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Heat stress is a challenge for the milk production chain, especially in tropical environments. Thus, the objective was to evaluate the knowledge and the perception of milk producers about heat stress and determine what corrective measures they adopted to minimize losses in the productive performance of dairy cows due to high temperatures. A questionnaire was applied to 112 dairy farmers in the states of Minas Gerais and Goiás, Brazil in 2019 and 2020. The collected data were submitted to descriptive statistics using the G test of independence and multivariate correspondence analysis. Among the surveyed producers, 89% stated that they had already been informed about what heat stress is and how it affects the animals; 94% declared that they had already noticed in their day-to-day activities that heat stress impairs productivity and milk quality, and 92% stated that they have tried to reduce the heat stress to which the animals in their herd are exposed. There was an association among previous knowledge about heat stress and farm size, daily volume of milk produced, number of lactating cows, type of milking and presence of technical assistance. There was also an association among the adoption of measures that minimize the negative effects of heat stress with the size of the property, the number of cows in lactation and with the producer's perception of heat stress in their daily lives. It was concluded that, in important municipalities of the Brazilian dairy chain, most milk producers surveyed have knowledge and perception of the negative effects of heat stress on the productive performance of dairy cows and sought to adopt measures that could alleviate them.

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Bombus brevivillus Franklin is a Neotropical Bombus species whose colonies are disappearing from most of its native range, and little is known about its biology and reproductive habits to help conservation or breeding efforts. Unlike Bombus species from temperate climates whose colonies perish every winter, there are suggestions of perennial colonies that Neotropical Bombus species can present. In this work, we investigated the development of two B. brevivillus colonies (i.e., number of workers, gynes, males, new cocoons, and brood area) between August 2012 and March 2013. We realized that while one colony collapsed and died after the males' and gynes' production, and the reduction of numbers of adult workers, in the other, a new queen assumed the posture at this phase and reactivated the old nest. Despite the reduced number of colonies investigated, this study shows the possibility of nest reactivation in the studied species in queen supersedure events in resemblance to perennial colonies of eusocial bees like Apis species and stingless bees. Such behavior has never been directly described to B. brevivillus in previous studies and opens the possibility for further research in the existence and the extension of perennial colonies in Neotropical Bombus species due to its importance to the species conservation in the tropical environment.

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Tortoises of the genus Gopherus evolved in North America and have survived major environmental challenges in the past 40 million years. However, this genus now faces multiple anthropogenic threats, such as the introduction of invasive plant species. Buffelgrass (Cenchrus ciliaris) is considered one of the greatest threats to arid and tropical ecosystems, where gopher tortoises inhabit, because the grass displaces native flora and fauna. Modification of the environment as a result of this invasive plant portends an alteration of the available thermal landscape. The aim of this paper is twofold: 1) to evaluate the thermal quality of the primary habitat of Gopherus evgoodei (tropical deciduous forest [TDF], and 2) determine the potential thermal changes due to habitat modification by buffelgrass. First, we obtained data on body temperature of active tortoises in semi-captivity. Second, we measured the operative environmental temperature during 5 years at three sites south of Sonora, Mexico that support G. evgoodei: a) a pristine TDF (Conserved-TDF); b) a forest patch surrounded by introduced buffelgrass pasture (Partial-TDF); and c) an introduced buffelgrass pasture area (Buffel-Pasture). Our results demonstrate that the intact microhabitats within the TDF provide G. evgoodei with high thermal quality at both spatial and temporal scales. However modified habitat by buffelgrass had higher operative temperatures for G. evgoodei than TDF. The thermal quality of the sites disturbed with buffelgrass can exceed the thermal requirements of G. evgoodei by up to 25 °C. Finally, we discussed potential collateral effects of habitat modification by invasion by buffelgrass.

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The present trial evaluated the effect of crossbred composition and Temperature and Humidity Index (THI) on vaginal temperature (VT) of Girolando dairy cows maintained under tropical pasture during warm seasons. The VT was monitored along 41 to 96 h in 615 Girolando cows with different Holstein (H) × Gir genetic composition (1/2 H = 284, 3/4 H = 248, and 7/8 H = 83) from six Brazilian farms in the summer of 2016 and 2017. VT of each cow at each hour of the day and the respective THI were averaged per hour across all monitoring days to generate an averaged value for VT and THI during 24 h. A linear mixed model with repeated measures using restricted maximum likelihood (REML) method for (co)variance components estimation procedure was employed. The final model adjusted the VT for the effects of cow, time, THI, farm, year, pregnancy status, body condition score (BCS), milk yield, genetic composition, and genetic composition*time interaction. Fixed effects were evaluated by ANOVA and tested with Tukey test in R software version 3.6.1 (R Core Team, 2019). Overall mean of VT, air temperature (AT), and THI were 39.06 ± 0.52 °C, 25.63 ± 0.40 °C, and 75.06 ± 3.96, respectively. VT had moderate positive correlation with THI (r² = 0.45, P < 0.001) and AT (r² = 0.46, P < 0.001). The VT had estimated linear increase of 0.05 °C for each THI unit increase (P < 0.001). Least square mean of VT varied among the farms (P < 0.001), pregnancy status (P < 0.001), and BCS (P < 0.05) but not for Milk yield (P > 0.05). The daily average VT was affected by genetic composition (P < 0.001) with highest temperature for 3/4 H (39.08 ± 0.06 °C a) and 7/8 H (39.09 ± 0.06 °C a) and lowest temperature for 1/2 H (38.95 ± 0.06 °C b). The difference of VT among the three crossbred groups varied in function of the time of the day, from 12:00 to 20:00 h (P < 0.001), with 3/4 Holstein and 7/8 Holstein cows reaching similar VT, above to the upper limit 39.1 °C and higher than 1/2 Holstein cows during all this period. In conclusion, Girolando cows are sensitive to heat stress in tropical condition during warm seasons. Moreover, Girolando cows with genetic composition higher than 3/4 Holstein display reduced thermoregulatory efficiency. Therefore, Girolando cows in tropical dairy farms require strategies to mitigate heat stress according to their genetic composition.

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In this work we critically assess the soil-to-plant transfer factors (TF) for 137Cs and 40K in edible fleshy organs of tropical plants that are often components of the human diet. Radionuclide concentrations in soil and plants were obtained from previous investigations developed in Brazil, after the Goiânia radiological accident occurred in 1987. Transfer factors were determined in specific plant compartments (main root, main stem, bark, old and new branches, twig, old and new leaves, mature and green edible organs) of tropical species such as lemon (Citrus aurantifolia), orange (Citrus sinensis), guava (Psidium guajava), chili pepper (Capsicum frutescens), pomegranate (Punica granatum), papaya (Carica papaya), banana (Musa paradisíaca), and manioc (Manihot esculenta). For 137Cs, soil-to-fruit transfer factor ranged from 0.80 × 10-2 (banana) to 3.65 × 10-1 (pomegranate); for 40K, this factor was from 4.42 × 10-1 (orange) to 1.74 (chili pepper). Considering all the plant compartments analysed, the transfer factors for 40K are between 24.5 (guava) and 90.5 (papaya) times higher than for 137Cs. For both radionuclides, considerable differences in soil-to-plant transfer were found when new growing parts of the plant (green edible organ, leaf, and twig) are considered with respect to those older parts (mature edible organ, old leaf and branches). Considering all the species analyzed, the relationship TF(40K)/TF(137Cs) does not seem to follow a characteristic pattern. However, if we compare the value of this relationship for two organs of the same plant, the result is approximately constant, regardless of the species considered. This confirms earlier evidence that both radionuclides are similarly distributed in the different organs of the studied species. The differences in the transfer factors according to the ripening status of edible organs must be particularly considered when estimating the dose from ingestion of fruits and their derivatives in dose assessment models.

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Determining the origin of eroded soil is essential to design effective soil erosion control strategies which preserve the soil resource, enhance agricultural productivity, and reduce the negative impacts of soil erosion, in-field and off-field. Magnetic properties have been widely used in temperate environments to identify sediment sources, pathways and links, but there have been very few applications in tropical and subtropical environments. Therefore, in this paper we investigated reservoir sediment sources in the Upper Grande River Basin, Southeastern Brazil, using sediment tracing techniques based on magnetic parameters (low and high frequency magnetic susceptibility, frequency dependent susceptibility). The different parent materials and subtropical weathering conditions resulted in soils having different Fe oxide minerals and Fe oxide contents, promoting magnetic variability that allowed comparison and identification of possible sources of reservoir sediments in order to reduce water erosion impacts. The results indicate the suitability of magnetic properties as a tracer for soil erosion studies in tropical environments.(AU)

Determinar a origem de solos erodidos é essencial para projetar estratégias efetivas de controle da erosão do solo que preservem os recursos do solo, aumentem a produtividade agrícola e reduzam os impactos negativos da erosão do solo, em campo e fora dele. As propriedades magnéticas têm sido amplamente utilizadas em ambientes temperados para identificar fontes, vias e elos de sedimentos, mas existem pouquíssimas aplicações em ambientes tropicais. Portanto, neste trabalho investigamos fontes de sedimentos de reservatórios na Bacia do Alto Rio Grande, Sudeste do Brasil, utilizando técnicas de rastreamento de sedimentos baseadas em parâmetros magnéticos (suscetibilidade magnética de baixa e alta freqüência, susceptibilidade dependente da freqüência). Os diferentes materiais de origem e condições de intemperismo tropical resultaram em solos com diferentes minerais de óxido de Fe e teores de óxidos de Fe, promovendo variabilidade magnética que permitiu a comparação e identificação de possíveis fontes de sedimentos de reservatórios para reduzir os impactos da erosão hídrica. Os resultados indicam a adequação das propriedades magnéticas como um traçador para estudos de erosão do solo em ambientes tropicais.(AU)

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Determining the origin of eroded soil is essential to design effective soil erosion control strategies which preserve the soil resource, enhance agricultural productivity, and reduce the negative impacts of soil erosion, in-field and off-field. Magnetic properties have been widely used in temperate environments to identify sediment sources, pathways and links, but there have been very few applications in tropical and subtropical environments. Therefore, in this paper we investigated reservoir sediment sources in the Upper Grande River Basin, Southeastern Brazil, using sediment tracing techniques based on magnetic parameters (low and high frequency magnetic susceptibility, frequency dependent susceptibility). The different parent materials and subtropical weathering conditions resulted in soils having different Fe oxide minerals and Fe oxide contents, promoting magnetic variability that allowed comparison and identification of possible sources of reservoir sediments in order to reduce water erosion impacts. The results indicate the suitability of magnetic properties as a tracer for soil erosion studies in tropical environments.

Determinar a origem de solos erodidos é essencial para projetar estratégias efetivas de controle da erosão do solo que preservem os recursos do solo, aumentem a produtividade agrícola e reduzam os impactos negativos da erosão do solo, em campo e fora dele. As propriedades magnéticas têm sido amplamente utilizadas em ambientes temperados para identificar fontes, vias e elos de sedimentos, mas existem pouquíssimas aplicações em ambientes tropicais. Portanto, neste trabalho investigamos fontes de sedimentos de reservatórios na Bacia do Alto Rio Grande, Sudeste do Brasil, utilizando técnicas de rastreamento de sedimentos baseadas em parâmetros magnéticos (suscetibilidade magnética de baixa e alta freqüência, susceptibilidade dependente da freqüência). Os diferentes materiais de origem e condições de intemperismo tropical resultaram em solos com diferentes minerais de óxido de Fe e teores de óxidos de Fe, promovendo variabilidade magnética que permitiu a comparação e identificação de possíveis fontes de sedimentos de reservatórios para reduzir os impactos da erosão hídrica. Os resultados indicam a adequação das propriedades magnéticas como um traçador para estudos de erosão do solo em ambientes tropicais.

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The objective of the study was to identify the different behavior of Etawah Grade does in early and late pregnancy period. This research using 14 head of Etawah Grade does in pregnant conditions with an age of fewer than 2 months as the early pregnancy group and gestational age of 4 to 5 months as the late pregnancy group in Farm of FacultyAnimal Science, Universitas Gadjah Mada. The method usedwas direct observation. The goats were observed for 24 hours. The data observed were consisted of activities including time and frequency of feeding, ruminating, standing, lying, urinating and defecating. Data behavior of goats was analyzed using T-test. The results showed that the temperature and humidity of the study ranged from 25 to 31 ºC and 65 to 90%, respectively. The heart rate frequency in late pregnancy higher (P < 0.05) than in early pregnancy conditions. There were significant differences (P < 0.05) on the behavior of early and late pregnancy of Etawah Grade does, in terms of frequency of feeding (17.11±1.33 and 13.61±2.85 times/day), and average in once feeding (10.24±1.64 and 12.88±2.36 minutes), standing duration (15.05±0.83 and 11.45±1.34 hours/day), laying duration (9.01±0.71 and 12.54±1.34 hours/day), average in once laying (31.32±3.6 and 47.89±5.68), and frequency of urination (6.56±0.34 and 9.55±2.01). The conclusion of the study is the Etawah Grade does during early pregnancy and late pregnancy has different behavior, especially on the frequency of feeding, average on once feeding, standing duration, time and average of once lying, and frequency of urination.

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The objective of the study was to identify the different behavior of Etawah Grade does in early and late pregnancy period. This research using 14 head of Etawah Grade does in pregnant conditions with an age of fewer than 2 months as the early pregnancy group and gestational age of 4 to 5 months as the late pregnancy group in Farm of FacultyAnimal Science, Universitas Gadjah Mada. The method usedwas direct observation. The goats were observed for 24 hours. The data observed were consisted of activities including time and frequency of feeding, ruminating, standing, lying, urinating and defecating. Data behavior of goats was analyzed using T-test. The results showed that the temperature and humidity of the study ranged from 25 to 31 ºC and 65 to 90%, respectively. The heart rate frequency in late pregnancy higher (P < 0.05) than in early pregnancy conditions. There were significant differences (P < 0.05) on the behavior of early and late pregnancy of Etawah Grade does, in terms of frequency of feeding (17.11±1.33 and 13.61±2.85 times/day), and average in once feeding (10.24±1.64 and 12.88±2.36 minutes), standing duration (15.05±0.83 and 11.45±1.34 hours/day), laying duration (9.01±0.71 and 12.54±1.34 hours/day), average in once laying (31.32±3.6 and 47.89±5.68), and frequency of urination (6.56±0.34 and 9.55±2.01). The conclusion of the study is the Etawah Grade does during early pregnancy and late pregnancy has different behavior, especially on the frequency of feeding, average on once feeding, standing duration, time and average of once lying, and frequency of urination.(AU)

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In tropical Indonesia, which has specific dry and wet seasons, it is difficult to provide high-quality forage in sufficient quantities throughout the year. Therefore, it is necessary to establish the availability and nutrient contents of forages and other natural feed resources during the dry and wet seasons in order to provide sufficient nutrients throughout the year, as an improvement effort the productivity of dairy cows. The method used was surveys conducted at dairy smallholder and groups selected in one of the areas of dairy cooperative in Yogyakarta; and observed environment condition (temperature and humidity). Feed samples were taken and analyzed in the Laboratory of Dairy Science and Milk Industry, Faculty of Animal Science UGM. Supplies of forages, agricultural by-products, feedstuffs, and commercial concentrates were available throughout the year, although the amounts were limited. Most of dairy smallholders had greater access to forages and agricultural by-products during wet season than during the dry season; this resulted directly in a better productivity of dairy cows during the wet season. In both seasons, farmers purchased commercial concentrates from other areas to support the cows feed requirements. Smallholder dairy farmers in the dairy areas of Yogyakarta had better access to forages and agricultural by-products during the wet season than during the dry season, but need to supplement their animals with commercial concentrates obtained from outside areas during both seasons. Assuring the continuity and availability of forages and concentrate in this area is of dire importance to reduce the dependency of feed from outside of the region.

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