Indonesia viz., Kedungwuluh, Kedungwringin, Kutasari, Karangsalam, and Karanggintung. Data analysis was conducted by Shannon Wiener and Evenness indexes. Analysis of variance was used to calculate the difference in prevalence among sample locations. Regression correlation analysis was used to determine the relationship between prevalence and chicken body weight. The results showed that there were six ectoparasite species  i.e., Menopon gallinae, Menacanthus cornutus, Lipeurus caponis, Dermanysus gallinae, Megninia ginglymura, and Haemaphysallis sp. parasitizing G. domesticus. The number of ectoparasite individuals among locations was significantly different (F 5.59 < 32.45; p <0.05). The most number of ectoparasite was found in Karangsalam (272 individuals). The most prevalent ectoparasite was M. cornutus (45%), followed by L. caponis (40%), and the lowest was M. synglineura (25%). Ectoparasite prevalence was associated with chicken weight loss (r = 0.98). The prevalence of ectoparasite of domestic chickens farm in the Banyumas Regency is classified as low but has the potential to influence body weight.


2019 ◽  
Vol 23 (2) ◽  
pp. 218-221
Author(s):  
L. V. Yanitskaya ◽  
L. F. Osinskaya ◽  
A. V. Redko

Hyperglycemia of diabetes mellitus leads to the activation of the polyol way of oxidation of glucose with the activation of the enzymes of aldose reductase and sorbitol dehydrogenase and of their coenzymes NADPH and NAD, which triggers the mechanism of formation of sorbitol. The consequences of these changes lead to microangiopathy of the tissues of the kidneys, which may be one of the pathogenetic mechanisms of diabetic nephropathy. In an accessible literature, the role of coenzymes of sorbitol pathway in the development of diabetic nephropathy is not sufficiently defined. The purpose of the study was to study the content of NAD and NADPH coenzymes, their correlation, and their role in the mechanism of kidney damage in diabetes mellitus and to predict the possible correction of these changes with the NAD-nicotinamide derivative. The study was conducted on a model of streptotrozectinic diabetes mellitus (single administration of streptozotocin in a dose of 60 mg per 1 kg of body weight). Four weeks after induction of diabetes, nicotinamide (100 mg per 1 kg body weight) was injected. The level of glucose was determined by the Accu-chek (Roshe Diagnostics, Switzerland) glucose meter. The content of NAD and NADH was determined in the non-protein extracts. The statistical analysis was carried out using the Microsoft Excel statistical analysis program. The difference between the indicators was considered statistically significant (p<0.05). The NAD level was reduced by 31%, the NAD/NADN ratio was 32%. The dependence of the ratio of NADP/NADPN in conditions of hyperglycemia of diabetes mellitus with clinical manifestations of diabetic nephropathy is determined. A decrease in the ratio of NADP/NADPN to 38% in the rat kidney in the cortical layer was detected. The introduction of nicotinamide normalized the reduced content of NAD diabetic rats. These results provide perspectives for further research in which nicotinamide can be used as a renal protector.


2019 ◽  
Vol 19 (2) ◽  
pp. 136-141
Author(s):  
Jakaria Jakaria ◽  
Edwar Edwar ◽  
Mokhamad Fakhrul Ulum ◽  
Rudy Priyanto

ABSTRAK. Tujuan penelitian ini adalah mengevaluasi kinerja pertumbuhan sapi persilangan Belgian Blue (BB) dan sapi Peranakan Ongole (PO) pada turunan pertama (F1). Sapi persilangan (BB dan PO) yang digunakan sebanyak 15 ekor terdiri atas jantan 6 ekor dan betina 9 ekor, selain itu digunakan 8 ekor sapi PO betina yang dipelihara di Balai Embrio Ternak (BET) Cipelang Bogor. Peubah yang diamati adalah bobot lahir (BW), bobot sapih (WW) 205 hari, bobot 1 tahun (YW), pertambahan bobot badan harian dari lahir (GBW) sampai sapih (GWW) dan pertambahan bobot badan harian dari sapih (GWW) sampai umur 1 tahun (GYW). Data dianalisis secara deskriptif dan perbedaan antar sapi silangan (BB-PO) dengan sapi PO dilakukan uji t. Hasil analisis bobot badan dan pertumbuhan menunjukkan bahwa, bobot badan sapi silangan BB dan PO lebih tinggi dibandingkan dengan sapi PO pada WW 205 hari (165,2±21,3 kg dan 115±15,2 kg), YW (365 hari) (240,7±28,1 kg dan 194,9±26,1 kg) dan GBW sampai GWW (0,675±0,097 kg dan 0,441±0,059 kg). BW dan GWW sampai GYW tidak berbeda antara sapi silangan BB-PO dengan PO. Hasil penelitian ini menunjukkan bahwa program cross-breeding sapi BB dengan PO dapat meningkatkan kinerja bobot badan dan pertumbuhan.  (Growth performance evaluation of belgian blue and ongole crossbreed) ABSTRACT. The purpose of this study was to evaluate the growth performance of cross-breeding of Belgian Blue (BB) and Ongole Grade (PO) cattle in the first generation (F1). Crossbred of BB and PO cattle used as many as 15 individuals consisting of 6 males and 9 females, also, 8 individual PO females are used which are kept in the Livestock Embryo Center (BET) Cipelang, Bogor. The observed variables were birth weight (BW), weaning weight (WW) 205 days, 1-year weight (YW) 365 days, daily body weight gain from birth (GBW) to weaning (GWW) and daily body weight gain from weaning (GWW) until the age of 1 year (GYW). Data were analyzed descriptively and the difference between cross-breeding (BB-PO) cattle and PO cattle was analyzed by t-test. The results of body weight and growth analysis showed that crossbred BB and PO cattle were higher than PO cattle at WW 205 days (165.2 ± 21.3 kg and 115 ± 15.2 kg), YW (365 days) (240.7 ± 28.1 kg and 194.9 ± 26.1 kg ) and GBW to GWW (0.675 ± 0.097 kg and 0.441 ± 0.059 kg). BW and GWW to GYW do not differ between crossbred BB-PO and PO cattle. The results of this study indicate that the cross-breeding program for BB cattle with PO cattle breeds can improve the performance of body weight and growth.


Author(s):  
R. S. Oseredchuk ◽  
N. P. Babik ◽  
V. V. Fedorovych ◽  
E. I. Fedorovych ◽  
V. R. Dutka

The data on the dynamics of body weight changes, absolute and average daily gains, frequency rate of increase in body weight, relative growth rate and intensity of body weight growth of Limousine and Volyn Meat breeds heifers. Both studied breeds characterized by different body weight at different age periods. Newborn Limousine breed heifers are weighed 2,7 kg more (P < 0.05) than Volyn Meat breed heifers; at 3 months age the difference was 8.5 kg (P < 0.05) at 6 months – 14.6 kg, at 9 month – 20.8 kg (P < 0.05), at 12 months – 25,6 kg (P < 0.05), at 15–months – 31.9 (P<0,05), and at 18 months – 23.5 kg. Total and average daily gains in animals of both breeds were the highest for a period of 3 to 6 months of age. In the period from birth to 15 months of age preference for average daily gains were in Limousine, however, the difference was statistically significant only for the period of 0 – 3 months and amounted to 63,9 g (P < 0,05). From 15 to 18 months of age Limousine slightly conceded to Volyn Meat breeds on this parameter. In animals of both breeds magnification of body weight increased with age, but over the entire period (from birth to 18 months) this parameter in Volyn Meat heifers was 0.6 times better than Limousine heifers. The coefficients of relative intensity and tension increase of body weight in animals of both breeds were highest in the period from birth to 3 months of age. With age, these indicators declined. Mainly, the advantage was in Volyn meat breed heifers, but the difference was not statistically significant.


1976 ◽  
Vol 33 (12) ◽  
pp. 2836-2840 ◽  
Author(s):  
Arne Bohn ◽  
R. O. McElroy

Arctic cod (Boreogadus saida) were captured by bottom trawl at depths of 120–300 m. Zooplankton were obtained by bottom to surface tows from the Arctic cod habitat. Average concentrations of arsenic (As) and zinc (Zn) were higher in Arctic cod fillets than in livers from the same fish; cadmium (Cd) and iron (Fe) concentrations were higher in livers. The difference between copper (Cu) concentrations in muscle and liver was not significant. As and Zn in whole fish, and As in fillets from seven specimens, were positively correlated to body weight. Cu and Fe in whole fish were negatively correlated to body weight, whereas Cd was not related to body weight. Examination of Arctic cod stomach contents indicated that planktonic copepods were important in the diet. Cd levels were 5–8 times higher in the unsorted copepods than in the Arctic cod, whereas As, Cu, Fe, and Zn were higher in the fish than in the copepods.


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