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Simple Summary: The selection of an appropriate diet is a key component of methods for the mass rearing of biocontrol agents. It is known that feeding on mixed, alternating, or changing foods often favor insect development. We investigated the effects of various combinations of high-quality (the green peach aphid) and low-quality (eggs of the grain moth) foods on the development of a predatory ladybird Cheilomenes propinqua. The benefits of mixed foods to larval development were only found in some treatments with limited supplies of aphids. Feeding on various combined diets never resulted in higher survival, faster development, or a larger size of emerging adults than those observed for feeding on unlimited amounts of aphids. We conclude that if necessary (for example, in the case of temporary shortage or a lack of aphids in mass rearing facilities or in the case of preventing release of adults for biological control of pests in greenhouses), C. propinqua larvae can be fed with grain moth eggs by replacing, mixing, or alternating with aphids, although this will result in a decrease in pre-adult survival, rate of development, and the size of emerging adults. On the other hand, even a minimal addition of aphids can have a substantial positive effect on larvae fed with grain moth eggs. Feeding on mixed, alternating, or changing diets often favor insect development. With the aim to optimize mass rearing and use for the biological control of insect pests, we investigated the effects of various combinations of high-quality (the green peach aphid Myzus persicae) and low-quality (eggs of the grain moth Sitotroga cerealella) foods on the larval development of a predatory ladybird Cheilomenes propinqua. In the first experiment, eggs and aphids were mixed in different proportions; in the second experiment, larvae switched from feeding on aphids to feeding on eggs. Although the beneficial additive effect of mixed foods was detected in some treatments with limited diets, feeding on various combinations of eggs with aphids never resulted in higher survival, faster development, or a larger size of emerging adults than those observed for feeding on unlimited amounts of aphids. For the practice of biological control, we conclude that, if necessary (for example, in the case of temporary shortage or a lack of aphids in mass rearing facilities or in the case of preventing release of C. propinqua adults in greenhouses), C. propinqua larvae can be fed with grain moth eggs by replacing, mixing, or alternating with aphids, although this will inevitably result in a proportional decrease in pre-adult survival, rate of development, weight, and size of the emerging adults. On the other hand, even a minimal addition of aphids can have a substantial positive effect on larvae fed with grain moth eggs. [ABSTRACT FROM AUTHOR]

Macrosiphum euphorbiae (aphid) is an important economic pest because it causes significant damage to several crops, notably on strawberry. The use of natural enemies, especially predators, is an alternative that is being explored to protect strawberry crops against this pest, notably the species Orius laevigatus is a promising predator for biological control. However, the lack of suitable habitats and/or food is a constraint to the growth and/or the establishment of the predator populations, reducing their effectiveness as control agent against M. euphorbiae. Using additional food resources such as companion plants or alternative food sources may support predator population and associated biocontrol services they provide. The objective of this study was to evaluate the efficacy of O. laevigatus as biological control agent against M. euphorbiae, mediated by the presence of companion plants and alternative prey. We evaluated under greenhouse conditions the effect of Lobularia maritima (alyssum) as possible companion plant, as well as Ephestia kuehniella eggs as alternative prey, on O. laevigatus populations and biocontrol service in strawberry cropping system. Predators were placed in the presence or absence of alyssum and/or E. kuehniella eggs on strawberry plants previously infested with aphids. We showed that the presence of alyssum and/or E. kuehniella eggs enhanced O. laevigatus population growth (when compared to a control group). Furthermore, we observed a steady reduction of M. euphorbiae populations when the companion plant was present alone or when it was associated with the alternative prey. Finally, the treatment with the combination of alyssum and alternative prey resulted in the highest yield (number of fruits per plant). Our study demonstrated that combining alyssum, as a companion plant, and E. kuehniella eggs, as an alternative prey, could be an effective option for establishing O. laevigatus populations and for controlling aphids in strawberry cropping systems. [ABSTRACT FROM AUTHOR]

Global climate change requires a paradigm change in diets, especially in affluent countries, with a reduction of animal-based food, including children. This will have direct consequences for Vitamin B12 supply as animal-based foods are the only food source. We examined these potential consequences using the German food based dietary guidelines for infants, children, and adults in Germany as the basis for the model calculation. The guidelines for 4 representative age groups were examined, representing exclusive milk feeding (2 months), complementary feeding (8 months), and mixed family diet (children: 4-6 years, adolescents: 11-14 years). For each age group (except 2 months), the contribution of animal-based food groups (milk/dairy, meat, fish, eggs) to the total daily intake of vitamin B12 was calculated based on 7-day menus with recipes for all meals. This allowed us to assess the potential Vitamin B12 deficits due to food group exclusion. Even in the guidelines diets, including exclusive breastfeeding, the vitamin B12 intakes just reached the reference values in all age groups. In infants on complementary feeding and also later in children and adolescents, cow's milk was by far the most important source of vitamin B12. Among the other animal-based foods, meat (16.9%-23.0%) ranked first, followed by fish (11.0%-16.5%), and eggs (8.1%). In our analysis of the German food-based guidelines for infant, child, and adolescent diets, the increased planetary health due to reduction of milk intake turned out severely to compromise vitamin B12 intake. In children, a reduction in the consumption of animal foods to improve the health of the planet must be weighed against the risk of inadequate intake of individual nutrients., Competing Interests: All authors declare that there are no conflicts of interest., (© 2024 The Author(s). Food Science & Nutrition published by Wiley Periodicals LLC.)

The development of rearing protocols promoting the larval development, pre and post-metamorphosis are key for echinoculture. Mixed diets combining diatom with other microalgae have been used with success and Rhodomonas sp. (Rho)-based diets showed promising results in larval survival. This study was aimed to evaluate the rearing success of Paracentrotus lividus larvae fed with mixed diets combining Rho with two diatoms, Phaedactylum tricornutum (Phae) and Chaetoceros calcitrans (Chae) in two experiments. In experiment I, the effect of the mixed diet of Rho and Phae (Mix I) was compared with monospecific diets of both species, while in experiment II, Rho was combined with Chae (Mix II) and compared with both monospecific diets. In experiment I, larvae fed with Rho I and Mix I diets grew faster than larvae fed with Phae I diet, attained the competence earlier with survival rates of 15-16%. In experiment II, the larvae fed with Rho were larger and the larvae fed with Mix II attained the highest survival rate (32.22%). The analysis of the larval biometric models showed that the larger larvae, with bigger stomachs, and shorter post-oral arm attained the age-at-competence earlier with higher survival rates. In conclusion, the larvae fed with a combination of Rho with the selected diatoms showed identical growth performance and condition to larvae fed with Rho monospecific diet but obtained higher survival rate. These results indicate that mixed-diatoms diets may be more suitable for P. lividus larval rearing. [ABSTRACT FROM AUTHOR]

1. The additivity of apparent ileal digestibility (AID) and standardised ileal digestibility (SID) of phosphorus (P) in mixed diets containing corn and canola meal (CCM) with or without phytase supplementation and the impact of age on the basal ileal endogenous loss (BEL) of P were investigated in broiler chickens. 2. Treatments were arranged as a 2 × 3 × 2 factorial with two ages (13 d or 21 d post hatching), three diets (corn, canola meal, or CCM), and two phytase levels (0 or 1,000 FYT/kg diet) in a randomised complete block design. There were eight or six birds per cage at 13 d and 21 d of age, respectively, and six replicate cages per treatment, with a total of 588 birds. A P-free diet (PFD) treatment was included at each age to determine the basal endogenous loss (BEL) of P. 3. Birds were fed a commercial starter diet from d 1 to d 10 or d 18 and then fed the experimental diets for 3 d until d 13 or d 21, respectively. Predicted digestibility values calculated from the individual feed ingredients were used to test additivity in the mixed diets. Chromium oxide was included in diets as an indigestible marker. 4. The ileal digesta, collected from birds at d 13 or d 21, was used to determine nutrient digestibility. 5. The AID and SID of P at d 13 was higher (P < 0.01) when compared with older birds at d 21, regardless of dietary phytase supplementation. Regardless of age or phytase supplementation, AID and SID of P were additive, as there were no differences between predicted and determined values in the mixed diets. The BEL of P (g/kg DM intake) in birds at d 13 was higher (P < 0.05) than birds at d 21 (0.197 vs. 0.159). 6. In conclusion, age had an impact on the BEL of P and the utilisation of minerals in the diets. The apparent and standardised ileal digestibility of P in the mixed diet containing corn and canola meal were additive, regardless of age or phytase supplementation. [ABSTRACT FROM AUTHOR]

The main objective of this study was to develop a dynamic energy balance model for dairy goats to describe and quantify energy partitioning between energy used for work (milk) and that lost to the environment. Increasing worldwide concerns regarding livestock contribution to global warming underscore the importance of improving energy efficiency utilization in dairy goats by reducing energy losses in feces, urine and methane (CH4). A dynamic model of CH4 emissions from experimental energy balance data in goats is proposed and parameterized (n = 48 individual animal observations). The model includes DM intake, NDF and lipid content of the diet as explanatory variables for CH4 emissions. An additional data set (n = 122 individual animals) from eight energy balance experiments was used to evaluate the model. The model adequately (root MS prediction error, RMSPE) represented energy in milk (E-milk; RMSPE = 5.6%), heat production (HP; RMSPE = 4.3%) and CH4 emissions (E-CH4; RMSPE = 11.9%). Residual analysis indicated that most of the prediction errors were due to unexplained variations with small mean and slope bias. Some mean bias was detected for HP (1.12%) and E-CH4 (1.27%) but was around zero for E-milk (0.14%). The slope bias was zero for HP (0.01%) and close to zero for E-milk (0.10%) and E-CH4 (0.22%). Random bias was >98% for E-CH4, HP and E-milk, indicating non-systematic errors and that mechanisms in the model are properly represented. As predicted energy increased, the model tended to underpredict E-CH4 and E-milk. The model is a first step toward a mechanistic description of nutrient use by goats and is useful as a research tool for investigating energy partitioning during lactation. The model described in this study could be used as a tool for making enteric CH4 emission inventories for goats. [ABSTRACT FROM AUTHOR]

The main objective of this study was to develop a dynamic energy balance model for dairy goats to describe and quantify energy partitioning between energy used for work (milk) and that lost to the environment. Increasing worldwide concerns regarding livestock contribution to global warming underscore the importance of improving energy efficiency utilization in dairy goats by reducing energy losses in feces, urine and methane (CH4). A dynamic model of CH4 emissions from experimental energy balance data in goats is proposed and parameterized (n = 48 individual animal observations). The model includes DM intake, NDF and lipid content of the diet as explanatory variables for CH4 emissions. An additional data set (n = 122 individual animals) from eight energy balance experiments was used to evaluate the model. The model adequately (root MS prediction error, RMSPE) represented energy in milk (E-milk; RMSPE = 5.6%), heat production (HP; RMSPE = 4.3%) and CH4 emissions (E-CH4; RMSPE = 11.9%). Residual analysis indicated that most of the prediction errors were due to unexplained variations with small mean and slope bias. Some mean bias was detected for HP (1.12%) and E-CH4 (1.27%) but was around zero for E-milk (0.14%). The slope bias was zero for HP (0.01%) and close to zero for E-milk (0.10%) and E-CH4 (0.22%). Random bias was >98% for E-CH4, HP and E-milk, indicating non-systematic errors and that mechanisms in the model are properly represented. As predicted energy increased, the model tended to underpredict E-CH4 and E-milk. The model is a first step toward a mechanistic description of nutrient use by goats and is useful as a research tool for investigating energy partitioning during lactation. The model described in this study could be used as a tool for making enteric CH4 emission inventories for goats.

Diets combining herbage and total mixed rations (TMR) are increasingly used in temperate regions for feeding ruminants, but little information is available regarding the effects on nutrient intake and digestion of this feeding management in beef cattle. The aim of this study was to determine the effects of combining TMR (10% CP and 13% ADF), and legume-based herbage (14% CP and 27% ADF) on intake, nutrient digestion, ruminal fermentation, microbial N flow and glucose and nitrogen metabolism in heifers. The experiment was a 3×3 Latin square design replicated three times; each period lasted 18 days (10 adaptation days and 8 measurement days). Nine cross-bred (Aberdeen Angus×Hereford) heifers (214±18 kg) fitted with permanent rumen catheters and housed in individual metabolic cages were assigned to one of three treatments: 24 h access to TMR (T), 24 h access to herbage (H) or combined diets with 18 h access to TMR and 6 h access to herbage (T+H). Data were evaluated using a mixed model. Animals fed T+H (TMR 71% and herbage 29%) diets tended to have a higher dry matter intake as a proportion of their BW than animals fed T. The T+H diet did not change ruminal fermentation (pH, N–NH3 and volatile fatty acids) or the N metabolism relative to the T diet, but increased the glucagon concentration and altered glucose metabolism. Conversely, animals fed T+H had increased purine derivatives excretion, increased N use efficiency for microbial protein synthesis and decreased plasma urea and urinary N excretion relative to animals fed H diet. The use of combined diets led to consumption of nutrients similar to a TMR diet, without reducing nutrient use and could improve N utilization compared with the herbage-only diet.

Summary: This study was conducted to investigate the effect of dietary crude protein (CP) levels of semi‐purified diets on the additivity of values for standardized ileal digestibility (SID) of amino acids (AA) in mixed diets from multiple protein sources for growing pigs. A total of 28 barrows (initial BW, 66.4 ± 1.3 kg) were surgically fitted with simple T‐cannulas at the distal ileum and assigned to a replicated 14 × 4 incomplete Latin square design with 14 diets and 4 periods. The 14 experimental diets consisted of a nitrogen‐free diet; a corn‐based diet (80 g CP/kg); nine semi‐purified diets containing soya bean meal (SBM), canola meal (CM) or corn distillers dried grains with solubles (cDDGS), each type (protein source) of semi‐purified diets supplied 80, 120 or 160 g CP/kg, respectively; three mixed diets based on corn, SBM, CM and cDDGS formulated to contain 120, 160 and 200 g CP/kg respectively. Pigs were fed each of the 14 diets during a seven‐day period, and ileal digesta were collected from 08:00 a.m to 6:00 p.m on day 6 and 7. Chromic oxide was added as an indigestible marker. Results indicated that the SID of CP and AA were not affected by CP levels (p > .05). Values for SID of AA were additive (p > .05) with the exception of His and Lys; Arg and Lys; Arg, Lys, Thr, Asp, Cys and Gly in the mixed diets containing 120, 160 and 200 g CP/kg respectively (p < .05). In conclusion, additivity of SID values of AA in the mixed diets at different CP levels was not affected by the CP levels of semi‐purified diets for growing pigs. Therefore, it is recommended that SID values of AA should be used to formulate practical diets containing multiple ingredients for pigs. [ABSTRACT FROM AUTHOR]

Diets combining herbage and total mixed rations (TMR) are increasingly used in temperate regions for feeding ruminants, but little information is available regarding the effects on nutrient intake and digestion of this feeding management in beef cattle. The aim of this study was to determine the effects of combining TMR (10% CP and 13% ADF), and legume-based herbage (14% CP and 27% ADF) on intake, nutrient digestion, ruminal fermentation, microbial N flow and glucose and nitrogen metabolism in heifers. The experiment was a 3×3 Latin square design replicated three times; each period lasted 18 days (10 adaptation days and 8 measurement days). Nine cross-bred (Aberdeen Angus×Hereford) heifers (214±18 kg) fitted with permanent rumen catheters and housed in individual metabolic cages were assigned to one of three treatments: 24 h access to TMR (T), 24 h access to herbage (H) or combined diets with 18 h access to TMR and 6 h access to herbage (T+H). Data were evaluated using a mixed model. Animals fed T+H (TMR 71% and herbage 29%) diets tended to have a higher dry matter intake as a proportion of their BW than animals fed T. The T+H diet did not change ruminal fermentation (pH, N–NH3 and volatile fatty acids) or the N metabolism relative to the T diet, but increased the glucagon concentration and altered glucose metabolism. Conversely, animals fed T+H had increased purine derivatives excretion, increased N use efficiency for microbial protein synthesis and decreased plasma urea and urinary N excretion relative to animals fed H diet. The use of combined diets led to consumption of nutrients similar to a TMR diet, without reducing nutrient use and could improve N utilization compared with the herbage-only diet. [ABSTRACT FROM PUBLISHER]

The diversity of prey and food sources in crops has a major effect on biological pest control by generalist predators. In this study, we tested if and how supplemental prey or food affects the control of the citrus mealybug Planococcus citri (Risso) by larvae of the green lacewing Chrysoperla lucasina (Lacroix). The larvae of this predator are the only stage that feed on prey, thus ideally the supplemental food should result in high larval survival but a low developmental rate. Juvenile survival and developmental time of lacewing larvae were measured on various food items, either alone or mixed with mealybugs. Mealybugs were a suboptimal prey: up to 50 % of the lacewing larvae died before they reached the pupal stage and the developmental time was relatively long when feeding exclusively on mealybugs. Mixing mealybugs with supplemental prey increased larval survival, but also reduced larval developmental time and thereby the period in which the larvae could prey on mealybugs. Moreover, adding eggs of Ephestia kuehniella Zeller, which appeared to be of high quality for lacewings, reduced the consumption of mealybugs by lacewing larvae in the laboratory. The addition of the prey mite Acarus siro (L.) also reduced larval mortality, but did not reduce mealybug predation rates by lacewing larvae. Greenhouse trials showed better mealybug control by lacewing larvae with supplemental prey of low quality (prey mites) rather than alternative prey of high quality ( Ephestia eggs). In conclusion, biological control of mealybugs by lacewing larvae was strongly affected by the nutritional quality of the supplemental food source. [ABSTRACT FROM AUTHOR]

We determined if combinations of adjacent pastures of 3 forage species led to complementary relationships that influenced animal behavior and performance over monocultures. Grazing bouts, behavioral levels of activity, blood urea N (BUN), chemical composition of feces, BW, and herbage biomass before and after grazing were monitored when beef calves strip-grazed 3 replications of 4 treatments from June 14 through August 23, 2013 (9 animals/treatment). Animals grazed monocultures of: 1) tall fescue (TF), 2) alfalfa (ALF), 3) sainfoin (SAN), or 4) a choice of strips of forages TF, ALF, and SAN (CHOICE). The lowest and greatest incidence of foraging bouts occurred for cattle in CHOICE and SAN, respectively (P < 0.01). Animals in CHOICE grazed SAN > ALF > TF (P < 0.01). Animals on TF and CHOICE took greater number of steps than animals grazing a monocultures of either legume (P = 0.01). Calves in TF had lower BUN (P < 0.01) and fecal CP concentration (P < 0.01) than calves grazing the remaining treatments, whereas animals in SAN showed the greatest concentrations of fecal CP (P < 0.01). Fecal NDF concentration was the greatest for animals grazing TF and the lowest for animals grazing SAN (P < 0.01), whereas fecal ADF concentration was greater for animals grazing TF and SAN than for animals grazing CHOICE and ALF (P = 0.02). Calcium, Mg, and Zn concentrations were the lowest in feces from calves grazing TF and the greatest for calves grazing a monoculture of either legume (P < 0.05). When averaging both periods, animals grazing SAN, ALF, or CHOICE gained more BW than animals grazing TF (P < 0.01). Thus, calves in CHOICE incorporated tall fescue into their diets, were more active, and displayed a lower number of grazing bouts than calves grazing monoculture of either legume. Herbage diversity may lead to levels of ADG comparable to legume monocultures with the potential benefit of maintaining plant species diversity in pasturelands. [ABSTRACT FROM AUTHOR]

Feed costs are overwhelmingly the largest expense for dairy producers. Thus, improving milk production efficiency (milk fat and protein are the main incomes for farmers) is of great economic importance in the dairy industry. The main objective of this study was to develop a dynamic energy partitioning model to describe and quantify how dietary energy from carbohydrate, protein, and fat is transferred to milk (protein, lactose, and fat) in dairy goats. In addition, due to increasing worldwide concerns regarding livestock contribution to global warming, methane (CH4) emission was quantified. For modeling purposes, 158 individual goat observations were used and randomly split into 2/3 for model development and 1/3 for internal evaluation. For external evaluation, 20 different energy balance studies from the literature (77 observations) were evaluated. The Root Mean Square Prediction Error (RMSPE) was 13.2% for loss of energy in CH4, 16.8% for energy in fat, 19.4% for energy in protein, and 22.3 energy in lactose. Mean bias was around zero for all variables and the slope bias was zero for milk energy in lactose, close to 1% for milk fat (1.01%), and around 3% and 10% for protein and CH4, respectively. Random bias was greater than 85% for energy in CH4 and milk energy components indicating non-systematic errors and that the equation in the model fitted the data properly. Analyses of residuals appeared to be randomly distributed around zero. Slopes of regression lines for residuals vs. predicted were positive for milk fat energy, zero for lactose, and negative for milk energy in protein and CH4. This model suggested for use with mixed diets and by-products to obtain balanced macronutrient supply, methane emissions, and milk performance during mid lactation could be an interesting tool to help farmers simulate scenarios that increase milk fat and protein, evaluate CH4 emissions, without the costs of running animal trials., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

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Mouse experimental models of diet-induced weight gain are commonly used as analogs to human obesity; however, a wide variety of feeding methods have been used and the most effective way to maximize weight gain is not known. Maximizing weight gain may allow for a reduction in the number of animals required for a given experiment. The purpose of this study was how to cause the greatest amount of weight gain in CD-1 mice by modifying the composition and source of their diet. To accomplish this goal, we completed two experiments: (1) Effect of dietary macronutrient fat intake (60% (HF60), 45% (HF45), 30% (HF30), or 13.5% (CON) fat diet for 18 weeks); and (2) Effect of 1:1 mixed HF60 and CON diets. Outcome measures included food intake, body mass, and body composition, which were measured bi-weekly and statistically analyzed using a repeated measures analysis of variance (RM–ANOVA). In Experiment 1, the greatest increase in body and fat mass was observed in HF60 (36%) and HF45 (29%) compared with HF30 and CON (P < 0.05). In Experiment 2, HF + stock diet (SK) gained 25% more body mass and 70% more fat mass than HF (P < 0.05). Collectively, these findings suggest that using a high-fat based diet (>45% calories from fat), mixed with a stock diet, results in substantially more weight gain over a similar period, of time, which would allow an investigator to use ∼40% fewer animals in their experimental model. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to investigate the effects of a Saccharomyces cerevisiae fermentation product (XP, Diamond V, Cedar Rapids, 1A) on in vitro ruminal fermentation of single forage and mixed diets. In Exp. 1, an in vitro test was used to determine the effects of various concentrations (0, 1,2, and 3 g/L) of XP on ruminal fermentation of the major forage sources of China (rice straw, RS; corn stover, CS; corn silage without grain, CSNG; and corn silage with grain, CSG). Total VFA reached a peak at 1 g/L XP for RS, CSNG, and CSG and increased linearly (P < 0.01) for CS. The molar proportion of acetate decreased and propionate increased linearly ( P < 0.01) with an increasing amount of XP for RS, CS, and CSNG. Microbial protein (MCP) increased linearly (P < 0.01) with an increasing level of XP for RS, and it reached peak values at 1 and 2 g/L XP for CSG and CSNG, respectively. Fungi population was increased {P < 0.05) with 1 g/L XP for all forages except CSNG. The population of Ruminococcusflavefaciens increased (P < 0.05) at 1 or 2 g/L XP for RS, CSNG, and CSG. In Exp. 2, the effects of 3 concentrations of XP (0, 1, and 2 g/L) were tested on in vitro ruminal fermentation of 3 mixed diets with various ingredient combinations: 1) CSC (corn:soybean meakcorn stover = 33:22:45), 2) CSCC (corn:soybean meakcorn stover:corn silage = 33:22:22.5:22.5), and 3) CSCCA (corn:soybean meakcorn stover:corn silage:alfalfa = 33:22:19:21:5). Total VFA concentrations were influenced by diets (P < 0.01) and were enhanced linearly by increasing concentrations of XP (P < 0.01). The molar proportion of acetate was reduced {P < 0.01), but the propionate proportion was enhanced with increasing concentrations of XP (P < 0.01). Ammonia N was decreased and MCP was increased by the addition of XP (linear, P < 0.01; quadratic, P < 0.05). The fungi population was greater with XP addition (quadratic, P < 0.01). The percentage of R. albus was affected by diets (P < 0.01), the level of XP (linear and quadratic, P < 0.01), and their interaction (P < 0.01). From these 2 in vitro studies, it is inferred that the addition of XP could improve the rumen fermentation of forages and mixed diets by stimulating the number of fiber-digesting rumen microbes, especially fungi populations. [ABSTRACT FROM AUTHOR]

Abstract: Development and sex differentiation in the copepod Temora stylifera was studied in the presence of maternal and larval diets of the diatoms Thalassiosira rotula and Skeletonema marinoi, either provided alone or supplemented with the control dinoflagellate Prorocentrum minimum. Both diatoms had deleterious effects on growth compared to the control when used as pure diets, inducing very low or even zero survival from hatching to adulthood. This effect was deleted when the diet was supplemented with a good food (P. minimum) only in the case of T. rotula. By contrast, with a maternal or larval diet of S. marinoi, nauplii did not pass metamorphosis even when this alga was mixed with P. minimum. Arrested development was not due to lack of feeding since early and late nauplii (NII and NV) ingested all three algae at similar rates when used as single diets, and did not show any preference when the algae were offered as mixtures. Since mortality rates with a mixed diet of S. marinoi + P. minimum were similar or even higher than those obtained with a single diet of S. marinoi, we suggest that this diatom is more toxic than nutritionally deficient for T. stlyfera development. No males were produced in cohorts reared on pure diatom diets or with a mixture of S. marinoi + P. minimum, and intermediate male:female sex ratios were obtained with the mixed T. rotula + P. minimum diet. Possibly some diatoms produce compounds such as oxylipins or new molecules that alter sex differentiation in T. stylifera. [Copyright &y& Elsevier]

Abstract: Genetic and molecular evidence to support the hypothesis that fungal secondary metabolites play a significant role in protecting the fungi against fungivory is scarce. We investigated the impact of fungal secondary metabolites on transcript regulation in the fungivorous springtail Folsomia candida feeding on mixed vs. single diets. Aspergillus nidulans, which is able to produce secondary metabolites including sterigmatocystin, and a knockout mutant with reduced secondary metabolism (A. nidulans ΔLaeA) were combined with the high quality fungus Cladosporium cladosporioides as mixed diets or offered as single diets. We hypothesized that (i) A. nidulans WT triggers more genes associated with stress responses compared to the A. nidulans ΔLaeA strain with suppressed secondary metabolism, (ii) C. cladosporioides causes significantly different transcript regulation than the A. nidulans strains ΔLaeA and WT, and (iii) mixed diets will cause significantly different transcript expression levels than single diets. All three hypotheses are generally supported regardless of the fact that functions of many of the differentially transcribed genes are still enigmatic and that a relatively subtle response, devoid of characteristic stress response genes, was observed towards the toxic fungi in the diet. The wild type A. nidulans strain elicited 30% more differentially expressed genes than the ΔLaeA mutant strain. Differentially expressed genes were not observed in the mixture diet of the C. cladosporoides × A. nidulans WT diet, indicating selective grazing on C. cladosporoides. The results bring molecular evidence for the existence of a link between fungal secondary metabolites and responses in springtails supporting the hypothesis that fungal secondary metabolites act as a shield against fungivory. [ABSTRACT FROM AUTHOR]

Abstract: Non-additive dietary effects occur when nutritional gains from a mixed diet are greater than or less than that predicted by summing the gains from individual diet items. Both positive and negative effects occur in adult slider turtles, Trachemys scripta. Such effects may also be important to juvenile T. scripta as they ontogenetically switch from carnivorous to herbivorous diets. The purpose of this study was to determine if juveniles experience non-additive effects and to assess the underlying mechanism. Two feeding trials were conducted. In Trial 1, juveniles were fed 100% duckweed, Lemna valdiviana, 100% grass shrimp, Palaemontes paludosus, or a mixed diet containing 81% duckweed and 19% shrimp. In Trial 2, juveniles were fed 100% duckweed, Lemna minor, 100% cricket, Acheta domesticus, or one of three mixed diets containing duckweed and cricket in varying percentages (22%, 39% and 66% cricket). Similar to adults, a negative non-additive effect was demonstrated on the 19% shrimp and 22% cricket diets. However, the positive effect found in adults was not observed. Intake varied dramatically between the plant and animal diets, resulting in differences in transit time that could explain the non-additive effect. These results offer some insight into understanding ontogenetic diet shifts in turtles. [Copyright &y& Elsevier]

Abstract: To find the best conditions for production, spat of the scallop Nodipecten subnodosus were grown for 10 weeks at 23, 26 or 29°C, and fed with 2:1 mixtures (cell:cell) of Chaetoceros calcitrans with Pavlova lutheri or Isochrysis sp. (diets M1 and M2) or with a 1:1 mixture of P. lutheri and Isochrysis sp. (diet M3). Mortality was 100% after 4weeks at 29°C. Survival was significantly higher with diet M1 than with the other diets, and was 51 and 46% at 23 and 26°C, respectively. With diets M2 and M3, the respective percentages of survival were 39.39 and 33.84% at 26°C and 23.03 and 19.85% at 23°C. The best growth in shell height was with diet M2, but there were no differences in final organic weight between diets M1 and M2; diet M3 gave the lowest spat growth. The highest protein content was with diet M1 at 23°C. This diet gave the lowest carbohydrate contents of the spat at both temperatures, and the lowest spat lipid content at 23°C. The fatty acid composition of spat was related to that of the respective diets, and there was no evident relation between dietary fatty acids and spat growth. Our results indicate that N. subnodosus spat should be kept at 26°C and fed a mixed diet containing C. calcitrans and either P. lutheri or Isochrysis sp. [Copyright &y& Elsevier]

We measured the growth and physiological condition of juveniles of the Cortez oyster Crassostrea corteziensis during the early grow-out phase in Sinaloa (Mexico) after using three experimental diets during the hatchery period: (1) 1:1 blend of the microalgae Isochrysis galbana and Chaetoceros muelleri as the control group; (2) mix of the same microalgae replaced by 50% of its wet weight with cornstarch; and (3) mix of the two microalgae replaced by 50% its wet weight with wheat flour. Specimens were cultivated under suspension conditions for 60 days and monitored weekly for growth (shell height and wet and dry weight) and the first 15 days for physiological response (condition index, digestive gland index and muscle index). Juveniles fed exclusively on microalgae attained larger sizes and had higher digestive gland and muscle indices, while those fed microalgae with cornstarch gained more biomass (wet and dry weight) and reached a better condition. The lowest values of these indicators occurred in oysters fed microalgae with wheat flour. Statistical data revealed that differences in the growth and condition of specimens between treatments were slight, confirming that mixed diets (particularly microalgae/cornstarch) have potential application for reducing hatchery-operating costs without affecting the performance of planted juveniles in the field. [ABSTRACT FROM AUTHOR]

Abstract: Non-prey foods are an integral component of the diets of most predaceous coccinellids. Under field conditions, numerous coccinellids consume nectar, honeydew, pollen, fruit, vegetation, and fungus. These non-prey foods are used by coccinellids to increase survival when prey is scarce, reduce mortality during diapause, fuel migration, and enhance reproductive capacity. Each of these non-prey foods has unique nutritional and defensive characteristics that influence its suitability for lady beetles. Quantitatively, nutrient and energy contents of these foods are often competitive with, or even exceed that, present in prey. Meta-analyses of literature were used to assess whether (1) some non-prey foods and prey are equivalent foods for coccinellids, and (2) prey-only diets and mixed diets involving prey and non-prey foods are equally suitable for coccinellids. Response variables were categorized as larval performance (e.g., development time, weight at eclosion), adult performance (e.g., adult longevity, weight change), and reproduction (e.g., fecundity, oviposition period). The analyses revealed that pollen is inferior to prey for supporting larval and adult performance, but that adult performance in sugar-fed adults was equal to that of prey-fed adults (although sugar alone does not support reproduction). Larval performance was enhanced substantially when they were reared on mixed diets compared to prey-only diets. Adding sugar to mixed diets strongly improved adult performance and reproduction over prey-only diets, but this was not the case with pollen in mixed diets. These results suggest that coccinellid larvae have more stringent nutritional requirements than adults, and that non-prey foods provide unique nutrients that enhance prey-only diets. Moreover, it suggests that simple carbohydrates are important dietary constituents capable of enhancing both adult performance and reproduction, although it is important to note that a range of prey species of variable quality for coccinellids are evaluated in this database. The literature review presented here suggests that non-prey foods are a critical component of coccinellid nutritional ecology, and may influence the success of conservation biological control programs. [Copyright &y& Elsevier]

Partial preference for feeds in ruminants is a well-documented phenomenon although their explanation can be elusive. The hypothesis was tested that sheep offered herbage of two annual grass species differing in chemical composition free-choice would select a diet that would maximize the nutritive value of the diet compared with sheep offered each herbage separately through a greater nutrient balance and synchronization of nutrient release for efficient ruminal microbial function. Fifteen male lambs were placed into metabolic cages, and randomly assigned to three treatments ( n = 5): Italian ryegrass fresh herbage (treatment R), barley fresh herbage (treatment B) or free-choice Italian ryegrass and barley fresh herbage (treatment RB). Both herbages had similar crude protein concentrations but Italian ryegrass herbage had higher concentration of water-soluble carbohydrates and lower concentration of fibre than barley herbage. Lambs were exposed to the treatments for 15 d. Lambs on treatment RB showed a partial preference of 0·82 (s.e. 0·031) for Italian ryegrass. Lambs on treatment RB had higher intakes of digestible dry matter and higher values for nitrogen retention than lambs on treatment B although similar to that of lambs on treatment R. The results for the dietary choices were not always consistent with maximizing the nutritive value of the diet. Other explanations, such as lambs needed to sample and track the nutritive value of dietary options or there was the development of transient food aversions, were also possible. [ABSTRACT FROM AUTHOR]

Abstract: Nonadditive interactions occur when diet items interact with one another such that the net energy or nutrient gain from a mixed diet differs from that predicted by summing the gains from individual diet components. We quantified nonadditive effects between duckweed, Lemma valdiviana, and grass shrimp, Palaemontes paludosus, in the freshwater turtle Trachemys scripta. We fed turtles 100% duckweed, 100% shrimp, and two mixed diets containing 67% duckweed, 33% shrimp and 14% duckweed, 86% shrimp (dry matter basis). During each feeding trial, we measured intake, digestibility, and transit time of the diet, and upon conclusion, short-chain fatty acid concentrations in turtle digestive tracts. Digestibility was lower on the 67% duckweed diet, but higher on the 14% diet. These apparent nonadditive interactions may be due to differences in transit time of duckweed and shrimp. We believe this is the first evidence of two diet items producing opposing nonadditive effects when fed in different ratios. [Copyright &y& Elsevier]

Abstract: This paper reviews the current theory and potential practical applications of research on the diet preference for grass and legumes in grazing domestic sheep and cattle. Although much of this work has focussed on grass and clover as a model system, it has wider theoretical implications and potential for practical exploitation. Research in this field is of particular relevance with the recent increased interest in maintaining and enhancing biodiversity, both in agricultural systems and semi-natural habitats. One of the most consistent findings of previous research is that sheep and cattle both eat mixed diets, showing a partial preference of approximately 70% for clover. There is a diurnal pattern to preference, with a stronger preference for clover in the morning, with the proportion of grass in the diet increasing towards the evening. Research has also shown that sheep and dairy cattle achieve higher intakes from grass and clover when these are offered as separate monocultures compared with animals grazing a traditional mixed sward. The initial findings were from studies where the animals had free choice, but similar results have been achieved in dairy cows being allocated to clover between morning and afternoon milking and grass for the remainder of the day. The intake benefits, which have been attributed to a lower selection cost, have the potential to be exploited on-farm to increase intake and production. Our increasing understanding of the factors influencing diet selection raises the possibility of developing grazing management practices to maintain and possibly enhance biodiversity. Various theories have been proposed to account for the fact that ruminants eat mixed diets. Although some, such as spatial memory and visual discrimination have been discounted, others, such as perceived predation risk and balancing nutrient intake, appear to be more valid. However, further research is still needed to explore and validate hypotheses related to these theories. [Copyright &y& Elsevier]

Eight (8) growing female Anglo-Nubian × Fiji local goats, 8–9-month-old, with a pre-trial mean live weight of 12.3±0.18 kg were allotted randomly in a double 4×4 Latin Square design after having balanced the groups for age and weight. They were used to investigate the nutritive value of sweet potato forage and its mixtures with batiki grass as goat feed in terms of voluntary feed intake, growth and digestibility. The four treatments used and offered to the goats were in the following ratios (sweet potato (%):batiki grass (%)): T1, 0:100; T2, 50:50; T3, 75:25, and T4, 100:0. The aerial parts of the sweet potato forage had low DM content. CP content was influenced by morphological parts of sweet potato. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) were higher in the stem and petiole than in the leaf portion. Among the morphological parts, the leaf had the lowest ADF and acid detergent lignin (ADL) contents. DM contents of the diets were between 37.3 and 40.5%. Batiki grass had a DM content slightly above that of sweet potato forage and the other experimental diets. Batiki grass had a low CP content (6.8%). Other diets had CP contents that ranged between 12.6 and 18.3%. All the diets had adequate concentrations of fibre (NDF, ADF, ADL, hemicellulose and cellulose), organic matter and metabolizable energy. There was no significant difference (P>0.05) between the consumption of batiki grass and sweet potato forage diets by the goats. The intakes of the mixed diets were significantly different from each other (P<0.05). The two mixed diets gave significantly (P<0.05) higher consumption than either batiki grass or sweet potato diets alone. Daily live weight gains of the goats were significantly affected (P<0.05) by forage type and ratios offered for consumption. The goats on the mixed diets gave better (P<0.05) live weight gains. The goats on sweet potato forage and mixed diets had significantly better-feed efficiencies (feed per gain) (P<0.05) than those on the batiki grass diet. Apparent nutrients digestibility (DM, CP, NDF, ADF, OM and energy) in the experimental diets by the goats were significantly different (P<0.05) from each other. The goats that received batiki grass gave the lowest digestibility of nutrients. In conclusion, this trial has demonstrated that sweet potato forage can support growth in goats and in combination with low quality grass such as batiki. Based on the data obtained sweet potato forage appears to be a cheap nitrogen source in the diets of growing goats. [Copyright &y& Elsevier]

It was studied whether the type of bread (i.e. a low-fibre wheat???rye mixed bread and coarse or fine wholemeal rye bread) either as part of a diet or alone, had an influence on the short-chain fatty acids (SCFA) produced during in vitro fermentation. Fermentation substrates were dietary fibre residues obtained from diets and breads. In addition, it was investigated whether the faecal SCFA pattern in the inoculum donors, who ingested the experimental diets, could be predicted by in vitro fermentation. Yields of SCFA in vitro were 0??51???0??62 g/g fermented polysaccharide. In vitro, the molar ratios of butyrate were higher for the two high-fibre diets containing coarse or fine wholemeal bread than for the low fibre diet containing wheat???rye mixed bread; the difference was significant for the coarse (P < 0??01), but not for the fine bread diet (P = 0??0678). The coarse wholemeal bread alone produced a higher molar ratio of butyrate than the fine wholemeal bread (P < 0??05) and the wheat???rye mixed bread (P < 0??01). Ingestion by the inoculum donors of the diets containing wholemeal bread led to higher faecal butyrate ratios (molar ratios: coarse bread diet 19??6, fine bread diet 17??7) compared with the wheat???rye mixed bread-containing diet (14??9), but the differences between the diets were not significant. For the diets investigated, there were no significant differences between faecal and in vitro SCFA patterns. [ABSTRACT FROM PUBLISHER]

Abstract: The copepod Pseudodiaptomus euryhalinus was fed 320 cells μL−1 of monoalgal cultures of Chaetoceros muelleri, Nannochloropsis oculata, Isochrysis galbana, Tetraselmis suecica, or a commercial frozen concentrate of Tetraselmis sp., and the diet which gave the best production was compared in a second experiment to three mixed diets: C. muelleri:I. galbana supplied in 1:1 and 2:1 cell ratios and C. muelleri:I. galbana:frozen Tetraselmis sp. in 2:2:1 ratio. These gave better results than the cultures of N. oculata, I. galbana, T. suecica and the frozen Tetraselmis concentrate, but the production was similar to that obtained with C. muelleri supplied as a monoalgal diet, showing that the addition of C. muelleri may improve the performance of other monoalgal diets, whereas the addition of other microalgae is unlikely to improve the results obtained when C. muelleri is supplied as a monoalgal diet. [Copyright &y& Elsevier]

The aim of this study was to explore the glycaemic response (GR) patterns of four dried fruits (DF) and the mixed meals containing dried fruits, rice and almonds. Dried apples (DApp), dried jujubes (DJ), raisins (Ra) and dried apricots (DApr) were tested in eleven healthy subjects in random order. Test meals included the following 3 groups: (1) dried fruits containing 50 g available carbohydrates; (2) mixed meals consisting of DF and rice (DF + R), each contributing 25 g available carbohydrates; (3) Group (2) supplemented with 30 g almonds (DF + R + A). The postprandial GR and other characteristics in 240 min were investigated. The GI values of 4 DFs were 43 for DApp, 55 for DJ, 56 for both Ra and DApr. The DApp displayed the smallest amplitude of glycaemic excursion within 240 min (MAGE0–240). Compared with rice, the DApp + R meal elicited a significantly reduced GR and a smaller MAGE0–240 (GI 81 vs. 65). With the addition of almonds, the GIs and MAGE0–240 decreased significantly in all DF + A + R combinations except DApp + R + A. The ratio of total fructose/glucose contents of test meals were negatively correlated to GIs. Dried fruits and nuts may have the potential to mitigate the postprandial GR when jointly introduced into glycaemic management diets. [ABSTRACT FROM AUTHOR]

The aim of this work was to investigate the growth performance of Diaphanosoma birgei fed with two Chlorophyceae algae, Ankistrodesmus gracilis and Haematococcus pluvialis using monoalgal diets and simpler mixed diets. D. birgei was daily fed on four treatments: 1) 100% Ankistrodesmus gracilis (Ag); 2) 100% Haematoccocus pluvialis (Hp); 3) 25% A. gracilis + 75% H. pluvialis (Ag-25+Hp-75) and 4) 75% A. gracilis + 25% H. pluvialis (Ag-75+Hp-25). The fecundity curve of D. birgei showed that the mixed feed Ag-25+Hp-75 and temperature 24±2°C triggered fast fecundity at approximately two days. The fecundity was low when based only on H. pluvialis (Hp), albeit with greater longevity (19 days) and a higher number of broods (8). D. birgei fed on Ag and Ag-75+Hp-25 diets in this experiment sustained higher growth rate and higher lipid content in these treatments. The present study showed that A. gracilis diet and mixed microalgae diets tested were able to support the egg production and development of D. birgei.