Relative Nutritive Value Research Articles

Chronic Malnutrition, Breastfeeding, and Ready To Use Supplementary Food in a Guatemalan Maya Town

Ready To Use Therapeutic Food (RUTF) and Ready To Use Supplementary Food (RUSF) have proliferated in recent years to treat acute and chronic malnutrition. Biomedical research has established the efficacy of these products, yet little is known about their actual effectiveness in real world settings. This article reports on an ethnographic study of the acceptance and use of RUSF within households in a rural Maya community in Guatemala (a country with the world's third highest rate of chronic malnutrition). We find a number of surprising obstacles to RUSF effectiveness. There is a strong commitment to breastfeeding (supported by public health messages of local NGOs as well as culturally perceived benefits) that leads to sub-optimal complementary feeding after six months. We also found instances of off-label sharing and confusion over relative nutritional values. We present a framework for maximizing RUSF effectiveness that involves nutritional education, positive peer support, and the framing of the product ...

A faecal index of diet quality that predicts reproductive success in a marsupial folivore

Estimating the nutritional value of a herbivore's diet is difficult because it requires knowing what the animal eats, the relative quality of each component and how these components interact in relation to animal physiology. Current methods are cumbersome and rely on many assumptions that are hard to evaluate. We describe a new method for estimating relative diet quality directly from faeces that avoids the problems inherent in other methods. We combine this method with near infrared reflectance spectroscopy (NIRS) to analyse many samples and thus provide a technique with immense value in ecological studies. The method stems from the correlation between the concentrations of dietary and faecal nitrogen in herbivores eating a tannin-free diet, but a weaker relationship in browsers that ingest substantial amounts of tannins, which form complexes with proteins. These complexes reduce the availability of nitrogen and may increase faecal nitrogen concentrations. Using the tannin-binding compound, polyethylene glycol, we showed that tannin-bound nitrogen is a significant and variable part of faecal nitrogen in wild common brushtail possums (Trichosurus vulpecula). We developed a technique to measure faecal available nitrogen and found that it predicted the reproductive success of female brushtail possums in northern Australia. Faecal available nitrogen combined with NIRS provides a powerful tool for estimating the relative nutritional value of the diets of browsing herbivores in many ecological systems. It is a better indicator of diet quality than other commonly used single-nutrient measures such as faecal nitrogen and foliage analysis paired with observed feeding behaviour.

The effects of season on fat and fatty acids contents of shrimp and prawn species

AbstractThe effects of seasons on the lipid content and fatty acid compositions of five different shrimp and prawn species (green tiger prawn – Penaeus semisulcatus, kuruma prawn – Marsupenaeus japonicus, caramote prawn – Melicertus kerathurus, deepwater pink shrimp – Parapenaeus longirostris, speckled shrimp – Metapenaeus monoceros) were evaluated. Results showed that lipid content ranged from 0.89 to 1.55% in muscle, showing that all species were considered as lean. There were significant differences (p<0.05) in the levels of saturated fatty acids (SFA), monounsaturated fatty acids and polyunsaturated fatty acids (PUFA) in terms of season and species. They were rich in n‐3 fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The highest proportions of EPA were obtained from kuruma prawn (180.9 mg/100 g) in spring and deepwater pink shrimp (173.2 mg/100 g) and caramote prawn (146.3 mg/100 g) in summer. Kuruma prawn had the highest DHA in spring (140.8 mg/100 g) followed by deepwater pink shrimp (132.2 mg/100 g) and caramote prawn (129.6 mg/100 g) in summer. The results also showed that the seasons affected lipid content and the fatty acid composition of shrimp and prawn species.Practical Application: The beneficial effect of seafood consumption on human health has been related to the high content of n‐3 fatty acids, especially EPA (20:5n‐3) and DHA (22:6n‐3). The ratios of n‐6/n‐3, PUFA/SFA and EPA + DHA are considered as useful criteria for comparing relative nutritional and oxidation values of marine oils. In the current study, the influence of seasonality on the lipid content and the fatty acid compositions of shrimp and prawn were investigated in order to find the best source of n‐3 fatty acids during the year.

Importance of protein quality versus quantity in alternative host plants for a leaf-feeding insect

The nutritional value of alternative host plants for leaf-feeding insects such as caterpillars is commonly measured in terms of protein quantity. However, nutritional value might also depend on the quality of the foliar protein [i.e., the composition of essential amino acids (EAAs)]. A lack of comparative work on the EAA compositions of herbivores and their host plants has hampered the testing of this hypothesis. We tested the "protein quality hypothesis" using the tree-feeding caterpillars of Lymantria dispar (gypsy moth) and two taxonomically unrelated host plants, red oak (Quercus rubra) and sugar maple (Acer saccharum). Because L. dispar has higher fitness on oak than on maple, support for the hypothesis would be found if protein were of higher quality from oak than from maple. The whole-body EAA composition of L. dispar larvae was measured to estimate its optimum dietary protein composition, which was compared with the EAA compositions of oak and maple leaves. Contrary to the protein quality hypothesis, the EAA compositions of oak and maple were not significantly different in the spring. The growth-limiting EAAs in both tree species were histidine and methionine. Similar results were observed in the summer, with the exception that the histidine composition of oak was between 10 and 15% greater than in maple leaves. The two main factors that affected the nutritional value of protein from the tree species were the quantities of EAAs, which were consistently higher in oak, and the efficiency of EAA utilization, which decreased from 80% in May to <50% in August. We conclude that the relative nutritional value of red oak and sugar maple for L. dispar is more strongly affected by protein quantity than quality. Surveys of many wild herbaceous species also suggest that leaf-feeding insects would be unlikely to specialize on plants based on protein quality.

Bioefficacy of a mono-component protease in the diets of pigs and poultry: a meta-analysis of effect on ileal amino acid digestibility

SummaryA meta-analysis of the effect of a mono-component bacterial protease (RONOZYME® ProAct) on the apparent ileal digestibility of amino acids in poultry and swine diets was conducted to examine functional patterns, mean effects and variability of response. A total of 25 independently-conducted experiments were included comprising a total of 804 datapoints. The mean response to protease was +3.74% (SE 1.1%, P &lt; 0.001) and this ranged from +5.6% for Thr (SE 1.2%, P &lt; 0.001) to +2.7% for Glu (SE 1.2%, P &lt; 0.05). For the most economically critical amino acids (Lys, Cys, Met and Thr) the mean response was 4.5%. The effect of protease was independent of geography, animal species and diet composition (P &gt; 0.05). However, the inherent digestibility of amino acids in the control diet as a single explanatory term explained around 47% of the variance (P &lt; 0.001) in effect. When the inherent digestibility of amino acids in the control diet was less than 70% protease addition improved amino acid digestibility in 90% of cases with a mean improvement of around 10%. When the inherent digestibility of amino acids in the control diet was more than 90% there was a protease-mediated improvement in digestibility in only 60% of cases with a mean improvement of around 2%. It can be concluded that the inherent digestibility of amino acids in the diet without protease supplementation is the primary explanatory term for the efficacy of this exogenous protease, demonstrating that it is highly effective in improving the digestibility of amino acids across a wide range of feed ingredients. Benchmarking diets or feed ingredients as to their relative nutritional value would enhance the ability of nutritionists to determine the likely return on investment on use of bacterial proteases in their operation.

EFFECT OF COOKING STYLES ON THE LIPID OXIDATION AND FATTY ACID COMPOSITION OF GRASS CARP (CTENOPHARYNYODON IDELLUS) FILLET

ABSTRACT The effects of six cooking styles, including boiling, steaming, microwaving, grilling, pan-frying and deep-frying, on the lipid oxidation and fatty acid composition of grass carp (Ctenopharyngodon idellus) fillets were investigated. All treatments reduced the moisture contents and increased the relative ratio of protein. Compared with raw samples, the proportions of polar lipid fractions of all samples were increased, while free amino acid contents were significantly decreased. Peroxide values decreased during pan-frying and deep-frying, but remained constant in the samples subjected to the other four cooking methods. Microwave baking and grilling increased the p-anisidine values and resulted in higher lipid oxidative extents. Boiling, steaming, microwave baking and grilling did not affect the fatty acid composition. Pan-frying and deep-frying increased the general polyunsaturated fatty acid content and decreased the n–3/n–6 ratio, especially for the deep-frying cooking method. PRACTICAL APPLICATIONS Fish consumption has been linked to health benefits such as reduced risk of coronary heart disease. This is largely attributed to the lipid, cholesterol, fatty acid composition and the polyunsaturated fatty acids present in fish oils. The ω–3 : ω–6 and polyunsaturated fatty acid/saturated fatty acid ratios are considered to be useful criteria for comparing relative nutritional and oxidation values of fish oils. This study was therefore conducted to determine the influence of different cooking styles on the lipid oxidation of grass carp. These features and information are very important to the food health industry because they could be potential guidelines for the clinical, community, foodservice and research dieticians to recommend the proper cooking methods to get better health effects. It is also useful for academic studies on food composition and nutrition.

Modern emu (Dromaius novaehollandiae) butchery, economic utility and analogues for the Australian archaeological record

Australia's largest flightless bird, the emu (Dromaius novaehollandiae), has been an important prey animal for Indigenous people for millennia, especially in arid/semi-arid areas where, along with large kangaroos, they can provide high economic returns from single kills. Understanding modern prey selection, butchering patterns and the relative nutritional value of the different body portions in these animals has important implications for interpreting patterns of species and body part representation in the archaeological record. A butchery study, economic utility assessment, and meat and marrow fatty acid analysis of the Australian emu has established the relative economic importance of different body parts. The results show that the femur/pelvic region yielded the greatest amount of meat, and that the quantity and quality of fats associated with these units makes bone fracturing for marrow extraction superfluous. The results provide new insights into the relative importance of emu in Australian Aboriginal diets, past and present, and establish useful comparative data for studies of the now extinct giant flightless bird Genyornis newtoni.

Carbonate-silicate ratio for soil correction and influence on nutrition, biomass production and quality of palisade grass

Silicates can be used as soil correctives, with the advantage of being a source of silicon, a beneficial element to the grasses. However, high concentrations of silicon in the plant would affect the digestibility of the forage. To evaluate the influence of the substitution of the calcium carbonate by calcium silicate on the nutrition, biomass production and the feed quality of the palisade grass [Urochloa brizantha (C. Hochstetter ex A. Rich.) R. Webster], three greenhouse experiments were conducted in completely randomized designs with four replications. Experimental units (pots) contained a clayey dystrophic Rhodic Haplustox, a sandy clay loam dystrophic Typic Haplustox and a sandy loam dystrophic Typic Haplustox. Each soil received substitution proportions (0, 25, 50, 75 and 100 %) of the carbonate by calcium silicate. The increase in the proportion of calcium silicate elevated the concentrations and accumulations of Si, Ca, Mg, and B, reduced Zn and did not alter P in the shoot of plants. The effects of the treatments on the other nutrients were influenced by the soil type. Inclusion of calcium silicate also increased the relative nutritional value and the digestibility and ingestion of the forage, while the concentration and accumulation of crude protein and the neutral detergent and acid detergent fibers decreased. Biomass production and feed quality of the palisade grass were generally higher with the 50 % calcium silicate treatment.

THE PARADOX OF LIMITED MAIZE STOVER USE IN INDIA'S SMALLHOLDER CROP-LIVESTOCK SYSTEMS

SUMMARYCereal residues are an important feed source for ruminants in smallholder crop-livestock systems in the (sub)tropics. In many areas of India maize is a relatively new cash crop where farmers and development agents alike generally perceive maize stover to have limited utility, in contrast with the intensive feeding of other cereal residues in India and the intensive use of maize stover in sub-Saharan Africa and Latin America. A comparative assessment of maize stover quality (based on a brief review and a feeding trial) indeed confirms its potential as a ruminant feed according to its relative nutritive value. The paper then explores the apparent paradox through a scoping study of maize stover use (based on village surveys) in three contrasting maize-growing districts in India – including both traditional and non-traditional maize producers. The limited maize stover use appears to alleviate seasonal shortages, with tradition and technology helping explain the preferential use of other cereal residues. The paper thereby provides further impetus to India's apparent food-feed paradigm – whereby farmers’ staple food preferences coincide with crop residue feed preferences. The paper argues the case for investing in maize stover R&amp;D in India and thus reigniting earlier feed research in general. Indeed, maize stover use is a relatively neglected area by India's agricultural R&amp;D and merits more attention so as to exploit its potential contribution and alleviate eventual tradeoffs.

Remembering Nutrient Quality of Sugar in Drosophila

Taste is an early stage in food and drink selection for most animals [1, 2]. Detecting sweetness indicates the presence of sugar and possible caloric content. However, sweet taste can be an unreliable predictor of nutrient value because some sugars cannot be metabolized. In addition, discrete sugars are detected by the same sensory neurons in the mammalian [3] and insect [4, 5] gustatory systems, making it difficult for animals to readily distinguish the identity of different sugars using taste alone [6-8]. Here we used an appetitive memory assay in Drosophila [9-11] to investigate the contribution of palatability and relative nutritional value of sugars to memory formation. We show that palatability and nutrient value both contribute to reinforcement of appetitive memory. Nonnutritious sugars formed less robust memory that could be augmented by supplementing with a tasteless but nutritious substance. Nutrient information is conveyed to the brain within minutes of training, when it can be used to guide expression of a sugar-preference memory. Therefore, flies can rapidly learn to discriminate between sugars using a postingestive reward evaluation system, and they preferentially remember nutritious sugars.

LIPID, CHOLESTEROL AND FATTY ACID PROFILE OF SOME COMMERCIALLY IMPORTANT FISH SPECIES FROM SOUTH CASPIAN SEA

The fatty acid, lipid, cholesterol and energy contents in five commercially important fish species from South Caspian Sea (common kilka, Caspian kutum, golden gray mullet, common carp and pike perch) were evaluated. The fatty acid compositions of these five fish species ranged from 28.99 to 41.05% saturated fatty acids, 40.99–56.25% monounsaturated fatty acids and 14.22–23.03% polyunsaturated fatty acids. Among these, those occurring in the highest proportions were palmitic acid (20.42–27.9%), palmitoleic acid (11.09–26.26%), oleic acid (16.1–36.94%), eicosapentaenoic acid (3.22–7.53%) and docosahexaenoic acid (3.86–11.36%). The lipid, cholesterol and energy contents ranged from 1.97% to 10.23%, 57–302 mg/100 g and 4365.4–5544.2 cal g/dm, respectively. The obtained Statistical results showed that in these fishes, many of the above mentioned indices had significant differences (P ≤ 0.01) and the cluster analysis results of fatty acid compositions showed that common carp and pike perch had good similarity, followed by the Caspian kutum and golden gray mullet. However, common kilka did not show any similarity to others. PRACTICAL APPLICATIONS Fish consumption has been linked to health benefits such as reduced risk of coronary heart disease. This is largely attributed to the lipid, cholesterol, energy contents, fatty acid compositions and the polyunsaturated fatty acids present in fish oils. The ω-3 : ω-6, polyunsaturated fatty acid/saturated fatty acid and eicosapentaenoic acid + docosahexaenoic acid/C16 ratios are considered to be useful criteria for comparing relative nutritional and oxidation values of fish oils.

Foods and nutritional components of diets of black bear in Rocky Mountain National Park, Colorado

We used scat analysis to determine diets and relative nutritional values of diets for black bears ( Ursus americanus Pallas, 1780) in Rocky Mountain National Park, Colorado, from 2003 to 2006, and compared foods consumed and nutritional components to identify important sources of fecal gross energy (GE), crude fat (CF), and fecal nitrogen (FN) in annual and seasonal diets. Patterns of use of food classes followed typical seasonal patterns for bears, although use of animal matter was among the highest reported (&gt;49% annually). Use of animal matter increased after spring, although crude protein levels in bear diets were always &gt;25%. GE was typically lowest for grasses and other herbaceous plants and highest for ants and ungulates; FN was strongly positively related to most animal sources, but negatively correlated with vegetative matter; and CF showed the strongest positive relationship with ungulates and berries, with the latter likely influenced by the presence of seeds. Compared with historic data (1984–1991), contemporary diets included substantially greater prevalence of anthropogenic foods, which likely contributed to increases in size, condition, and productivity of the contemporary bear population. Management strategies are needed to increase quantity and quality of natural foods while minimizing dependence on anthropogenic sources.

The information supermarket

PurposeThe purpose of this paper is to examine how finances in an academic library might differ from household finances; in particular, how a library budget might be unbalanced throughout a fiscal year.Design/methodology/approachThe author compares typical library resources to representative groceries purchased for a home and assess the relative nutritional value of each.FindingsThe author concludes that using a library‐style budget is likely to result in a less interesting diet, but such a budget is, with planning, adequate to sustain a minimum level of health. In future columns the author plans to examine ways a library budget might be altered in order to move beyond adequacy to higher performance levels.Originality/valueThe approach should be worthy of note for administrators who struggle with the “use it or lose it” philosophy common in libraries.

Do some naturalised legumes have the potential to improve pasture production in the Victorian Mallee?

Some naturalised (not commercialised or deliberately sown) annual pasture legumes may be valuable pasture components, but their production relative to commercial species is poorly defined. This study aimed to determine the relative productivity, morphology, nutritive value, ecotype variation and sulfonylurea tolerance of some naturalised species in the Victorian Mallee. A series of 3 glasshouse and 2 ungrazed field experiments compared the production of haresfoot clover (Trifolium arvense L.), little woolly burr medic (Medicago minima L.), spineless M. minima, and M. monspeliaca (L.) Trautv. with the commercial species strand medic (M. littoralis Loisel cv. Herald) and barrel medic (M. truncatula Gaertn cv. Paraggio). The crude protein and in vitro digestibility of leaf and stem components were similar among species. The proportion of leaf was associated with species maturity, with later maturing species having a greater proportion of leaf at each harvest. There was a range of 52 days among species for date of first flowering. T. arvense produced similar or more biomass than the commercial species in spring, but had lower winter production. A 38-day range in days to first flower and a 2-fold range in winter biomass production among T. arvense ecotypes indicate potential for selection within this species. T. arvense also appears to have greater tolerance of triasulfuron residues than M. littoralis. Spineless M. minima requires further evaluation for persistence in this environment, but the low production of M. monspeliaca limits its value as a component of pastures. T. arvense, spineless and spiny M. minima all have some characteristics which could enhance pasture production in low-rainfall, low-input mixed farming systems.

Relative Effectiveness of Methionine Sources in Turkeys - Scientific and New Commercial Data

Introduction Knowing the relative nutritive value of liquid MHA-FA compared to DL-methionine (DL-Met) is an important precondition to cost-effective purchasing, feed formulation and animal production. Over the last few years there has been new and intriguing research published, mainly with broiler chickens, about the nutritional effectiveness of liquid MHA-FA relative to DLmethionine and the reasons for the difference (EsteveGarcia and Austic, 1993; Huyghebaert, 1993; Rostagno and Barbosa, 1995; Schutte and De Jong, 1996; Thomas et al., 1991; Van Weerden et al., 1992; Wallis et al., 1999; Lemme et al., 2002; Hoehler et al., 2003). bioefficacy of 71% (weight/weight) can be calculated for Consequently, a relative bioefficacy of 65% of liquid MHA-FA relative to DL-methionine on a weight basis (1 kg liquid MHA-FA to 0.65 kg of DL-Met) has found increasing acceptance among broiler nutritionists around the world. In contrast, scientific data in turkeys are rather scarce. In this paper, scientific and commercial data on relative effectiveness of methionine sources in turkeys will be presented and discussed. The first part of the data originated with Dr. Larry Potter and co-workers at Virginia Tech, Blacksburg, Virginia in the 1980s and remained unpublished at that time (copies in Degussa Corporation files). The second part is a study conducted at the Akey Nutrition and Research Center in Lewisburg, Ohio in 2002 and the third part consists of four “commercial comparison” trials with DL-Met versus liquid MHA-FA in Minnesota and South Dakota from 2001 to 2003.

Nutritional quality of food resources for zooplankton (Daphnia) in a tidal freshwater system (Sacramento‐San Joaquin River Delta)

We examined the relative nutritional values of natural phytoplankton and particulate detritus for zooplankton growth in a detritus‐rich environment. Seston was collected seasonally from four different habitat types in a tidal freshwater system and fed to juvenile Daphnia magna under controlled culture conditions by use of a flow‐through design. Seston particulate organic carbon (POC) and chlorophyll a contents ranged from ~330 to 3,800 µg L-1 POC and 1.4 to 45 µg L-1 Chl a. A partial residual analysis revealed that detrital carbon concentrations were only weakly related to Daphnia growth, whereas Chl a proved to be highly predictive of Daphnia growth rates across all investigated habitat types. Overall, habitat type had a strong effect on growth rates, whereas season of seston collection did not, but differences among habitats could be attributed to differing Chl a concentrations. The results from this study imply that, even in systems with overwhelming amounts of detrital carbon from a variety of sources, nutritional factors associated with phytoplankton can be dominant in regulating zooplankton growth.

The rôle of livestock in natural resources management

AbstractThis paper discusses some of the unique aspects of the interactions of livestock with the natural resources base. It argues the nature of these interactions make the use of a systems approach of particular importance when planning and executing livestock research if it is to be of any relevance to farmers in developing countries. The key issues are illustrated in two contrasting case studies.In Nepal, shifts in land use patterns have led to marked changes in the availability and use of fodder resources. Farmers indicate that they are no longer able to use these optimally. Fodder from at least 90 different types of tree (some of which have yet to be properly classified botanically) are used to supplement the diets of buffalo, cattle and goats during dry seasons when food is in short supply. The nutritive value of each of these is affected by a wide range of management and environmental factors. Furthermore, diet selectivity means that fractions consumed differ markedly amongst both tree species and classes of livestock. It is clearly not feasible for researchers to evaluate this diversity using existing in vitro or in vivo indicators of nutritive value. Initial studies suggest that this variability is implicitly catered for in farmers' own assessments of relative nutritive values. A mechanistic understanding of this indigenous technical knowledge and the development of appropriate techniques for integrating it with models of the biological responses of animals to nutrients might, therefore, allow more effective assessment of strategies for tree fodder utilization.Highland dairy systems in the humid tropics of Costa Rica (3000+ mm/year rainfall) could be very productive but suffer from a substantial dependence on imported inputs. Concentrate use is very high causing substantial underutilization of grazed pasture (the local resource), which is available year-round under these high-rainfall conditions. Over-supplementation with protein, which is the most expensive nutrient in the diet, at levels in excess of 200% of the requirement has been reported widely in these regions. Farmers want new strategies that enable them to manage their land and other resources in an alternative way, in order to be less dependent on grains and other imports. A decision-support system based on simulation and multiple criteria models representing a dairy farm has enabled the design and development of such strategies. Using this approach, farmers' objectives can be incorporated with a holistic understanding of the farming system in terms of management practices that will permit demand-driven animal production research at the farm level.

Effects of diet on longevity and fecundity of the spined stilt bug, Jalysus wickhami

AbstractWe evaluated the suitability of selected food items for the adult spined stilt bug, Jalysus wickhami Van Duzee (Hemiptera: Berytidae), by providing one of seven diet treatments: (1) prepupae of the parasitoid, Cotesia congregata (Say) (Hymenoptera: Braconidae), on a leaf of tobacco (Nicotiana tabacum L., ‘NC 2326’) (Solanaceae); (2) C. congregata prepupae alone (i.e., no tobacco leaf); (3) eggs of the parasitoid's host, Manduca sexta (L.) (Lepidoptera: Sphingidae), on a tobacco leaf; (4) M. sexta eggs alone; (5) tobacco aphids, Myzus nicotianae Blackman (Homoptera: Aphididae), on a tobacco leaf; (6) a tobacco leaf alone; and (7) no prey and no tobacco. A tobacco leaf was necessary for the long‐term survival of stilt bugs, but prey source did not affect longevity. Regardless of the prey type, stilt bugs with access to a tobacco leaf lived 21–23 days, while stilt bugs without access to tobacco lived less than 12 days. Animal prey provided a protein source required for egg deposition in J. wickhami, and prey species differed in their relative nutritive values. Female stilt bugs that fed on M. sexta eggs or on C. congregata prepupae were significantly more fecund (102 and 106 nymphs per female, respectively) than females that fed on tobacco aphids (24 nymphs per female). Results suggest that stilt bugs may feed on tobacco aphids and C. congregata prepupae when other prey are unavailable.

The trophic significance of Phaeocystis blooms

Both colonies and solitary cells of the prymnesiophyte Phaeocystis are ingested by a wide array of marine vertebrates. Grazers include protozoa, bivalves, amphipods, euphausiids and many copepod species. Common fish species such as mackerel ( Scomber scombrus) and flounder ( Pleuronectus flesus) have also been reported to feed upon Phaeocystis. While qualitative observations on the potential trophic significance of Phaeocystis exist for a long time, attempts to quantify feeding rates on Phaeocystis have begun only during the last decade. In feeding experiments, copepods have received most attention. Many copepod species appear to consume Phaeocystis colonies and solitary cells in the North Atlantic and in polar seas. Ingestion rates are highly variable depending on size and physiological state of Phaeocystis as well as on copepod species. Within the same species, large variations in individual feeding rates have been reported from different areas and investigators. When Phaeocystis co-occurs with larger amounts of diatoms, the latter seem to be preferred by some copepod species while others do not select against Phaeocystis. At present it is unclear whether this is primarily due to unsuitable size of Phaeocystis or because it is poor quality food. The relative nutritive value of Phaeocystis single cells and colonies should be investigated in more detail. Feeding of protozoa on Phaeocystis has been little studied. Ciliates and the giant dinoflagellate Noctiluca are known to consume Phaeocystis solitary cells. Protozoa might efficiently control Phaeocystis blooms during their initial phases when the share of solitary cells relative to total Phaeocystis biomass is higher than during later stages of the bloom. By switching their food preference towards heterotrophic food, copepods might benefit from enhanced protozoan biomass during Phaeocystis blooms. The potential succession of protozoan and metazoan grazers in the course of a Phaeocystis bloom awaits further research.

Physical, chemical, and nutritional characteristics of distillers dried grains with solubles for chicks and pigs

The physical characteristics, chemical composition, and nutritional value of distillers dried grains with solubles (DDGS) from seven beverage alcohol and two fuel alcohol manufacturers were evaluated in studies with chicks and pigs. Color scores of the DDGS ranged from very light to very dark and odor scores ranged from normal to burnt or smoky. The DDGS ranged from 23.4 to 28.7% CP, 2.9 to 12.8% fat, 8.8 to 36.9% ADIN, 28.8 to 40.3% NDF, 10.3 to 18.1% ADF, and 3.4 to 7.3% ash. Lysine concentrations of the DDGS ranged from .43 to .89%. In the first experiment, 12 corn-based diets were fed to 1-d-old chicks for 21 d to assess the nutritional value of the DDGS sources. A low-protein basal diet was supplemented with soybean meal to provide 13.6, 16.5, or 19.0% CP or supplemented with 20% DDGS, which supplied approximately the same amount of CP as the highest level of soybean meal. Weight gain, feed intake, and feed/gain were influenced (P < .01) by source of DDGS. The weight gain of chicks fed the DDGS sources ranged from 85% of that chicks fed the highest level of soybean meal to less than that of chicks fed the low-protein basal diet. Blends of the three best sources of DDGS and the three poorest sources of DDGS were evaluated in a subsequent chick trial. The relative nutritional values of the two blends were similar to the average of the sources that made up the blends. Performance responses to various blends of DDGS in the pig experiment paralleled those of the chick trial.(ABSTRACT TRUNCATED AT 250 WORDS)