Use Of Agro-industrial By-products Research Articles

Bioactive Ingredients Obtained from Agro-industrial Byproducts: Recent Advances and Innovation in Micro- and Nanoencapsulation.

The agro-industry produces numerous byproducts that are currently underused, and its waste contributes to environmental pollution. These byproducts represent an important and economical source of bioactive ingredients, which can promote the sustainable development of high-value-added functional foods. In this context, micro- and nanoencapsulation systems allow for the incorporation and stabilization of the bioactive agents in foods. This perspective will review recent advances in the use of agro-industrial byproducts as a source of bioactive agents. In addition, the latest advances in micro- and nanoencapsulation to improve the stability, solubility, and bioaccessibility of bioactive agents as functional food ingredients are exposed.

Investigation on thermal properties of rice husk ash-blended palm kernel shell concrete

The contribution of buildings to climate change as a result of energy consumption and greenhouse gas emissions necessitates the use of agro-industrial by-products as alternative construction materials. The present study examines the thermal properties of Rice husk ash-blended Palm Kernel Shell Concrete (RHA-blended PKSC). Three control concrete mixes with mix ratios of 1:1½:3, 1:2:4 and 1:3:6 using water-to-cement (w/c) ratios of 0.5, 0.6 and 0.7, respectively were made with cement, river sand and granite. For each mix ratio with the respective w/c ratio, five concrete mixes containing RHA fixed at 15% as replacement for cement and PKS at 20, 40, 60, 80 and 100% as replacement for crushed granite were produced. The oven-dry density, compressive strength and thermal properties (thermal conductivity, thermal diffusivity, volumetric heat capacity and thermal resistivity) were determined. The results showed that the oven-dry density and compressive strength of concrete declined with increasing PKS content. Nevertheless, the compressive strength increased with curing age and the gain in strength of RHA-blended PKSC were higher than the control at the later age. The thermal conductivity and diffusivity decreased with increasing PKS contents but increase with curing age while volumetric heat capacity and thermal resistivity increased as PKS content increases but decreased with curing age. In addition, concrete with 1:3:6 mix ratio exhibited the lowest thermal conductivity and diffusivity but higher volumetric heat capacity and thermal resistivity than those with 1:1½:3, 1:2:4 mix ratios. RHA-blended PKSC with 40% PKS and 15% RHA for 1:1½:3 mix ratio attained the compressive strength and thermal conductivity values recommended for lightweight aggregate concrete which is suitable for structural and insulation purposes. It was concluded that the combined use of PKS and RHA as raw materials in concrete is effective in improving concrete's thermal and insulation properties.

Agro-industrial byproducts in rabbit food: Case of the complex of detoxified apricot kernel cake and dehydrated tomato pulp.

Background and Aim:The use of agro-industrial byproducts as an unconventional source of raw materials for monogastric feed is one possible solution. This study aimed to determine the effects of incorporating detoxified apricot kernel meal (DAKM) as a substitute for soybean meal and dehydrated tomato pulp (DTP) as a substitute for alfalfa hay on the local rabbit fattening.Materials and Methods:A total of 120 white strain rabbits, weaned at 33 days, were randomly assigned to four groups of 30. The rabbits in each group were ringed, placed in cages at 6 rabbits/cage, and fed according to DAKM and DTP incorporation rates (0%, 30%, 40%, and 60%).Results:The weights at 77 days were improved (p<0.05) with unchanged mean daily intakes. The vast majority of slaughter parameters and carcass characteristics improved. The chemical composition of the meat constituents improved significantly, with a 60% increase in the protein content of the batch (26.55% vs. 28.53%), 38% reduction in the total feed cost, and 40 DA saved for each kilogram of feed consumed per rabbit. The relative economic efficiency improved in proportion to the substitution rates of soybean meal by DAKM and alfalfa hay by DTP.Conclusion:Substituting DAKM and DTP, as byproducts of agro-industrial processing, for up to 60% induced satisfactory results in rabbit fattening. Therefore, it would be more insightful to increase the incorporation rates to determine the optimal threshold.

Effect of selenium uptake on growth metabolism in yeasts for the production of enriched single-cell protein using agro-industrial by-products

The use of agro-industrial by-products as feedstock for selenium-enriched yeast biomass production is an innovative and low-cost method. Thus, the present study aims for the utilization of sugarcane bagasse and corn bran hydrolysates for the production of selenium-enriched yeast and the evaluation of the effect of selenium in growth and cell composition. The hydrolysates were obtained using acid pretreatment, and yeasts were evaluated in different medium compositions. All evaluated yeasts were able to grow in the presence of 15 mg/L selenium. S. cerevisiae strains presented the major tolerance to selenium and better relation between selenium uptake and cell growth, with maximum cell biomass production of 7.97 ± 0.24 g/L and maximum selenium uptake of 1193 ± 336 ppm and 99% cell viability. Selenium also enhanced the lipid and protein concentration in cell extracts obtained after mechanical disruption. Regarding agro-industrial hydrolysates, corn bran hydrolysate allowed a better growth, with the production of 4.25 ± 0.49 g/L of biomass enriched with 167 ± 18 ppm selenium and 100% of viability. Starchy and lignocellulosic biomasses presented potential as low-cost alternatives for single-cell protein contributing to the development of sustainable and economically viable technologies.

Starch-Based Foam Packaging Developed from a By-Product of Potato Industrialization (Solanum tuberosum L.)

The use of petroleum-based packaging and its disposal in the environment poses several environmental problems, driving research into the development of biopolymers as substitutes for conventional polymers. Therefore, this study used the by-product of potato industrialization as the main raw material, xanthan gum as a plasticizer, and natural oat fiber as reinforcement to develop a biodegradable foam through thermo-pressing. The morphology, mechanical properties, and biodegradability of the final product were investigated. The water absorption and solubility index were highest in the sample with 20% plasticizer and 20% fiber. The water activity was not affected by variations in additives. The samples with the highest concentration of additives had the highest mechanical tensile strength, but there was a limit to these levels for foam resistance. The most accentuated visual effect was the yellow color. It is believed that hydrolysis was the main foam degradation mechanism, which took between 14 and 20 days for total decomposition. The combination of a by-product from potato industrialization with xanthan gum and natural oat fiber made it possible to produce a promising substitute for synthetic polymers, providing an environmentally friendly solution for both the use of agro-industrial by-products and reducing the volume of petroleum-based packaging waste.

Can Agro-Industrial By-Products Rich in Polyphenols be Advantageously Used in the Feeding and Nutrition of Dairy Small Ruminants?

Simple SummaryIn the Mediterranean area, where dairy sheep and goats are widespread, the use of by-products in the diet of small ruminants is an ancient practice. Today the great availability of industrial by-products produced at the local level (e.g., grape, olive, tomato and myrtle residues), appears to be a promising strategy for reducing competition with human edible foods and the cost of off-farm produced feeds since they are imported worldwide. Moreover, these co-feeds can contribute to reducing the ecological and water footprint associated with crop cultivation. The presence of bioactive compounds, such as polyphenols, confers added value to these materials. Several positive aspects are apparent when such by-products are included in the diets of small dairy ruminants, in particular on ruminal metabolism, animal health, and the quality of derived products.Recently, the interest in industrial by-products produced at the local level in Mediterranean areas, resulting from fruit and vegetable processes, has increased because of their considerable amounts of bioactive compounds, including polyphenols. In this review, we analyze the most recent scientific results concerning the use of agro-industrial by-products, naturally rich in polyphenols (BPRP), in the diets of small dairy ruminants. Effects on milk production, milk and rumen liquor fatty acid profile, metabolic parameters, and methane production are reviewed. The feed intake and digestibility coefficients were generally depressed by BPRP, even though they were not always reflected in the milk yield. The main observed positive effects of BPRP were on quality of the milk’s FA profile, antioxidant activity in milk and blood, a reduction of rumen ammonia, and, consequently, a reduction of milk and blood urea. The expected beneficial effects of dietary polyphenols in small ruminants were not always observed because of their complex and variable matrices. However, owing to the large quantities of these products available at low prices, the use of BPRB in small ruminant nutrition offers a convenient solution to the valorization of residues arising from agricultural activities, reducing feed costs for farmers and conferring added value to dairy products at the local level, in a sustainable way.

Partially defatted olive cake in finishing pig diets: implications on performance, faecal microbiota, carcass quality, slurry composition and gas emission

One of the key factors to improve swine production sustainability is the use of agro-industrial by-products in feeds, such as olive by-products. However, it is necessary to assess its effects on the overall production process, including the animal and the environment. With this aim, an experiment was conducted to determine the effects of including a partially defatted olive cake (PDOC) in pig diets on growth performance, faecal microbiota, carcass quality and gas emission from the slurry. Two finishing diets were formulated, a control (C) diet and a diet with PDOC included at 120 g/kg. Eighty finishing male pigs Duroc-Danbred × (Landrace × Large White) of 60.4 ± 7.00 kg BW were divided between these two treatments. During the finishing period (60 to 110 kg BW, 55 days) average daily gain, average daily feed intake and feed conversion ratio were recorded. Faecal samples from the rectum of 16 animals per treatment were incubated for bacteria enumeration. At the end of finishing period, backfat thickness and loin depth (LD) were measured. Animals were slaughtered to obtain carcass weight and carcass composition parameters, and subcutaneous fat was sampled to analyse the fatty acid (FA) profile. In addition greenhouse gas and ammonia emissions were measured during pig slurry storage using the methodology of dynamic flux chambers. An initial slurry characterisation and biochemical methane potential (B0) were also determined. No significant differences between treatments were found in performance, carcass quality and microbial counts with the exception of LD, which was lower in PDOC compared with C animals (45.5 v. 47.5 mm, SEM: 0.62; P = 0.020). The FA profile of the subcutaneous fat did not differ between treatments, but the monounsaturated FA (MUFA) concentration was higher and the polyunsaturated FA was lower in the animals fed PDOC (50.9 v. 48.3, SEM: 0.48, P < 0.001; 17.6 v. 19.3, SEM: 0.30, P < 0.001 in mg/100 g of Total FA, for PDOC and C animals, respectively). The initial pig slurry characterisation only showed differences in ADF concentration that was higher (P < 0.05) in the slurry from PDOC treatment. Regarding gas emission, slurries from both treatments emitted similar amounts of ammonia (NH3), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), as well as B0 values. The results obtained suggest that PDOC may be included in balanced pig diets at rates of up to 120 g/kg without negative effects on performance, carcass quality, gut microflora and slurry gas emission, while improving the MUFA concentration of subcutaneous fat.

Nutritional value of babassu cake as a replacement for roughage in sheep feed

The use of agro-industrial by-products in feeding ruminants has nutritional, environmental and economic advantages, and helps to sustain the production system. The aim of this study was to evaluate the nutritional value of diets containing babassu cake as a substitute for Tifton-85 hay (70, 140, 210, 280 and 350 g kg-1 dry matter: DM). Twenty-five castrated male sheep with a mean body weight of 49.6 ± 9.4 kg were used, distributed in metabolic cages in a completely randomised design. Voluntary intake was obtained from the difference between the amount of feed provided and the leftovers the following morning. To evaluate nutrient digestibility and nitrogen (N) balance, samples of urine and faeces were collected separately. There was no effect on DM intake; however, crude protein (CP) and ether extract intake increased linearly increased linearly. The addition of babassu cake had no effect on DM digestibility (mean value of 604.6 ± 272.8 g kg-1). Apparent CP digestibility and total digestible nutrient content showed increasing linear behaviour, while the digestibility of acid detergent fibre decreased linearly. The level of retained N varied from 9.72 ± 1.12 to 15.51 ± 1.84 g day-1 with the ratio to ingested N ranging from 521.0 ± 26.7 to 578.4 ± 31.8 g kg-1 N. The addition of babassu cake to replace the roughage, increased the nutritional value of the diet. Babassu cake can be included up to a total of 350 g kg-1 DM in the diet as a substitute for Tifton-85 hay.

Effect of Feeding Different Mixtures of Short Milled Wheat and Sesame Seed Cake on Intake, Digestibility, and Live Bodyweight Changes for Abergelle Sheep in Tigray

Background: The use of agro-industrial by-products is an alternative to enhance the performance of animals. Objective: To improve feed intake, digestibility, and live bodyweight changes for Abergelle sheep fed different mixtures prepared using short milled wheat and sesame seed cake mixtures. Methods: The experiment was designed using yearling male rams and was divided into four blocks based on initial live weight and assigned to each dietary feed randomly. The diets were prepared at a level of 0, 120, 240, and 360 gram dry matter base/day for diet1, diet2, diet3, and diet4, respectively, with a proportion of 65:35 (short milled wheat: sesame seed cake) combinations. Digestibility trial was conducted for 7 consecutive days following the 90 days feeding stage. Results: Total dry matter and nutrient intake were significant (P&lt;0.001) in the order of diet4&gt; diet3&gt; diet2 level of supplementation than the control group (diet1). Feed conversion efficiency and final bodyweight gain were significant (P&lt;0.01) for the supplemented groups. Apparent digestibility of crude protein was observed highest in diet4 (81.32) and lowest in diet1 (61.55). Similarly, dry matter and organic matter digestibility were significantly higher in diet4 (74.47, 76.38) and lowest in diet1 (58.71, 60.42), respectively. In general, supplementation with different levels of sesame seed cake and short milled wheat improves the biological performance of Abergelle sheep. Conclusion: The growth performance of rams can be realized supplementing with diets prepared using short milled wheat and sesame seed cake mixtures.

Effect of formulated feed (containing common bean and leftover flour) on growth performance of Nile tilapia (Oreochromis niloticus L.) in earthen ponds at Nono district, Ethiopia

Fish feed plays a critical role in aquaculture; it influences production costs, fish growth, health and fish production. One of the approaches to tackle this problem has been to experimentally test the use of agro-industrial byproducts to grow fish in ponds. Thirty (30) fingerlings of Nile tilapia were stocked in each pond and fed with five percent of their body weight twice a day. Fish growth was measured using measuring board and sensitive balance and recorded fortnightly. Feed 1 performed better body weight gain (BWG) and Feed 3 produced the lowest BWG. The formulated Feed 1 which formulated from 50% of leftover flours from local grain mill machine and 50% of common bean indicated also a better profit index than others. In addition, Feed 1 showed the highest mean PR 88.59, which indicates the yield that it can produce in the given area and showed statistically significant (ANOVA (F = 2.39), P = 0.02). It is ascertained that the formulated Feed 1 can be recommended for farming Nile tilapia in the study area.

Production and characterization of Gluconacetobacter xylinus bacterial cellulose using cashew apple juice and soybean molasses

Bacterial cellulose (BC) has been largely used in biomedical and technological fields. The use of agro-industrial byproducts as alternative source of carbon and nitrogen in culture media reduces the BC cost production, adds value to the byproducts and minimizes the environmental impact. In this study, the use of cashew apple juice and soybean molasses were evaluated to produce BC by Gluconacetobacter xylinus in comparison to the usual Hestrin and Schramm medium (HS). BC produced in static cultivation was characterized by X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The BC production (4.50 g L−1) obtained from the medium using cashew apple juice as carbon source (20 g L−1) with soybean molasses as nitrogen source (10 g L−1) was superior than HS medium (4.03 g L−1). Morphological analysis showed that bacterial celluloses produced with agro-industrial byproducts combined were similar to those found for the pellicle obtained from HS medium.

Effects of agroindustrial by-product supplementation on dairy goat milk characteristics, nutrient utilization, ruminal fermentation, and methane production

The use of agroindustrial by-products, such as dried distillers grains with solubles (DDGS) and dried citrus pulp (DCP), has been widely investigated in dairy cows, but information on their effects in dairy goats is limited. The influence of feeding olive cake (a by-product of olive oil production) to dairy goats has been assessed in some studies, but exhausted olive cake (EOC) has been much less investigated. Twelve Murciano-Granadina goats were used in a crossover design trial with 2 periods to assess the effects of including agroindustrial by-products on nutrient digestibility, ruminal fermentation, methane production, urinary excretion of purine derivatives, and milk yield and composition. In each period, 6 goats received daily a control diet comprising 1 kg of alfalfa hay and 1 kg of high-cereal concentrate, and another 6 goats received a diet (BYP) comprising 1 kg of alfalfa hay and 1 kg of a concentrate including corn DDGS, DCP, and EOC in proportions of 180, 180, and 80 g/kg of concentrate (as-fed basis), respectively. Diet had no effect on total dry matter intake, but intake of alfalfa hay, CP, and fat was greater for the BYP group than for the control group. There were no differences between diets in nutrient apparent digestibility, with the exception of fat, which was greater for the BYP diet compared with the control diet. Although fecal N tended to be greater for the BYP diet, there were no differences in N utilization. Compared with the control diet, milk yield tended to be greater and daily production of milk CP, fat, whey protein, and TS as well as milk gross energy were greater for the BYP diet. The concentration of C12:0, C14:0, and C16:0 fatty acids (FA) was or tended to be lower and the concentration of polyunsaturated FA was greater in the milk of BYP-fed goats compared with goats fed the control diet. Diet had no effect on ruminal parameters (pH, volatile FA, and NH3-N concentrations) and methane emissions, but urinary excretion of total purine derivatives tended to be lower in BYP-fed goats than in those fed the control diet. A mixture of corn DDGS (180 g), DCP (180 g), and EOC (80 g) could replace 44% of cereal grains and protein feeds in the concentrate for dairy goats without compromising nutrient utilization, ruminal fermentation, or milk yield and led to a more unsaturated FA profile in milk.

Use of agro-industrial by-products for the elaboration of functional foods

Use of agro-industrial by-products for the elaboration of functional foods

Use of agroindustrial byproducts as substrate for production of carotenoids with antioxidant potential by wild yeasts

Abstract In order to produce carotenoids with antioxidant potential from the wild yeast Rhodotorula mucilaginosa, Sporidiobolus pararoseus and Pichia fermentans, isolated from the ecosystem of Escudo Sul-Rio Grandense (Brazil), cultivations were performed with: raw glycerol and corn steep liquor (M1), sugar cane molasses and corn steep liquor (M2) and Yeast Malt (YM) broth. Production of β-carotene more than 63% was obtained in all the experiments. The antioxidant activity of the extracts was analyzed by the methods DPPH, ABTS and FRAP. S. pararoseus is highlighted, showing 635 and 830 μg.L−1 of carotenoids in M1 and M2, respectively. The extracts of P. fermentans in M2 were promising in relation to the antioxidant activity, presented results not reported in the literature until the present moment. Based on these results and the importance of obtaining carotenoid compounds from alternative sources, the proposed means, as well as the yeasts used, were shown to be promising choices. The use of agroindustrials media and microorganisms isolated from the ecosystems intensify the importance of this study providing new sources of biocompounds from the biodiversity and biotechnological potential of Brazil.

Effect of Molasses and Dried Orange Pulp as Sheep Dietary Supplementation on Physico-Chemical, Microbiological and Fatty Acid Profile of Comisana Ewe's Milk and Cheese.

The use of agro-industrial by-products for ruminant feed represents both an economical and environmental convenient way for reducing waste discharge and waste management costs for food industries. Large amounts of waste from citrus processing industries are available in Sicily, Italy. In the present study, the effect of dried citrus pulp as sheep dietary supplementation was evaluated on physico-chemical, microbiological and fatty acid composition of resulting milk and cheese. Pelleted feed integrated with molasses and blond orange pulp, replacing cane molasses, beet pulp and part of the maize and sunflower in ration, were administrated to ewes as an experimental treatment The experiment involved sixty Comisana breed sheep divided into two groups and two feeding trials (experimental and control). Ewe's milk and cheese samples were collected from January to April and analyzed for physico-chemical, microbiological and fatty acid profile composition. Results suggested that both the experimental milk and cheese were different from the controls. In particular, an increase of experimental milk yield and fat content were registered whilst the cheese samples exhibited a significant decrease of pH values and an increase in fat and protein contents. In addition, an increase of conjugated linoleic acids as well as of the oxidative stability were observed indicating the beneficial effect of dietary supplementation. Furthermore, among the main microbial groups, the experimental and control samples, no differences were detected. However, with the exception of streptococci, which was found higher in experimental cheeses, and staphylococci, which was significantly reduced by experimental feed. Moreover, the application of culture-independent methods highlighted the dominance of Lactobacillus rhamnosus/casei group in the experimental cheese, suggesting a driving role of the dietary supplementation in the cheese microbiota composition. The present study demonstrated that the inclusion of citrus by-products in the diet of small dairy ruminants is a promising feeding, which could positively affect milk composition and cheese manufacture.

Use of Agro-Industrial By-Products in Animal Feed at Modern and Semi-Modern Farms of Urban Community of Niamey (UCN): State Places

&lt;em&gt;The study was conducted in Urban Community of Niamey at modern and semi-modern farms provided an overview use of agro-industrial by-products in animal feed. Among 57 farms only 17 farms, including 10 beef farms, 2 sheep farms and 5 poultry farms were systematically surveyed. All farm managers are men. 60 and 33% are respectively officials at the level of poultry farms and ruminant farms. Farmers make up 25%, all of which own beef farms. There is also a predominance of adults, 60% at poultry level and 58.33% at ruminant farms. We note the use of a variety of agro-industrial by-products in animal feeds, in this case by-products derived from vegetable processing (wheat bran, exfoliated cotton cake) and animal processing (fish and fish meal ...). There are also some concentrates for poultry feed. Agribusiness by-products are increasingly used in urban livestock production but their valorization needs to be improved.&lt;/em&gt;

Extracción y encapsulación de compuestos fenólicos provenientes de cascarilla de arroz

En la actualidad, el aprovechamiento de los subproductos agroindustriales es de vital importancia. El objetivo del presente trabajo fue estudiar una alternativa de valorización de la cascarilla de arroz, mediante la extracción y la encapsulación de compuestos fenólicos provenientes de las cascarillas. Este proceso fue llevado a cabo en un reactor batch con agitación mecánica a 453,15 K y 1 MPa durante 1 h, se usó agua como solvente. Se evaluó la micro-encapsulación de los componentes del extracto mediante liofilización usando como material encapsulante maltodextrina en diferentes proporciones.Los extractos acuosos mostraron un pH de 3,7, contenido de compuestos fenólicos de 8,2 mg equivalentes de ácido gálico/g de cascarilla, y una actividad antioxidante de 14,6 mg Eq.trolox/g de cascarilla. Mediante análisis de espectroscopía de infrarrojo se identificaron bandas representativas de grupos funcionales presentes en los compuestos fenólicos, reconocidos por su actividad antioxidante. La eficiencia de encapsulación fue de 99,8 % usando 14,3 % de maltodextrina, se obtuvieron cápsulas con 10,08 mg fenoles/g de encapsulado y un tamaño de partícula adecuado para la liberación y retención de los compuestos fenólicos de 63µm. Posteriormente, se estudió la estructura semicristalina de las cápsulas mediante difracción de rayos X. Como conclusión, estas microcápsulas antioxidantes pueden ser adecuadas para su utilización en la industria farmacéutica o de alimentos como componente de envases alimentarios.

Intake and performance of lambs finished in feedlot with wet brewer\u2019s grains

BackgroundThe use of agroindustrial by-products in ruminant nutrition to be an interesting alternative in order to reduce production costs and environmental impacts arising from the inadequate destination of residues. The initial step of beer production yields a large volume of wet brewer’s grains all year around, which is available at a low cost and has a high nutritional quality, and hence a big potential for animal production.MethodsTwenty-four Suffolk non-castrated male lambs, from simple parturition were kept in individual spots and allocated to four treatments constituted by four levels of substitution of sorghum silage by WBG (i.e.0; 33.5; 66.5 and 100% of substitution). It was used roughage: concentrate rate of 50:50, based on dry matter.ResultsThe ether extract intake increased while the acid detergent fiber intake decreased linearly (P ≤ 0.05). Substituion of sorghum silage by WBG did not change lambs’ feed DMI, daily weight gain and feed conversion.ConclusionThe substitution of sorghum silage by WBG as roughage showed to be a viable alternative from the productive and economic point of view for finishing of feedlot lambs.

Effects of feeding systems on rumen environment, degradability and passage kinetics in Ankole × Friesian crossbred steers

Natural pastures constitute a large proportion of the feed resource base for meat and milk production in Sub-Saharan Africa. However, there is increasing use of agro-industrial by-products, especially those that are cereal-based as supplementary feedstuff to grazing animals and in diets under semi-intensive and intensive production systems. This study evaluated the influence of feeding systems on rumen environment, degradability and passage kinetics. Six Ankole x Friesian F1 crossbred steers weighing 339 ± 29 kg (about two years of age), each fitted with permanent rumen cannula were used in a replicated 3 × 3 Latin square design (ns = 2). Two steers were allocated per period to one of three feeding systems i.e. (1) sole grazing (control), (2) control plus concentrate supplement (composition g/kg DM: 375 maize bran, 559 brewer's spent grain, 62.5 molasses and 3.75 NaCl), and (3) feedlot systems where steers were fed total mixed ration (TMR) comprising g/kg DM: 200 maize stover, 300 maize bran, 447 brewers’ spent grain, 50 molasses and 3 NaCl. Data was collected on rumen pH, ammonia-nitrogen (NH3-N), volatile fatty acids (VFA) and degradability of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF). Rumen pH was lowest (P < 0.001) at feedlot (5.3) but highest (P < 0.001) under sole grazing (6.2). Rumen NH3-N ranged between 62.8 and 120 mg/l and was higher (P < 0.001) in sole grazing than in grazing but supplemented steers and those at the feedlot. Total VFA concentration for sole grazing steers (124 mmol/Mol) was higher (P < 0.05) than values observed under feedlot (102 mmol/Mol) while grazing but supplemented steers showed an intermediate value (108 mmol/Mol), not differing significantly from the two other systems. Molar proportion of acetate was higher (P < 0.001) in grazing steers compared to values for either grazing but supplemented or those under feedlot while the reverse was true for propionate. The degradation characteristics of DM, CP and NDF were generally higher in sole grazing steers. Although, in most cases, the influence of feeding system on degradability was dependent on the type of feedstuff, feeding systems did not influence total mean retention time. The high extent of DM, CP and fiber degradation in grazing steers compared to supplemented and feedlot steers demonstrates that forage diversity under grazing positively influences degradability. However, attention to the nature and fermentation characteristics of proteins and carbohydrate sources and how they modify rumen environment in different production systems is needed to improve utilization of supplements and TMR.

Co-production of thermoplastic composites with solid residue from enzymatic hydrolysis of recycled paper sludge

The aim of this study is to enhance the use of agro-industrial byproducts and to address the environmental concerns by a novel method of co-production of thermoplastic composites with a solid residue constituting biorefinery. Accordingly, the reuse of 10–30 wt. % solid residues (SRH) from the enzymatic hydrolysis of recycled paper sludge (PS) in the production of thermoplastic composites with polypropylene (PP) was investigated. Thermal properties, water absorption, tensile strength and morphology of the prepared composites were evaluated. Higher thermal stability, rougher and wetter surface, and characteristics of a brittle material were observed in PP-SRH composites in comparison to the pristine PS-PP composites and the neat PP. The water absorption increased with increasing amount of SRH, but in lower proportion compared to other common raw materials used in the preparation of composites. Use of SRH resulted in similar or better properties compared to the composites made with the unhydrolyzed paper sludge, suggesting that SRH has potential for recycling and utilization as filler in the development of thermoplastic composites.