A 10-year record of the weathering rates of surficial pebbles in Kärkevagge, Swedish Lapland

Between 1999 and 2004, nylon mesh bags containing  6.2 mm diameter fragments of crushed dolomite or granite were exposed to weathering on the surfaces of birch, Dryas heath, heath, meadow, solifluction meadow, and willow vegetation communities in Kärkevagge, a glaciated trough in Swedish Lapland. The material in the bags had previously been in the same locations from either 1994 or 1995 when it had been placed in the field as freshly crushed pebbles. Results of the mass losses resulting from chemical weathering during the first 4- or 5-year period were reported in Dixon et al. [Dixon, J.C., Thorn, C.E., Darmody, R.G., Schlyter, P. 2001. Weathering rates of fine pebbles at the soil surface in Kärkevagge, Swedish Lapland. Catena 45, 273–286.] in Catena. The spatial results of the second 5-year period confirm those determined during the first period. In general, wetter, more acidic sites promoted greater losses from the dolomite, but the losses from the granite were too small to reveal distinctive spatial patterns. Dolomite consistently weathered faster than granite in at-a-site comparisons with total mass losses between 1999 and 2004 ranging from 1.90% to 9.98% for dolomite and − 0.07% to 4.02% for granite. Spatial distinctions were blurred during the second period due to significant losses of bags at dry sites from atmospheric exposure. However, at-a-site comparisons between the two study periods revealed statistically significantly greater losses during the second period when compared to the first. In the absence of appropriate ground climate data, it is worth noting that air climates were both warmer and wetter during both study periods when compared to the 1961–1990 averages, and the second 5-year study period was also warmer and wetter than the first.     

Effect of housing environment on laying hen meat quality: Assessing Pectoralis major pH,colour and tenderness in three strains of 80–81 week-old layers housed in conventional and furnished cages

1. Meat quality is affected by factors such as stress, genetic strain and activity and is determined in part by measures of pH, colour and tenderness. In conventional laying hen cages (CC), lack of physical space and inability to perform highly motivated behaviours leads to stress and inactivity. Furnished cages (FCs) permit expression of highly motivated behaviours, but typically house larger group sizes than CC, thereby contributing to social stress. The objective of this study was to evaluate the effects of CC and FC laying hen housing environments and strain differences on meat quality of 80–81-week-old birds.

2. Pectoralis major meat quality was assessed for two flocks of Shaver White (SH), Lohmann Lite (LL) and Lohmann Brown (LB) hens housed in either 5-hen CC or 40-hen FC. Between 80 and 81 weeks, muscle samples were collected from randomly selected hens and analysed for muscle pH, colour and shear force (SF) using established methods.

3. In both flocks, the combined treatment body weights (BWs) were higher for CC than FC hens and the combined strain BWs were higher for LB than LL and SH hens. Flock 1 LB had lower initial and ultimate pH than SH and LL, and greater pH decline than SH. Muscle redness (a*) was higher for CC SH than FC SH in both flocks. Muscle a* was higher for LL than SH and LB in Flock 1, and higher than SH in Flock 2. Housing differences in muscle SF were absent. In CC, SF was higher for SH than LL and LB in Flock 1, and higher than LB in Flock 2.

4. Lack of housing differences suggests that environmental stressors present in both housing systems similarly affected meat quality. Strain differences for muscle pH, a* and SF indicate increased stress experienced by SH and LL hens. The absence of Flock 2 strain differences is consistent with the cannibalism outbreak that occurred in this flock and most severely impacted LB hens.     

Computed tomographic contrast tenography of the digital flexor tendon sheath of the equine hindlimb

Pre‐surgical investigation of digital flexor tendon sheath pathology remains challenging with current standard imaging techniques. The aim of this prospective, anatomical, pilot study was to describe the anatomy of the equine hind limb digital flexor tendon sheath using a combination of computed tomography (CT) and computed tomographic contrast tenography in clinically normal cadaver limbs. Ten pairs of hind limbs with no external abnormalities were examined from the level of the tarsometatarsal joint distally. Limbs initially underwent non‐contrast CT examination using 120 kVp, 300 mAs, and 1.5 mm slice thickness. Sixty millilitres of ioversol iodinated contrast media and saline (final concentration 100 mg/ml) were injected using a basilar sesamoidean approach. The computed tomographic contrast tenography examination was then repeated, before dissection of the specimens to compare gross and imaging findings. The combined CT and computed tomographic contrast tenography examinations provided excellent anatomical detail of intra‐thecal structures. The borders of the superficial and deep digital flexor tendons, and the manica flexoria were consistently identifiable in all limbs. Detailed anatomy including that of the mesotenons, two of which are previously undescribed, and the plantar annular ligament were also consistently identifiable. Dissection of all 10 pairs of limbs revealed there to be no pathology, in accordance with the imaging findings. In conclusion, the combination of CT and computed tomographic contrast tenography may be useful adjunctive diagnostic techniques to define digital flexor tendon sheath pathology prior to surgical exploration in horses.