Use of mid‐infrared spectroscopy in the diffuse‐reflectance mode for the prediction of the composition of organic matter in soil and litter

Mid‐infrared spectroscopy (MIRS) is assumed to be superior to near‐infrared spectroscopy (NIRS) for the prediction of soil constituents, but its usefulness is still not sufficiently explored. The objective of this study was to evaluate the ability of MIRS to predict the chemical and biological properties of organic matter in soils and litter. Reflectance spectra of the mid‐infrared region including part of the near‐infrared region (7000–400 cm^–1) were recorded for 56 soil and litter samples from agricultural and forest sites. Spectra were used to predict general and biological characteristics of the samples as well as the C composition which was measured by ¹³C CPMAS‐NMR spectroscopy. A partial least‐square method and cross‐validation were used to develop equations for the different constituents over selected spectra ranges after several mathematical treatments of the spectra. Mid‐infrared spectroscopy predicted well the C : N ratio: the modeling efficiency EF was 0.95, the regression coefficient (a) of a linear regression (measured against predicted values) was 1.0, and the correlation coefficient (r) was 0.98. Satisfactorily (EF ≥ 0.70, 0.8 ≤ a ≤ 1.2, r ≥ 0.80) assessed were the contents of C, N, and lignin, the production of dissolved organic carbon, and the contents of carbonyl C, aromatic C, O‐alkyl C, and alkyl C. However, the N mineralization rate, the microbial biomass and the alkyl–to–aromatic C ratio were predicted less satisfactorily (EF < 0.70). Limiting the sample set to mineral soils did generally not result in improved predictions. The good and satisfactory predictions reported above indicate a marked usefulness of MIRS in the assessment of chemical characteristics of soils and litter, but the accuracies of the MIRS predictions in the diffuse‐reflectance mode were generally not superior to those of NIRS.     

Effects of temperature and temperature‐humidity index on the reproductive performance of sows during summer months under a temperate climate

Heat stress is known to influence sow reproduction, but it is unknown to which extent under temperate climates. Therefore, the impact of temperature and temperature‐humidity index (THI) on the reproductive performance of sows during summer months from 2009 to 2011 were studied. Reproductive parameters of 22 264 inseminations and 21 610 resulting farrowings of 22 German commercial farms were analyzed. Climatic records were available from the nearest weather station. Effects of temperature and THI at different periods of the reproductive cycle were estimated from May to September where temperatures were expected to influence climatic conditions indoors. High temperatures and THI values 5 days pre‐ and 14 days post‐breeding reduced litter size by 0.01 to 0.03 piglets (P < 0.05). Prior to farrowing, the number of liveborn piglets was reduced (P < 0.05) and of stillborns increased with rising climatic variables (P < 0.001). On the day of farrowing, reduced numbers of weaned piglets were observed when temperature and THI values were elevated (P < 0.05), but pre‐weaning mortality was not influenced (P > 0.05). In conclusion, even under temperate conditions adverse effects of climatic variables on the reproductive performance of sows are present. Thereby, the number of liveborn piglets can be considered as the most sensitive parameter to heat stress. Considering the impact of climate change and predicted heat waves, strategies to mitigate the impact of heat stress are necessary.     

Effects of Sex,Feed and Pre-slaughter Routines on Technological Meat Quality in Carriers and Non-carriers of the RN − allele

The aim of this project was to study the effects of feeding system (dry or wet feeding with whey), dietary lysine level and pre-slaughter routines on technological meat quality in entire male, female and castrated male pigs, which were carriers or non-carriers of the RN ^? allele. The feeding system only affected the yield of processed meat, resulting in lower Napole yield (87.5% vs 89.4%) for meat of whey fed pigs. Further, lower dietary lysine levels resulted in higher drip loss of the meat compared with high dietary levels (5.3% vs 4.8%). Mixing of unfamiliar pigs prior to slaughter led to meat with lower internal reflectance values (28.3 vs 32.2) and glucose+G-6-P concentrations of the meat juice (46.3 vs 49.7 μmol/ml) compared with pen-wise slaughtering. In comparison with non-carriers, RN ^? carriers had significantly lower ultimate pH, shear force values and water-holding capacity. Mixing of non-carrier pigs prior to slaughter gave higher Napole yield compared with those handled pen-wise. Females had lower ultimate pH and higher Napole yield compared with entire males.     

Metabolic Diversity of Xanthomonas axonopodis pv. vignicola, Causal Agent of Cowpea Bacterial Blight and Pustule

Fifty-five strains of Xanthomonas axonopodis pv. vignicola, isolated from blight and pustule symptoms of cowpea leaves, originating from 11 countries, were characterized for their carbon-source metabolization pattern using the Biolog GN microplate system. Great variation was found between strains according to origin. Dextrin, glycogen and succinamic acid were not used by strains from Benin, Uganda or Thailand, but by all the other strains (excluding two strains from Mozambique), whereas N-acetyl-D-glucosamine and malonic acid were used by the strains from Benin, Uganda and Thailand, but generally not by the other strains. The strains from Benin, Uganda and Thailand, as well as strains from Venezuela, Brazil and Mozambique, clustered separately from the others in multivariate analysis. Nineteen substrates were used by all the strains, 47 not by any strain and 29 only by some strains. No considerable differences were found between strains isolated from blight symptoms and from pustules. Virulence of strains was not related to the metabolic pattern. The Biolog database was not representative of the diversity of X. axonopodis pv. vignicola, since all strains were identified as Xanthomonas campestris, although belonging to eight pathovars, while only eight of nine strains from Benin and both strains from Thailand were identified as X. campestris pv. vignicola. The Biolog system appeared to be useful for characterizing the diversity of X. axonopodis pv. vignicola strains. A set of representative strains based on metabolic and molecular diversity, virulence and geographic origin is suggested for screening for resistant cowpea cultivars.     

Tentative Avenanthramide‐Modifying Enzyme in Oats

A decrease of the concentration of the synthetic avenanthramide N‐(4′‐hydroxy‐(E)‐cinnamoyl)‐5‐hydroxyanthranilic acid in a buffered slurry of milled oat groats (Avena sativa L.) was temperature and pH‐dependent, with a maximum rate at 30°C and pH 9. The reaction was inhibited in the presence of 2‐mercaptoethanol, acetic acid and at high temperature; suggestive of enzymatically catalyzed nature. Among eight different synthetic avenanthramides tested, the tentative enzyme had highest affinity for avenanthramides comprising caffeic and p‐coumaric acids and lowest for those comprising sinapic and ferulic acids. The activity was found in samples from several oat cultivars and was equally pronounced in both bran and endosperm flour of oats. Steeping of oat grains did not influence the reaction.     

Standardization of canine meningioma grading: Validation of new guidelines for reproducible histopathologic criteria

Canine meningiomas are currently graded using the human grading system. Recently published guidelines have adapted the human grading system for use in dogs. The goal of this study was to validate the new guidelines for canine meningiomas. To evaluate the inter-observer agreement, 5 veterinary surgical pathologists graded 158 canine meningiomas following the human grading system alone or with the new guidelines. The inter-observer agreement for histologic grade and each of the grading criteria (mitotic grade, invasion, spontaneous necrosis, macronucleoli, small cells, hypercellularity, pattern loss and anaplasia) was evaluated using the Fleiss kappa index. The diagnostic accuracy (sensitivity and specificity) was assessed by comparing the diagnoses obtained with the 2 grading systems with a consensus grade (considered the reference classification). The consensus histologic grade was obtained by agreement between 4 experienced veterinary neuropathologists following the guidelines. Compared with the human grading alone, the canine-specific guidelines increased the inter-observer agreement for: histologic grade (κ = 0.52); invasion (κ = 0.67); necrosis (κ = 0.62); small cells (κ = 0.36); pattern loss (κ = 0.49) and anaplasia (κ = 0.55). Mitotic grade agreement remained substantial (κ = 0.63). The guidelines improved the sensitivity in identifying grade 1 (95.6%) and the specificity in identifying grade 2 (96.2%) meningiomas. In conclusion, the new grading guidelines for canine meningiomas are associated with an overall improvement in the inter-observer agreement and higher diagnostic accuracy in diagnosing grade 1 and grade 2 meningiomas.     

Stability of Oat Avenanthramides

The three main oat avenanthramides, N‐(4′‐hydroxy)‐(E)‐cinnamoyl‐5‐hydroxyanthranilic acid ( Bp ), N‐(4′‐hydroxy‐3′‐methoxy)‐(E)‐cinnamoyl‐5‐hydroxyanthranilic acid ( Bf ), and N‐(3′,4′‐dihydroxy)‐(E)‐cinnamoyl‐5‐hydroxyanthranilic acid ( Bc ), and their corresponding cinnamic acids, p‐coumaric ( P ), ferulic ( F ), and caffeic ( C ), were investigated for stability to pH, temperature, and UV‐light treatment. The retention of the avenanthramides after processing of oat‐based food products was also analyzed. The avenanthramide Bc and the cinnamic acid C were sensitive to alkali and neutral conditions, especially in combination with heat treatment, whereas the other compounds studied were more stable. The cinnamic acids but not the avenanthramides were isomerized when irradiated with UV‐light. The avenanthramides were restored after processing of oat‐based products.