Nitrate fertilization enhances manganese phytoextraction in Tanzania guinea grass: a novel hyperaccumulator plant?

Manganese (Mn) is essential for plants but very toxic at high rates. However, hyperaccumulators can tolerate high Mn concentrations in plant tissue, especially when properly fertilized with N. Tanzania guinea grass (Megathyrsus maximus Jacq.) has been indicated as metal tolerant and a good candidate for Mn phytoextraction due to its fast growth and high biomass. The objective was to evaluate the Mn hyperaccumulator potential of Tanzania guinea grass grown as affected by proportions of nitrate/ammonium (NO3-/NH4+). An experiment in a growth chamber with nutrient solution, combining NO3-/NH4+ proportions (100/0 and 70/30) and Mn rates (10, 500, 1500, and 3000 µmol L-1), was carried out. The highest Mn concentration was verified in plants grown with 100/0 NO3-/NH4+ and Mn at 3000 µmol L-1, reaching up to 5500 and 21,187 mg kg-1 in shoots and roots, respectively, an overall concentration of 13,345 mg kg-1. These numbers are typically seen in hyperaccumulators. At that combination, Mn accumulation in shoots was also the highest, reaching up to 76.2 mg per pot, a phytoextraction rate of 23.1%. Excess Mn increased both H2O2 concentration in roots and non-photochemical quenching and therefore decreased net photosynthesis, stomatal conductance, electron transport rate, and photochemical quenching. Nevertheless, proline concentration in roots affected by excess Mn was high and indicates its important role for mitigating stress since Mn rates did not even affect the dry biomass. Tanzania guinea grass is highly tolerant to excess Mn as much as a hyperaccumulator. However, to show all its potential, the grass needs to be supplied with N as NO3-. We indicate Tanzania guinea grass as a Mn hyperaccumulator plant.

Acid selenites as new selenium precursor for CdSe quantum dot synthesis.

Chemical precursors for nanomaterials synthesis have become essential to tune particle size, composition, morphology, and unique properties. New inexpensive precursors investigation that precisely controls these characteristics is highly relevant. We studied new Se precursors, the acid selenites (R-O-SeOOH), to synthesize CdSe quantum dots (QDs). They were produced at room temperature by the Image 1 reaction with alcohols having different alkyl chains and were characterized by 1H NMR confirming their structures. This unprecedented precursor generates high-quality CdSe nanocrystals with narrow size distribution in the zinc-blend structure showing controlled optical properties. Advanced characterization detailed the CdSe structure showing stacking fault defects and its dependence on the used R-O-SeOOH. The QDs formation was examined using a time-dependent growth kinetics model. Differences in the nanoparticle surface structure influenced the optical properties, and they were correlated to the Se-precursor nature. Small alkyl chain acid selenites generally lead to more controlled QDs morphology, while the bigger alkyl chain leads to slightly upper quantum yields. Acid selenites can potentially replace Se-precursors at competitive costs in the metallic chalcogenide nanoparticles. Image 1 is chemically stable, and alcohols are cheap and less toxic than the reactants used today, making acid selenites a more sustainable Se precursor.

The autumn low milk yield syndrome in Brown Swiss cows in continental climates: hypotheses and facts.

Extensive research has been conducted globally on the impact of heat stress (HS) on animal health and milk production in dairy cows. In this article, we examine the possible reasons for the decrease in milk production in Brown Swiss (BS) cows during the autumn season, known as the autumn low milk yield syndrome (ALMYS). This condition has been extensively studied in high-yielding Holstein Friesian (HF) cattle and has also been observed in BS cows with a daily milk yield of around 30 kg. Our hypothesis is that the drop in milk yield and the increased prevalence of mastitis in autumn, as found in our recent studies, may be a long-term consequence of summer HS. We re-evaluate our previous findings in light of the possible manifestation of an HS-related form of ALMYS in BS cows. As milk yield, mastitis spread, and reproductive function of cows are interrelated and have seasonal dependence, we examine the consistency of our hypothesis with existing data. The significant drop in milk yield in BS cows in autumn (by 2.0-3.2 kg), as well as the threshold of milk yield decrease (temperature-humidity index of 70.7), may point in favour of the manifestation of ALMYS in BS cows, similar to HF cows. Only the percentage effect of seasonal factor (59.4%; p < 0.05) on milk yield of BS cows was significant. HS-related ALMYS provides a robust conceptual framework for diverse sets of productive and animal health data in BS cows, similar to observations in high-yielding HF cattle. However, the limitations associated with the lack of additional data (e.g. immunological indicators) suggest the need for further research to confirm ALMYS in BS breed.

Cryopreservation efficiency of red-rumped agouti (Dasyprocta leporina) sperm obtained from different origins through epididymal retrograde flushing or electroejaculation.

This study investigated whether the origin of sperm (epididymal vs. ejaculate) affects the cryopreservation efficiency in agouti (Dasyprocta leporina). Five sexually mature agoutis underwent electroejaculation, resulting in obtaining four semen samples. After 15 days, the same animals were euthanized, and through retrograde flushing, sperm samples were obtained from the epididymis tails. In both collection methods, samples were evaluated for sperm parameters (sperm concentration, motility, vigor, membrane integrity, osmotic response, and morphology). Then, samples were diluted in ACP 109c, added with 20% egg yolk, and a final concentration of 6% glycerol. Finally, the samples were packaged in 0.25 mL straws and frozen in liquid nitrogen. After one week, samples were thawed and evaluated in the same way as fresh samples, with the addition of membrane integrity analysis using fluorescent probes (C-FDA/PI) and computerized analysis (CASA). Immediately after obtaining the sperm, samples obtained directly from the epididymis presented higher values (P ≤ 0.05) than those obtained by electroejaculation concerning the parameters of volume, sperm concentration, and total number of sperm (1,398.25 ± 206.0 x106 and 184.5 ± 78.0 x106 sperm). On the other hand, in the classical evaluation of the other sperm parameters and the computerized analysis (CASA) after thawing, such as total motility, no statistical differences were observed between sperm from both origins (ejaculate: 16.7 ± 8.2% and epididymal: 24.8 ± 12.0%, P > 0.05). This demonstrates the possibility of direct application of the cryopreservation protocol for agouti (D. leporina) sperm obtained via the epididymis or ejaculate.

Background optimization of powder electron diffraction for implementation of the e-PDF technique and study of the local structure of iron oxide nanocrystals.

The local structural characterization of iron oxide nanoparticles is explored using a total scattering analysis method known as pair distribution function (PDF) (also known as reduced density function) analysis. The PDF profiles are derived from background-corrected powder electron diffraction patterns (the e-PDF technique). Due to the strong Coulombic interaction between the electron beam and the sample, electron diffraction generally leads to multiple scattering, causing redistribution of intensities towards higher scattering angles and an increased background in the diffraction profile. In addition to this, the electron-specimen interaction gives rise to an undesirable inelastic scattering signal that contributes primarily to the background. The present work demonstrates the efficacy of a pre-treatment of the underlying complex background function, which is a combination of both incoherent multiple and inelastic scatterings that cannot be identical for different electron beam energies. Therefore, two different background subtraction approaches are proposed for the electron diffraction patterns acquired at 80 kV and 300 kV beam energies. From the least-square refinement (small-box modelling), both approaches are found to be very promising, leading to a successful implementation of the e-PDF technique to study the local structure of the considered nanomaterial.

The effect of propolis extract on milk production and composition, serum biochemistry, and physiological parameters of heat-stressed dairy cows.

The aim of this study was to evaluate whether feeding propolis extract (PE) influences nutrient intake, milk production and composition, serum biochemistry, and physiological parameters of heat-stressed dairy cows. For this purpose, we used three primiparous Holstein cows with a lactation period of 94 ± 4 days and with 485 ± 13 kg body weight. The treatments were 0 mL/day, 32 mL/day, and 64 mL/day of PE randomly assigned in a 3x3 Latin square design, repeated over time. The experiment lasted a total of 102 days; each Latin square lasted 51 days divided into three 17-day periods (12 days for adaptation and five days for data collection). The PE supply did not influence (P > 0.05) the cows' intake of dry matter (18.96 kg/d), crude protein (2.83 kg/d), and neutral detergent-insoluble fiber (7.36 kg/d), but there was an increase in feeding time with the 64 ml/day PE supply (P < 0.05). Providing 64 ml/day of PE tended (P = 0.06) to increase milk production by 11.64% and improve gross feed efficiency of cows by 12.04%. The PE supply did not influence milk composition and blood parameters of cows (P > 0.05). Offering 32 mL/day of PE decreased (P < 0.05) the rectal temperature and respiratory rate of cows. We recommend a supply of 64 mL/day of PE for heat-stressed dairy cows.

Impact of environmental variables on some reproductive metrics of white-lipped peccaries (Tayassu pecari) raised in Atlantic Forest of Brazil.

Knowledge on male reproductive physiology is essential for the development of effective conservation strategies. This study investigated the influence of environmental variables on certain reproductive metrics in white-lipped peccaries (Tayassu pecari) raised in the Atlantic Forest. After anesthetization, testicular and cauda epididymis biometry were evaluated in nine adult male individuals subjected to electroejaculation. Semen was evaluated for volume, pH, concentration, total number of sperm, sperm morphology, membrane integrity, and kinematic parameters. Concurrently, environmental variables were collected from the day before, for the previous 14 days (estimated for sperm maturation in epididymis), and the period of 51-55 days (corresponding to the spermatogenic cycle) before semen collection. Overall, it was observed that rainfall is the most important environmental variable influencing the reproductive parameters of white-lipped peccaries, being positively correlated with the amplitude of lateral sperm head displacement (ρ = 0.62, P < 0.05) and the appearance of proximal cytoplasmic droplets in sperm (ρ = 0.62, P < 0.05). In addition, the testicular biometry of the species is influenced by the set of environmental variables of air temperature, rainfall, and relative humidity (ρ ≥ 0.60, P < 0.05). On the other hand, epididymal biometric data showed numerous correlations between cauda epididymis metrics and sperm parameters (ρ = 0.68, P < 0.05). This information will be useful to improving conservation strategies for these animals, contributing to their management in captivity and to reintroduction programs, especially in the Atlantic Forest where the species is declining.

Effect of Detergents Based on Sodium Dodecyl Sulfate on Functional Metrics of Frozen-Thawed Collared Peccary (Pecari tajacu) Semen.

We evaluated the effects of detergents based on sodium dodecyl sulfoxide (SDS) on the functional parameters of collared peccary frozen-thawed sperm. Semen aliquots from ten individuals were diluted in a Tris-egg yolk-glycerol extender alone or with 0.5% Equex STM® paste or SDS (at 0.1%, 0.3% or 0.5% (v/v) concentration). Samples were fast frozen in liquid nitrogen with a post-thaw evaluation of motility, membrane functionality and integrity, mitochondrial activity, sperm binding ability and thermal resistance. The treatments without SDS (41.8 ± 3.5%) and those containing Equex (41.8 ± 4.4%) or 0.1% SDS (41.2 ± 5.5%) provided greater sperm motility (p < 0.05) than those containing SDS 0.3% (30.5 ± 4.7%) and 0.5% (31.2 ± 6.3%). Immediately after thawing, only treatments containing 0.1% SDS effectively preserved sperm straightness (STR) when compared to the negative control. All treatments preserved the amplitude of lateral head (ALH) and straightness (STR) during a thermal resistance test (p > 0.05), but SDS 0.5% impaired the membrane functionality and mitochondrial activity after thawing (p < 0.05). All treatments provided a similar recovery of sperm binding ability after thawing (p < 0.05). Our results showed that the addition of 0.1% SDS to the Tris-yolk-glycerol extender optimized the freeze-thaw recovery of peccary semen.

Investigating the need for antibiotic supplementation to the extender used for semen cryopreservation in collared peccaries.

The objective was to investigate the effects of semen freezing extender supplementation with antibiotics on bacterial load of semen samples, sperm functional and morphological metrics in the collared peccary. Fresh ejaculates from 10 males were extended in Tris-egg yolk-glycerol supplemented or not (control) with gentamicin (70 µg/mL) streptomycin-penicillin (SP; 1 mg/mL-1000 IU/mL) or and cryopreserved in liquid nitrogen. Bacterial load, sperm motility patterns, morphology, membrane functionality and integrity, mitochondrial activity, chromatin integrity and sperm-binding ability were evaluated in fresh and frozen-thawed samples. Regardless of the use of antibiotics, the sole cryopreservation provoked a significant decrease (P < 0.05) in bacterial load compared to fresh samples (from average values > 1 x 106 CFU/mL to <0.4 × 106 CFU/mL). Post-thawing sperm kinetic parameters were not affected by the absence or presence of different antibiotics, except for beat cross frequency that was significantly (P < 0.05) impaired by SP supplementation compared to the group without antibiotics. After thawing, sperm morphology, membrane functionality and integrity, and mitochondrial activity were also not affected by the presence or absence of antibiotics; however, a significant decrease was observed in the group without antibiotics (P < 0.05) in comparison to fresh samples. Regarding sperm-binding ability, there were no differences among the different groups. While collared peccary semen could be efficiently cryopreserved in the absence of antibiotics in the extender, the use of both gentamicin or the streptomycin-penicillin combination is recommended as effective antibiotic supplementation for a further control of bacterial loads without affecting sperm parameters.

Stability and Rupture of an Ultrathin Ionic Wire.

Using a combination of in situ high-resolution transmission electron microscopy and density functional theory, we report the formation and rupture of ZrO_{2} atomic ionic wires. Near rupture, under tensile stress, the system favors the spontaneous formation of oxygen vacancies, a critical step in the formation of the monatomic bridge. In this length scale, vacancies provide ductilelike behavior, an unexpected mechanical behavior for ionic systems. Our results add an ionic compound to the very selective list of materials that can form monatomic wires and they contribute to the fundamental understanding of the mechanical properties of ceramic materials at the nanoscale.

Effect of distance and daily periods on heat-stressed pigs and pre-slaughter losses in a semiarid region.

Effective planning animal transport is essential to safeguard animal welfare and reduce production losses. Environmental conditions, specifically extreme temperatures in combination with ranges of relative humidity are highlighted as one of the main risk factors for production losses during transport (e.g., fatalities). The majority of research evaluating both welfare and production impacts of pig transport have been primarily undertaken in Europe and North America, which cover a relatively limited range of distinct climates (e.g., temperate, sub-arctic, etc.). As a result, research on pig transport in semi-arid conditions is lacking. In this study, we evaluated the effects of both distance (short, 30 km; and long, 170 km) and transport daily periods (morning, (05:00-11:00); afternoon (12:00-17:00); and night, (23:00-04:00)) on the preslaughter losses and heat stress of pigs in commercial transport in a semiarid region. Across 19 journeys of standard slaughter-weight pig loads (124.0 ± 2.8 kg), 684 focal animals (36 per journey) were evaluated. For each journey, the load's thermal profile (THIadj and enthalpy) and physiological responses of individual pigs were recorded. On arrival at designated slaughterhouses, the percentage pig of non-ambulatory non-injured (NANI), non-ambulatory injured (NAI), death on arrival (DOA), and total losses were recorded. Short journeys in the afternoon were shown to be more detrimental to the thermal comfort of pigs, with higher rectal temperatures recorded. The highest percentage of total losses and DOA occurred in afternoon journeys, irrespective of distance, followed by the morning, with the lowest losses observed in pigs transported at night. Additionally, total losses and DOA were further exacerbated by journey distance, with higher rates observed in short journeys. Higher percentage averages of NANI and NAI were observed in shorter journeys, but daily periods effects were only observed for NANI. These results further demonstrate the welfare and production loss risks associated with journey distance and time of day (representing varying environmental conditions) during road transport of pigs, whilst providing novel data in semiarid conditions. Careful and effective planning for pig transportation is essential to minimize heat stress and production losses. Consideration of the thermal environment on the day of travel, as well as providing flexibility to adjust travel times (e.g., early morning or evening), should help to mitigate risks of heat stress and production losses during pig transport.

Advances in Engineered Metal Oxide Thin Films by Low-Cost, Solution-Based Techniques for Green Hydrogen Production.

Functional oxide materials have become crucial in the continuous development of various fields, including those for energy applications. In this aspect, the synthesis of nanomaterials for low-cost green hydrogen production represents a huge challenge that needs to be overcome to move toward the next generation of efficient systems and devices. This perspective presents a critical assessment of hydrothermal and polymeric precursor methods as potential approaches to designing photoelectrodes for future industrial implementation. The main conditions that can affect the photoanode's physical and chemical characteristics, such as morphology, particle size, defects chemistry, dimensionality, and crystal orientation, and how they influence the photoelectrochemical performance are highlighted in this report. Strategies to tune and engineer photoelectrode and an outlook for developing efficient solar-to-hydrogen conversion using an inexpensive and stable material will also be addressed.

Morphological, morphometric, ultrastructural, and functional evaluation of red-rumped agouti (Dasyprocta leporina) sperm during epididymal transit.

The red-rumped agouti (Dasyprocta leporina) is a hystricognath rodent with reproductive anatomical peculiarities presenting as an intra-abdominal testes-epididymis complex. This study was carried out to describe, for the first time, details related to the morphological and functional changes in sperm along the epididymal transit in agoutis. The testes-epididymal complexes were sampled from seven sexually mature agoutis. Sperm from different epididymal regions (caput, corpus, and cauda) were collected using the floating technique, and their morphology, morphometry, ultrastructure, mitochondrial activity, membrane structural integrity, and kinetic parameters were determined. The number of sperm collected (823.5 ×106 sperm) was higher in the epididymis cauda. No significant differences in normal sperm morphology among the different epididymal regions (caput, 82.42%; corpus, 86.71%; and cauda, 88.86 %) were observed. The mean head length, head width, and tail length were highest in the caput (5.15 µm, 3.44 µm, and 32.04 µm, respectively), decreasing along the epididymal transit. Ultrastructure by scanning electron microscopy (SEM) revealed agglomeration of spermatozoa from caput and corpus, thus, enabling analysis of the gametes from only the epididymal cauda with clarity. Sperm from epididymis cauda showed the greatest proportion of membrane integrity and mitochondrial activity, followed by those from corpus and caput (79.71 %, 58.9 %, 47.7 %, respectively). Significant increase in total motility, progressive motility, velocity average pathway -VAP, velocity straightline - VSL, velocity curvilinear - VCL, and rapid sperm in the caput-corpus-cauda direction were observed. These novel data contribute to the knowledge of sperm maturation in the red-rumped agouti.

The Influence of Magnetic Field and Nanoparticle Concentration on the Thin Film Colloidal Deposition Process of Magnetic Nanoparticles: The Search for High-Efficiency Hematite Photoanodes.

Hematite is considered a promising photoanode material for photoelectrochemical water splitting, and the literature has shown that the photoanode production process has an impact on the final efficiency of hydrogen generation. Among the methods used to process hematite photoanode, we can highlight the thin films from the colloidal deposition process of magnetic nanoparticles. This technique leads to the production of high-performance hematite photoanode. However, little is known about the influence of the magnetic field and heat treatment parameters on the final properties of hematite photoanodes. Here, we will evaluate those processing parameters in the morphology and photoelectrochemical properties of nanostructured hematite anodes. The analysis of thickness demonstrated a relationship between the magnetic field and nanoparticles concentration utilized to prepare the thin films, showing that the higher magnetic fields decrease the thickness. The Jabs results corroborate to influence the magnetic field since the use of a higher magnetic field decreases the deposited material amount, consequently decreasing the absorption of the thin films. The PEC measurements showed that at higher concentrations, the use of higher magnetic fields increases the JPH values, and lower magnetic fields cause a decrease in JPH when using the higher nanoparticle concentrations.

Influence of antibiotics on bacterial load and sperm parameters during short-term preservation of collared peccary semen.

Studies on semen and sperm cells are critical to develop assisted reproductive technologies for the conservation of the collared peccary. The objective of the study was to compare the effect of different antibiotics on the bacterial load and sperm quality during short-term storage of peccary semen. Fresh semen samples from 10 males were extended in Tris-egg yolk or Tris-Aloe vera supplemented with streptomycin-penicillin (SP; 1 mg/mL - 1000 IU/mL or 2 mg/mL - 2000 IU/mL) or gentamicin (30 µg/mL or 70 µg/mL) before storage at 5°C. Bacterial load and sperm motility, membrane integrity and function, mitochondrial activity, and morphology, were evaluated at different time points for 36 h. The SP and gentamicin treatments concentration inhibited (p < 0.05) bacterial growth for 36 h regardless of the extender. Compared to the other treatments, Tris-egg yolk plus 70 µg/mL gentamicin maintained the sperm parameters for longer, including total motility (41.9 ± 6.1%) at 24 h, and membrane integrity (58.3 ± 2.1%) at 36 h. In contrast, the highest SP concentration in both extenders impaired sperm membrane integrity at 36 h (p < 0.05). For the liquid storage of collared peccary semen, it therefore is recommended to use Tris extender supplemented with egg yolk and gentamicin (70 µg/mL).

Understanding how environmental factors influence reproductive aspects of wild myomorphic and hystricomorphic rodents.

Myomorphic and hystricomorphic rodents are vital for maintaining various ecosystems around the planet. This review enables a better understanding of how these rodents respond to environmental factors and adapt to climate adversities. Innumerable factors, such as photoperiod, rainfall, and temperature, can impair or contribute to the quality of rodent reproductive parameters. Prolonged animal exposure to high ambient temperatures alters thermoregulation mechanisms and causes testicular and ovarian tissue degeneration and hormonal deregulation. Photoperiod influences the biological circannual rhythm and reproductive cycles of rodents because it strongly regulates melatonin secretion by the pineal gland, which modulates gonadotropic hormone secretion. Rainfall quantity directly regulates the abundance of fruits in an ecosystem, which modulates the reproductive seasonality of species which are most dependent on a seasonal fruit-based diet. Species with a more diversified fruit diet have smaller reproductive seasonality. As such, habitats are chosen by animals for various reasons, including the availability of food, sexual partners, intra-and inter-specific competition, and predation. This knowledge allows us to monitor and establish management plans to aid in conservation strategies for wild rodent species.

Oficinas pedagógicas de enfrentamento ao trabalho infantil: memória, oralidade e expressão estética / Pedagogical workshops to coping child labor: memory, orality and aesthetic expression

Resumo: Este relato reporta a experiência em curso de formação acerca do trabalho infantil, no qual, por meio de oficinas pedagógicas que envolveram as memórias, a oralidade e as expressões estéticas dos participantes, buscava-se desnaturalizar o fenômeno, ressignificando-o, favorecendo assim a sua identificação e o seu enfrentamento. O curso foi ofertado a 333 técnicos da Assistência Social provenientes de 98 municípios mineiros.

Abstract: This article reports the experience in a training course about child labor, in which, through pedagogical workshops that involved the participants' memories, orality and aesthetic expressions, sought to denaturalize the phenomenon, giving it a new meaning, thus favoring their identification and coping. The course was offered to 333 Social Assistance technicians from 98 municipalities in Minas Gerais.

Identification of trailer heat zones and associated heat stress in weaner pigs transported by road in tropical climates.

Heat stress is major welfare concern during transport of pigs in tropical climates, which can also lead to direct production costs. This study evaluated the dynamics of heat zones through the load and their relationship with heat stress of weaner pigs during road transport in a tropical climate. Both environmental (e.g. temperature and relative humidity) and physiological (e.g. respiratory frequency and lactate) measures were recorded from four vehicle journeys (70 km distance, 216 weaner pigs within each trailer load) within Ceará, northeastern Brazil. Geostatistics and fluid dynamics simulation techniques were applied to understand the dynamics of heat zones and ventilation patterns the truckload. Statistics based on canonical discriminant analysis and ANOVA were performed to verify the relationship between heat zones and heat stress in pigs. The results showed that, during transport, the generation of heat zones occurred with different magnitudes along the load (P < 0.05), which was harmonized by the ventilation dynamics. There was a heat core with high energy content, in the front region of the lower deck (LD) of the trailer. In this zone, weaners pigs had higher rectal temperature (+1.8 °C temperature difference), respiratory frequency (LD = 94 ± 1.3 breaths/min; UD = 86 ± 1.3 breaths/min), and blood cortisol concentration (LD = 32.9 ± 0.8 ng/mL; UD = 30.18 ± 0.6 ng/mL) (all P < 0.05). Weaners pigs transported in the upper deck (UD) compartments had the highest skin temperature (LD = 38.13 ± 0.3 °C; UD = 38.9 ± 0.22 °C) and the highest mean values of blood lactate (LD = 65.5 ± 1.11 m/M; UD = 71.60 ± 1.19 m/M) and Creatine kinase (LD = 3891.23 ± 69U/L; UD = 4107.43 ± 62U/L) (P < 0.05). Weaners transported in compartments of the LD of trailer were more susceptible to heat stress, while weaners in the UD compartments were more susceptible to physical stress and muscle exhaustion. These results provide additional evidence of heat zones within trailer compartments and highlight the requirement for the planning of pig transport operations in tropical climates to mitigate risks of heat stress.

Influence of freezing techniques and glycerol-based cryoprotectant combinations on the survival of testicular tissues from adult collared peccaries.

The objective of the study was to evaluate the effects of different cryopreservation techniques including glycerol-based cryoprotectant combinations on the structure and viability of testicular tissues from adult collared peccaries. Tissue biopsies (3.0 mm³) from 5 different individuals were allocated to 10 different groups: fresh control; slow freezing (SF), conventional vitrification (CV), or solid-surface vitrification (SSV); each of them using three different combinations of cryoprotectants [dimethyl sulfoxide (DMSO) + ethylene glycol (EG); DMSO + Glycerol; and EG + Glycerol]. After thawing/warming, samples were evaluated for histomorphology, viability, proliferative capacity potential, and DNA integrity. Most effective preservation of testicular histomorphology was achieved using SF and CV with DMSO + EG. However, the use of glycerol-based cryoprotectant combinations increased the occurrence of tubular cell swelling, tubular cell loss and shrinkage from the basal membrane. Cell viability was comparable among cryopreservation methods and cryoprotectant combinations. Regarding cell proliferative capacity, the use of SF with EG + Glycerol and SSV with DMSO + Glycerol impaired the conservation of spermatogonia proliferative potential compared to other treatments. Moreover, CV with DMSO + EG was better than SF with EG + Glycerol for Sertoli cell proliferation potential. Regarding DNA integrity, less damage occurred when using SF with DMSO + EG while more fragmentations were observed when using CV with EG + Glycerol or DMSO + Glycerol as well as SSV with EG + Glycerol or DMSO + Glycerol. In sum, SF and CV appeared to be the most suitable methods for the cryopreservation of adult peccary testicular tissues. Additionally, the use of glycerol-based cryoprotectant combinations did not improve testicular tissues preservation with DMSO + EG being the most efficient option.

An updated review on cattle thermoregulation: physiological responses, biophysical mechanisms, and heat stress alleviation pathways.

Heat stress is one of the main obstacles to achieving efficient cattle production systems, and it may have numerous adverse effects on cattle. As the planet undergoes climatic changes, which is predicted to raise the earth's average temperature by 1.5 °C between 2030 and 2052, its impact may trigger several stressful factors for livestock. Among these, an increase in core body temperature would trigger physiological imbalance, consequently affecting reproduction, animal health, and dry matter intake adversely. Core body temperature increase is commonly observed and poses challenges to livestock farmers. In cattle farming, thermal stress severely affects milk production and weight gain, and can compromise food security in the coming years. This review presents an updated approach to the physiological and thermoregulatory responses of cattle under various environmental conditions. Strategies for mitigating the harmful effects of heat stress on livestock are suggested as viable alternatives for the betterment of production systems.