In Brazil, one of the world's largest agricultural producers, beehives have declined due to the mismanagement of pesticides, affecting pollination and compromising food availability. For this purpose, bee products are used as bioindicators to define environmental impacts resulting from anthropogenic changes in biodiversity. Thus, an analytical method to quantify glyphosate (GLY) and its main metabolite aminomethylphosphonic acid (AMPA), in beeswax was validated using a fluorescence detector and postcolumn reaction. The quantification limit was 0.05 mg/kg, and the recoveries ranged from 75% to 93% with a coefficient of variation of less than 11% for GLY and AMPA. The validated method was applied to 18 beeswax samples from areas with extensive agriculture and forest. None of them showed GLY or AMPA contamination. The fact that no contamination was found in Brazilian samples, even with the widespread use of GLY, emphasizes the significance of continuous studies and monitoring to protect bee health and ensure apiculture product safety.
Due the losses caused by the Rhipicephalus (boophilus) microplus tick in dairy cattle in several countries, this research evaluated the action of Factor P® as an aid in this ectoparasite control. This organic additive is supplied daily in the diet through supplementation. For this, 20 lactating Holstein cows were selected. The animals were divided into two groups, Treated Group (TG) and Control Group (CG). The animals were stratified based on the count of telegynes above 4.5 mm, present on the left side of each animal. To evaluate the action of the additive, counts were performed on days 3, 5, 7, 14, 21, 28, 57, 86, 115, 144, 172, 200, 227, 254 and 281 after the beginning of treatment. Over the 281 days, the control group received 28 sprays and the group treated with Factor P® received 10 sprays, 64% fewer interventions. Thus, it is concluded that the additive had an auxiliary effect in the control of bovine ticks, reducing the percentage of infestation, the use of acaricides and reducing additional management, favoring animal and environmental well-being with cost reduction, since using the additive Factor P®, the milk doesn't need to be discarded as in the case of conventional treatment.
The study aims to assess the zootechnical performance of post-larvae of Steindachneridion scriptum, fed with feed enriched with thyme essential oil ( (Thymus vulgaris). The experiment employed a control group (T1; control-0.0%) and feed enriched with varying concentrations of thyme essential oil: T2 (0.1%), T3 (0.5%), T4 (1.0%), T5 (2.0%), and T6 (3.0%). A total of 960 S. scriptum larvae were utilized in experimental units over a 15-day period. Zootechnical performance and histomorphometric analysis were carried out to evaluate the effects of thyme on larval feeding. The increase in villi surface area suggests an increased nutrient absorption capacity in S. scriptum larvae, improving zootechnical results at the 0.5% thyme essential oil concentration. In conclusion, the inclusion of thyme essential oil at a concentration of 0.5% proved effective in enhancing zootechnical outcomes in S. scriptum larvae. However, at higher concentrations, thyme essential oil inclusion demonstrated potential lethality to S. scriptum larvae.
Pre-slaughter handling of cattle can increase animal stress, making them more susceptible to carcass bruising. Such bruising negatively impacts the beef production chain, affecting both producers and slaughterhouses. In this context, the present study aimed to evaluate the incidence of bruises in cattle carcasses at a slaughterhouse located in the northwest region of S & atilde;o Paulo State, Brazil, under the supervision of the State Inspection Service (SISP). A total of 1,068 carcasses were assessed between September and December 2021. Data were collected on breed type, sex, age, travel distance, and truck model, along with the extent, severity, and location of the bruises. Among the evaluated carcasses, 64.7% were crossbred (zebu and taurine). The findings indicated that older females, with slaughter age of 25 to 36 months, were more susceptible to bruises compared to males. The hindquarter cuts were the most affected areas, with a predominance of bruises in animals transported by truck over distances of 101 to 150 km. Furthermore, the most frequent bruises were classified as grade II (51.4%) and measured between 6 and 10 cm in size (36.8%). Various factors contribute to the occurrence of bruises in beef cattle such as racial pattern, gender, age and distance travel, however, most of these factors could be prevented or mitigated through proper management practices during the pre-slaughter period.
Soil correction and fertilization are important in the formation of pastures, but many producers neglect them or use ineffective alternatives. Slow-release fertilizers may harm the establishment of forage plants, as this is a crucial moment during the pasture formation stage. The objective was to evaluate establishment fertilization strategies on the morphogenic, structural characteristics and productivity of Xara & eacute;s grass (Urochloa brizantha cv. Xara & eacute;s). To this purpose, two experimental trials were conducted in a greenhouse, both under a completely randomized design. In the first one, three establishment fertilization strategies were tested (strategy 1: without lime/NPK; strategy 2: lime + NPK; strategy 3: natural reactive phosphate), with six replications. In the second, a 3 x 10 factorial scheme was used, corresponding to the three establishment fertilization strategies and 10 evaluation dates (32, 39, 46, 53, 60, 67, 74, 81, 88, and 95 days) after emergence of plants (DAE). In experiment 1 the morphogenic characteristics of the plant were evaluated, in the second experiment the structure and dry mass production of the aerial part and roots of Xara & eacute;s grass were evaluated higher (P<0.05) rates of leaf elongation and appearance, stem elongation, and leaf senescence, in addition to higher (P<0.05) tiller densities and dry mass production, were obtained in strategy 2 than in the others. Forage production of Xara & eacute;s grass increased linearly (P<0.05) as a function of higher DAE. Therefore, using lime together with NPK fertilization provides greater growth and production of Xara & eacute;s grass.
Soil correction and fertilization are important in the formation of pastures, but many producers neglect them or use ineffective alternatives. Slow-release fertilizers may harm the establishment of forage plants, as this is a crucial moment during the pasture formation stage. The objective was to evaluate establishment fertilization strategies on the morphogenic, structural characteristics and productivity of Xaraés grass (Urochloa brizantha cv. Xaraés). To this end, two experimental trials were conducted in a greenhouse, both under a completely randomized design. In the first, three establishment fertilization strategies were tested (strategy 1: without lime/NPK; strategy 2: lime + NPK; strategy 3: natural reactive phosphate), with six replications. In the second, a 3 × 10 factorial scheme was used, corresponding to the three establishment fertilization strategies and 10 evaluation dates (32, 39, 46, 53, 60, 67, 74, 81, 88, and 95 days) after emergence. of plants (DAE). In experiment 1 the morphogenic characteristics of the plant were evaluated, in the second the structure and dry mass production of the aerial part and roots of Xaraés grass were evaluated Higher (P<0.05) rates of leaf elongation and appearance, stem elongation, and leaf senescence, in addition to higher (P<0.05) tiller densities and dry mass production, were obtained in strategy 2 than in the others. Forage production of Xaraés grass increased linearly (P<0.05) as a function of higher DAE. Therefore, using lime together with NPK fertilization provides greater growth and production of Xaraés grass.
The objective was to evaluate the effects of including different proportions of Wet Brewery Residue (WBR) using inoculants on rehydrated ground corn silage quality. The experiment was conducted in a completely randomized design in a 4 x 3 factorial scheme with four replications. Four combinations of WBR and ground corn were evaluated to achieve 45 (DM45), 50 (DM50), 55 (DM55), and 65% (DM65) of dry matter (DM) in the homogenized material before siling, and three types of inoculation: without inoculant, with L. plantarum + P. acidylactici (Homo) and with L. buchneri (L. B). Ensiling was done in experimental PVC silos (±4.0kg) and stored for 180 days. The variables obtained were analyzed by the analysis of variance and regression procedures (P<0.05) using the R software. The percentage of real DM included in the treatments was 47%, 52%, 56%, and 66%. No impairment of the pH-reducing capacity of corn rehydrated with WBR was observed. Total dry matter losses were within the acceptable limit in silage with 52% DM (DM50), regardless of the type of inoculation. Gas losses were within the permissible limit only in the DM50 treatments with Homo inoculant and in the DM50 treatment without inoculation. Effluent losses were outside the tolerable limit in the treatment with 47% DM (DM45) in the presence of the inoculant LB. There was a significant interaction between the inoculant LB and the silages, with 47% (DM45) and 56% (DM55) DM for the Crude Protein (CP) levels. The ADF and NDF variables reduced linearly as a function of the increase in dry matter of the ensiled material, with a tendency for the lowest values to be found in treatments without inoculation. For all variables, an increase in energy levels (Non-Fibrous Carbohydrates, starch, Total Digestible Nutrients, and Net Energy gain) was observed with the increase in the DM content of the silage. It is concluded that silage with 52% DM (DM50) obtained the best results for fermentative losses. For bromatological and energetic characteristics, silage with 66% DM was the best, except for the CP variable, where 47% DM silage achieved superior results. In general, the addition of additives did not show any improvement in relation to treatments without inoculants.
The condition of pastures during the wet-dry transition period reduces livestock production since there is an increase in dead material and a reduction in green tissues. This study evaluated the influence of grazing management strategies on the structure of the forage canopy during the wet-dry transition period. The pastures were composed of Aruana guineagrass (Megathyrsus maximum Syn. Panicum maximum cv. Aruana) and three legumes: Macrotyloma (Macrotyloma axillare), Calopo (Calopogoinum mucunoides), and Stylo (Stylosanthes macrocephala + Stylosanthes capitata). The treatments corresponded to four forage canopy heights (15, 30, 45, and 60 cm), and the grazing management strategies involved steady or variable stocking rates with sheep. The experiment was conducted in a randomized complete block design with four replications totaling 16 experimental units (paddocks). The masses of grass leaf blades and stems were higher at heights of 45 and 60 cm (P = 0.002), while the proportion of dead material was smaller in these than in the short pastures (15 and 30 cm) (P = 0.0497). There was an increase in the proportion of dead material over the dry-water transition period. The presence of grass and legume leaves was higher in the upper stratum of tall pastures (45 and 60 cm) and the proportion of legumes did not differ between grazing management strategies (P > 0.05). These strategies were represented by canopy heights of 45 to 60 cm and showed more leaf mass, less dead material, and better pasture structure, so these parameters can be used during the wet-dry transition period.
The objective was to evaluate the quantitative and qualitative effect of fertilization of Brachiaria brizantha cv. Marandu using nitrogen from liquid cattle manure and organomineral fertilizer. The experiment was developed in a pasture already established and soil analysis of this area was made for the necessary corrections. The experimental design was randomized blocks in a 4 x 2 factorial scheme. The treatments consisted of control with 0 kg/ha of N, 3 treatments with application of bovine liquid manure and 3 treatments with organomineral fertilizer in the dosages of 60, 120 and 180 kg/ha of N. Three cuts were made in Marandu grass when the pasture reached 30 cm in height, leaving a residue of 15 cm, the production of DM, leaf production, stem, CP, NDF and ADF were evaluated. At the end of the experiment, the cost of fertilizing with manure and organomineral fertilizer was done. To compare the averages obtained and the morphological components of each sample, the Tukey test at 5% significance was used, with the aid of the SISVAR statistical program. With the highest nitrogen levels of organomineral fertilizer and the bovine liquid manure, a higher CP content was obtained, reaching 9.30; 7.78 and 7.90% in the first cut, with organo 180, 120 and manure 180 respectively. Fertilizations with manure 60 and 180, organomineral 120 and 180 showed the lowest values for NDF in the first cut, the ADF only showed a significant difference in the second cut with organo 60, manure 120 and 60 with the highest values. Organomineral fertilizer in different doses provided higher production, but at a higher cost. Fertilization improved the quality of the forage.
The consumer fishing operation can be engaged in fishing problems in consumer health, so the present work as structural conditions and manipulation of the municipal fair of Manaus. Observations were made at three Centro, Santo Antônio and Betânia district fairs. Note that the hygienic and sanitary conditions of the workers are precarious; in one of the fairs, it was possible to verify the protective equipment such as gloves, caps, the presence of animals near the window where the fish is exposed for sale, styrofoam boxes used for the storage in an inappropriate state, dirty and the company of parcels with fish on the floor without any secondary packaging for protection. Therefore, it is concluded that it is necessary to train users on the dangers that can affect the lack of adequate handling of the consumer's health, which may interfere directly with the local fishing sector.
Revisores que atuaram no Boletim de Indústria Animal, na revisão de artigos que tramitaram em 2023, referentes aos artigos publicados.
The objective was to evaluate the carcass and meat characteristics of feedlot steers based on sexual condition and age at the beginning of the finishing phase, through a systematic review and meta-analysis. The selection of articles was carried out by two reviewers, who selected articles from the Google Scholar and Scielo platforms. The criteria for choosing articles followed the PICO tool. After searching for articles, they were subjected to analysis under the methodological conditions of the research. After this phase, 61 research articles carried out in Brazil remained, from which information was extracted from the material, methods and results. The data were compared according to the age of the steers: young (between 20 and 26 months of age) and super young (between 10 and 16 months of age); and depending on sexual condition: castrated or not castrated. Young steers have higher slaughter weights and higher hot and cold carcass weights. Meat from super young steers presented a higher score for tenderness when evaluated by the panel of evaluators. Uncastrated steers had higher slaughter weight, hot and cold carcass weight and rib eye area, while castrated steers demonstrated greater thickness of subcutaneous fat in the carcass and meat with higher marbling score. Slaughtering super young and castrated steers improves the quality aspects of the carcass and meat, however it reduces the amount of meat.
The goal was to evaluate the chemical composition of Urochloa brizantha cv. Marandu through the use of fertilization with nitrogen and potassium. The experiment was carried out at the Experimental Farm of UFMT, Cuiabá Campus, from December to April 2017/2018 and 2018/2019 - rainy season; and from May to September in 2018 and 2019 – dry season. Treatments corresponded to a 5x2 factorial scheme, with five nitrogen doses (0; 25; 50; 75; 100 kg ha-¹) and two potassium doses (0; 25 kg ha-1). The sample was unified as one for each individual period. The chemical characteristics evaluated were crude protein (CP), mineral matter (MM), neutral detergent fiber (NDF), acid detergent fiber (ADF), indigestible neutral detergent fiber (iNDF), total digestible nutrients (TDN) and net energy of lactation (NEF). For CP, a positive linear effect was observed for nitrogen fertilization, with 15.87% and 11.68% for the highest dose in the rainy and dry seasons, respectively. Likewise, a linear increase in TDN and in NEL was observed. For NDF, ADF and iNDF content there was a linear reduction in both rainy and dry seasons. For potassium fertilization, there is little influence on the chemical characteristics, in fact, only in the rainy season for fiber, TDN and NEL contents. However, nitrogen fertilization promoted an increase of 51.13% in the CP content at the highest applied dose. The NDE, ADF and iNDF content decrease linearly with nitrogen input, on the contrary, there was an increase in TDN and NEL.
This work aimed to characterize coproducts from extra virgin olive oil extraction, its chemical composition and nutritive value of two olive cultivars (Arbequina and Koroneiki) in industries in Brazil Southern region. Sampling from cultivar Arbequina was done at two moments (time 0 and 48h post processing) and from cultivar Koroneiki, only at time zero was sampled. The composition of the two cultivars was different, as expected. Higher levels of carbohydrates (CHO) and lower levels of neutral detergent fiber (NDF) contributed to improve in situ degradability (61.0 vs 43.5% ) of Koroneiki cultivar. Both co-products obtained on the day of processing showed high levels of lignin, which led to a lower level of in situ degradability of the NDF (21.1%). High levels of EE (19.4% DM), total phenols (FT; 1.8% DM), total tannins (TT; 1.11% DM) and TDN (72.7% DM) were also observed. These results demonstrate that the byproduct represents a potential source of lipids and phenolic compounds that can be used to adjust diets as well as the aggregation of functional molecules in meat and milk products. The care in obtaining and preserving the product is important because the material obtained 48 hours after the processing showed losses in the contents of CHO, CNF, FT and TT, which can impair its nutritional value and the potential of use.
The aim of this research was to evaluate the performance and carcass characteristics of immunocastrated cattle, in comparison to castrated and non-castrated cattle supplemented on pasture. 36 bovines were used, distributed in a completely randomized design, in 3 treatments: non-castrated animals (ANC), animals castrated late by the surgical method (ACC) and immunocastrated animals (AIC), with 12 replicates each. Immunocastration was performed following the protocol of two doses of the immunocastrating vaccine, with an interval of 60 days, promoting a castrated effect of 120 days. The animals were kept on mixed pasture in an extensive rearing system using rotational grazing, they received mineral supplement in the first 3 months and specific feed for the fattening season in the subsequent 3 months, according to the property’s standards. The total experimental period was 180 days. Data were hidden from the normality test, analysis of variance and mean comparisons were performed using the Tukey test, except for the variable degree of finishing, which was maintained at the chi-square test, at 5%. Average daily weight and total weight gains, hot and cold carcass weights and hot and cold carcass yield did not show statistical differences (P>0.05) for animals submitted to different treatments. However, the cooling loss was lower in immunocastrated animals (P<0.05), followed by surgically castrated and non-castrated animals. Immunocastrated and surgically castrated animals showed better carcass finishing (P<0.05) than non-castrated animals. The initial temperature of the carcass was lower (P<0.05) in the immunocastrated group, while for the final temperature no statistical differences (P>0.05) were verified for the animals submitted to different treatments. Final carcass pH was higher (P<0.05) in immunocastrated than in surgically castrated animals, but did not differ (P>0.05) from non-castrated animals. Immunocastrated animals, in a grazing system receiving supplementation, showed similar gains in weight and carcass weight in relation to non-castrated and surgically castrated animals, however, with lower losses to carcass cooling.
This paper targets the quality of tifton bermudagrass (Cynodon spp.) and alfalfa (Medicago sativa) hays in isoproteic and isoenergetic diets on horse body biometrics. Six equines, between 6.5±0.5 years old and with an mean body weight of 354±50kg, were used in this study. The treatments consisted of six diets and the experimental delineation was the Latin square (6x6). The diet’s forage was composed by a combination of hays, in a factorial scheme (2x3), with two forages (tifton bermudagrass and alfalfa) and three types of hay (A, B and C). There was a significant effect in the variables body weight, abdominal girth, fecal water content, and fecal production for the forage type. Greater digestibility coefficient of dietary dry matter values were identified in the diets composed by type A and B alfalfa hay (64.71±2.38% and 63.45±2.41%, respectively), that have significantly surpassed (P = 0.0061) the results obtained for the type C hay diets. It was possible to conclude that the alfalfa hay provided a reduction in the horse’s body weight and thoracic perimeter, what can be explained by the greater verified digestibility, as well as the lesser fecal water retention with the diets containing only the legume.
Morphometric measurements are easy tools to adopt for characterization of breeds, as well to select the best animals for breeding. Therefore, the objective of this study was to characterize the morphology of Dorper lambs of different age groups. The study was conducted at Sheep Unit of the Instituto de Zootecnia, located in Nova Odessa, SP. A total of 26 registered uncastrated male lambs from nine sheep farms in three different states (São Paulo, 7; Santa Catarina, 1; Paraná, 1) were used. The average age was 102.30 ± 16.30 days and average body weight was 26.10 ± 4.14 kg. Initially, the animals were weighed (kg) and then 13 morphometric traits were measured: withers height (WH), rump height (RH), withers depth (WD), rump depth (RD), chest width (CW), withers width (WW), rump width (RW), body length (BL), chest girth (CG), rump girth (RG), shoulder girth (SG), leg girth (LG) and scrotal circumference (SC). The lambs were separated into three age groups, divided according to ± 0.5* age standard deviation: AG1 (67 to 93 days, n = 9), AG2 (99 to 105 days, n = 8) and AG3 (112 to 135 days, n = 9). The effect of age group was used to compare the morphometric measurements by the Tukey test at 5% significance (SAS). No significant differences were identified according to the age groups. However, some measures of the AG3 group had lower values (CW = 23.42 ± 1.70; WW = 23.65 ± 1.60; RW = 25.82 ± 1.79; BL = 59.45 ± 2.97; CG = 69.33 ± 4.5; RG = 69.45 ± 4.47; and SG = 23.73 ± 1.34; LG = 36.47 ± 3.58), although the lambs were older. Therefore, the morphometric characterization of Dorper lambs did not differ using a 72-day interval.
The metabolic challenge imposed by the intensification of animal production can cause an imbalance between the body's demand for nutrients on the one hand, and the ability to metabolize them and the level of production sought on the other hand. Urea is an option as a supplementary source of non-protein nitrogen (NPN) in sheep diets due to its low cost, plentiful availability and ease of use. The blood serum urea nitrogen (SUN) content has been measured to obtain additional information about the protein nutrition of ruminants, through the metabolic response to a given diet. Thus, the objective of this study was to evaluate the effects of the inclusion of increasing levels of urea in the diet of confined lambs to replace the crude protein in the concentrated feed. Thirty-two crossbred lambs were used, with average initial body weight of 29 kg and average initial age of 5 months. The experiment was carried out in a completely randomized design using a 2 x 4 factorial scheme: 2 sexes (male and female) and 4 levels of urea inclusion: 0%; 1.5%; 3.0% and 4.5% urea based on total diet. The analyses were carried out using the R statistical program, to perform multiple comparison of means using the Tukey test at 5% probability and linear regression. All feed samples were submitted to chemical analysis. From the 47th to the 52nd day of the experiment, to determine serum N-urea, blood samples were collected by jugular vein puncture, at 0h, 2h, 4h, 6h, 8h after feeding at 7:00 am. The blood samples were immediately centrifuged at 4250 rpm for 15 minutes and the resulting serum was frozen (-20 ºC). Blood samples were collected at different times after feeding during the 5 days of the experiment, with a collection being performed on each day of the period. The concentration of N-urea in the blood serum was obtained through the product of the concentration of urea in the plasma and 0.466, corresponding to the N content in the urea. Interactions between sex and time of blood collection after feeding, as well as between level of urea inclusion and collection time were significant (P<0.05) for SUN values. Regarding the time after feeding, greater variability was observed between the collection times in male animals (σ̂ = 4.11) than in female animals (σ̂ = 3.26). Greater variability was observed among females (σ̂ = 1.81) than among males (σ̂ = 0.91). A quadratic effect was observed between SUN and collection times for both male and female animals. The peak SUN values after feeding occurred at 2:03 a.m. for females and at 2:50 a.m. for males. No effect (P>0.05) was observed for SUN considering the increasing levels of urea in the diet. Among the SUN levels at each collection time, the treatment with a level of 0.0% urea inclusion (0%RH) was associated with a higher concentration of SUN at the collection time 2 hours after feeding in relation to the concentration at the collection time 8 hours after feeding. In the supply of the 4.5%RH diet, a higher value of SUN was observed at the times 2h and 4h after feeding in relation to the times 0h and 8h. The treatments with urea levels of 3.0% and 4.5% had the highest concentration of SUN at the collection time 2h after feeding. In general, values of SUN at 0 and 8h were less than at 4 and 6h, and these were lower than at 2h. No increase in SUN concentrations was observed as the PDR level increased, as expected, which can be explained by the fact that the animals were able to use a good part of the N consumed. The inclusion of up to 4.5% urea/ammonium sulfate (9:1) in relation to the dry matter of the diets to replace the crude protein in the concentrate for confined lambs did not compromise the productive performance of the animals.
The pyrolysis of agricultural wastes process in an environment with absence or deficiency of oxygen has drawn much attention for generating products such as biochar with potential to act as soil conditioners. Characteristics of biochar reinforce its performance as soil conditioner, such as high porosity, aromatic structure and presence of acid functional groups, which result in accumulation and persistence of carbon in the soil, generation of electrical charges, and retention and availability of nutrients. Considering that the time of adopting a management system can influence the quantity of total organic carbon (TOC) contents, but this may not indicate differences between the treatments evaluated, some authors have proposed to fractionate TOC according to four decreasing degrees of oxidation, through the use of different concentrations of sulfuric acid. This method, called TOC fractionation by degrees of oxidation, allows the classification of soil carbon into the fractions F1, F2, F3 and F4. Fractions F1 and F2 are more labile and are more related to the availability of nutrients and the formation and stabilization of macroaggregates, while fractions F3 and F4 are related to compounds with greater chemical stability and molecular weight. This work aimed to evaluate the influence of doses of eucalyptus bark biochar on TOC content and oxidizable organic carbon fractions in dry-separated soil aggregate classes. The study conducted in the field consisted of the application at a Eucaliptus urograndis plantation of five doses of eucalyptus bark biochar (0; 0.25; 0.5; 1 and 2% v v, equivalent to 0; 2.5; 5; 10; 20 t ha-1) produced at two pyrolysis temperatures (350 °C and 600 °C). Two soil samples were taken (365 days and 730 days) at depths of 0.0-0.10 m and 0.10-0.30 m. Through regression analysis of the biochar produced at 350 ºC, we observed a linear increase in the content of the fraction F2, in the classes of aggregates 4.00-2.00 mm (p<0.05) and <0.250 mm (p<0.01); F4 in the class of aggregates 4.00-2.00 mm (p<0.1), at depth 0.00-0.10 m; in F1int aggregate class <0.250 mm (p<0.1) and F2 in aggregate class 4.00-2.00 mm (p<0.1), at sampling depth 0.10-0.30 m, in the samples collected at 365 days. At 730 days, quadratic increases were found for F3 in aggregate class 2.00-0.25 mm (p<0.05) and linear increment of F4 fraction in aggregate class <0.250 mm (p<0.1), at depth 0.00-0.10 m. For the depth of 0.10-0.30 m linear increases in TOC contents were found in aggregate class 4.00-2.00 mm (p<0.05) and a quadratic increase in the F3 fraction in aggregate class <0.250 mm (p<0.05). The application of biochar produced at 600 ºC promoted, in the first collection, linear increases in TOC contents in aggregate class 2.00-0.25 mm (p<0.05) and in the F4 fraction in aggregate class 2.00-0.25 mm (p<0.05), at the 0.00-0.10 m depth. At sampling depth of 0.10-0.30 m, an increase occurred in fractions F1 in aggregate class 2.00-0.25 (p<0.1) and F3 in aggregate class 4.00-2.00 mm (p<0.1). For the F4 fraction, in aggregate class 4.00-2.00 mm, there was a quadratic increase (p<0.05). In the second collection (730 days), these effects were noted, in the form of a quadratic equation, for the F3 fraction in aggregate class 4.00-2.00 mm (p<0.05) for the collection performed at 0.00-0.10 m. At depth 0.10-0.30 m, linear increases in TOC were found in aggregate class 2.00-0.25 mm (p<0.05), F2 in aggregate class 4.00-2.00 mm (p<0.1) and F4 in aggregate class <0.250 mm (p<0.1). Few significant results were observed regarding the applied doses of the biochar on TOC contents and organic carbon fractions. We believe the possible causes for not obtaining more significant results from the application of eucalyptus bark biochar in the soil in this experiment were, first, the dosages chosen, which could have been higher, and the texture of the soil studied, which did not have a great need for cementing agents for soil aggregation. Another factor to be observed is the time of the experiment, since the evaluations were performed two years after implementation. We can conclude that according to studies in the area, changes in TOC levels in tropical climate soils are usually noted in the medium and long term after the implementation of new management practices.
Brazil has one of the largest pasture areas for livestock on the planet, and estimates of dry matter intake (DMI) are necessary for adequate nutritional plans to improve animal performance. This study evaluated the dry matter intake (DMI) of Nellore cattle in different production systems, including a Cajanus cajan legume-grass mixed pasture. The experiment was carried out at the experimental farm of Embrapa Southeast Livestock, São Carlos, SP, Brazil, in two seasons of 2021: rainy (January) and dry (July). Eighteen Nellore steers (approximately 445 ± 44 kg and 15 ± 16 months old) were randomly distributed in three treatments with three replications (1.5 ha each): 1) degraded pasture of Urochloa decumbens cv. Basilisk (DEG); 2) mixture of grasses and legumes, U. decumbens Stapf cv. Basilisk, U. brizantha Stapf cv. Marandu and Cajanus cajan cv. BRS Mandarin (MIX); and 3) pasture with a mixture of U. decumbens cv. Basilisk and U. brizantha cv. Marandu with liming, P, K, S, micronutrient fertilization of 200 kg N-urea ha-1 year-1; and three applications of 66.7 kg N ha-1 every 60 days in the rainy season (REC). All pastures were grazed by Nellore cattle and submitted to stocking rate adjustments using the €œput and take€ technique. The animals received 15 g of the titanium dioxide (TiO2) orally for nine consecutive days. Feces were collected at 6:00 a.m. by spontaneous defecation during four days after the beginning of TiO2 administration until the tenth day. Daily the samples were frozen, and at the end of the experimental period were dried in a forced-air oven (65 ºC - 72 h), ground to 1 mm in a Wiley mill and analyzed by ICP-OES (Thermo iCAP 6000 series - Dual View Thermo Fisher Scientific, Waltham, Massachusetts, USA). The statistical model considered treatment, season and treatment x season interaction as fixed effects. Data were submitted to analysis of variance (PROC MIXED) and means were compared by the Fisher test at 5%. Significance (P = 0.0168) was observed for treatment x season interaction. The DMI (kg of DM day-1) in the rainy season presented values of 11.8, 10.0 and 13.8, and in the dry season 4.9, 7.8 and 4.7 for DEG, MIX and REC, respectively. In the dry season, the MIX treatment differed significantly from the others. In the rainy season, the MIX was different from the REC, while the DEG treatment showed no difference in relation to REC and MIX. In the dry season, Cajanus cajan consumption was higher than the other treatments. This behavior can be explained by the greater availability of forage mass and the inferior quality of the grass and by the grazing behavior of the animals, which consumed more legume as the dry season extended.
