Clinical application of multidetector computed tomography and magnetic resonance imaging for evaluation of cranial nerves in horses in comparison with high resolution imaging standards

Although horses are affected by cranial nerve disease, our understanding of these structures' imaging anatomy is limited, and the optimal modality for imaging of each of these nerves is unclear. The aim of this study was to describe the imaging appearance of the equine cranial nerves on high‐resolution 1.5T magnetic resonance imaging (MRI) and computed tomography (CT) scans of a cadaver head, and with these as standards, examine the utility of MRI and CT performed in clinical cases. High‐resolution MRI and CT images were prospectively acquired of the head of a normal Thoroughbred gelding following euthanasia. Ten clinical cases undergoing high‐field MRI under general anaesthesia and 10 clinical cases undergoing CT in the standing horse under sedation were retrospectively evaluated by three reviewers to assess cranial nerve visibility. On high‐resolution, thin‐slice, MRI scans of the normal cadaver head, each of the 12 cranial nerves and their topographic location could be appreciated. On high‐resolution cadaver CT, cranial nerves II, V and VII were clearly visible, but others were less easily identified; osseous structures were clearly visualised. Clinical MRI and CT allowed for variable visualisation of the cranial nerves, dependent on the sequence and the orientation of scan planes. High‐field MRI allowed excellent visualisation of equine cranial nerves, whereas CT allowed for more detailed visualisation of the osseous canals and foramina. In live horses, the ability to identify all 12 nerves is challenging with either MRI or CT; however, high‐field MRI enables better visualisation of the nerve bundles than CT.     

Effect of Early Postpartum Ovulation on Fertility in Dairy Cows

Our objectives were to determine the effects of early ovulation on fertility and uterine health of dairy cows. Four hundred and forty‐five Holstein cows (185 primiparous and 260 multiparous) from five herds were used. Blood samples were collected at 21, 35 and 49 days in milk (DIM) and cows were considered to be cyclic at 21 DIM (Cyc21) if serum progesterone (P4) concentration was above 1 ng/ml, cyclic by 49 DIM (Cyc49) if P4 concentration was above 1 ng/ml at 35 or 49 DIM, or not cyclic (NotCyc) if P4 concentration was below 1 ng/ml at all sample times. Endometrial cytology for diagnosis of subclinical endometritis was examined at 49 DIM in a subset of 414 cows. Cows in the group Cyc21 had increased hazard of insemination, for the first service, compared with cows in Cyc49 [hazard ratio (HR) = 1.40; 95% CI = 1.10–1.79; p = 0.006] and NotCyc (HR = 2.07; 95% CI = 1.52–2.82; p < 0.001). Cows in the Cyc49 group also had increased hazard of insemination compared with cows in the NotCyc group (HR = 1.47; 95% CI = 1.13–1.93; p = 0.005). Median days to insemination were, respectively, 71, 76 and 96 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in Cyc21 had greater first service pregnancy per AI than Cyc49 [38.6 vs 28.1%; adjusted odds ratio (AOR) = 1.67; 95% CI = 1.01–2.75; p = 0.04] and NotCyc (38.6 vs 23.6%; AOR = 2.08; 95% CI = 1.08–4.00; p = 0.03). Pregnancy per AI was similar in Cyc49 and NotCyc cows (28.1 vs 23.6%; AOR = 1.25; 95% CI = 0.70–2.24; p = 0.45). Cows in Cyc21 had increased hazard of pregnancy up to 300 DIM compared with Cyc49 (HR = 1.52; 95% CI = 1.17–1.96; p = 0.002) and NotCyc (HR = 1.98; 95% CI = 1.41–2.78; p < 0.001). Cows in Cyc49 tended to have increased hazard of pregnancy compared with NotCyc (HR = 1.31; 95% CI = 0.96–1.77; p = 0.09). Median days to pregnancy were, respectively, 103, 147 and 173 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in the Cyc21 group had decreased prevalence of subclinical endometritis compared with cows in the NotCyc group (29.9 vs 43.7%; AOR = 0.53; 95% CI = 0.29–0.97; p = 0.04); however, the prevalence did not differ from the Cyc49 group (29.9 vs 39.1%; AOR = 0.68; 95% CI = 0.41–1.14; p = 0.15). Cyc49 cows had similar prevalence of subclinical endometritis compared with NotCyc cows (AOR = 0.77; 95% CI = 0.46–1.29; p = 0.32). Early postpartum ovulation was associated with improved uterine health and fertility.     

Relative differences in sugar content of basal and apical portions of Russet Burbank potatoes

Basal and apical portions of mature and immature Russet Burbank tubers stored at 42 F (5.6 C), 45 F (7.2 C), and 48 F (8.0 C) were analyzed for sucrose and reducing sugars at seven monthly intervals for three seasons. Percent relative difference of reducing sugars (between mature and immature tubers) was greater in the apical than the basal portion. On the other hand, seasonal differences in percent reducing sugars were reflected more in the basal portion by greater relative differences among seasons than in the apical portion. Statistical analysis showed no trend or influence of maturity or storage temperature in affecting the relativeratio of reducing sugars between the basal and apical portions. Differences among growing seasons appeared to affect this ratio. Tubers from the 1970–71 season had more equal relative amounts of sugars in the two portions than did the tubers from 1968–69 or 1969–70 seasons. Ratio ofsucrose between the basal and apical portions was not affected appreciably by maturity, storage temperature or season, although immaturity and lower storage temperatures caused slightly greater overall sucrose accumulation. Sucrose and reducing sugar contents were poorly correlated regardless of maturity, storage temperature or different seasons.     

Plant growth response from aged potato seed-tubers as affected by meristem selection and NAA

Plant growth from Russet Burbank seed-tubers of different ages was compared as affected by source of meristematic tissue (apical or basal) and NAA treatment. In controlled environment studies, single-eye seedcores from 17-mo-old seed-tubers produced twice as many shoots compared to those from 5-and 29-mo-old seed-tubers. Seed-tuber age and shoot dry weight/core were inversely related. Dry weight/shoot decreased as age increased to 17 mo and then remained unchanged from 17 to 29 mo. Apical meristems lost growth potential faster than basal meristems as age advanced. Meristem physiological age apparently depends on relative position of the buds as well as on the chronological age of the seed-tuber. NAA (10–40 mg/l) decreased the number of shoots/core, had no effect on shoot dry weight/core but increased the dry weight/shoot when applied to seedcores from 20-mo-old seed-tubers. On seedcores from 8-mo-old seed-tubers. NAA decreased the shoot dry weight (g/core, g/shoot). In field studies, NAA (100 mg/l) increased the total tuber yield of plants grown from seedpieces cut from 8-and 20-mo-old seed-tubers. These increases were manifested in age-specific effects on tuber grade. The effects of seedtuber age on plant growth and tuber yield were partially overcome by seedpiece treatment with NAA.     

Relationship of specific gravity to sugar accumulation in stored Norgold and Russet Burbank potatoes

Studies were made on the influence of growing season and low fertility on reducing sugar accumulation in storage of the stem and bud portions of Russet Burbank and Norgold Russet potatoes separated into different specific gravity groups. The stem portion of Russet Burbank had a significantly different intercept and slope of regression line (between specific gravity and reducing sugar accumulation) than the bud portions of the same tubers indicating higher reducing sugar accumulation in the stem portion as well as differences in behavior as to amount accumulated at the different specific gravity levels. No significant difference in sugar content or behavior at the different specific gravity levels was obtained between stem and bud portions of Norgold Russet. Growing season did not cause significant differences in total sugar content or slope of the regression lines within the stem or bud portions of Russet Burbank. Low fertility level resulted in significantly higher sugar accumulation in the stem portion of Russet Burbank as compared to adequate fertility and there was also a trend toward less influence of specific gravity on sugar accumulation at the lower fertility level. Low specific gravity Russet Burbank potatoes tended to be more variable in sugar accumulation from year to year and also had wider differences in sugar accumulation between stem and bud portions than high specific gravity potatoes.     

Seasonal changes in the crude protein concentration of mixed swards of white clover/perennial ryegrass grown without fertilizer N in an organic farming system in the United Kingdom

Changes in the crude protein (CP) concentration of white clover and perennial ryegrass herbage from a mixed sward were determined on six sampling dates from May to October in each of 2 years. The swards were grown without fertilizer N in an organic farming system and continuously grazed by dairy cows during the grazing season. The annual mean contents of white clover in the dry matter (DM) of the sward were 272·3 and 307·0 g kg⁻¹ in Years 1 and 2. The mean CP concentrations of the white clover and perennial ryegrass herbage were 251·6 and 151·9 g kg⁻¹ DM in Year 1 and 271·9 and 174·0 g kg⁻¹ DM in Year 2 respectively. The CP concentration of the white clover increased significantly during the grazing season from 220·0 to 284·1 g kg⁻¹ DM in Year 1 and from 269·0 to 315·5 g kg⁻¹ DM in Year 2. In the perennial ryegrass herbage the CP concentration increased from 112·2 to 172·6 g kg⁻¹ DM in Year 1 and from 142·7 to 239·5 g kg⁻¹ DM in Year 2. The rate of increase during the season in the CP concentration of the perennial ryegrass herbage was similar to the rate of increase recorded in the white clover herbage.     

Primary pulmonary chondrosarcoma in a dog.

Extraosseous chondrosarcomas are uncommon in the dog, and those originating in the lung are rare. This report presents a 9-year-old Beagle dog with a pulmonary mass which caused depression, fever, tachypnea, cough, and laboratory abnormalities. The mass was composed predominantly of chondroid tissue, and was histologically diagnosed as chondrosarcoma.