COMPUTED TOMOGRAPHIC EVALUATION OF DINOSAUR EGG SHELL INTEGRITY

The purpose of this study was to determine whether computed tomography (CT) could be used to identify hatching holes in partially embedded dinosaur eggs. One Faveololithus and two Dendroolithus eggs were examined using a fourth generation CT scanner. The eggs were partially embedded in a fossilized sediment matrix, with the exposed portion of the shell appearing intact. In CT images of all three eggs, the shells appeared hyperdense relative to the matrix. Hatching holes were visible as large gaps in the embedded portion of the shell, with inwardly displaced shell fragments. It was concluded that CT is an effective technique for nondestructively assessing dinosaur egg shell integrity.     

CANINE HIP DYSPLASIA EVALUATION

The ventrodorsal radiograph of the pelvis and femurs with the hind limbs extended, femurs parallel to each other, patellae superimposed over the distal femurs, and the pelvis symmetrical has become the standard method by which to evaluate animals for hip dysplasia. The following illustrated guide details the methods of positioning recommended by the American Veterinary Medical Association¹ and used by the Orthopedic Foundation for Animals (OFA). Additionally, some commonly encountered positioning errors and methods of labeling radiographs are shown. The authors stress positioning requirements and aids they feel are necessary to produce an adequately positioned radiograph.     

Evaluation of the performance of different cleaning treatments in reducing microbial contamination of poultry transport crates

1. The present systems for cleaning the plastic crates (drawers) used to transport live poultry to the processing plant are known to be inadequate for removing microbial contamination. 2. To investigate possible improvements, a mobile experimental rig was constructed and operated in the lairage of a poultry processing plant. The cleaning rig could simulate the conditions of commercial cleaning systems and utilise freshly emptied crates from the processing plant. 3. The aim of the study was to improve cleaning by enhancing the removal of adherent organic material on the crates and by reducing microbial contamination by at least 4 log(10) units. 4. Trials showed that the most effective treatments against Campylobacter were either (a) the combination of soaking at 55 degrees C, brushing for 90 s, washing for 15 s at 60 degrees C, followed by the application of disinfectant (Virkon S in this study) or (b) the use of ultrasound (4 kW) at 65 degrees C for 3 to 6 min, with or without mechanical brushing of crates. 5. Both of these treatments also achieved a 4 log(10) reduction or more in the counts of Enterobacteriaceae but were less effective in reducing aerobic plate counts. 6. It was noted that there was little correlation between the visual assessment of crate cleanliness and microbiological counts. 7. It was concluded that the demonstrated enhanced cleaning could contribute significantly to overall hygiene control in poultry meat production.     

Effect of ultrasonic treatment during cleaning on the microbiological condition of poultry transport crates

1. Small sections cut from commercial crates used to transport live poultry to the processing plant were artificially contaminated with effluent taken from a commercial crate-cleaning system. 2. Laboratory trials, involving the immersion of these sections in an ultrasonic water bath (4 kW energy) showed that aerobic plate counts (APC) and counts of Enterobacteriaceae were progressively reduced as the immersion time was increased from 0 to 120 s and the water temperature raised from 35 to 58 degrees C. 3. In subsequent trials at a processing plant, using commercially cleaned crates, there was relatively little effect of ultrasound (or pressure washing) on the biofilm present. However, ultrasonic treatment in combination with an immersion temperature of 60 degrees C reduced counts of Enterobacteriaceae to below the detection limit (log(10) 2.3 cfu) within 1 to 3 min, while APC were reduced by >2 log(10) units after 3 min. 4. It was concluded that ultrasonic treatment has a possible role in the crate-cleaning process, when used in conjunction with higher immersion temperatures. In this way, it could contribute significantly to hygiene control.     

Sexual Performance of Rams Sequentially Exposed to Short-tailed and Fat-tailed Ewes

The objective of the study was to compare sexual performance of pure and crossbred rams, and to evaluate whether prior exposure of rams to short-tailed females would enhance their mating ability when later exposed to fat-tailed females. Twenty-two virgin, yearling Awassi (A; n = 7), F₁ Charollais × Awassi (CA; n = 7) and F₁ Romanov × Awassi (RA; n = 8) rams were subjected to sexual performance tests on six 20-min occasions. Each ram was individually exposed to two short-tailed oestrous ewes for three 20-min occasions on three consecutive days. Following 1 day of rest, the same 3-day procedure was repeated for each ram with fat-tailed ewes. Leg kicking bout frequency increased in CA and RA rams and decreased in A rams, when they were exposed to fat-tailed compared with short-tailed ewes. No differences in anogenital sniffing were observed among rams exposed to either short-tailed or fat-tailed ewes. However, greater (p < 0.001) anogenital sniffing bouts were recorded, when rams were exposed to short-tailed females. Upon exposure to fat-tailed ewes, CA and RA rams experienced a marked increase in mounting frequency compared with a slight increase in mounting of A rams (p < 0.001). The ability of Awassi rams to raise the fat tail of Awassi ewes was greater (p < 0.001) than CA and RA rams. Mating was improved in A while declining in CA and RA, when they were exposed to fat-tailed compared with short-tailed ewes (p < 0.001). Based on the results of the current study, it seems that all yearling rams were capable of mating with short-tailed ewes, whereas only Awassi rams managed to mate with fat-tailed ewes. It appears that brief exposures of yearling crossbred rams to short-tailed ewes do not improve their mating ability when later exposed to fat-tailed ewes.     

An investigation of shedding and super‐shedding of Shiga toxigenic Escherichia coli O157 and E. coli O26 in cattle presented for slaughter in the Republic of Ireland

Shiga toxigenic Escherichia coli (STEC) are an important group of pathogens and can be transmitted to humans from direct or indirect contact with cattle faeces. This study investigated the shedding of E. coli O157 and O26 in cattle at the time of slaughter and factors associated with super‐shedding (SS) animals. Rectoanal mucosal swab (RAMS) samples were collected from cattle (n = 1,317) at three large Irish commercial beef abattoirs over an 18 month period, and metadata were collected at the time of sampling regarding farm of origin, animal age, breed and gender. RAMS swabs were examined for the presence and numbers of E. coli O157 and O26 using a previously developed quantitative real‐time PCR protocol. Samples positive by PCR were culturally examined and isolates analysed for the presence of stx subtypes, eae and phylogroup. Any samples with counts >10⁴ CFU/swab of STEC O157 or O26 were deemed to be super‐shedders. Overall, 4.18% (55/1,317) of RAMS samples were positive for STEC O157, and 2.13% (28/1,317) were classified as STEC O157 SS. For STEC O26, 0.76% (10/1,317) of cattle were positive for STEC O26, and 0.23% (3/1,317) were classified as super‐shedders. Fewer STEC shedders and SS were noted among older animals (>37 months). There was a seasonal trend observed for STEC O157, with the highest prevalence of shedding and SS events in the autumn (August to October). The majority of E. coli O157 (50/55) isolates had stx2 and were eae positive, with no significant difference between SS and low shedders (LS). Interestingly, all STEC O26 (n = 10) were eae negative and had varied stx profiles. This study demonstrates that, while the overall shedding rates are relatively low in cattle at slaughter, among positive animals there is a high level of SS, which may pose a higher risk of cross‐contamination during slaughter.     

Variability in reproductive fitness and virulence of four Radopholus similis nematode populations associated with plantains and banana (Musa spp.) in Uganda

Burrowing nematodes (Radopholus similis) are among the most serious nematode pests affecting banana and plantain (Musa spp.). In Uganda, bananas, which are known locally as “matooke”, are the main staple. Radopholus similis populations collected in four banana-growing locations (Namulonge, Mbarara, Ikulwe and Mukono) were cultured monoxenically on carrot discs, and we compared the variability in reproductive fitness and virulence (as a function of time and inoculum level) of different populations of R. similis from Uganda. Their level of pathogenicity was determined by assessing the nematode reproductive ratio; that is, final population divided by the initial population. These in vitro experiments showed that the R. similis population from Mbarara had the highest reproduction ratio, while the population from Mukono had the lowest reproduction ratio. This assessment along with pathogenicity experiments on host Musa plants provides a means for defining pathogenicity groups among R. similis populations.     

Contribution to the Development of the Stapedius Muscle Structure in Human Fetuses

The purpose of this report is to contribute to the knowledge of the morphogenesis of the human stapedius muscle. We have studied the stapedius structure development in 17 temporal bones from human fetuses. Chronological ages were from 48 days (21 mm) to 29 weeks (270 mm). Samples were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in sequence of 7 microns and were stained with haematoxylin & eosin and Martins' trichrome. Four maturation stages were observed in the development of the stapedius muscle structure. First, the formation of the 'primordium muscularis' in the mesenchyme of the tympanic cavity (promyoblasts) was observed in a 36-mm embryo. Second, its differentiation into myoblasts, and its next cellular fusion to form muscle tubes, was seen in a 99-mm foetus. In the third stage, myofibrogenesis phenomena were developed, to synthesize, the myotube myoblasts, myofilaments, phenomena we observed that took place during the 14th to 17th weeks of development. The last stage was characterized by the presence of striated muscle fibres, at first intermingled with myotubes (18th to 26th weeks), until in the 29th week fetuses (270 mm) the skeletal muscle fibre was completely differentiated. We conclude that in the 29th week of development (270 mm) the stapedius muscle structure is completely differentiated, although the functional development is not complete until birth.     

Real-time ultrasonic scanning in the diagnosis of pregnancy and the estimation of gestational age in cattle

Diagnoses of pregnancy were made on 110 Hereford cross Friesian and 69 blue grey (white shorthorn cross Galloway) cows between 92 and 202 days after last service using a real-time ultrasonic scanning instrument with a 3.5 MHz rectal transducer. Of the 174 cows which subsequently calved, one was wrongly diagnosed as non-pregnant. Of the five cows which did not subsequently calve two were diagnosed as pregnant and may in fact have been pregnant at the time of scanning. The overall level of accuracy of pregnancy diagnosis was 98.3 per cent. In further trials with 16 Hereford cross Friesian and 16 blue grey cows scanned at regular intervals between 20 and 140 days of gestation, pregnancy was diagnosed with confidence from 30 days, and relationships were established whereby gestational age could be estimated from measurements of certain uterine and fetal dimensions. Crown-rump length provided the most precise estimate of gestational age (residual sd +/- 4.5 days) and uterine diameter the least (+/- 12.6 days) with head length and the diameters of trunk, head and nose being intermediate (+/- 6.9 to 8.7 days).     

Screening Musa germplasm for resistance to burrowing nematode populations from Uganda

Nematode pathogenicity experiments on Musa host plants were carried out in pot trials. Both the final nematode population densities and percentages root necrosis on different host plants were higher for the Radopholus similis population from Mbarara than for the populations from Namulonge, Ikulwe and Mukono (Uganda). The R. similis population from Mbarara managed to break the resistance of the diploid banana Pisang Jari Buaya, a known worldwide source of resistance to R. similis. The diploid banana hybrid TMB2× 9128-3 and the triploid dessert banana Yangambi km5 showed resistance against the four R. similis populations. These results indicate that differences in pathogenicity among different R. similis populations exist and should be taken into consideration for plantain and banana germplasm enhancement.