Association of polymorphisms for nuclear receptor coactivator 1 gene with egg production traits in the maternal line of Shaobo hens

1. The objectives of the study were to find polymorphic sites and elucidate the association between SNPs in the nuclear receptor coactivator 1 (NCOA1) gene and reproductive traits. 2. SNPs were detected by PCR-SSCP and DNA sequencing. Four SNPs were detected, including T10155007A, T10125838C, G10118492A and G10109315T. Three polymorphisms were associated with total egg production at the age of 300 d and the G10109315T polymorphism was associated with age at first egg. 3. In conclusion, the NCOA1 gene can be used as a molecular marker for reproductive traits in hens.     

Tibial tuberosity advancement for treatment of CrCL injury: complications and owner satisfaction

The purpose of this retrospective study of 171 dogs that underwent 193 tibial tuberosity advancement (TTA) surgeries was to describe complications and owner satisfaction associated with the procedure. Complications occurred in 21 cases (11%). Subsequent meniscal tear was the most common complication (10/193, 5.2%). Increasing body weight (P=0.02-0.04) and small cage size (P=0.06) were significantly associated with postsurgical complications. Ninety-two percent of owners were satisfied with the outcome of the TTA procedure, but only 84% stated that they would be willing to have the procedure performed again. The authors concluded that TTA had a complication rate and owner satisfaction similar to other tibial osteotomies for the surgical correction of cranial cruciate ligament disease.     

MEASUREMENT OF BODY COMPOSITION IN CATS USING COMPUTED TOMOGRAPHY AND DUAL ENERGY X‐RAY ABSORPTIOMETRY

Dual energy X‐ray absorptiometry (DEXA) is a reference method for assessing body composition but is seldom `accessible in veterinary settings. Computed tomography (CT) can provide similar body composition estimates and we propose that it can be used in body composition studies in animals. We compared CT and DEXA data from 73 healthy adult neutered domestic cats. Three approaches for measuring adipose tissue percentage from full‐body CT scans were explored. By examining the frequency distribution of voxels by Hounsfield unit (HU) value, it is possible to calculate a fat index (Fat%) that is in close agreement with the fat percentages obtained from DEXA scans. Fat% values obtained by the best of the methods had a mean difference of 0.96% (95% confidence interval 0.33–1.59%) from the DEXA results. Fat% obtained by the other two methods were characterized by good correlation but poor agreement and in one of the methods, the difference between the values from the two modalities was proportional to their mean. By using CT, it is possible to obtain body composition estimates that are in close agreement with those available using DEXA. While the significance of individual Fat% measurements obtained from CT can be difficult to interpret and to compare between centers, CT can contribute to research studies concerned either with nutrition or with obesity‐related disorders.     

Demographic characteristics of scrapie-affected holdings identified by active and passive surveillance schemes in Great Britain: 2002–2005

Several surveillance techniques have been used to quantify the prevalence of both classical and atypical scrapie in British sheep, namely the recording of clinical suspects (RC) and the testing of animals slaughtered at abattoir (AS) or reported as fallen stock (FS). Any estimate of prevalence based on a particular source is likely to have been affected by demographic differences in the populations sampled. In this study, the demographic characteristics of scrapie-affected holdings detected by each of the surveillance streams (RC, AS, FS) in Great Britain were compared. Analyses of all three streams indicated that the probability of an affected holding being detected by a particular stream differed by geographical area, the number of animals brought onto the holding, the type of scrapie identified (classical vs. atypical) and the year. More detailed analysis of AS and FS suggested that the annual and regional differences between these surveys could be explained by differences in sampling effort.     

Optimized Frequency Measures for Monitoring Trends in Tallgrass Prairie

Prairies exhibit a bimodal frequency distribution of patch occupancy with a few dominant species accounting for most of the primary production and plant biomass and numerous other species occurring infrequently over time and space. Consequently, management interest is often focused on the abundance of common species, and on the persistence of less common species. We used spatially nested arrays of various sized plots to simultaneously measure species’ persistence and abundance at Tallgrass Prairie National Preserve, Kansas. Larger plots captured more species, with 127 species identified at the 10-m scale. Smaller plots, however, provided useful frequency data for measuring the abundance of common species. We defined a plot frame size that delivers a frequency in a 20–50% target range as the optimal plot size, and the frequency of a species sampled at its optimal plot size is termed the optimized frequency. Optimized frequency was estimated for 27 common species for the years 2002–2006. Of the nine perennial grasses in this group, five exhibited significant interannual variation within the 5-yr period. Bouteloua curtipendula exhibited a significant linear change over the 5-yr period, decreasing in frequency over time. From year to year, changes in optimized frequency among the 27 common species varied in both their trajectory (i.e., the average change), and amplitude (i.e., the average magnitude of change). Between 2005 and 2006, the average change in optimized frequency was -9.1%, the only year with an overall declining trajectory. The declining trajectory between 2005 and 2006 was significantly different from the increasing trajectories observed between 2002 and 2003 and between 2004 and 2005. No significant differences were observed in amplitude. We offer these techniques for aggregating information from multiple spatial scales to characterize the amplitude and trajectory of community-wide changes as tools to help scientists convey the results of multiscale research projects to land managers.     

Vegetation Response to a One-Time Spent Drilling Mud Application to Semiarid,Mixed-Grass Prairie

Landspraying while drilling (LWD) is an approved disposal method for water-based drilling mud (WBM) systems in western Canada. The mud is applied either on cultivated land, where it is incorporated by cultivation, or on vegetated land where it is not incorporated. This study examined the effects of summer WBM application (0, 15, 20, 40, and 80 m³ · ha^?1) on native vegetation properties. Our results indicated that LWD increased bare ground but decreased lichen cover at the 80 m³ · ha^?1 rate relative to the untreated control. Nitrogen (N), sulfur (S), and magnesium (Mg) concentrations in aboveground plant tissue increased with increasing LWD rate in samples taken 45 d after WBM application, but these differences disappeared 1 yr after treatment. Increase in tissue concentration of phosphorus (P) with LWD rate, however, was only detected 3 yr after LWD. Nonetheless, these changes in tissue chemistry were not associated with significant changes in biomass yield or species composition. Overall, our results suggest that single WBM applications at rates (≤ 20 m³ · ha^?1) commonly used in western Canada, if properly managed, are unlikely to adversely affect native prairie vegetation.