Investigation of Genomic Variability of Xanthomonas Arboricola Pv. juglandis by AFLP Analysis

Xanthomonas arboricola pv. juglandis is the causal agent of walnut blight, one of the most important and widespread diseases of Persian (English) walnut (Juglans regiaL.), causing severe damage to leaves, twigs and nuts. To investigate the genomic variability of X. arboricolapv. juglandis, 66 isolates obtained from different countries (England, France, Italy, The Netherlands, Romania, Spain, USA, and New Zealand) were analysed using the Amplified Fragment Length Polymorphism (AFLP) technique. EcoRI and MseI were used as restriction endonucleases. Primers with a core sequence including endonuclease recognition sites and a 3^prime-terminal cytosine selective base for MseI primer, or no selective base for EcoRI primer, were used. Data were analysed by means of a multiple correspondence analysis. A total of 76 amplified polymorphic DNA fragments were used to compute relationships among isolates. The AFLP profiles of X. arboricola pv. juglandis isolates appeared to be reliably distinguishable from X. arboricola pv. pruni and X. arboricola pv. corylina, and from other Xanthomonas species, i.e. X. campestris pv. campestris, X. fragariae, X. hortorum, X. axonopodis pv. vesicatoria. Though this pathogen is associated with one single host genus, a high level of genomic diversity was found. This diversity might be partly explained by the geographic origin. Nevertheless, isolates with different patterns were collected within one country, and similar molecular patterns were found in isolates collected at different sites. However, genetic diversity might be influenced by exchanging vegetative material from different countries. Mixing of X. arboricola pv. juglandis isolates might have partly concealed the influence of the geographic location from which the bacteria were isolated.     

Soybean grain is a suitable replacement with soybean meal in multiple supplements for Nellore heifers grazing tropical pastures

The research aimed to evaluate the effect of replacing soybean meal with soybean grain on the nutritional parameters and productivity of heifers grazing on Urochloa decumbens in the rainy-dry transition period. Forty crossbred heifers with the initial age and weight of 18 months and 292?±?6.1 kg, respectively, were used. The experimental design was a completely randomized design, with five treatments and eight replications. The evaluated treatments were as follows: SM_0.5—supply of 0.5 kg/animal/day of soybean meal supplement; SG_0.5—supply of 0.5 kg/animal/day of soybean grain supplement; SM_1.0—supply of 1.0 kg/animal/day of soybean meal supplement; SG_1.0—supply of 1.0 kg/animal/day of soybean grain supplement; MM—only mineral mix ad libitum. The supplement was isoprotein with 350 g of crude protein/kg of dry matter. Supplementation improved the performance of the heifers and this fact can be verified by the higher average daily gain (ADG) and final BW (fBW) of the supplemented animals (P?<?0.10). The two supplemented treatments with 1 kg/day demonstrated similar performance (P?>?0.10), the same happens for the two treatments receiving 0.5 kg/day (P?>?0.10). However, animals receiving 1 kg/day of supplementation had an ADG and final BW higher than animals receiving 0.5 kg/day (P?<?0.10). Supplementation (P?<?0.10) affected the intake of dry matter (DM), organic matter, crude protein, ether extract, non-fiber carbohydrates, total digestible nutrients, and neutral detergent fiber corrected for ash and protein (apNDF). Supplementation improved DM digestibility and all constituents of the diet (P?<?0.10), except for apNDF (P?>?0.10). In summary, it is concluded that multiple supplementations improve the performance of grazing heifers in the rainy-dry transition period and the total replacement of soybean meal by soybean grain does not alter the performance of the animals.     

Estimation of daily milk yield of Nellore cows grazing tropical pastures

Beef cows’ milk yield is typically determined by measuring milk yield once daily and then doubling this value to estimate daily production. However, it is not known whether this is accurate. Thus, we aimed to determine the association between morning and afternoon milk yield in grazing Nellore cows. Eighty Nellore cows were used, with initial weight of 516.0?±?1.0 kg. The experiment was a completely randomized factorial scheme, with 20 replications and four treatments (i.e., +?or ??pre-partum supplementation in combination with +?or ??post-partum supplementation): PRMM—1 kg of supplement/cow/day for 90 days pre-partum; MMPS—1 kg of supplement/cow/day for 90 days post-partum; PRPS—1 kg of supplement/cow/day for 90 days pre-partum and 90 days post-partum; and MM—only mineral mix ad libitum during pre- and post-partum. Milk was sampled on days 45, 135, and 225 post-partum (early, middle, and late lactation, respectively). No effects were observed of pre- and post-partum supplementation on milk yield (P?>?0.05). The afternoon/morning proportion of 0.45 in the early third of lactation was higher than other stages, which had a proportion of 0.41 (P?<?0.05). Post-partum supplementation increased milk protein in the morning and afternoon milking (P?<?0.05). There was also no effect of pre- and post-partum supplementation on afternoon-morning proportion other milk components (P?>?0.05). We conclude that estimating daily milk production of grazing beef cattle by multiplying a once daily milking amount times two is not accurate. Under the conditions of this study, proportion of total daily production represented by the ratio of afternoon/morning milking was 0.45 in early lactation (first third) and 0.41 in mid- and late lactation.     

Dairy calf rearing unit and infectious diseases: diarrhea outbreak by bovine coronavirus as a model for the dispersion of pathogenic microorganisms

Dairy calf rearing unit is a management system that is only recently being implemented by some milk producer’s cooperatives in southern Brazil. However, aspects related to the health profile of the heifer calves that arrive in the rearing unit as well as about biosecurity practices and microbiological challenges have not yet been evaluated in this rearing system in a tropical country. Diarrhea is the main and most frequent consequence of enteric infections in newborn calves. This study, through some etiological and epidemiological characteristics of an outbreak of neonatal diarrhea, has the aim to alert to the possibility of pathogenic microorganism spread in a dairy heifer calf rearing unit. The diarrhea outbreak presented some non-regular characteristics observed in bovine coronavirus (BCoV) enteric infections in dairy calves. The spread of infection was extremely rapid (1 week); the attack rate (>?50%) was much higher than that observed in calves subjected to conventional rearing; and the age range (5 to 90 days) of the affected heifer calves was much broader than that often observed in the BCoV diarrhea worldwide. These unusual epidemiological characteristics observed in this BCoV diarrhea outbreak raise awareness of the health threat present in calf rearing units as well as of the easy and rapid viral spread in a population of young animals from different dairy herds and, therefore, with very distinct immunological status.

     

Performance of dual and triple fungicide premixes for managing soybean rust across years and regions in Brazil: A meta-analysis

Soybean rust in Brazil is currently controlled with several commercial fungicide premixes composed of demethylation inhibitors (EPOXiconazole, CYPRoconazole, PROThioconazole, TEBUconazole), quinone-outside inhibitors (AZOXystrobin, TriFLoXystrobin, PYRAclostrobin, PICOxystrobin), and succinate demethylation inhibitors (BENZovindiflupyr, BIXaFen, FLUXapyroxad). Here, we summarize the performance of eight premixes evaluated in 177 cooperative trials conducted in 46 locations across 10 states from 2015 to 2020. All fungicide treatments were sprayed three times starting at R1/R2. Percentage control (, %), from back-transforming meta-analytic estimates of the log of the ratio, ranged from 56.2% (PICO + CYPR) to 76.8% (BIXF + TFLX + PROT). Estimates of mean yield difference (, kg/ha) between fungicide-treated and untreated plots were greatest for BIXF + TFLX + PROT (1,080) followed by PICO + BENZ (1,010), PYRA + EPOX + FLUX (981.5), AZOX + BENZ (910), TFLX + PROT (891), PICO +TEBU (682), TFLX + CYPR (646), and PICO + CYPR (600). Significant declines in both and in as little as 4 years were detected for AZOX + BENZ (35.3%; 550 kg/ha) and PICO + BENZ (15.5%; 359.8 kg/ha). Variance in was reduced by the inclusion of baseline severity as covariate. In trials where baseline disease was ≥70%, yield was 250 kg/ha greater compared to areas with low baseline disease. Disease control and yield response were generally greater in the south-east, where the frequency of profitable scenarios was 30% higher on average than in the north-west. Results of this meta-analysis are critical for supporting decisions during planning of fungicide programmes.     

Mit fremden Hölzern eingeschleppte Insekten,insbesondereScolytidae undPlatypodidae

Summary Scolytidae and Platypodidae as well as other insects and mites found in imported wood. Part II The new list deals with insect and mite species collected in imported wood byWichmann () andCola last years. 40 species were found in 11 kinds of wood, most of them inPinus echinata Mill, imported from Norfolk, Virginia (U.S.A.). Nearer information onReticulitermes flavipes Koll, found byWichmann inPinus echinata in Mannheim, 1957, is given. Finally completitions are made of the list of species published in Anz. f. Schädlk. u. Pflanzenschtz. XLIV (5) p. 65–68, 1971. This list contents 41 species of insects and mites found in 9 kinds of imported wood.     

Virulence-associated gene profiling of Streptococcus suis isolates by PCR

Definition of virulent Streptococcus suis strains is controversial. One successful approach for identification of virulent European strains is differentiation of capsular serotypes (or the corresponding cps types) and subsequent detection of virulence-associated factors, namely the extracellular factor (EF, epf), the muramidase-released protein (MRP, mrp) and the hemolysin suilysin (SLY, sly). In this work we present a novel multiplex PCR (MP-PCR) and an mrp variant PCR for identification and characterization of virulent S. suis strains. These new methods were used to identify association of disease with particular profiles of virulence-associated genes. The MP-PCR allowed identification of S. suis through detection of the housekeeping gene gdh, differentiation of four cps types (1, 2, 7 and 9), and detection of epf, mrp, sly and arcA (arginine deiminase from S. suis). Furthermore, this study describes the first PCR assay for differentiation of at least six mrp variants. Expression of the corresponding size variants of MRP was shown for four of the six mrp variants, but was undetectable for the two larger mrp variants in the particular strains investigated. The results of this study suggest that cps7 strains are associated with pneumonia and that variation of mrp is very pronounced among these strains. Gene profiles of invasive, pneumonia and carrier S. suis isolates by combination of PCR assays allowed differentiation of 24 different genotypes among cps1, 2, 7 and 9 strains. Forty-five percent of the invasive S. suis diseases investigated in this study were caused by only two of these genotypes, namely cps2/mrp+/epf+/sly+ and cps9/mrp(*)/epf-/sly+. Thus, this study demonstrates for the first time a uniform profile of the particular virulence-associated genes for the vast majority of the investigated invasive cps9 strains.