International Journal of Nanoparticles

This review illustrates the relationships between additives in the diets of ruminants and the consequence for ruminant nutrition. Feed additives are used to improve animal performance and/or the quality of the products. There are several categories of additives available for ruminant nutrition, with emphasis on antibiotics, prebiotics, probiotics, plant extracts, and exogenous enzymes. Antibiotics, essential oils, and chitosan act by selecting sensitive bacteria, consequently modulating the ruminal fermentation pattern. Prebiotics favor microbial growth, providing greater digestion and the production of volatile fatty acids. Probiotics are living microorganisms that improve the ruminal environment, promoting microbial growth and resulting in increased digestion and the production of volatile fatty acids. Exogenous enzymes act synergistically with the enzymes secreted by the ruminal microorganisms, besides favoring microbial adhesion and colonization and facilitating feed degradation. Tannins, whether altering the fermentation standard and/or modifying the ruminal microbiota population, are effective in improving animal performance. However, the effects of additives on the quality of the products are linked to diet quality. Highlights Exogenous enzymes act synergistically with the enzymes secreted by the ruminal microorganisms. Exogenous enzymes favoring the microbial adhesion and colonization of the particles, aid in the degradation of the feed. Tannins can altering the fermentation standard and/or modifying the ruminal microbiota population. Essential oils and chitosan act by selecting sensitive bacteria and consequently modulate the ruminal fermentation.

Seeding pastures or forage crops by no-tillage methods usually involves the spray of glyphosate to suppress the existing vegetation. While  many studies found detrimentaleffects of glyphosate on seed germination and seedling growth of the subsequent crop, others found negligible effects. This study aimed to evaluate the effect of glyphosate spraying on germination, seedling emergence and seedling growth of four forage species: Trifolium repens, Lotus tenuis, Festuca arundinacea and Paspalum dilatatum. The experiment was carried out spraying glyphosate on the pre-existing vegetation and on bare soil 1, 30, 60 and 90 days before sowing, and a control  treatmentsprayed with water. Glyphosate sprayed on pre-existing vegetation 1 to 60 days before seeding reduced emergence, while sprayed 1 to 30 or 1 to 60 days before seeding reduced seedlings belowground biomass and root length of all species and aboveground biomass of legumes respect to sprayed 90 days before seeding, sprayed on bare soil, and control treatment. This herbicide would remain active in the soil environment for at least 60 days after spraying when it was previously absorbed by plants, causing a severe damage to seedlings emergence and growth. Highlights: Glyphosate sprayed on pre-existing vegetation 1 to 60 days before seeding reduced seedling emergence of Trifolium repens, Lotus tenuis, Festuca arundinacea and Paspalum dilatatum. Glyphosate sprayed on pre-existing vegetation 1-30 or 1-60 days before seeding reduced seedlings belowground biomass and root length of all species and aboveground biomass of legumes Gyphosate sprayed 90 days before seeding or sprayed on bare soil did not affect seggling emergence and growth. Gyphosate would remain active in the soil environment for at least 60 days after spraying when it was previously absorbed by plants.

The largest corn yeld in Brazil is currently in the second harvest, which is the most susceptible period to climatic adversities occurring during the cycle. Thus, introducing beneficial elements for maintaining the adequate development of the plant can help producers in obtaining greater kernel yields. Among studied elements, nicotinamide has potential use since it is associated with accumulating secondary metabolites and manifesting defence metabolism in plants. The objective of this work was to evaluate the influence of nicotinamide applied in different doses (only once or in instalments) on the biometric and productive characteristics of corn. The treatments were composed by the number of nicotinamide applications (one or two) and five doses (0, 50, 100, 150 and 200 mg L-1). Plant diameter, plant height, ear insertion height, leaf area and dry matter, yield and 100-kernel mass were evaluated. It was found that doses close to 100 mg L-1 resulted in increases in vegetative and reproductive development, regardless of the number of applications. In this way, foliar nicotinamide application positively influences the biometric and productive characteristics of second crop corn. Highlights The use of nicotinamide in corn plants improves its growth, yield components and grain yield. A single application of nicotinamide during vegetative stage V3 at a dose of 100 mg L-1 is sufficient to increase the leaf area of corn plants. Corn grain yield can be increased by 12.6% with a single application of nicotinamide. There was no need for two applications of nicotinamide in corn crop.

Soursop is an exotic tropical fruit, highly perishable, presents losses around 30% in postharvest, has marked commercial importance especially for internal consumption and a maximum shelf life. The objective of the present work was to study the effect of thermosonication (TS) on some physicochemical properties and the enzymatic oxidation of soursop pulp. The thermosonication treatments used on the samples were at 40 kHz, in a temperature range between 20-60 ºC, for 25 minutes. The soluble solids, pH, vitamin C concentration, inactivation of peroxidase (POD) and polyphenoloxidase (PPO) in the soursop pulp were evaluated before and after the treatments. The results indicate a loss of vitamin C was observed in a 2.63; 13.16 and 28.95% for temperatures at 20, 40 and 60 ºC, respectively. On the other hand, a partial inactivation of the enzymes, POD, in 48.41; 69.83 and 74.24% and for PPO in 56.38; 74.47 and 81.91% was achieved at temperatures at 20, 40 and 60 ºC respectively. Finally, it was demonstrated that the US combined with heat (TS) inactivates in a large percentage the POD and PPO enzymes in the soursop pulp needing less heat, which could make it more efficient in comparison with the thermal treatments. Highlights Ultrasound combined with heat (TS) can inactivate POD and PPO enzymes in the soursop pulp, achieving considerable retention of vitamin C. Peroxidase (POD) and Polyphenoloxidase (PPO) trigger enzymatic processes affecting product natural color. Soursop is an exotic fruit with high levels of bioactive compounds, and great agro-industrial potential given its high recovery yields and excellent sensory characteristics. A vitamin C retention level of 71.05- to 86.84% was achieved in soursop pulps that have undergone thermosonification.

Vegetable intercropping has advantages over single cultivation in terms of less environmental impact. However, to convince farmers to adopt this production system, it is necessary to prove greater efficiency in the production of more food per unit area and therefore an increase in productivity. An experiment was carried out aiming to evaluate the effect of the chicory transplant time in intercrops with collard greens on crop yields and land use efficiency index (LUE). The experimental design was a randomized block, with nine treatments in a 2 × 4 + 1 factorial scheme, and four replications. Crop systems (intercrop and monoculture) and chicory transplant time (0, 14, 28 and 42 days after transplant (DAT) of collard greens) were evaluated. The collard greens yield increased as the chicory transplant time was delayed. The total and per harvest yields of chicory were not influenced by its transplant time. Regardless of chicory transplant time, collard greens and chicory intercropping provided greater LUE than their monocultures and reached the maximum value (52% higher) when the chicory was transplanted 42 days after collard greens. Highlights: The collard green yield increased by 11 kg ha-1 for each day of delay in the chicory transplant (0 to 42 days). The total and per harvest chicory yields were not influenced by its transplant time in relation to collard green transplant. The collard green and chicory intercropping provided 52% higher land use efficiency than their monocultures when the chicory was transplanted 42 days after collard green.

The present study aimed to investigate the effect of defoliation frequency (low and high) and water stress (excess or deficit) on biomass production, P and N nutrition, and symbiosis with native soil microorganisms on a Lotus tenuis and Schedonorus arundinaceus co-culture in a pot experiment. Combined effects of defoliation frequency and water stress affected plant accumulated shoot biomass. L. tenuis root biomass decreased in response to defoliation and water stress, while S. arundinaceus root biomass was similar between non-defoliated and defoliated plants, at all water levels. Low and high frequencies of defoliation in a waterlogged soil can be considered the most stressful scenario for L. tenuis and S. arundinaceus co-culture. Colonization of arbuscular mycorrhizal fungi in L. tenuis roots and dark septate endophytes colonization in S. arundinaceus roots were affected by both factors, whereas arbuscular mycorrhizal colonization in S. arundinaceus was affected only by water stress. Both plants tolerated defoliation and water stress due to the interaction between the translocation of nutrients and carbon compounds from roots to shoots, and P and N absorption (plus N2 fixation in L. tenuis). Highlights: Both plants tolerated defoliation and water stress due to the interaction between the translocation of nutrients and carbon compounds from roots to shoots, and P and N absorption (plus N2 fixation in tenuis). Low and high frequencies of defoliation in a waterlogged soil can be considered the most stressful scenario for tenuis and S. arundinaceus co-culture. Defoliation frequency increased AM colonization in plant roots under well watered and water deficit conditions. arundinaceus roots were co-colonized by AM fungi and DSE. Promoting the presence of tenuis through low defoliation frequency would improve forage yield and quality with the maintenance of AM symbiosis in legume–grass communities.

Worldwide, one-third of the food produced is inconsumable due to marketable quality losses. Parallelly, and given the growing world population, levels of waste have become unacceptable. Supply channels play a fundamental role in establishing strategies for food waste mitigation. The objective of this research was to analyze if good operational practices with different dimensions of distribution and commercialization logistics may contribute to reduce fruit and vegetable waste. The studied dimensions were: logistics, operations, technology, trade and management. Several questionnaires were administered to 83 specialized wholesale merchants from a large supply center in Brazil, for lettuce, potato, orange, papaya and tomato. The results indicated that for papaya and potato, low and high waste generation are associated with a greater number of anti-waste actions (p = 0.0071 and p = 0.0469 respectively). For tomato, lettuce and orange, no significant differences for found. These results represent a first approach to understanding the reasons for food waste at wholesale centers. Highlights: Worldwide, one-third of the food produced is inconsumable due to marketable quality losses. In Brazil, about 40 thousand tons of food is wasted per year. Food waste in the fruit and vegetable supply chain is associated with the following dimensions: logistics, operation, technology, trade and management. For papaya and potatoes, low levels of residues are associated with a greater number of anti-waste actions such use of a cold chamber and use of promotional pricing, respectively. For tomato, lettuce and orange, no significant differences  was found for high and low levels of waste in relation to the number of actions undertaken in these chains.


 Platelets are essential elements of human blood. In addition to their normal role, platelets are involved in causing myocardial infarction, stroke and other thrombotic disorders. Platelet activation in vivo, probably involves a combination of agonists. Garlic has beneficial effects due to its ability to inhibit platelet aggregation and thromboxane formation. The aim of this work was to evaluate the ability of garlic extracts to inhibit platelet aggregation induced by different agonists and their mixtures in different donors. Significant differences were found in platelet aggregation in response to each agonist (P ≤ 0.05). The highest antiaggregatory effect was observed with arachidonic acid and the lowest effect with collagen-arachidonic acid mixture. Interaction effects between donor and agonist (or mixtures) were detected. The study showed the potential of aqueous garlic extracts to prevent platelet aggregation induced by different agonist.
 Highlights
 
 Platelets play a central role in the progression of atherosclerotic lesions.
 Blood from nine non-smoker healthy donors was used for in vitro platelet aggregation study.
 Significant differences were found in platelet aggregation in response to each agonist.
 Aqueous garlic extracts could prevent platelet aggregation induced by different agonist.


 This study analyzed the genetic diversity in Coffea canephora genotypes by univariate and multivariate statistical analysis, based on concentrations of macro- and micronutrients in coffee leaves in the stages of pre-flowering and grain filling. The experiment was arranged in randomized blocks with three replications, in a 42x2 factorial design, in which factor one represented the evaluated genotypes and factor two the periods of leaf sampling, i.e., pre-flowering and grain filling. The data of leaf nutrient concentrations were subjected to analysis of variance by the F test (p <0.01), and genetic parameters were estimated. For the study of genetic diversity, the genotypes were grouped by the hierarchical unweighted pair-group method using arithmetic averages (UPGMA). The relative importance of a trait to predict genetic diversity was also studied. There is genetic divergence for leaf nutrient concentration in C. canephora genotypes. With a maximum limit of 60% of dissimilarity between genotypes, four groups were also formed by UPGMA. For the 42 evaluated genotypes, leaf S concentration was the most important trait for genetic diversity; this genotypic variability should be investigated to enhance the efficiency of nutritional diagnosis.
 Highlights
 
 There is genetic variability for leaf nutrient concentration in Coffea canephora
 The leaf concentration of nutrients in the phenological stage of pre-anthesis is different from the leaf concentration of nutrients in the coffee bean filling period.
 Leaf concentration of sulfur was the characteristic that contributed most to the genetic diversity among the 42 genotypes, followed by the concentration of copper, boron and magnesium.
 Genotypic variability for leaf nutrient concentration should be considered for better nutritional management.

This paper analyzes how decision-making, management capacity and technology adoption by beekeepers, affect the technical efficiency (TE) of Argentinean beekeeping through the case study of the province of La Pampa (Argentina). The assessment of TE is currently receiving ever-growing attention as an indicator of sustainability and usage of sufficient natural resources in beekeeping activities. This study aimed to identify the key factors affecting the technical efficiency of bee farms in the province of La Pampa. The study included a sample of 40 bee farms and estimated their TE score through an input-oriented Data Envelopment Analysis (DEA) model. In a second stage, Tobit regression was determined to evaluate the technical inefficiency determinants. This paper found that most beekeeping production units have low TE levels. Only 25 % of bee farms produce either at or close to the frontier. The Tobit model revealed that variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on pure technical efficiency. These results are considered to be of great interest for structured beekeeping systems on small-scale and family farms, as well as for political decision-makers, regarding a public program in apiculture. Highlights: Argentina is the leading country in America, exporting honey worldwide. DEA approach and Tobit model based on a two-stage analysis is a useful tool when evaluating livestock production systems. Bee farmers in La Pampa (Argentina) are operating below the production frontier, which indicates there is still scope for improvement. Variables such as marital status, educational level, primary family income, source information usage, planning and health area, affect positively on technical efficiency. Beekeepers should be encouraged by the government to improve their efficiency through training programs to ease decision-making and management, therefore enhancing productivity.

Symptomatic sweet potato cv Arapey INIA samples were collected from a commercial production field in Colonia Molina, Guaymallén department, Mendoza province, Argentina. They showed dark rounded lesions, sometimes coalescing with white granular mycelium. Fungus was obtained from symptomatic sweet potatoes, which represented the generalized infection that affected the crop. They were seeded in PDA with streptomycin sulfate and incubated for seven days at 21°C, alternating white/black (UV400nm) light. Observations with an optical microscope revealed the presence of hyaline, not septated, cylindrical endoconidia with rounded ends. They were 8-16 μm length and 4–6 μm width. Phialides were 43-46 μm length, rounded bases (7-9 μm width) and tapering to the neck´s tip (4-6 μm width). Brown chlamydospores (aleuriospores), 9-13 μm length and 8-12 μm width, in chains of 2-8 spores were observed. For molecular identification, total genomic DNA was extracted. ITS fragment of 565 pb was amplified using ITS5/ITS4 primers and sequenced. The sequence indicated 99% identity with Berkeleyomyces basicola (synonymous: Thielaviopsis basicola). This was deposited in GenBank as (KX580957) (CBS: C430.74, Gen Bank accession number AF275482.1). This is the first report of B. basicola in sweet potato in Argentina, a potential threat to storage root yields. Highlights: Sweet potato black root rot, new disease in Argentina. First report of Berkeleyomyces basicola  causing black root rot on sweet potato in Mendoza, Argentina.

The objective of this study was to evaluate the effect of residual nitrogen (N) on pastures of Mombaça grass and its impact on pasture structure and the nutritive value and performance of beef cattle. The experiment analyzed randomized blocks subdivided into plots, with three replications. The research focused on a number of pastures having received three annual doses of N (100, 200 and 300 kg ha-1) from 2015 to 2017, with no N fertilization in 2018. The results indicated that pastures under residual effect of 300 kg ha-1 of N were characterized by higher (P<0.05) rates of forage accumulation than those under the residual effect of 100 kg ha-1 N. Furthermore, this study indicated no effect (P>0.05) on the pasture nutritive value and average daily gain (0.490 kg day-1). The stocking rate was higher (P<0.05) in pastures under the residual effect of 300 kg ha-1 of N, and lower in those at 100 kg ha-1 of N, while weight gain per area followed the trend observed in the stocking rate. The results thus suggest that the suspension of N fertilization for one year after three years of sequential fertilization was responsible for an immediate loss of 50 and 55% of the productivity of plants and animals, respectively. Highlights: Fundamental nitrogen fertilization to ensure pasture productivity. The use of nitrogen fertilization has been limited by cost, due to the extension of the areas involved and the need for frequent applications. We suspended nitrogen fertilization for one year after using the same doses of nitrogen for three years in order to evaluate a possible residual effect on plant and animal production. Suspending the N fertilization of Mombaça grass for one year after three years of sequential fertilization with the same doses leaves a residual effect on the pasture structure and performance of beef cattle. The suspension of nitrogen fertilization reduces the rate of forage accumulation by an average of 50%, causing a 55% reduction in animal productivity.


 It is important to look for alternative substrates to replace non-renewable resources such as peat used in growing media in horticulture. The aim of this work was to evaluate if the compost of pear and apple pomace could be used as an alternative to a commercial substrate for the production of tomato seedlings. Two experiments were carried out on trays with alveoli of 100 cm3 (experiment 1) and 30 cm3 (experiment 2). In experiment 1, three substrates were used: commercial substrate (CS), mixture of CS and pomace compost (CS+C) and pure compost (C). In experiment 2 a fourth treatment with a mixture of compost and perlite (C+P) was incorporated. The obtained results indicate that the development of the seedlings using CS+C and CS as a substrate was similar in cells of 100 cm3 and higher in cells of 30 cm3. In addition, the growth of seedlings on C+P in relation to CS showed similar or higher values in some variables. These results indicate that it would be feasible to replace the use of non-renewable resources such as peat in the production of tomato seedlings by a product obtained from a residue.
 Tomato seedling growth was evaluated on trays with 100 cm3 alveoli and 30 cm3 alveoli on different substrates mixtures: commercial substrate (CS), mixture of CS and pomace compost (CS+C), pure compost (C) and mixture of compost and perlite (C+P).
 Highlights
 
 Seedling development using CS+C and CS as substrates was similar in cells of 100 cm3 and higher in cells of 30 cm3.
 Seedling growth on C+P in relation to CS, showed similar or higher values for some variables such as root dry weight, shoot dry weight, stem diameter and shoot height.
 In 30 cm3 cell trays of the compost and perlite treatment (3:1 v/v), obtained seedling quality would enable a high post-transplant survival percentage.
 Pear and apple pomace compost may be an alternative to a commercial substrate containing peat for tomato seedlings production (Lycopersicon esculentum Mill.).


 In subtropical and humid environments the ‘winter-active’ cultivars of lucerne usually produce more forage with lower leaf proportion (i.e. leaf to stem ratio) than the ‘winter-dormant’ ones. Present research analyze (i) if differences in forage production changes with cutting frequency, and (ii) if differences in leaf proportion are intrinsic (i.e. ‘cultivar differences’) or are due to variations in plant morphology (i.e. ‘aerial biomass and canopy height’). In two subtropical locations a factorial experiment including three alfalfa cultivars (FD4= ‘winter-dormant’, FD6=‘semi-dormant’, FD9=‘winter-active’) and three cutting frequencies (‘high’, ‘intermediate’ and ‘low’) was established. As the cutting frequency decrease (i.e. from ‘high’ to ‘low’) the more winter-active cultivars were more productive than the more winter-dormant ones (FD9>FD6>FD4) due mainly to a higher stem production. However, differences between cultivars disappear (FD9=FD6=FD4) as the cutting frequency increases (i.e. from ‘low’ to ‘high’ cutting frequency). Compared at similar canopy height, differences between cultivars in leaf proportion were practically irrelevant. We confirm that (i) in subtropical and humid environments, the differences in forage production between cultivars contrasting in their winter activity depend of the cutting frequency, and that (ii) the leaf proportion depends mainly of plant morphology, especially canopy height’, being irrelevant the cultivar and the environment.
 Highlights
 
 This paper shows that (i) differences in forage production between cultivars of lucerne depend on the cutting frequency, and that (ii) leaf proportion is governed by plant morphology, especially canopy height.
 Forage production was similar between cultivars at high cutting frequency but at low cutting frequency winter-active and semi-dormant cultivars (FD6 and FD9) produce more forage than winter dormant (FD4) ones.
 Lucerne cultivars showing the same leaf proportion when they were compared at similar canopy height suggesting that leaf proportion is not an intrinsic trait
 Changes in leaf proportion were better explained by changes in canopy height than by changes in thermal time.


 There have been few studies on the use of diets and strategies to reduce the length of postpartum anoestrus in dairy goats, especially in tropical semi-arid regions. This review discusses the factors influencing the return of postpartum ovarian activity in goats. During the postpartum period, goats are in puerperal anoestrus and their reproductive tract is being prepared for a new conception. Anoestrus is necessary for tissue renewal in the uterus (uterine involution) associated with the return of cyclic ovarian activity, and is influenced by factors such as suckling of the offspring, social interactions, body condition score (BCS) before and after birth, intensity of negative energy balance (NEB) and stress from adverse climatic conditions. The anoestrus period can be extended by delays in the resumption of reproductive activity of females in puerperium. The duration of puerperal anoestrus in goats directly affects the productivity of the herd and is mainly influenced by nutrition, lactation period and heat stress. To minimize the negative effects of postpartum anoestrus on productivity, we recommend a mating season and a plan for the kidding period, as well as a program to monitor the body condition score during pregnancy so that the animals will have a better BCS at parturition. To minimize the effects of a negative energy balance, we suggest nutritional supplementation with levels of energy above the requirements for maintenance.
 Highlights
 
 The duration of postpartum anoestrus in goats is influenced by nutrition and body condition score.
 Heat stress can intensify the negative energy balance, consequently increased the period of anoestrus.
 Puerperal anoestrus occurs as a result of tissue renewal in the uterus.
 Suckling of the offspring associated with the period of lactation and social interactions can modified the puerperal anoestrus period.
 Use of diets and strategies to reduce the postpartum anoestrus in goats.