Progress in breeding interspecific hybrid ryegrasses

Stable hybrids were produced between tetraploid perennial and Italian ryegrasses derived from commercial varieties and germplasm introduced from European collections. Spaced plant characteristics were used to select Fl plants for the production of F2 families which were assessed in small plots for growth and quality traits. Ten of the 19 selected hybrid families were based on perennial ryegrass collected from the Zurich Uplands. The influence of this parental material in improving vegetative growth during early spring, late summer and autumn was demonstrated. Its use in improving feeding value by increasing the water-soluble carbohydrate content of hybrids was also shown. Consequently, selected hybrid varieties based on this new genetic resource showed considerable improvements in seasonal growth and quality over the older hybrid variety Augusta and Italian ryegrass variety RvP.     

Effect of body condition score and reuse of progesterone‐releasing intravaginal devices on conception rate following timed artificial insemination in Nelore cows

This study had the aim of investigating the efficiency of timed artificial insemination (TAI) through the progesterone‐releasing intravaginal device (PRID), used in new condition and for the second and third times in Nelore cows. The effects of device reuse and body condition score (BCS) on the conception rate (CR) were evaluated in 1,122 multiparous Nelore cows (mean BCS of 2.7 ± 0.4), which were randomly distributed into three groups that received new (n = 330), once (n = 439) and twice used (n = 353) PRID. Among the 1,122 females that underwent TAI, 573 became pregnant, thus representing an overall CR of 51.06%. Cows with BCS between 2.75 and 4.0 had greater (p < .0001) CR (69.75%) than cows with BSC of 2.0–2.5 (32.98%). It was observed that the CR through using PRID was 60.00%, 51.71% and 41.93% for new, once and twice used PRID, respectively, with difference between all groups (p < .0001). Under tropical conditions, animals with BCS greater than 2.5 had a higher CR, and the CR decreased proportionally with the number of times that the PRID had been used.     

Concentration and prevalence of Escherichia coli O157 and Salmonella serotypes in sheep during slaughter at two Australian abattoirs

Objective This study aimed to determine the presence and concentration of Escherichia coli O157 and Salmonella spp. on fleece, faeces and carcases of sheep during slaughter. Procedure Faeces, fleece and pre-chill carcase samples were collected from 164 sheep slaughtered at two Australian abattoirs. The presence of E. coli O157 and Salmonella spp. were determined by use of automated immunomagnetic separation (AIMS) with enumeration by use of the ‘most probable number’ (MPN) method. Results Escherichia coli O157 was isolated from 5% of faeces, 3% of fleeces and 0.6% of pre-chill carcases. The mean log₁₀ count of E. coli O157 positive faecal samples was 2.32 MPN/g, but counts on fleeces and carcases were below the countable limit (−1 log₁₀ MPN/cm²). Salmonella spp. were isolated from 20% of faeces, 13% of fleeces and 1.3% of pre-chill carcases. The mean log₁₀ count of Salmonella spp. in faeces was 1.43 MPN/g and on fleece was −0.24 MPN/cm², but counts on carcases were below the countable limit (−1 log₁₀ MPN/cm²). Conclusion The prevalence and concentration of pathogens were low in the sheep tested in this study, indicating a low risk of human infection from products derived from these animals.     

Sonographic characteristics of presumptively normal main axillary and superficial cervical lymph nodes in dogs

Objective-To evaluate the B-mode and Doppler ultrasonographic appearance of presumptively normal main axillary and large superficial cervical lymph nodes (MALNs and SCLNs, respectively) in adult dogs. Animals-51 healthy adult dogs (data from 1 dog were not analyzed). Procedures-For each dog, weight, distance from the cranial aspect of the first sternebra to the caudal aspect of the left ischiatic tuberosity, and thoracic height and width at the level of the xiphoid process were recorded. Via B-mode and Doppler ultrasonography, echogenic characteristics, size in relation to body size and weight, and vascular supply of the MALNs and the SCLNs were evaluated (1 SCLN in 1 dog was not ultrasonographically visible). Results-Most MALNs were clearly margined, solitary, and ovoid; echopatterns were homogenous or cortical and hypo- to isoechoic, compared with surrounding soft tissues. Size measurements of MALNs correlated with dogs' body length, thoracic width and height, and body weight. Most SCLNs were clearly margined, fusiform, and hypoechoic (compared with surrounding soft tissues) with a cortical or homogenous echopattern. Size measurements of SCLNs correlated with dogs' body length, thoracic width and height, and body weight. In 50 of the 100 MALNs, an intranodal vascular supply was detected; in contrast, an intranodal vascular supply in SCLNs was detected infrequently. Conclusions and Clinical Relevance-Results indicated that, in dogs, anatomically separate lymph nodes have different echogenic and vascular characteristics; body size (skeletal length, height, and width), along with body weight, were correlated with sizes of presumptively normal MALNs and SCLNs.     

HIGH FIELD STRENGTH (4.7T) MAGNETIC RESONANCE IMAGING OF HYDROCEPHALUS IN AN AFRICAN GREY PARROT (PSITTACUS ERITHACUS)

Hydrocephalus was diagnosed in a juvenile African Grey parrot by high-field strength (4.7-Tesla) magnetic resonance imaging (MRI). Excellent anatomic detail was achieved, and there was severe dilation of all ventricles. Relative obstruction was localized to the level of or beyond the outflow of the fourth ventricle. There have been several reports of hydrocephalus diagnosed postmortem in psittacines (i.e., hook-billed parrots), however, this is the first report of an antemortem diagnosis in a psittacine using high-field strength MRI.