Sole Diet Research Articles

Nitrogen Fixation and Diazotrophic Community in Plastic-Eating Mealworms Tenebrio molitor L.

Mealworms, the larvae of a coleopteran insect Tenebrio molitor L., are capable of eating, living on, and degrading non-hydrolyzable vinyl plastics as sole diet. However, vinyl plastics are carbon-rich but nitrogen-deficient. It remains puzzling how plastic-eating mealworms overcome the nutritional obstacle of nitrogen limitation. Here, we provide the evidence for nitrogen fixation activity within plastic-eating mealworms. Acetylene reduction assays illustrate that the nitrogen-fixing activity ranges from 12.3 ± 0.7 to 32.9 ± 9.3nmol ethylene·h-1·gut-1 and the corresponding fixed nitrogen equivalents of protein are estimated as 8.6 to 23.0µg per day per mealworm. Nature nitrogen isotopic analyses of plastic-eating mealworms provide further evidence for the assimilation of fixed nitrogen as a new nitrogen source. Eliminating the gut microbial microbiota with antibiotics impairs the mealworm's ability to fix nitrogen from the atmosphere, indicating the contribution of gut microbiota to nitrogen fixation. By using the traditional culture-dependent technique, PCR and RT-PCR of nifH gene, nitrogen-fixing bacteria diversity within the gut was detected, and the genus Klebsiella was demonstrated to be an important nitrogen-fixing symbiont. These findings first build the relationship between plastic degradation (carbon metabolism) and nitrogen fixation (nitrogen metabolism) within mealworms. Combined with previously reported plastic-degrading capability and nitrogen-fixing activity, mealworms may be potential candidates for up-recycling of plastic waste to produce protein sources.

Availability of donor milk improves enteral feeding but has limited effect on body growth of infants with very-low birthweight: Data from a historic cohort study.

Compare with preterm formula, donor human milk (DM) is associated with a lower risk of mortality and morbidity in preterm infants. It is thus deemed superior to preterm formula as the sole diet or supplement to own mother's milk (OMM) for preterm infants, especially for those with very low birthweight (VLBW). This historic cohort study investigated the relationship between DM availability, and enteral feeding, body growth of VLBW infants by comparing two cohorts before and after the establishment of a human milk bank. A sub‐analysis was also conducted between small‐for‐gestational‐age (SGA) and non‐SGA infants in our cohorts. Our results showed that DM availability was associated with earlier initiation and faster advancement of enteral feeding, earlier attainment of full enteral feeding, and a higher proportion of OMM in enteral feeding. DM availability was also associated with earlier regain of birthweight, but not with better body growth. SGA and non‐SGA infants responded differently to DM availability with only the non‐SGA group showing improved enteral feeding associated with DM availability. The poor growth of VLBW infants with fortified DM warrants further investigations on better fortification strategies to further improve body growth. Studies are also needed on long‐term effects of DM feeding on the development of VLBW infants.

Tenebrio molitor: possible source of polystyrene-degrading bacteria

BackgroundThe excessive use of polystyrene as a packaging material has resulted in a rise in environmental pollution. Polystyrene waste has continually increased water pollution, soil pollution and the closing of landfill sites since it is durable and resistant to biodegradation. Therefore, the challenge in polystyrene disposal has caused researchers to look for urgent innovative and eco-friendly solutions for plastic degradation. The current study focuses on the isolation and identification of bacteria produced by the larvae of beetle Tenebrio molitor (yellow mealworms), that enable them to survive when fed with polystyrene foam as their sole carbon diet.Materials and methodsThe biodegradation of polystyrene by Tenebrio molitor was investigated by breeding and rearing the mealworms in the presence and absence of polystyrene. A comparison was made between those fed with a normal diet and those fed on polystyrene. The mealworms which were fed with polystyrene were then dissected and the guts were collected to isolate and identify the bacteria in their guts. The viability and metabolic activity of the isolates were investigated. The polymerase chain reaction (PCR) followed by sequencing was used for molecular identification of the isolates. The PCR products were directly sequenced using Sanger’s method and the phylogenetic tree and molecular evolutionary analyses were constructed using MEGAX software with the Neighbour Joining algorithm. The evolutionary distances were computed using the Maximum Composite Likelihood method.ResultsThe decrease in mass of the polystyrene as feedstock confirmed that the mealworms were depending on polystyrene as their sole carbon diet. The frass egested by mealworms also confirmed the biodegradation of polystyrene as it contained very tiny residues of polystyrene. Three isolates were obtained from the mealworms guts, and all were found to be gram-negative. The sequencing results showed that the isolates were Klebsiella oxytoca ATCC 13182, Klebsiella oxytoca NBRC 102593 and Klebsiella oxytoca JCM 1665.ConclusionKlebsiella oxytoca ATCC 13182, Klebsiella oxytoca NBRC 102593 and Klebsiella oxytoca JCM 1665 maybe some of the bacteria responsible for polystyrene biodegradation.

New insights into dietary management of polar bears (Ursus maritimus) and brown bears (U. arctos).

Although polar bears (Ursus maritimus) and brown bears (U. arctos) have been exhibited in zoological gardens for centuries, little is known about their nutritional needs. Multiple recent studies on both wild and captive polar bears and brown bears have found that they voluntarily select dietary macronutrient proportions resulting in much lower dietary protein and higher fat or digestible carbohydrate concentrations than are currently fed in most zoos. These lower protein concentrations selected by both species maximized growth rates and efficiencies of energy utilization in brown bears and may play a role in reducing kidney, liver, and cardiovascular diseases in both species. Therefore, we propose the need for the development of new dietary regimens for both species in managed care that better reflect their macronutrient needs. We developed a new kibble that is higher in fat and lower in protein than typical diets that have been fed in managed care, has a fatty acid profile more consistent with wild bear diets, and has been readily consumed by both brown bears and polar bears. The kibble can be fed as the sole diet or as part of more complex diets with additional fruits, meats, or vegetables. Because many nutritional deficiencies and related diseases can take months or years to appear, we urge caution and continued long-term monitoring of bears and their diets to ensure their optimal health.

Effect of feeding Asystasia gangetica weed on intake, nutrient utilization, and gain in Kacang goat

A high concentration of nitrate and total nitrogen (N) in Chinese violet (CV) weed (Asystasia gangetica) has a potential benefit as a digestible protein source for ruminant production in humid tropical regions. We conducted a study using twelve Kacang goats in a crossover design to investigate the effect of CV weed on intake, nutrient utilization, and growth. Four dietary treatments were tested: Guinea grass (Panicum maximum) ad libitum (GG), GG ad libitum and CV (1% live weight, LW) (GG + CV), CV ad libitum (CV), and CV ad libitum plus cassava chip (1% LW) (CV + CC) (dry matter, DM basis). No sign of nitrite toxicity was observed when the goat fed CV diet while intake, N retention, and LW gain was higher than goats on the GG and GG + CV diets (P < 0.001). Digestibility of DM was similar to the goats on the GG + CV diet but higher than the goats on the GG diet (P < 0.001). However, the goats on the CV diet had a higher urinary N loss compared to the goats on GG and GG + CV diets (P < 0.001). The cassava supplementation (CV + CC) increased DM digestibility and lowered urinary N loss (P < 0.001). Hence, the CV weed could be fed as a sole diet or as a supplement to the Kacang goat fed a low-quality forage for improvement of nutrients intake, digestibility, and gain, while the urinary N loss could be lowered by cassava supplementation.

Sustainable strategy for lignocellulosic crop wastes reduction by Tenebrio molitor Linnaeus (mealworm) and potential use of mealworm frass as a fertilizer

Lignocellulosic crop wastes (LCW) are refractory solid wastes that are not biodegradable at appreciable rates in most environments, causing management of LCW been environmental concerns for years. This study investigated the feasibility of low waste emission complete LCW (rice straw (RS), rice husk (RH), and corn straw (CS)) recycling through feeding to Tenebrio molitor Linnaeus larvae (mealworms) using egested frass to produce organic fertilizers. For larvae fed RS, CS, and RH plus nutrients co-diets groups, the 48-day average specific rates of LCW consumption increased by 118.09%, 155.30%, and 87.14%, respectively when compared with that of sole diet groups. The order of the feed consumption rate and conversion rate in a mealworm farm fed on the three LCWs agreed with the trend obtained with lab-scale experiments, with RS＞CS＞RH. The forty-eight days cellulose, hemicellulose, and lignin biodegradation increased by 1.48–17.61%, 4.26–11.50%, and 4.20–15.75%, respectively, for co-fed larvae. Enterococcus sp. and Erwinia sp., which previous reports have indicated are strongly associated with lignocellulose degradation, were identified in the gut microbiome of mealworms fed with RS and CS co-diets. Furthermore, the RS-fed frass quickly formed a high-quality compost within 32 days of composting, which had a germination rate ratio of 8% and 17% higher than that of WB and CS-fed frass. LCA (life cycle assessment) proved a relatively promising environmental-friendly alternative to dispose of RS, using their excreted frass for composting with low waste emissions. This study provides new insight into insect-involved crop waste utilization, and economical strategies for sustainable in situ recycling of LCWs into high-value-added products.

Type of Dietary Fiber Is Associated with Changes in Ileal and Hindgut Microbial Communities in Growing Pigs and Influences In Vitro Ileal and Hindgut Fermentation

BackgroundThe degree of ileal organic matter (OM) fermentation appears to be comparable to hindgut fermentation in growing pigs. ObjectivesThis study aimed to determine if dietary fiber sources with known different total gastrointestinal tract (GIT) fermentability in humans affect ileal and hindgut microbial communities and ileal fermentation in growing pigs used as an animal model for human adults. MethodsMale pigs (21 kg bodyweight; 9 wk old; PIC Camborough 46 × PIC boar 356L; n = 8/diet) were fed for 42 d a diet containing cellulose (CEL, low fermentability) as the sole fiber source (4.5%) or diets in which half of the CEL was replaced by moderately fermentable fiber, psyllium (PSY), or kiwifruit (KF) fiber. For each diet, terminal jejunal (substrate) and ileal (inoculum) digesta were collected from euthanized animals for in vitro ileal fermentation (2 h). Terminal ileal (substrate) and cecal (inoculum) digesta were used for in vitro hindgut fermentation (24 h). After in vitro fermentations, OM fermentation and short-chain fatty acid (SCFA) production were determined. Ileal digesta and feces were collected for microbial analysis. Data were analyzed by 2-factor ANOVA (diet × GIT region). ResultsIn vitro ileal OM fermentation was on average 22% and comparable to hindgut OM fermentation. Ileal and hindgut OM fermentation, SCFA production, and microbial community composition changed (P < 0.05) when CEL was partially replaced by KF or PSY. For instance, pigs fed the PSY diet had 3-fold higher (P ≤ 0.05) number of ileal and fecal bacteria than pigs fed the CEL and KF diets. Pigs fed the CEL diet had 4-fold higher (P ≤ 0.05) hindgut valeric acid production than pigs fed the other diets. ConclusionsIleal fermentation is quantitatively significant. Partial substitution of CEL with more fermentable fibers influences both ileal and hindgut microbial communities and the fermentation in growing pigs.

Dairy Beef Production from Mixtures of Sugarcane Bagasse and Concentrates

Sixteen Holstein-Friesian and Brown Swiss male calves, ranging in age from 212 to 278 days and in weight from 162 to 339 pounds, were fed to slaughter weights of approximately 1,000 pounds on four mixtures of sugarcane bagasse and concentrates. All four mixtures were fed ad libitum as the sole diet to two pairs of animals in two separate pens. The diets contained two levels of bagasse (20 and 30 percent) and two levels of crude protein (approximately 12.5 and 16 percent), thus constituting a 2X2 factorial design. The following respective average responses were observed on diets A (low bagasse-low protein), B (low bagasse-high protein), C (high bagasse-low protein), and D (high bagasse-high protein): Daily liveweight gain, 2.46, 2.61, 2.54, and 2.33 pounds; daily feed consumption, 19.3, 19.0, 20.5, and 19.7 pounds; and feed consumed per pound of gain, 7.84, 7.28, 8.07, and 8.45 pounds. None of these differences among treatments were significant. The feed conversion ratios were in the range of 4.5 to 5.5 during the first month and thereafter increased steadily to values approaching and/or above 10.0. During the 24-hour pre-slaughter shrink the animals fed the high-bagasse diets lost proportionately more liveweight than the animals fed the lowbagasse rations (5.13 and 5.09 vs. 3.10 and 3.35 percent). The same result was found as to weight lost by the carcass upon chilling (1.98 and 1.55 vs. 1.32 and 1.33 percent). The diets had no significant effects on chilled carcass dressing percentages, the averages being 54.3, 54.8, 52.6, and 53.4 for A through D, respectively. Neither were there any significant differences among treatments in the percentages of chilled carcass weight represented by the various wholesale cuts nor in the Wamer-Bratzler shear force-scores of meat samples from the rib or round. It is concluded that all four formulas gave excellent and comparable results in growth response of the animals and their carcass yields. The higher level of protein was not significantly beneficial, nor the higher level of bagasse significantly detrimental.

Haematological Indices of Growing Rabbits Fed Herbaceous Plants as Sole Diet

Haematological Indices of Growing Rabbits Fed Herbaceous Plants as Sole Diet

Economic Returns from Cereal and Cereal/Vetch Forage Crops Grown as Fodder Conservation Options for Beef and Sheepmeat Production

The economic return from cereal or cereal/vetch crops was determined using previously published and new agronomic and herbage quality data from experiments conducted at four sites across southern New South Wales, Australia, over four years (2008 to 2011), to evaluate the agronomic and quality parameters of two wheat (Triticum aestivum L.), two barley (Hordeum vulgare L.), two oat (Avena sativa L.), and one triticale (x Triticosecale) variety, grown as monocultures or in combination with purple vetch (Vicia benghalensis L.). The crops (n = 193) were harvested at different stages of cereal maturity and ranged in metabolisable energy (ME) from 6.9 to 13.1 MJ/kg DM and crude protein (CP) content from 49.8 to 215.4 g/kg DM. Individual crop ME and CP content was used to predict dry matter intake and liveweight gain using Grazfeed decision support tool, assuming the forages were fed as the sole diet to either crossbred lambs or British breed steers, with initial liveweights of 30 or 300 kg respectively. Animal parameters and yield were used to estimate gross margins (GM) for each crop based on estimated fixed and variable costs, including sowing and fertiliser costs, and harvesting and feedout costs. Feed quality determined animal production and potential income per animal, while yield determined potential income per hectare for any given level of animal production. Across the three years GM ranged from −$1489 to $5788 in sheep and from −$1764 to $647 in cattle. Reducing costs or increasing livestock value improved the GM. The highest GM were for lambs fed crops with high ME, adequate CP, and good yields. Increasing yield reduced the GM when growth rates were low, and costs exceeded the value of liveweight gain.

Human milk feeding and cognitive outcome in preterm infants: the role of infection and NEC reduction

BackgroundBreast milk has been associated with lower risk of infection and necrotising enterocolitis (NEC) and improved long-term cognitive outcomes in preterm infants but, if unsupplemented, does not meet the nutritional requirements of preterm infants.MethodsPreterm infants were randomised to receive a high nutrient intervention diet: preterm formula (PTF) or the standard diet: term formula (TF) or banked donor breast milk (BBM), either as their sole diet or as supplement to maternal breast milk (MBM). IQ tests were performed at ages 7, 15, 20, and 30 years.ResultsAn increase in MBM and BBM intake was associated with a lower chance of neonatal infection/NEC. Neonatal infection/NEC was associated with lower Full Scale IQ (FSIQ) and Performance IQ (PIQ) score at ages 7 and 30 years. The relationship between higher intake of MBM and PIQ at age 7 years was partly mediated by neonatal infection/NEC. The intervention diet was associated with higher Verbal IQ (VIQ) scores compared to the standard diet. There was no evidence that these effects changed from childhood through to adulthood.ConclusionsNeonatal diet is an important modifiable factor that can affect long-term cognitive outcome through a ‘human milk’ factor, protecting against infection/NEC, and a ‘nutrient content’ factor.ImpactThis is the first study to demonstrate the effects of neonatal infection/necrotising enterocolitis (NEC) on IQ in the same cohort in childhood and adulthood.Diet can be a key factor in long-term cognitive outcome in people born preterm by preventing neonatal infection/NEC and providing adequate nutrients.Human milk, whether MBM or BBM, is associated with a reduced risk of infection/NEC.A higher nutrient diet is associated with better cognitive outcome in childhood.Performance IQ is particularly vulnerable to the effects of infection/NEC and verbal IQ to the quantity of (macro)nutrients in the diet.

Ameliorative effects of colostrum against DMBA hepatotoxicity in rats.

Colostrum, the sole diet for newborns, is an emerging nutraceutical. To date, the chemopreventive effect of Bovine Colostrum against liver injury induced by the potent carcinogen, 7,12-dimethyl-Benz[a]anthracene (DMBA) is unexplored. Humans are daily exposed to DMBA which is a highly lipophilic environmental organic pollutant. The study aimed to investigate the hepatoprotective role of Bovine Colostrum against DMBA-induced hepatotoxicity using a rat model. Fifty male rats were divided into five groups; GI (control), GII (olive oil, vehicle for DMBA), GIII (DMBA), GIV (DMBA + Bovine Colostrum), GV (Bovine Colostrum). After 12 weeks, body weight changes and mortality were calculated. Histological and ultrastructural examinations of liver tissue were performed. Expressions of p53, TGFβ2, TNF-α, S6K2, and c20orf20 were assessed by RT-PCR. Post-treatment with Bovine Colostrum increased both the body weight and the survival rate of rats treated with DMBA. In addition, remarkable protection against the pathological effect of DMBA was noted. Ultrastructurally, Bovine Colostrum ameliorated/prevented most of the toxic effects of DMBA on hepatocytes, including irregularities of nuclear envelope, clumping, and margination of heterochromatin aggregates, segregated nucleoli, and mitochondrial pleomorphism. Bovine Colostrum administration down-regulated p53, C20orf20, and S6K2 mRNA levels, and up-regulated TNF-α and TGFβ2. In conclusion, Bovine Colostrum have a protective effect against DMBA-induced toxicity on the liver of albino rats. Consequently, Bovine Colostrum may prevent polycyclic aromatic hydrocarbons-induced hepatotoxicity and may be useful in promoting human health if supplemented in the diet.

Feeding value of shrimp waste meal for West African Dwarf sheep fed soybean stover basal diet

A degradability and feeding trial was carried out to estimate the utilization of soybean stover (SBS), Shrimp waste meal (SWM) and their mixtures (SBS+SWM) in West African Dwarf sheep. Sole sammples of SBS&lt; SWM and mixture of SBS+SWM were incubated in the rumen of castrated West African Dwarf rams. Degradation lasted 48 hours. Feeding trial entailed feding levels (0%, 5%, 10%, 15%) of SWM to a sole SBS diet. The growth study lasted for eight weeks. Results obtained in the degradability trial showed that there were significant (P&lt;0.05) differnces in the dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), and acid detergentfibre (ADF) degradability parameters for the feedstuffs. The effective DM degradability 'ED' was highest in SBS (343.0g/kg) and lowest in SWM (250.0g/kg). Crude protein effective degradability 'ED' ranged between 101.0 and 301.0g/kg for SBS and SBS+SWM respectively. NDF 'ED' ranged between 398.6g/kg for SWM and 815.7g/kg for SBS. ADF degradation characteristics for the constituents were also significantly (P&lt;0.05) different with the soluble fraction 'a' values ranging between 126.0 and 624.0g/kg. When graded levels of shrimp waste meal was used as supplement to soybean stover, there were significant differences (P&lt;0.05) in the average daily weight gain, which ranged from 9.52 to 22.85gd-1.The mean live weight gain was highest at 10% level of inclusion. Average daily DM intake increased significantly (P&lt;0.05) with increasing level of SWM in the diet. The sole soybean stover diet however had the least DMI. MD, OM, NDF and ADF apparent digestibility coefficients were not significantly affected by the treatment imposed. CP digestibiliy increased (P&lt;0.05) with increasing level of SWM to peak at the 15% level of inclusion (0.767) compared to the sole SBS treatment (0.593). Nitrogen balance was significantly (P&lt;0.05) increased as the level of inclusion of SWM increased. Results suggest that feeding soybean stover as roughage along with up to 10% SWM to sheep may be sufficient to meet the requirements for weight gain and proper nutrient utilization

Performance of West African dwarf sheep fed cassava peel-based diets

Chemical compositions of ensiled cassava peels, dried cassava peels and gliricidia on the performance of West African Dwarf sheep were evaluated. Twelve grower rams and ewes between 5-7 months of age were allotted to three treatment diets: D1 (control) diet was 100% gliricidia (GLI) (leaves with bark and soft stem), D2 consisted of 80% ensiled cassava peels plus 20% gliricidia (ENP/GNI) while D3 consisted of 80% dried cassava peels plus 20% gliricidia (DP/GLI). The three test feeds were observed to have more comparable crude fibre contents ranging from 16.07% for ensiled cassava peels to 18.20% for gliricidia. The gross energy values were also comparable ranging from 3.93kcal/gDM for ensiled cassava peels to 4.64kcal/gDM for gliricidia. Gliricidia was however observed to be richer in crude protein and minerals compared to ensiled cassava peels and dried cassava peels. Dry matter intakes, dry matter digestibility and growth rates showed significant (P&lt;0.05) differences with the tilt being in favor of the animals fed on the sole glricidia diet. The energy digestibility of 79.83% for the animals fed on ensiled cassava peels and gliricidia diet was not significanyly (P&gt;0.05) different from the corresponding value of 82.67% observable for animals fed on the sole gliricidia diet. Both values were however significantly higher (P&lt;0.05) than the values of 74.17% obtained for animals on the dried cassava peel plus gliricidia diet. Feed conversion values showed no significant (P&gt;0.05) differences for the three groups ranging from 8.8. (ENP/GLI) to 10.80 (DP/GLI). Cassava peels supplemented with gliricidia can be used in practical production diets for West African Dwarf sheep with better prospects of utilization through ensiling of the peels.

Ranking Species for Veld Restoration in Semi-Arid Regions Using Agronomic, Morphological and Chemical Parameters of Selected Grass Species at Different Developmental Stages under Controlled Environment

The establishment of complementary native grass species could be an ideal method of dealing with existing problems of veld degradation and inadequate forage quantity and quality of pastures. A greenhouse experiment was conducted to evaluate the effect of native grasses viz., Anthephora pubescens, Cenchrus ciliaris, Chloris gayana, Dactylis glomerata, Digitaria eriantha, Eragrostis curvula, Festuca arundinacea, Panicum maximum and Themeda triandra. Attributes at different growth stages on agronomy, morphology and chemical composition were checked. Panicum maximum had the broader (p &lt; 0.05) leaves across all growth stages when compared to all other grass species. Festuca arundinacea had highest (p &lt; 0.05) number of tillers than C. ciliaris, C. gayana, D. glomerata, D. eriantha, E. curvula, P. maximum and T. triandra at 2–4-months age. Within each species, all grasses had the highest (p &lt; 0.05) number of leaves at maturity. Chloris gayana, D. glomerata and P. maximum had the highest (p &lt; 0.05) biomass yield when compared to F. arundinacea at the elongation stage. Eragrostis curvula had the highest (p &lt; 0.05) crude protein (CP) values when compared to all other grasses, except for D. glomerata, F. arundinacea and P. maximum at the elongation stage. Panicum maximum and T. triandra had the least (p &lt; 0.05) acid detergent lignin (ADL) values when compared to all other grasses at both vegetative and the elongation stages. In the ranking, C. ciliaris, C. gayana, D. eriantha, E. curvula, P. maximum and A. pubescens outperformed the rest of the grasses on most parameters. With the low crude protein (CP) content of these grasses, protein supplementation is highly crucial for high performing ruminants, especially those animals that graze grasses as their sole diets.

Nutritive attributes of Sesbania parchycapa fodder in a crop-livestock farming system

Two experiments were conducted to investigate and compare the nutritive attributes of Sesbania parchycapa (SP) in a crop-livestock farming system. In Experiment 1, the feeding attributes of Sesbania parchycapa (SP) fodder was investigated with 15 West African Dwarf (WAD) sheep, by feeding Panicum maximum (PM) alone and P. maximum supplemented with S. parchycapa (SP) in the ratio of 70:30. The study lasted 28 days, during which feed intake was monitored daily. In Experiment 2, the nutritive value of SP was investigated with WAD sheep and goats by feeding them as sole diets. The study lasted 15 days consisting of 10 days adjustment and 5 days of data collection using 5 each of bucks and rams in a completely randomised design. In the first trial, DM intake (99.5g/kgBW0.75) was higher for the control PM and least (72.8g/kgBW0.75) for SP. Total DM intake followed similar trend. In the second trial, DM (185g/kgBW0.75), CP (40%) and NDF (645g/kgBW0.75) intakes were generally higher (p&lt;0.05). for sheep than for goats. DAM (562), CP (421) and NDF 680g/kg digestibility coefficients were also higher (p&lt;0.05)for sheep than for goats. The N balance and retention (g/h/d) was higher in sheep. Results indicated that intake, digestibility and N- utilisation of S. parcyhcapa by sheep is better than goats although both had a positive N-balance. It could be concluded that apart from the well known positive impact of S. Parchycapa in agro forestry and alley farming systems, it can effectively serve as protein supplement in a small holder crop-livestock farming system.

Biodegradation of polypropylene by yellow mealworms (Tenebrio molitor) and superworms (Zophobas atratus) via gut-microbe-dependent depolymerization

Polypropylene (PP), a fossil-based polyolefin plastics widely used worldwide, is non-hydrolyzable and resistant to biodegradation as a major source of plastic pollutants in environment. This study focused on feasibility of PP biodegradation in the larvae of two species of darkling beetles (Coleoptera: Tenebrionidae) i.e., yellow mealworms (Tenebrio molitor) and superworms (Zophobas atratus) using PP foam with number-, weight-, and size-average molecular weights (Mn, Mw, and Mz) of 109.8, 356.2, and 765.0 kDa, respectively. The tests were conducted in duplicates with respective larvae (300 T. molitor and 200 Z. atratus each incubator) at 25 °C and 65% humidity for over a 35-day period. The larvae of T. molitor and Z. atratus fed with PP foam as sole diet consumed PP at 1.0 ± 0.4 and 3.1 ± 0.4 mg 100 larvae−1 days−1, respectively; when fed the PP foam plus wheat bran, the consumption rates were enhanced by 68.11% and 39.70%, respectively. Gel permeation chromatography analyses of the frass of T. molitor and Z. atratus larvae fed PP only indicated that Mw was decreased by 20.4 ± 0.8% and 9.0 ± 0.4%; Mn was increased by 12.1 ± 0.4% and 61.5 ± 2.5%; Mz was decreased by 33.8 ± 1.5% and 32.0 ± 1.1%, indicating limited extent depolymerization. Oxidation and biodegradation of PP was confirmed through analysis of the residual PP in frass. Depression of gut microbes with the antibiotic gentamicin inhibited PP depolymerization in both T. molitor and Z. atratus larvae. High throughput 16S rRNA sequencing revealed that Citrobacter sp. and Enterobacter sp. were associated with PP diets in the gut microbiome of Z. atratus larvae while Kluyvera was predominant in the T. molitor larvae. The results indicated that PP can be biodegraded in both T. molitor and Z. atratus larvae via gut microbe-dependent depolymerization with diversified microbiomes.

Assessment of Growth, Lipid Metabolism and Gene Expression Responses in Senegalese Sole Larvae Fed With Low Dietary Phospholipid Levels.

Phospholipids (PL) are essential molecules for larval growth and development. In this study, growth, lipid metabolism and gene expression responses associated with different dietary PL levels in pelagic sole larvae were evaluated. In a first trial, the long-term effects on growth and survival of two experimental microdiets (MD) containing high (High-PL) or low (Low-PL) PL levels were tested and compared to a diet based on live prey (rotifers). The MD were supplied from 3 to 10 days post-hatch (dph) and Artemia from day 8 to 29 dph. High-PL fed larvae had higher dry mass (1.2-fold) than Low-PL fed larvae at 8 dph and both MD were smaller (2.9-fold) than larvae fed live preys. However, a compensatory growth (33% between 8 and 20 dph) occurred when MD were substituted by Artemia and by the end of the trial no significant differences in mass or survival occurred between the dietary treatments. In a second trial, growth, lipid metabolism and gene expression profiles of larvae fed with MD up to 8 dph were analyzed. Growth data confirmed that mass of larvae fed with High-PL was higher (1.3-fold) than the those fed Low-PL and they had lower levels of triacylglycerol (2.8-fold), cholesterol (1.2-fold) and cetoleic acid (1.7-fold). Histological analysis indicated an excess of lipid vacuoles in larvae fed with Low-PL and the expression analysis revealed a coordinated response to enhance lipid mobilization since the expression of genes involved in PL intermediate synthesis, PL remodeling as well as eight apolipoprotein was up-regulated. The down-regulation of apolipoprotein apob2 in larvae fed with Low-PL indicated a specific regulation by PL levels. The present work provides insight into the responses associated with dietary PL in early fish larvae, which will be of use for future studies aimed as designing effective larval sole diets.

Biodegradation of Polyvinyl Chloride (PVC) in Tenebrio molitor (Coleoptera: Tenebrionidae) larvae

Tenebrio molitor larvae (Coleoptera: Tenebrionidae) are capable of depolymerizing and biodegrading polystyrene and polyethylene. We tested for biodegradation of Polyvinyl Chloride (PVC) in T. molitor larvae using rigid PVC microplastic powders (MPs) (70–150 μm) with weight-, number-, and size-average molecular weights (Mw, Mn and Mz) of 143,800, 82,200 and 244,900 Da, respectively, as sole diet at 25 °C. The ingestion rate was 36.62 ± 6.79 mg MPs 100 larvae-1 d-1 during a 16-day period. The egested frass contained about 34.6% of residual PVC polymer, and chlorinated organic carbons. Gel permeation chromatography (GPC) analysis indicated a decrease in the Mw, Mn and Mz by 33.4%, 32.8%, and 36.4%, respectively, demonstrating broad depolymerization. Biodegradation and oxidation of the PVC MPs was supported by the formation of OC and OC functional groups using frontier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR), and by significant changes in the thermal characteristics using thermo-gravimetric analysis (TGA). Chloride released was counted as about 2.9% of the PVC ingested, indicating limited mineralization of the PVC MPs. T. molitor larvae survived with PVC as sole diet at up to 80% over 5 weeks but did not complete their life cycle with a low survival rate of 39% in three months. With PVC plus co-diet wheat bran (1:5, w/w), they completed growth and pupation as same as bran only in 91 days. Suppression of gut microbes with the antibiotic gentamicin severely inhibited PVC depolymerization, indicating that the PVC depolymerization/biodegradation was gut microbe-dependent. Significant population shifts and clustering in the gut microbiome and unique OTUs were observed after PVC MPs consumption. The results indicated that T. molitor larvae are capable of performing broad depolymerization/biodegradation but limited mineralization of PVC MPs.

GC-MS Analysis of Phthalates and Di-(2-thylhexyl) Adipate in Canadian Human Milk for Exposure Assessment of Infant Population.

Although more information has become available on the occurrence of phthalates and di(2-ethylhexyl) adipate (DEHA) in foods including cow's milk, information on their presence in human milk, the important and recommended sole diet for infants up to six months of age, is very limited, especially for DEHA. To develop a GC-MS method for simultaneous analysis of DEHA and phthalates in human milk samples and generate occurrence data for exposure assessment. Human milk samples were extracted with acetonitrile followed by dispersive solid-phase extraction and GC-MS analysis. Among the 305 human milk samples collected from the Canadian Maternal-Infant Research on Environmental Chemicals Study, some phthalates (DHxP, BBzP, and DOP) were not detected in any of the samples, while DEHA and the other phthalates (DMP, DEP, DBP, DiBP, and DEHP) were detected at low frequencies with levels from 30.4-237 ng/g in up to 31 of the 305 human milk samples. In general, DEHA and phthalates were detected at low frequencies and low levels in the 305 human milk samples. A GC-MS method based on dispersive solid phase extraction was developed for analysis of DEHA and eight phthalates in 305 human milk samples for exposure assessment.