Animal Feed Supplement Research Articles

Rhodotorula paludigena CM33 cultivation process development for high β-carotene single cell protein production

Rhodotorula yeast has potential in terms of biotechnology for the production of various compounds for the environmental, industrial, and medical sectors. It is well known to generate carotenoid pigments that are beneficially distinguished. This investigation aimed to optimize the growth of Rhodotorula paludigena CM33 and its production of β-carotene. Response Surface Methodology was employed to optimize temperature, ammonium sulfate, and ferric chloride concentrations in a 5L-bioreactor batch culture. The optimal conditions of 30 °C, 6.2 g/L of ammonium sulfate, and 75.0 mg/L of ferric chloride provided biomass of 17.71 g/L, a specific growth rate of 0.22 h−1, and β-carotene concentration of 40.29 mg/L. Upon scaling up the cultivation process, the 22L-bioreactor displayed similar growth patterns to those of the 5L-bioreactor. However, the 22L-bioreactor exhibited higher product yields in a shorter time period. The maximum biomass production of 18.96 ± 1.31 g/L and the maximum β-carotene production of 42.81 ± 0.61 mg/L were achieved at 28 h. This scaling-up strategy resulted in improved production efficiency. Additionally, the nutritional value of the cells was evaluated, suggesting their potential as animal feed supplements. R. paludigena CM33 demonstrated a β-carotene single-cell protein content, making it a valuable source for aquaculture and livestock feed. These findings highlight the potential of this yeast strain for large-scale production of β-carotene and single-cell protein, offering nutritional benefits for animal feed.

Gamma-Aminobutyric Acid (GABA) Producing Lactobacillus plantarum TSUB-17 and Probiotic Properties for Using as Probiotics Additive in Swine Feed

Due to the use of probiotics in animal husbandry has recently increased, the selection of high-quality probiotic strains is crucial. Since the uses of probiotics for animal feed supplements have to be applied at high doses of bacteria to be effective, the cultures’ safety is essential. This study successfully isolated the novel Lactobacillus sp. from swine fecal samples and identified it as L. plantarum TSUB-17. The L. plantarum TSUB-17 exhibited excellent probiotic properties, including 100 % resistance to 3 % acids and 1 % bile salts, and effectively inhibits pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella Typhimurium (isolated ESBL strain). L. plantarum TSUB-17 was also found to adhere to the intestinal wall and form a biofilm. Furthermore, the bacteria have revealed some unique properties of GABA production and detected the glutamate decarboxylase B (gadB) gene similar to L. brevis both in nucleotide sequence and secondary structure of the glutamate decarboxylase enzyme that was deduced from the nucleotide. The isolated bacteria also have antioxidant activity, and most importantly, the isolated strain was safe; it is non-hemolysis and susceptible to the tested antimicrobials. Therefore, L. plantarum TSUB-17 is suitable for further development as a probiotic additive in animal feed. HIGHLIGHTS This study successfully isolated Lactobacillus plantarum TSUB-17 with a high potential to develop as a probiotic for animals. The isolated bacterium has excellent properties: It tolerates high levels of acids and bile salts. It is effective against many pathogenic bacteria, produces gamma-aminobutyric acid (GABA) and shows high levels of antioxidant activity. Moreover, L. plantarum TSUB-17 is very safe due to its non-hemolytic strain and susceptibility to numerous antimicrobial drugs. GRAPHICAL ABSTRACT

Forage Properties of Fresh and Composted Cotton Gin Byproducts as Feed Supplements

Cotton ginning generates millions of tons of byproducts every year. If not properly managed, these materials become waste, which may constitute significant environmental, economic, and logistical issues. The objectives of this study were to characterize fresh and composted cotton gin byproducts (CGBs) for utilization as animal feed supplements and investigate the effects of composting on the forage properties. The study analyzed and compared the nutrients and energy contents of fresh and composted CGB from four commercial cotton gins in Arkansas, Mississippi, Missouri, and Tennessee states, USA. The results suggest that composting CGB may result in more than a 47% increase in fiber and crude protein and at least a 25% decrease in total digestible nutrients and net energy estimations. The differences in macro- and micro-nutrient contents and feed properties suggest that composting CGB may improve the potential for utilization as an animal feed supplement. Establishing the forage properties of CGB is crucial for determining animal feed formulations using CGB as supplements.

The nutritional and industrial significance of cottonseeds and genetic techniques in gossypol detoxification

Societal Impact StatementGossypol and its derivatives represent a class of toxic and immunosuppressive compounds that are naturally synthesized in cottonseed. These compounds pose several health hazards to humans and animals, such as heart and lung damage, breathing difficulties, and death in swine. In poultry, gossypol reduces egg production and slows growth. Studies have also shown that gossypol can indirectly harm humans and animals through the food chain. Although several physical and chemical approaches are adopted to reduce gossypol levels in cottonseed before food and feed processing, these techniques are expensive. Therefore, genetically regulating gossypol production in cotton could provide a cheaper alternative.SummaryCotton (Gossypium spp.), the most important fiber crop, is cultivated in over a hundred countries to provide raw materials for the growing textile industry. The seed obtained after delinting cotton is a rich source of protein with a vast potential for oil and feed production. Cottonseed oil production is estimated at 5.08 million metric tons and is expected to generate over 6.56 billion United States Dollars in revenue by 2029. The cake from defatted cottonseed is used as animal feed and food supplements. However, the contamination of gossypol in cottonseed limits its use. Gossypol ingestion impairs weight gain and causes anorexia, respiratory distress, and death under extreme exposure. This review highlights the significance of cottonseed oil and meal; the pharmacological uses and impact of gossypol; the chemistry, toxicity, and bioactivity of gossypol; and the physical and chemical methods used in gossypol removal during feed and food supplement processing. In addition, the biosynthetic pathway of gossypol and attempts to genetically transform some key regulators of this pathway to produce glandless cottonseed or reduce the gossypol levels in the seed are discussed.

Genomic insights into antimicrobial potential and optimization of fermentation conditions of pig-derived Bacillus subtilis BS21.

Bacillus spp. have been widely used as probiotic supplements in animal feed as alternatives to antibiotics. In the present study, we screened a Bacillus subtilis strain named BS21 from pig feces. Antimicrobial activities, whole genome mining and UHPLC-MS/MS analysis were used to explore its antimicrobial mechanism. Strain BS21 showed Significant growth inhibition against a variety of animal pathogens, including Escherichia coli, Salmonella enterica Pullorum, Salmonella enterica Typhimurium, Citrobacter rodentium, Shigella flexneri and Staphylococcus aureus. Seven gene clusters involved in antimicrobial biosynthesis of secondary metabolites were encoded by strain BS21 genome, including four non-ribosomal peptides (bacillibactin, fengycin, surfactin and zwittermicin A), one ribosomal peptide (subtilosin A), one dipeptide (bacilysin) and one polyketide (bacillaene). Among them, production of surfactin, fengycin, bacillibactin, bacilysin and bacillaene was detected in the supernatant of B. subtilis strain BS21. To develop the potential application of BS21 in animal production, medium components and fermentation parameters optimization was carried out using response surface methodology (RSM). Production of antimicrobial secondary metabolites of strain BS21 was increased by 43.4%, and the best medium formula after optimization was corn flour 2%, soybean meal 1.7% and NaCl 0.5% with optimum culture parameters of initial pH 7.0, temperature 30°C, rotating speed at 220 rpm for 26 h. Our results suggested that strain BS21 has the potential for large-scale production and application as a potential source of probiotics and alternative to antibiotics for animal production.

Toxicological analysis of metals content in agro-food wastes as possible supplement in animal feed

The agro-food surplus is considered the most abundant renewable resource, interesting for the economic and environmental impact, with a possible employment in different productive fields such as supplement in animal feed. For a safe and effective enhancement of agro-food wastes it is needed a toxicological analysis before of their employment, to avoid potential risks to animals, humans and environment. The purpose of this study was to evaluate the metals content (Cu, Fe, Zn, Mg, Na, K, Ca, Mn, Se, Zn, Co, Ni, V, Sb, Mo, Cr and Pb, Cd, As, Ba), in agro-food wastes through ICP-MS analysis. The results obtained showed the presence of metals analysed with a significant content of essential micro and macro-elements; with regard to toxic metals, only strawberries and fennel samples showed Pb levels above the MRL. These data confirm, from the toxicological point of view, a possible and safe reuse of the most of all agro-food wastes, as raw material at low cost and rich of essential nutrients and particularly as supplement in animal feed.

Bioenergy-livestock integration in Brazil: Unraveling potentials for energy production and climate change mitigation

Future projections indicate an expansion for both food and energy demands, which can increase pressure on land use, while there is an urgent global need for climate change mitigation. Bioenergy is foreseen as key option to meet future energy demands and reduce greenhouse gas (GHG) emissions, however its sustainability depends on locations and regional characteristics. Simultaneously, agricultural production models that co-produce food, feed, and energy offer sustainability synergies and co-benefits, but site-specific sustainability assessments of their large-scale implementation are missing. This study presents a bottom-up approach to assess spatially explicit sustainability aspects of bioenergy-livestock integrated systems (BLI) in Brazil and shed light on their contribution to future energy demands, to climate change mitigation targets, and their impacts on selected ecosystem services, including bioenergy production, climate change mitigation, reduction of food competition, biodiversity conservation, and avoided deforestation. The proposed integration considers livestock intensification and use of biofuels by-products as animal feed supplement, taking advantage of synergies between these two value chains. The expansion of the BLI system in the Center-South region of Brazil produce up to 89 billion liters of ethanol, enough to meet future domestic ethanol demands from multiple shared socioeconomic pathways and generating surpluses for export. This production takes place on 16 million hectares of pastureland within the Sugarcane Agroecological Zoning, excluding the Amazon and Pantanal biomes, and biodiversity hotspots. BLI expansion mitigate up to 250 million tonnes of CO2eq and generate 15 billion dollars of profits. The best locations to maximize the selected ecosystem services are west of São Paulo, east of Mato Grosso do Sul, and the south-central region of the states of Goiás. This study may encourage the formulation of enhanced public policies for the integration of bioenergy and livestock value chains and guide a sustainable large-scale deployment of BLI systems.

Valorization of Olive Mill Byproducts: Recovery of Biophenol Compounds and Application in Animal Feed.

This study aimed to recover the phenols from olive oil mill wastewater, a major pollutant of the oil industry, by using spray-drying technology to produce a new feed with a nutraceutical value for animal feed supplementation and to evaluate its effect on the productivity and nutritional quality of ewe milk. Forty-five Sarda ewes in late lactation (150 ± 2 d) and with homogeneous live weight (52 ± 1.5 kg) were randomly allotted into three groups and fed with three dietary treatments containing increasing levels of polyphenols: 0% (C), 0.1% (T0.1), and 0.2% (T0.2) of dry matter. No effect of the dietary treatments was found on the milk yield and composition. Interestingly, milk urea content (p < 0.0001) and somatic cell counts (p < 0.001) decreased as the level of polyphenols inclusion in the diet increased. The inclusion of phenols (0.2% of dry matter) in the diet of sheep was effective in increasing the vaccenic (C18:1 trans-11) and rumenic acid (C18: cis-9 trans-11) levels, which are beneficial for human health. Finally, the recovery of polyphenols via spray-drying technology and their incorporation into a new fortified feed can be a valid strategy for naturally improving the nutritional value of milk while valorizing an oil industry byproduct, reducing environmental impact, and promoting waste reuse that is in line with circular economy principles.

Brewer’s yeast as a diet supplement in carp aquaculture: impact on production coefficients and haematological and biochemical plasma parameters

While brewer’s yeast (Saccharomyces cerevisiae), a rich source of proteins and B vitamins, is commonly used as an animal feed supplement, its use in aquaculture has been limited. Here, we assess its impact on 192 individuals of common carp (Cyprinus carpio) production and haematological and biochemical parameters from blood plasma using a control group fed commercial feed with 20% soybean meal and three test groups fed commercial feed with (i) 17.50% soybean + 2.50% brewer’s yeast (group B-2.5), (ii) 15% soybean + 5% yeast (group B-5) and (iii) 10% soybean and 10% yeast (group B-10). At the end of the experiment, all fish were weighed and measured and subsequently blood samples were taken from eight fish in each tank. There was a significant increase in total length (3%) and weight (5.37%) in group B-5. While fish muscle nitrogenous matter and protein efficiency ratio increased slowly across experimental groups, Fulton’s and Clark’s condition factors changed minimally (range 2.73–2.89%). Apparent net protein utilisation increased to 17.63% in B-10, suggesting that increasing yeast levels result in improved nitrogen utilisation. All fish muscle fat levels were within optimal range (4.16–4.68%) and, while there was a significant increase in erythrocytes in B-5 (up 0.40 T.L−1), haemoglobin levels increased only slightly in B-5 and B-10 (average 4.50 g.L−1) and B-10 had the lowest number of leukocytes (6.8 G.L−1). No significant changes were recorded in blood plasma biochemical parameters. Our results suggest that a 5% brewer’s yeast feed supplement represents a useful protein source for carp aquaculture.

Analysis of intensification of zeolite drying on a vibrating conveyor dryer with infrared emitters

The object of the research is the drying process of zeolite. The work is dedicated to analyzing an effective method for intensifying the drying process of zeolite while preserving its structural integrity. For the given task, it was necessary to choose a promising drying method with minimized heat loss and preservation of the quality indicators of zeolite. Zeolite has a wide range of applications, including soil improvement, mineral fertilizer for plant growth, dietary supplement for animal feed, air, and water purification. The crucial process for obtaining high-quality natural zeolite is the drying process. In its natural state, zeolite contains moisture, and an excess of it can deteriorate its consumer properties. Therefore, considering the best and most efficient method of zeolite drying is a promising task today. There is no available data on drying zeolite using radiation methods in the literature. Typically, this material is dried in rotary dryers. However, this drying method often results in a significant percentage of zeolite being crushed into dust. Many industries require a granular structure for zeolite. With radiation drying, this drawback is absent or the percentage of crushed zeolite into dust is minimal. The main methods of drying zeolite have been examined, revealing a fact that indicates an incorrect approach to the drying process. Factors influencing the deterioration of zeolite's quality during drying have been analyzed. These factors have several drawbacks that affect the final product, namely: crushing zeolite into powder, over-drying, which affects its quality and poses a general scientific problem. The drawbacks of drying zeolite using the main methods have been identified. The authors have developed a dryer design that minimizes the deterioration of the mentioned qualitative characteristics of zeolite, addressing an important scientific and technical challenge of creating an efficient and environmentally friendly method of zeolite drying using infrared radiation energy and the development of appropriate equipment. The proposed dryer has suggested applications in various fields.

Dietary Live Yeast Supplementation Influence on Cow’s Milk, Teat and Bedding Microbiota in a Grass-Diet Dairy System

The supplementation of animal feed with microbial additives remains questioning for the traditional or quality label raw milk cheeses with regard to microbial transfer to milk. We evaluated the effect of dietary administration of live yeast on performance and microbiota of raw milk, teat skin, and bedding material of dairy cows. Two balanced groups of cows (21 primiparous 114 ± 24 DIM, 18 multiparous 115 ± 33 DIM) received either a concentrate supplemented with Saccharomyces cerevisiae CNCM I-1077 (1 × 1010 CFU/d) during four months (LY group) or no live yeast (C group). The microbiota in individual milk samples, teat skins, and bedding material were analysed using culture dependent techniques and high-throughput amplicon sequencing. The live yeast supplementation showed a numerical increase on body weight over the experiment and there was a tendency for higher milk yield for LY group. A sequence with 100% identity to that of the live yeast was sporadically found in fungal amplicon datasets of teat skin and bedding material but never detected in milk samples. The bedding material and teat skin from LY group presented a higher abundance of Pichia kudriavzevii reaching 53% (p < 0.05) and 10% (p < 0.05) respectively. A significant proportion of bacterial and fungal ASVs shared between the teat skin and the milk of the corresponding individual was highlighted.

Effect of pH and Different Fermentation Time Intervals on the Production of Single Cell Proteins (SCPs) from Potato Peels

Dried cells of microorganisms such as fungi, algae, and bacteria, known as Single-Cell Proteins (SCPs), are utilized as a source of protein supplements in animal feed or human food. These SCPs can be produced through the use of low-cost feedstocks and waste materials as sources of carbon and energy, which can be converted into biomass and concentrated proteins. Objective: To optimize the yield and growth of dry cell biomass through the manipulation of fermentation conditions. Methods: A batch fermentation process was used to produce dry cell biomass from a microorganism. Different pH values, fermentation times, and reactor configurations were tested, and the resulting biomass was analyzed for its protein content. Results: The maximum yield of dry cell biomass was achieved at pH 4.5, with a yield of 1.951 g/100 ml. The maximum dry biomass was achieved after 72 hours of fermentation, with a yield of 2.824 g/100 ml. The maximum yield of dry biomass was achieved with an Airlift fermenter at an aeration rate of 1.0 vvm and a temperature of 35°C for 72 hours, resulting in a yield of 5.452 g/L. The protein content of the dried cell biomass was found to be in the range of 45-55%. Conclusions: This study demonstrates that the yield and growth of dry cell biomass can be optimized by controlling the fermentation conditions, specifically pH, fermentation time, and reactor configuration. These findings may have implications for the industrial-scale production of dry cell biomass, as they offer insight into how to maximize yield and protein content.

Estimating Black Oat Biomass Using Digital Surface Models and a Vegetation Index Derived from RGB-Based Aerial Images

Responsible for food production and industry inputs, agriculture needs to adapt to worldwide increasing demands and environmental requirements. In this scenario, black oat has gained environmental and economic importance since it can be used in no-tillage systems, green manure, or animal feed supplementation. Despite its importance, few studies have been conducted to introduce more accurate and technological applications. Plant height (H) correlates with biomass production, which is related to yield. Similarly, productivity status can be estimated from vegetation indices (VIs). The use of unmanned aerial vehicles (UAV) for imaging enables greater spatial and temporal resolutions from which to derive information such as H and VI. However, faster and more accurate methodologies are necessary for the application of this technology. This study intended to obtain high-quality digital surface models (DSMs) and orthoimages from UAV-based RGB images via a direct-to-process means; that is, without the use of ground control points or image pre-processing. DSMs and orthoimages were used to derive H (HDSM) and VIs (VIRGB), which were used for H and dry biomass (DB) modeling. Results showed that HDSM presented a strong correlation with actual plant height (HREF) (R2 = 0.85). Modeling biomass based on HDSM demonstrated better performance for data collected up until and including the grain filling (R2 = 0.84) and flowering (R2 = 0.82) stages. Biomass modeling based on VIRGB performed better for data collected up until and including the booting stage (R2 = 0.80). The best results for biomass estimation were obtained by combining HDSM and VIRGB, with data collected up until and including the grain filling stage (R2 = 0.86). Therefore, the presented methodology has permitted the generation of trustworthy models for estimating the H and DB of black oats.

Pasture Quality Monitoring Based on Proximal and Remote Optical Sensors: A Case Study in the Montado Mediterranean Ecosystem

Permanent dryland pastures are the basis of animal feed in extensive grazing systems. Seasonality and inter-annual climatic variability, associated with shallow, acidic, and not very fertile soils, result in low productivity and rapid degradation of pasture quality, which requires the supplementation of animal feed. In this study, carried out in a biodiverse pasture field in the Mediterranean region of southern Portugal, the vegetation index (NDVI, Normalized Difference Vegetation Index) obtained from measurements performed by a proximal optical sensor (PS) and satellite images (RS) was used to assess pasture quality parameters (pasture moisture content, PMC, crude protein, CP, and neutral detergent fiber, NDF). The monitoring was carried out throughout the 2021/2022 pasture growing season. Significant correlations were obtained between the NDVI obtained by PS and RS (R2 of 0.84) and the reference values of pasture parameters obtained in laboratory protocols: PMC (R2 of 0.88 and 0.78, respectively), CP (R2 of 0.67 and 0.63, respectively), and NDF (R2 of 0.50 and 0.46, respectively). This case study also demonstrated the spatial and temporal variability of vegetative vigour and, consequently, of pasture quality in the Montado, the characteristic Mediterranean ecosystem. These results show the pertinence of these technologies in supporting the decision-making process of the farm manager, namely, to estimate the supplementation needs of animals in critical phases, especially after the spring production peak and before the autumn production peak.

ATR-FTIR spectroscopy as a method for the determination of mineral chelation in high concentration manganese and zinc proteinates used as animal feed additives

Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy is an essential tool for the determination of mineral chelation in proteinates used as animal feed additives. With advances in feed formulations and stringent regulatory requirements to confirm the degree of chelation in animal feed supplements, the aim of this work was to further refine the method and demonstrate its applicability to newly formulated, higher concentration (20% (w/w)) manganese and zinc proteinates of industrial relevance. Calibration and prediction models were created using multivariate analysis with R2 > 0.99 for both mineral proteinates tested. Root mean square error of calibration (RMSEC) values were found to be 1.7% and 2.1% respectively for the manganese and zinc products. The refined method produced reliable data for various applications with excellent specificity, selectivity, and reproducibility. Consequently, the proposed refinements are expected to be of interest from a regulatory perspective and for those in the feed industry for conclusively determining the percentage chelation of minerals in high concentration proteinate products.

Isolation of Chitosan From Dogol Shrimp Skin (Parapenaeopsis sculptilis)

In Indonesia, shrimp underwent a "cold storage" process where the heads, tails, and shells were discarded as waste. This shrimp waste could pollute the environment around the factory so it needed to be utilized. So far, shrimp shells had only been used as ingredients for making crackers, shrimp paste, and animal feed supplements. The remaining shrimp shells that had been separated were made into chitosan which was then subjected to characterization tests. The three steps of the chitosan isolation process were deproteinization, demineralization, and deacetylation. The analytical tests carried out were testing the water content, ash content, and functional groups contained in chitosan which were identified using the Fourier Transform Infra Red (FT-IR) Spectrophotometer. Based on the test results, there was a moisture content of 9.27% ​​and an ash content of 1.69% in the chitosan samples made from shrimp shells. Functional groups of shrimp shell chitosan were identified using FT-IR characteristics. The -NH- group, which was represented by the N-H and O-H stretching groups, could be seen in the absorption band 1456.26 in the wave range 3000–30500. The conclusion of this study was that chitosan could be extracted from shrimp shells and meet the characterization criteria.

Moringa (Moringa oleifera) as an alternative feed supplement for dairy animals

Moringa (Moringa oleifera) as an alternative feed supplement for dairy animals

Penyuluhan dan Pelatihan Pembuatan UMB (Urea Molasses Block) Pada Peternak Sapi Potong di Desa Blengorwetan, Kecamatan Ambal, Kabupaten Kebumen

Blengorwetan Village, Ambal District, Kebumen Regency is an area with the potential for developing Kebumen PO cattle farms, but has problems in terms of fulfilling animal feed nutrients. The majority of farmers provide feed in the form of dry rice straw, which is low in protein, vitamins, and minerals, and high in crude fiber. Based on these problems, this community service activity aims to provide counseling and training on the manufacture of Urea Molasses Block (UMB) to farmers. Urea Molasses Block (UMB) is an animal feed supplement that serves to improve the nutritional value of animal feed; digestion and digestibility of animal feed substances will be more efficient and improved; consumption of ruminant feed will increase, and avoid vitamin and mineral deficiencies. The methods used include field surveys, discussions with village officials, socialization to increase the knowledge of farmers about UMB, and training in making UMB which is followed in a participatory manner by the community. Trials of giving UMB to livestock by the community show UMB is favored by livestock and can increase animal feed consumption. Based on the activities that have been carried out, it can be concluded several things, namely (1) the training on making UMB has been successfully implemented with indicators of understanding and skills of cattle farmers increasing regarding UMB products and how to manufacture them, (2) UMB products produced are of sufficient quality and favored by livestock. , (3) further breeders wish to make UMB products independently for consumption by their own livestock, with the hope of increasing livestock productivity. Keywords: Urea Molasses Block, Livestock, Feed Supplement

Sustainable Management and Valorization of Agri-Food Industrial Wastes and By-Products as Animal Feed: For Ruminants, Non-Ruminants and as Poultry Feed

Substantial increase in the production of agri-food commodities over the past years has resulted in the generation of enormous volumes of wastes and by-products, thus contributing to increased environmental pollution. Being an under-exploited raw material which are rich in bioactive compounds (e.g., polyphenols, dietary fibre, oils, essential vitamins, minerals, etc), novel strategies and initiatives have been proposed and implemented for the effective management and valorization of these wastes and by-products. The proposed initiatives and strategies support the concepts of EU circular economy and green biorefinery, thus promoting sustainability. One of the strategies of management of waste and by-products includes the effectual development of nutritious low-cost sustainable animal feed. Currently, in the world market, there are a range of fruit and vegetable wastes and by-products that have been effectively introduced in animal diets. Within this context, this systematic review focuses on a diversified group of agri-food wastes (and the industrial by-products), their bioactive components, the opportunities for the development of animal feed or feed supplements (for Ruminants, Non-Ruminants and as Poultry feed) and conclusively the health benefits imparted. In addition, the safety issues and regulations aspects are also covered.

Genotoxicity and Toxicity Assessment of a Formulation Containing Silver Nanoparticles and Kaolin: An In Vivo Integrative Approach.

A new material composed of a kaolin base with silver nanoparticles (AgNPs) attached to its surface was developed, as an alternative to antibiotics used as supplements in animal feed. As part of its safety assessment, an in vivo geno-toxicological evaluation of this material was conducted in rats. First, a preliminary dose finding study was carried out to decide the doses to be tested in the main study: 50, 300 and 2000 mg/kg b.w. For the main study, a combined strategy composed of the MN test (TG 474) and the comet assay (TG 489), integrated in a repeated dose 28-day oral toxicity study (TG 407), was performed. A No Observed Adverse Effect Level (NOAEL) of 2000 mg of the silver-kaolin formulation/kg b.w. by oral route, for 28 days, was determined. The silver-kaolin formulation did not induce micronuclei in bone marrow, or DNA strand breaks (SBs) or alkali labile sites (ALS) in liver, spleen, kidney or duodenum at any dose. The modified Fpg comet assay did not reveal oxidized bases in the same tissues at the dose of 2000 mg/kg b.w. Silver was quantified by ICP-MS in all the target organs, confirming the negative results obtained under these conditions.