scholarly journals Arthropod prey vary among orders in their nutrient and exoskeleton content

Author(s):  
Jacob Reeves ◽  
Samuel Fuhlendorf ◽  
Craig Davis ◽  
Shawn Wilder

Insectivores gain macronutrients and elements from consuming arthropod prey, but must also deal with indigestible components (i.e., exoskeleton) of prey. For example, avian chicks (e.g. northern bobwhites; Colinus virginianus) have limited gut space, and ingesting prey with relatively higher proportions of indigestible components may impact assimilation efficiency, growth, and survival. The ability of insectivores to choose higher quality prey would depend on prey taxa varying consistently in nutritional content. We tested if there were consistent differences among taxonomic orders of arthropod prey in their macronutrient (protein and lipid), elemental (C and N), and exoskeleton content. We used northern bobwhite chicks as our focal insectivore and focused on their potential prey as a case study. We also tested the influence of indigestible exoskeleton on the measurement of macronutrient content and the ability of elemental content to predict macronutrients. We found large and consistent variation in macronutrient and elemental content within and between arthropod orders. Some orders had consistently high protein content and low exoskeleton content (i.e., Araneae) and are likely higher quality prey for insectivores. Abundant orders common in the diets of insectivores, like Hymenoptera and Coleoptera, had high exoskeleton content and low protein content. We also found support for the ability of elements to predict macronutrients, and found that metabolizable (i.e. exoskeleton removed) elemental content better predicted macronutrient content. A better understanding of arthropod nutrient content is critical for elucidating the role of spatial and temporal variation in prey communities in shaping the growth and survival of insectivores.

1992 ◽  
Vol 55 (2) ◽  
pp. 227-232 ◽  
Author(s):  
M. M. V. Bradford ◽  
R. M. Gous

AbstractTwo experiments were designed to test the hypothesis that young growing pigs between 7 and 25 kg live weight are capable of selecting a diet which closely matches their changing requirement for amino acids, when offered a choke between two balanced foods differing only in their protein content. In the first experiment, three single-food treatments (8·6,11·7 and 17·4 g lysine per kg food) and one choice-feeding treatment (8·6 v. 17·4 g lysine per kg food), were used. In the second experiment, three foods of similar nutrient composition (approx. 14·7 g lysine per kg food) were formulated using different ingredients (fish meal, soya-bean oilcake meal and a combination of sunflower-, cottonseed- and groundnut-oilcake meals). These were fed either alone or as a choice with each other or with a low protein food (8·3 g lysine per kg food) to test whether palatability or anti-nutritional factors would override the selection based on protein alone. In both experiments, 10 pigs were housed per pen, with males and females being penned separately. One food bin with a central partition was supplied per pen, and an initial 6-day training period was used, in which pigs experienced each of the two foods on offer, separately, at daily intervals. All pigs were weighed weekly, as was the amount of food consumed in each pen. The conclusions reached were that growing pigs are able to differentiate successfully between two foods on the basis of their amino acid contents, and of changing the selected diet to match their changing requirement for dietary amino acids. However, one of the foods on offer appeared to contain either anti-nutritive factors or unpalatable components, and whereas the piglets performed as well on this as on the other foods of similar nutrient content when these foods were offered as the sole source of food, they actively selected against this food when it was offered as a choice, even if this meant their growing at a significantly slower rate than that of which they were capable.


2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Katalin Hubai ◽  
Nora Kováts ◽  
Gábor Teke

AbstractAtmospheric particulate matter (PM) is one of the major environmental concerns in Europe. A wide range of studies has proved the ecotoxic potential of atmospheric particles. PM exerts chemical stress on vegetation by its potentially toxic constituents; however, relatively few studies are available on assessing phytotoxic effects under laboratory conditions. In our study, aqueous extract of particulate matter was prepared and used for treatment. Experiment was following the procedure defined by the No. 227 OECD Guideline for the Testing of Chemicals: Terrestrial Plant Test. Tomato (Lycopersicon esculentum Mill.) plants were used; elucidated toxicity was assessed based on morphological and biochemical endpoints such as biomass, chlorophyll-a and chlorophyll-b, carotenoids, and protein content. Biomass reduction and protein content showed a clear dose–effect relationship; the biomass decreased in comparison with the control (100%) in all test groups (TG) at a steady rate (TG1: 87.73%; TG2: 71.77%; TG3: 67.01%; TG4: 63.63%). The tendency in protein concentrations compared to the control was TG1: 113.61%; TG2: 148.21% TG3: 160.52%; TG4: 157.31%. However, pigments showed a ‘Janus-faced’ effect: nutrient content of the sample caused slight increase at lower doses; actual toxicity became apparent only at higher doses (chlorophyll-a concentration decrease was 84.47% in TG4, chlorophyll-b was 77.17%, and finally, carotene showed 83.60% decrease in TG4).


1914 ◽  
Vol 20 (4) ◽  
pp. 334-345 ◽  
Author(s):  
Albert A. Epstein

A comparison of the results obtained in the analysis of the different effusions shows that they vary, (1) according to location, and (2) according to the disease in which they are produced. Thus the subcutaneous effusions are totally different in their composition from the abdominal or pleuritic fluids; and again the abdominal fluid of nephritic origin is different from those of cardiac or other origin. The cutaneous effusions are characterized by a very low protein content and a small amount of incoagulable nitrogen. Of the protein present in these fluids, the globulin constitutes the greater portion. In the mixed cardionephritic fluids the ratio of globulin to albumin is lower than that in normal blood serum; but when compared with the blood sera of cardionephritic cases there appears to be a certain parallelism. The chloride content of these fluids is considerably above that found in normal blood serum, but is comparable with those of corresponding cases. The effusions occurring in serous cavities differ from the cutaneous ones by their higher protein content. The highest values are attained in the pleural fluids, in which the protein present is almost the same as that in normal blood serum. The incoagulable nitrogen in these fluids is uniformly low. The chlorides vary in amount according to the nature of the case. In the effusions of inflammatory origin the values are lower than those found in the blood. In the pleural fluids of other than inflammatory origin the chloride content is either the same or higher than that of blood serum. The globulin-albumin ratio in all of these fluids except one (table III, fluid 61) is higher than that of normal blood serum. Otherwise the highest value is presented by a pleural fluid from a case of nephritis (table III, fluid 205) and the lowest by an empyema fluid (table III, fluid 30). The latter case is of especial interest because of the theory, first propounded by Schmidt, that the leucocytes in the purulent fluid are largely responsible for high globulin content. The abdominal fluids in general are less rich in protein than the pleural effusions. Those of cardiac origin give the highest protein values, but the globulin-albumin ratios are lower than in the pleural fluids or in the blood sera of corresponding cases. Only in two fluids does the globulin reach a percentage of 62 and 52.2. In both these cases the chloride content is also high. The incoagulable nitrogen in all of them is rather low. In one fluid of purely nephritic origin the protein content is low and all of it is globulin. This is suggestive, when compared with the values obtained in the analysis of the blood sera from nephritic cases. The results obtained in the analysis of abdominal fluids from cardionephritic cases approach very closely those obtained in purely cardiac cases.


1954 ◽  
Vol 44 (2) ◽  
pp. 140-151 ◽  
Author(s):  
F. E. Moon

1. Examination of the composition of hay grown in the east of Scotland during the 4-year period 1948–51 has confirmed earlier work indicating the low protein content of this material. In addition, the digestibility of the protein was found to be low, particularly in the case of the seeds-hays, most of which contained insufficient digestible protein to balance the starch equivalent in meeting the maintenance requirements of cattle.2. In nutritive value the seeds -hays were markedly inferior to samples from England and Wales examined by other workers, but very similar to mature ryegrass hay grown in Northern Ireland. The meadow hays examined were of similar starch equivalent but somewhat richer in protein, and this was associated with a higher digestibility of the protein; in consequence the ratio between digestible protein and starch equivalent was more nearly balanced for the maintenance feeding of cattle.3. Applications of sodium nitrate or ‘Nitrochalk’ about 10–20 days before mowing produced very variable responses in the unusually dry season of 1949, but in other years significant increases in protein content were almost invariably obtained. Low protein seeds-hays of the type commonly found in the Lothians were more responsive to this fertilizer treatment than timothy meadow hay, and while increases in protein content of 20–30% were commonly obtained, when relatively heavy dressings of fertilizer (3 cwt. or more per acre) were used, increases in the region of 50% were sometimes recorded. In most years treatment about 10 days before mowing was fully effective in improving the protein content of the hay. Earlier treatment may be preferable in a very dry season, but in more normal years this may increase the yield of the hay and so diminish the effect on protein percentage.


2000 ◽  
Vol 80 (4) ◽  
pp. 633-642 ◽  
Author(s):  
Palle V. Rasmussen ◽  
Christian F. Børsting

The effect of different and shifting dietary protein levels on hair growth and the resulting pelt quality in mink was studied. Two groups of pastel female mink were fed either 59% (high protein, HP) or 40% (low protein, LP) of metabolisable energy (ME) from protein during pregnancy and lactation. Shortly after weaning, kits from females fed the LP diet were put on a new LP diet (21% protein of ME). Kits from females fed HP were randomly distributed to four experimental groups fed a new HP diet (34% protein of ME) and three of these groups were shifted to diets with 21% protein at different times during June until September. Skin biopsies were taken at 4, 6, 23 and, 29 wk of age. Histological techniques and computer-assisted light microscopy were used to determine the ratio of activity (ROA) of underfur and guard hairs, respectively, defined as the number of growing hairs as a percentage of the total number of hairs. The hair fibre length and thickness were determined by morphometric methods and correlated with fur properties of dried pelts judged by sensory methods. It was documented that 40% of ME from protein during pregnancy and lactation was sufficient for mink kits to express their genetic capacity to produce hair follicles. In males, a reduced protein level from the age of 15 wk or 22 wk until pelting disturbed moulting, indicated by a low ROA of underfur hairs at 23 wk, and consequently reduced the growth and development of the winter coat. A constantly low protein level from conception until the age of 29 wk did not disturb moulting, but led to a reduction of primeness and especially of the underfur length and fibre thickness of the winter coat. A low protein level from the age of 9 wk only reduced the thickness of the underfur fibres. Hair growth, final fur volume, and general quality of the winter coat of males were influenced negatively and to the same degree in all groups fed the LP diet in part of the growth period. The number of underfur hairs per area (hair density) of the winter coat was not influenced by the dietary treatment meaning that the protein content of 21% of ME in the LP diet was high enough for the mink to express its genetic capacity to develop hair follicles. However, this low protein content led to a reduction of hair fibre length and hair fibre thickness of the underfur. Overall, this study demonstrated that hair growth and hair properties in pelts are very dependent on the dietary protein supply in the period from 22 wk of age until pelting, irrespective of the supply in the preceding periods. Key words: Fur properties, hair fibres, nutrition, pelage, protein requirement


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 482
Author(s):  
Ama Frempomaa Oduro ◽  
Firibu Kwesi Saalia ◽  
Maame Yaakwaah Blay Adjei

Limitations of plant-based dairy alternatives as sustainable foods are their relatively low protein content and low sensory appeal. In this study, we used a consumer-led product development approach to improve the sensory appeal of existing prototypes of 3-blend dairy alternatives produced from melon seeds, peanuts and coconut. We used Relative Preference Mapping (RPM) and consumer acceptance testing using the 9-point hedonic scale to respectively identify innovative flavours and deduce the effect of ingredient components on consumer sensory appeal. Mixture design was used as the formulation tool to obtain optimized prototypes of the 3-blend dairy alternatives. Proximate analysis of the new prototypes, instrumental color assessment and consumer testing provided a basis to select a sustainable 3-blend dairy alternative. This prototype had a relatively high protein content (2.16%), was considered innovative by target consumers and also had a moderate liking score (6.55 ± 1.88) on the 9-point hedonic scale. Prototypes with higher protein content had low sensory appeal and were not considered innovative. Other prototypes with innovative sensory appeal had low protein content. By combining different plant raw materials and utilizing different sensory testing methods, we were able to design sustainable plant-based dairy alternatives which can be further optimized.


2015 ◽  
Vol 44 (2) ◽  
pp. 113-119
Author(s):  
MR Alam ◽  
MM Haque ◽  
KR Sumi ◽  
MM Ali

An experiment was conducted to evaluate the effects of Pangasius pond sediment on the nutrient uptake by para-grass (Brachiaria mutica) during the period from March to October, 2011 in a Pangasius farm, Dhanikhola, Trishal, Mymensingh. Initially soil chemistry of Pangasius pond sediment and para-grass producing virgin soil was analyzed at the laboratory. The fodder was cultivated at various level of inorganic fertilizer with Pangasius pond sediment having three replications in each treatment. The size of each replication was 25 m2 (5m×5m). The fodder was harvested at the pre-flowering stage (45 days after transplantation). After first cutting, experimental plot was irrigated, and again after 45 days of first cutting second cutting was done. After proper collection and preparation the para-grass samples and rice straw, their proximate composition analysis was done. The nutrient content of para-grass was also compared with rice-straw being used as dairy feed. The analytical results indicated that the nutrients content of Pangasius pond sediment was higher than the virgin soil which was the stimulating factor for para-grass growth and production. The basic nutrients such as crude lipid and protein content of para-grass were found increasing from first to second sampling. However, crude lipid and protein of para-grass at second sampling was found much higher than those of rice straw. Application of Pangasius pond sediment as alternative source of fertilizer enriched nutrient content of para-grass much higher than those of rice straw. Therefore, it could be argued that higher level of lipid and protein content of para-grass is the stimulating factor to dairy cattle production under integrated aquaculture–fodder grass production using Pangasius pond sediment.Bang. J. Anim. Sci. 2015. 44(2): 113-119


1963 ◽  
Vol 117 (1) ◽  
pp. 105-125 ◽  
Author(s):  
Manuel E. Kaplan ◽  
James H. Jandl

Studies were undertaken in man and in the rat comparing the effects of rheumatoid factors and immune antiglobulins on red cells sensitized with incomplete antibodies. The interaction of immune antiglobulins with sensitized red cells produced (a) agglutination in vitro and (b) an accelerated sequestration of the sensitized cells in vivo. In contrast, rheumatoid macroglobulins, although capable of agglutinating Rh-sensitized red cells in vitro, did not modify their destruction in vivo. The failure of rheumatoid factors to function as antiglobulins in vivo appears to reflect their non-reactivity with sensitized cells in whole serum. It is suggested: (a) that the native (7S) gamma globulins of plasma competitively inhibit rheumatoid factors from reacting with fixed antibody in the blood stream; (b) that if these macroglobulins do indeed have pathogenetic activity, this may be limited to body fluids of low protein content.


2006 ◽  
Vol 6 (1) ◽  
pp. 47-59
Author(s):  
Nancy Montilla ◽  
◽  
Lolito Bestil ◽  
Sulpecio Bantugan ◽  

A feeding trial with broilers was conducted to evaluate the effects of amino acids (lysine and methionine) supplementation of diets low in protein content on the voluntary intake, feed conversion efficiency, broiler performance, and cost and return of broiler production. Results showed cumulative voluntary feed intake was not significantly affected by lowering the protein content of the diet. Cumulative weight gain of broilers was lower with diet when supplemented iwht lysine and methionine to meet requirements. Birds fed with diets low in protein has less efficient feed converstion, but became comparable with those receiveing diets high in protein when supplemented with amino acids. Feed cost per kilogram broiler produced was not significantly affected by diets used in the study, although the low-protien diet with amino acid supplement had the lowest values. In terms of return above feed and chick cost, broilers fed with high-protein diet had the greatest value, but not significantly different from birds fed with low-protien diet with amino acid supplementation which gave about P10 per bird higher returns than those fed low-protein diet without amino acid supplementation.


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