Prevalence and risk factors for agents causing diarrhea (Coronavirus,Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes helminthes) according to age in dairy calves from Brazil

The present study attempted to verify the prevalence of and risk factors for diarrhea-causing agents in dairy calves from Brazil. Additionally, ages with a higher risk of occurrence for each agent were verified by means of the receiver operating characteristic (ROC) curve. The collections were performed on 39 farms, belonging to 29 municipalities located in eight states of Brazil. It was possible to conclude that the prevalence of Coronavirus, Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes was 7.20% (95% CI 4.54–9.78), 6.37% (95% CI 3.85–8.89), 51.52% (95% CI 45.26–55.57), 3.46% (95% CI 2.24–4.67), and 3.46% (95% CI 2.24–4.67), respectively. Ages with higher probabilities of occurrence of these diseases in calves were <?10, >?8, >?6, >?37, and >?36 days, respectively. Diarrhea occurred more significantly (P?<?0.0001) in animals less than 21 days old and mainly on those receiving milk through automatic feeders (P?<?0.001). Cryptosporidium spp. were a risk factor for the occurrence of Rotavirus, and vice versa (P?=?0.0039) and presented a positive correlation with Coronavirus (P?=?0.0089). Calves that drink water from rivers, streams, and ponds had a higher chance of being infected by Eimeria spp. (P?<?0.0001), as well as developing infection by nematodes (P?<?0.0001). The results found in this study highlight the importance of studying the agents of diarrhea together, once they act as coinfection where the losses triggered for the owners will involve some of these agents simultaneously.

     

Single superphosphate fertilizer distribution among seeder-fertilizer rows

The objective was to verify the uniformity of single superphosphate distribution among seeder-fertilizer rows and its consequences on crops. The experiment was installed in the municipality of Tibagi—PR, involving the following crop rotation in the same area: black oat (Avena strigosa) in 2012, corn (Zea mays) in the 2012–13 season, wheat (Triticum aestivum) in 2013, soybeans (Glycine max) in the 2013–14 season, black oat in 2014 and corn closing the cycle in the 2014–15 season. The experimental design was used in randomized blocks, considering the number of rows of the seeder-fertilizer (ranging from 11 for corn to 27 for wheat) as treatments; with three replicates. During the experimental period, 250 kg ha^?1 of single superphosphate were distributed per crop at sowing, with a mean deviation of up to 14% and variation in the fertilizer mass among the seeder-fertilizer rows in up to 52%. The variables evaluated were initial population and income components. It was concluded that it is not possible to correlate the variation of fertilizer distribution among rows of the seeder-fertilizer with the variables that presented significant differences in the crops through three agricultural seasons. This fact may be related to the alternation of the highest and lowest doses of simple superphosphate. Due to the succession of seeder-fertilizers used over the years to crops seeding, there was a compensation for the random variation of fertilizer among rows and crop spacings along the crop seasons.

     

Comparison of clinical parameters in captive Cracidae fed traditional and extruded diets

The Cracidae family of neotropical birds is regarded as one of the most severely threatened in the world. They traditionally have been extensively hunted, and, thus, ex situ efforts for their conservation are recommended and involve the optimization of their care in captivity. Nutrition is a fundamental aspect of husbandry, which influences survival and reproduction in captivity. In this study, a total of 29 animals, including 3 species (Penelope obscura, Penelope superciliaris, and Aburria jacutinga), were subjected to monthly physical examination and blood sampling before and after dietary conversion from the traditional diet of broiler feed, fruits, and vegetables to a nutritionally balanced commercial diet specifically designed for wild Galliformes. The diet change produced differences in several parameters tested, including an increase (P < 0.05) in hemoglobin concentration for all species. Increases (P < 0.05) in erythrocyte count, packed cell volume, and body weight were observed in P. obscura, with a concomitant decrease in the standard deviation for such parameters that show improved uniformity. Globulins and lipase also were reduced (P < 0.05) in P. obscura. Although leukocyte count was lowered and eosinophils were increased in all 3 species after dietary conversion, only these 2 changes were significant (P < 0.05) in P. superciliaris. A. jacutinga had higher (P < 0.05) blood glucose concentrations than the other species, but diet had no effect on this parameter. Blood uric acid concentrations were higher (P < 0.05) after conversion to the commercial diet in P superciliaris. The provision of a commercial extruded diet as a single food source was beneficial, which led to a general improvement in clinical aspects and group uniformity in these 3 species of Cracidae.     

Practical diets with essential oils of plants activate the complement system and alter the intestinal morphology of Nile tilapia

The effect of the essential oils (EOs) of peppermint, Mentha piperita L., and tea tree, Melaleuca alternifolia (Maiden & Betche) Cheel, on the haematological, biochemical, and immunological parameters and intestinal morphology of Nile tilapia, Oreochromis niloticus L., was evaluated. Fish (58.09 ± 5.87 g) were fed 100 mg/kg and 250 mg/kg of each EO and sampled on days 7, 14, 30 and 60 after starting supplementation. The haematological and biochemical parameters were not altered by the supplementation of EOs compared to the control (p > .05). With regard to the immunological parameters, the activation of the complement system of fish fed 250 mg/kg peppermint and 100 mg/kg and 250 mg/kg tea tree EOs were significantly higher compared to the control after 60 days of feeding (p < .05). The complement system plays an essential role in innate immunity and contributes significantly to the acquired immune response; thus, its activation through supplementation with EOs is promising for the formulation of nutritional additives in aquaculture. Regarding intestinal morphology, fish fed 250 mg/kg tea tree EO presented higher villus size compared to all other groups (p < .05), which represents a healthier gut. These fish present a larger intestinal surface, which can result in better absorption and utilization of the nutrients. Based on the responses found in this study, both EOs were considered promising for the formulation of feed additives for Nile tilapia.     

Nose-to-nose transmission of Salmonella Typhimurium between weaned pigs

Little attention has been paid to the possibility of transmission of Salmonella in intensive pig production systems through alternate methods, such as airborne or direct nose-to-nose contact. This experimental study tested the hypothesis of nose-to-nose transmission of Salmonella enterica serovars Typhimurium (Trial I) and Agona (Trial II) in weaned pigs using stainless steel/glass isolation cabinets. In each trial, cabinet 1 (control pigs) and cabinet 2 (sentinel pigs) were connected directly to the fan unit. Cabinet 3 (seeded pigs) was not directly linked to the fan, but was arranged to receive a constant unidirectional airflow from cabinet 2 (sentinel pigs) through a 10cm diameter hole, which also allowed nose-to-nose contact between pigs housed in these two cabinets. Air was taken out of the system through ducts connecting cabinets 1 and 3 to the exhauster. Therefore, direct contact among seeded and sentinel pigs was allowed but possible aerial transference of contaminated particles between those cabinets was prevented. The system was opened 21 days post-inoculation and tissue samples were collected for bacteriological analysis. The recovery of nalidixic acid-resistant Salmonella Typhimurium from sentinel pigs corroborates the hypothesis of nose-to-nose transmission of that pathogen in pigs. However, serovar-related differences might exist regarding the nose-to-nose transmissibility of Salmonella in pigs, since Salmonella Agona was not detected in sentinel pigs (Trial II).     

Factor analysis applied in genomic selection studies in the breeding of Coffea canephora

Euphytica - Head splitting is a major physiological disease in cabbage. The most effective approach for controlling head splitting is to deploy genetic resistance by breeding cabbage cultivars with...     

SLAG EFFICACY AS A LIME AND SILICON SOURCE FOR RICE CROPS THROUGH THE BIOLOGICAL METHOD

There is little information about the best silicon (Si) sources for agricultural use, and yet some products have already been marketed as sources of this element. One of these products is slag, which is used as a source for Si and lime. This study evaluated the silicon supply availability and efficacy of different silicate slag types for rice crops. The experiment was conducted in a greenhouse, used Entisol Quatzipsamment soil and was set up in randomized blocks with three replications. Si source reactivity was evaluated using five metallurgic slag types and Wollastonite, which is considered a standard in Si studies. Doses of each Si source were 1000 and 2000 mg dm^?3 of Si and a control (additional treatment). Soil data [soluble Si, calcium (Ca²⁺), magnesium (Mg²⁺) and pH] and rice growth and yield were recorded. Data were evaluated by analysis of variance and contrasts were made for comparisons between each slag type and the additional treatment. Averages were compared by the Scott Knott test at 5% with the statistics program SISVAR. The efficacy of the slag types in supplying Si for the plants (ESSi) and in increasing Si availability in the soil (ESiA) was determined from the values of contrast estimates. Slag E3 and Wollastonite were effective in increasing soil silicon availability and, consequently, the efficacy of supplying silicon for the plants, while the other slag types had low efficacy.     

Evidence of no horizontal or vertical transmission of tomato severe rugose virus by Bemisia tabaci MEAM1

Bemisia tabaci is important in agriculture worldwide, mainly because it is a vector of numerous plant viruses, probably the most important of which are members of the genus Begomovirus. Dozens of begomoviruses have been reported to infect tomato plants in Brazil, although tomato severe rugose virus (ToSRV) predominates in tomato crops. ToSRV, found so far only in Brazil, is efficiently transmitted by B. tabaci MEAM1. However, no studies have assessed the occurrence of vertical and horizontal transmission of the virus in the insect, which may have epidemiological consequences affecting disease management. This study evaluated the possibility of transmission of ToSRV between whiteflies during copulation and transovarial transmission from viruliferous females of B. tabaci MEAM1 to their progeny. Transmission of ToSRV did not occur during mating between males and females of B. tabaci MEAM1. Aviruliferous males and females confined with viruliferous insects of the opposite sex were also unable to transmit the virus to tomato plants. ToSRV was detected, by PCR, in the ovaries of viruliferous females of B. tabaci MEAM1 but not in eggs, nymphs, or adults of the progeny of viruliferous females. Adult progeny of viruliferous females also did not transmit ToSRV to tomato plants. Together, the results indicate that vertical and horizontal transmission of ToSRV by B. tabaci MEAM1 is unlikely. Sustainable management of the tomato golden mosaic disease caused by ToSRV should continue to focus on using resistant varieties, managing sources of inoculum around tomato fields, and rational chemical control of the vector.     

Soil organic matter pools and carbon-protection mechanisms in aggregate classes influenced by surface liming in a no-till system

The stabilisation of soil organic matter (SOM) is the result of the simultaneous action of three mechanisms: chemical stabilisation, biochemical stabilisation and physical protection. The objectives of this study were (i) to evaluate carbon-protection mechanisms in different SOM pools in soil aggregates and (ii) to identify the association of Ca^2 + with total organic carbon (TOC) under the influence of surface liming in a medium-textured Oxisol in a long-term experiment under no-till system (NTS) in southern Brazil (25° 10′ S, 50° 05′ W). The treatments consisted of application of zero or 6 tons ha^? 1 of dolomitic lime on the soil surface in 1993 and a reapplication of zero or 3 tons ha^? 1 of dolomitic lime in 2000 to plots with or without previous lime application. Soil samples collected at depths of 0–2.5, 2.5–5, 5–10 and 10–20 cm were separated into seven aggregate classes. In each of these classes, TOC, particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) were analysed. The 8–19 mm sized aggregates from the 0–2.5 cm layer were assessed by energy-dispersive X-ray spectroscopy (EDS) for the elemental analysis of carbon (C) and calcium (Ca). The liming caused an accumulation of TOC in the aggregates, mainly at a depth of 0–2.5 cm. The aggregates from soils treated with lime had a higher mean weight diameter (MWD) that resulted in the accumulation of TOC, especially in the 8–19 mm aggregate class, that was linear and closely related with C input (R² = 0.99). The proportion of large aggregates in the treatments with lime was closely correlated with the TOC content of the whole sample. The largest dose of lime (9 tons ha^? 1) resulted in higher TOC, POC and MAOC values, mainly in the 8–19 mm aggregate class. The elemental analyses for C and Ca revealed similar spectra between them for the surface-liming treatments in the clay fraction found in the centres of the 8–19 mm aggregates. The surface application of lime to NT fields provided greater stability and protection of the intra-aggregate C, presumably due to Ca^2 + acting as a cationic bridge between OC and the kaolinite in the clay fraction.