Ultrasonographic diagnosis of closed pedal bone fractures in bovine claws: An ex-vivo study in slaughterhouse specimens.

Pedal bone fractures are one of the most common fracture locations in adult cattle and can be diagnosed by radiographs in two planes. Most bovine practitioners do not have access to such X-ray machines, but many use ultrasound units on a daily basis, primarily for reproductive medicine. For this reason, in this double-masked, randomized controlled study, we aimed to investigate the suitability of ultrasonographic examination using a 5 MHz linear transducer for diagnosing closed fractures of the pedal bone in cattle. A total of 54 hindlimb claws from slaughtered cattle were prepared and approximately 50% of the claws were artificially fractured. All claws were ultrasonographically examined twice by two examiners to determine the presence or absence of fractures and their locations. Ultrasound results were confirmed using radiographs of the claws as the reference standard method. All fracture locations as determined by ultrasonography were situated within ±2 mm of the radiographically-determined fracture zone. Ultrasound examination yielded a calculated sensitivity of 93%, a specificity of 91% and an inter-rater reliability of 0.77. The intra-rater reliability for the examiners were 0.96 and 0.88. Examiner experience with ultrasound examination and using ultrasound images for diagnosis could have influenced diagnostic accuracy. We conclude that artificially-created pedal bone fractures in ex-vivo bovine claws can be diagnosed using ultrasonography; similar results are expected in live animals. These results should encourage veterinarians to use ultrasonography for diagnosing pedal bone fractures in cattle.

Claw health and prevalence of lameness in cows from compost bedded and cubicle freestall dairy barns in Austria.

Claw health and lameness data from five dairies with compost bedded barns (n = 201 data sets) were evaluated and compared with data from five dairy herds housed in freestall cubicle barns (n = 297 data sets). They were matched for having the same cow numbers, flooring type and similar milk yield. The prevalence of lameness, claw lesions and their severity grades were analysed. Two claw health indicators, the cow claw score (CCS) and the farm claw score (FCS), were calculated using a computerised claw trimming database programme; there was no significant difference in overall lameness prevalence in cows from five compost bedded barns (18.7%) compared to cows from five freestall cubicle herds (14.9%). A cumulative link mixed model (CLMM) did not show significant differences in locomotion between different types of bedding material, flooring system, breed, visit number, observer and time since last trimming, but locomotion was significantly influenced by CCS. Another CLMM tested the impact of parameters mentioned on CCS and showed significant influence of flooring type, visit number and cattle breed. Statistically significant differences in the prevalence of claw disorders between compost bedded and freestall cubicle barns were found for white line disease (WLD; 20.4% and 46.6%, respectively), heel horn erosion (HHE; 26.9% and 59.9%, respectively), concave dorsal wall as a result of chronic laminitis (6.5% and 15.9%, respectively) and for interdigital hyperplasia (0.2% and 3.1%, respectively). The results of this study indicate that compost dairy barns are a good alternative to common cubicle housing systems in terms of lameness, claw health and animal welfare.

Phenotypic differentiation is associated with divergent sexual selection among closely related barn swallow populations.

Sexual selection plays a key role in the diversification of numerous animal clades and may accelerate trait divergence during speciation. However, much of our understanding of this process comes from phylogenetic comparative studies, which rely on surrogate measures such as dimorphism that may not represent selection in wild populations. In this study, we assess sexual selection pressures for multiple male visual signals across four barn swallow (Hirundo rustica) populations. Our sample encompassed 2400 linear km and two described subspecies: European H. r. rustica (in the Czech Republic and Romania) and eastern Mediterranean H. r. transitiva (in Israel), as well as a potential area of contact (in Turkey). We demonstrate significant phenotypic differentiation in four sexual signalling axes, despite very low-level genomic divergence and no comparable divergence in an ecological trait. Moreover, the direction of phenotypic divergence is consistent with differences in sexual selection pressures among subspecies. Thus, H. r. transitiva, which have the darkest ventral plumage of any population, experience directional selection for darker plumage. Similarly, H. r. rustica, which have the longest tail feathers of any population, experience directional selection for elongated tail feathers and disruptive selection for ventral plumage saturation. These results suggest that sexual selection is the primary driver of phenotypic differentiation in this species. Our findings add to growing evidence of phenotypic divergence with gene flow. However, to our knowledge, this is the first study to relate direct measures of the strength and targets of sexual selection to phenotypic divergence among closely related wild populations.

QTLs for the elongation of axile and lateral roots of maize in response to low water potential.

Changes in root architecture and the maintenance of root growth in drying soil are key traits for the adaptation of maize (Zea mays L.) to drought environments. The goal of this study was to map quantitative trait loci (QTLs) for root growth and its response to dehydration in a population of 208 recombinant inbred lines from the International Maize and Wheat Improvement Center (CIMMYT). The parents, Ac7643 and Ac7729/TZSRW, are known to be drought-tolerant and drought-sensitive, respectively. Roots were grown in pouches under well-watered conditions or at low water potential induced by the osmolyte polyethylene glycol (PEG 8000). Axile root length (L (Ax)) increased linearly, while lateral root length (L (Lat)) increased exponentially over time. Thirteen QTLs were identified for six seedling traits: elongation rates of axile roots (ER(Ax)), the rate constant of lateral root elongation (k (Lat)), the final respective lengths (L (Ax) and L (Lat)), and the ratios k (Lat)/ER(Ax) and L (Lat)/L (Ax.) While QTLs for lateral root traits were constitutively expressed, most QTLs for axile root traits responded to water stress. For axile roots, common QTLs existed for ER(Ax) and L (Ax). Quantitative trait loci for the elongation rates of axile roots responded more clearly to water stress compared to root length. Two major QTLs were detected: a QTL for general vigor in bin 2.02, affecting most of the traits, and a QTL for the constitutive increase in k (Lat) and k (Lat)/ER(Ax) in bins 6.04-6.05. The latter co-located with a major QTL for the anthesis-silking interval (ASI) reported in published field experiments, suggesting an involvement of root morphology in drought tolerance. Rapid seedling tests are feasible for elucidating the genetic response of root growth to low water potential. Some loci may even have pleiotropic effects on yield-related traits under drought stress.

QTL controlling root and shoot traits of maize seedlings under cold stress.

The improvement of early vigour is crucial for the adaptation of maize (Zea mays L.) to the climatic conditions of central Europe and the northern Mediterranean, where early sowing is an important strategy for avoiding the effect of summer drought. The objectives of this study were to identify quantitative trait loci (QTL) controlling cold-related traits and to investigate the relationships among them. A set of 168 F2:4 families of the Lo964 x Lo1016 cross was grown in a sand-vermiculite substrate at 15/13 degrees C (day/night) until the one-leaf stage. Twenty QTL were identified for the four shoot and two seed traits examined. Analysis of root weight and digital measurements of the length and diameter of primary and seminal roots led to the identification of 40 QTL. The operating efficiency of photosystem II (PhiPSII) was related to seedling dry weight at both the phenotypic and genetic level (r = 0.46, two matching loci, respectively) but was not related to root traits. Cluster analysis and QTL association revealed that the different root traits were largely independently inherited and that root lengths and diameters were mostly negatively correlated. The major QTL for root traits detected in an earlier study in hydroponics were confirmed in this study. The length of the primary lateral roots was negatively associated with the germination index (r = -0.38, two matching loci). Therefore, we found a large number of independently inherited loci suitable for the improvement of early seedling growth through better seed vigour and/or a higher rate of photosynthesis.

The development of memory for location: what role do spatial prototypes play?

Two experiments investigated the role of spatial prototypes in estimates of location. In Experiment 1 (N = 144), children and adults learned the locations of 20 objects in an open, square box designed to look like a model house. In two conditions, opaque lines or walls divided the house into four regions, and in the other condition, no boundaries were present. Following learning, the dots marking the locations were removed, and participants attempted to replace the objects. Children and adults overestimated distances between target locations in different regions. Contrary to Huttenlocher, Hedges, and Duncan's hierarchical theory of spatial memory, none of the groups displaced the objects toward the region centers. In Experiment 2 (N = 96), boundaries were removed during testing to determine whether children and adults were more likely to displace objects toward region centers when uncertainty about location increased. Again, all age groups overestimated distances between target objects in different regions. In addition, adults and 11-year-olds in the most salient boundary condition displaced objects toward the region centers. Discussion focuses on the implications of these results for understanding how children and adults estimate location.

Light-dependent carotenoid synthesis : X. Lag-phase after a second illumination period in Fusarium aquaeductuum and Neurospora crassa.

In dark grown mycelia of the fungi Fusarium aquaeductuum Lagh. and Neurospora crassa the kinetics of carotenoid accumulation after brief illuminations were investigated. Following a second illumination period photoinduced carotenoid biosynthesis started also only after a lag-phase. Such a "secondary" lag-phase not only appeared when the pigment accumulation induced by the first light treatment had been completed, but also when the second illumination was given during the period of rapid carotenoid synthesis induced by the first illumination. The length of the lag-phase, the intensity of the subsequent pigment accumulation as well as the gradual inhibition by cycloheximide is identical after the first and the second illumination. From these results we conclude that in the pgotoregulation of carotenogenesis in fungi by blue light, a second light treatment of preilluminated mycelia gives rise to a renewed induction of the whole sequence of dark reactions.