Lactose Synthase Components in Milk: Concentrations of α-Lactalbumin and β1,4-Galactosyltransferase in Milk of Cows from Several Breeds at Various Stages of Lactation

It is believed that milk production is determined by the number and activity of mammary secretory cells. Secretory activity, as assessed by milk volume, depends on secretion of the major osmole in milk, lactose, which is produced by lactose synthase. The amount of either of the two proteins in lactose synthase may regulate milk production. The objective of this study was to determine whether the concentrations in milk of the two components of lactose synthase, α‐lactalbumin (α‐LA) and β1,4‐galactosyltransferase (B4GALT), were related to genetic background, stage of lactation, breed or parity of dairy cows. α‐Lactalbumin and B4GALT concentrations were measured by ELISA and by enzyme assays, respectively, from single milk samples. Two herds with a total of 279 cows were used in the analysis. One herd contained Ayrshire, Brown Swiss, Holstein and Jersey cows; the second herd contained two groups of cows; Holsteins selected for high milk production and Holsteins with 1960s genetics. The α‐LA concentration in milk was greater in Jerseys and Ayrshires than in Holsteins and Brown Swiss. However, no difference in α‐LA concentration was observed in milk from high and low genetic merit cows in the Minnesota herd or among different genetic backgrounds in the Illinois herd. β1,4‐Galactosyltransferase concentrations were similar for all groups that were analyzed. α‐Lactalbumin concentrations were positively correlated with milk protein concentration, milk fat concentration and lactose concentration. β1,4‐Galactosyltransferase concentration in milk exhibited a strong positive correlation with number of days in milk. Although the concentration of B4GALT increased as lactation progressed, the values did not show any correlation with persistency of lactation or late lactation milk production. In conclusion, this survey shows that the two components of lactose synthase are each correlated to protein concentration and individually correlated to the concentration of other milk components and stage of lactation.     

Follicular Dynamics, Ovulation and Conception Rates in Bitches

Real-time ultrasound imaging was used in a clinical study to estimate the number of follicles of different sizes, ovulation and conception rates, and to study follicle dynamics following oestrus-induction of bitches.
Follicles were identified during late anoestrus (between 100 and 60 days prior to the pre-ovulatory LH surge) and there appeared to be a shift in the population from small follicles (1–3 mm in diameter) to large follicles (>4 mm diameter) approximately 2 days prior to the LH surge. Corpora lutea could be reliably identified although the majority were cavitated. High ovulation rates (97–100%) and pregnant rates (86–100%) were detected, and although the conception rate was approximately 70% it varied between 8 and 92%. Within the narrow range of the clinical population studied there were trends relating age to reproduction performance. Oestrus induction with a gonadotrophin regime appeared to result in large numbers of small follicles that did not ovulate, whilst when using cabergoline the number of small and large follicels and the number of copora lutea were similar to those of control cycles.     

Prostatic Perfusion in the Dog Using Contrast-Enhanced Doppler Ultrasound

Ultrasonography has become the imaging modality of choice for evaluation of the prostate gland in the dog. Unfortunately, despite providing excellent images, it may be difficult to differentiate the common canine prostatic diseases with ultrasound because many have a similar ultrasonographic appearance. Real-time contrast-enhanced ultrasound was used to monitor and characterise the normal perfusion pattern and perfusion dynamics of the canine prostate gland when using a micro bubble contrast agent. In all contrast studies, the prostatic artery, entered the prostate gland on the dorso-lateral surface then tunnelled into the prostatic capsule and branched into many small parenchymal arteries which were directed medially towards the urethra to supply the body of the prostate gland. The flow of the contrast medium into the prostatic parenchyma was visible after 15 s. During the wash-in phase, there was an homogenous enhancement of the prostatic parenchyma. During the wash-out phase, an homogenous decrease of the echogenicity was visible in all cases.     

Cytopathological and histopathological diagnosis of canine splenic disorders

Objectives To determine (1) the common types of canine splenic disorders, and the breeds affected, that are diagnosed by cytopathological and histopathological examination in Sydney, Australia and (2) the accuracy of cytopathological examination compared with histopathological examination for the diagnosis of canine splenic disorders. Design 69 cytopathological and 51 histopathological diagnoses of canine splenic disorders presented to the Veterinary Pathology Diagnostic Services, The University of Sydney during 2006 and 2007 were tabulated and analysed; 17 cases examined both cytopathologically and histopathologically during 2001–07 were also analysed. Results The most common cytopathological diagnoses were benign disorders of growth, vascular disturbances and necrosis (29%), followed by no abnormalities detectable (28%), malignant neoplasms (20%), equivocal diagnoses (20%) and inflammatory disorders (3%). The most common breeds were Kelpie crosses and mixed breeds. The most common histopathological diagnoses were benign disorders of growth, vascular disturbances and necrosis (49%), followed by malignant neoplasms (43%) and inflammatory disorders (8%). The most common breeds were German Shepherd Dogs, Boxers and Maltese Terriers. Cytopathological and histopathological diagnoses were in complete agreement in 59% of cases, partial agreement in 29% and disagreement in 12%. Conclusion Benign disorders of growth, vascular disturbances and necrosis were the most commonly diagnosed canine splenic disorders, both cytopathologically and histopathologically. Kelpie crosses presented most frequently for cytopathological examination. German Shepherd Dogs were the most common breed diagnosed histopathologically with haemangiosarcoma. Although cytopathological and histopathological splenic examinations are complementary for diagnosis, this study has shown a high correlation for complete and partial agreement between the two.     

Long‐Term Outcome after Arthroscopic Debridement of Distal Phalanx Extensor Process Fragmentation in 13 Horses

Objective— To report long-term outcome after arthroscopic removal of fragmentation of the extensor process of the distal phalanx in horses.
Study Design— Case series.
Animals— Adult horses (n=13).
Methods— Medical records (2003–2004) of horses that had arthroscopic debridement of fragmentation of the extensor process of the distal phalanx were reviewed. Inclusion criteria included: lameness localized to the foot, fragmentation of the extensor process of the distal phalanx debrided arthroscopically, and a follow-up period of ≥4 years.
Results— Of the 13 horses, lameness was resolved in 11 (85%) initially but distal interphalangeal joint pain recurred in 2 (15%) within 1 year of surgery. Three (23%) other horses were retired because of lameness at other sites during the follow-up period resulting in 46% (6/13) being not lame and in full work after 4 years. Substantial changes were identified at surgery in the contralateral joint of 7 horses, even when fragments were only present unilaterally.
Conclusions— Arthroscopic debridement of fragmentation of the extensor process of the forelimb distal phalanx has a good short-term prognosis for resolution of lameness and return to work but a more guarded prognosis for long-term soundness.
Clinical Relevance— These results allow for more accurate prognostication preoperatively and may support early debridement of fragmentation of the extensor process of the distal phalanx.     

Mating and dispersal behaviour of Scirpophaga incertulas and Chilo suppressalis (Lepidoptera; Pyralidae) in relation to resistance management for rice transformed with Bacillus thuringiensis toxin genes

Information on the mating and dispersal behaviour of the rice stem borers Scirpophaga incertulas and Chilo suppressalis is necessary for the design of resistance management strategies for rice varieties genetically engineered with toxin genes from Bacillus thuringiensis (Bt). We investigated whether S. incertulas and C. suppressalis move from the site of adult eclosion before mating to determine the likelihood that random mating will occur between adults eclosing in fields of Bt rice and refuge fields of non-Bt rice. Observations were made under laboratory, screenhouse and field conditions. Almost all S. incertulas males and females flew out of sight after cuticle expansion and hardening, as did most C. suppressalis. Approximately 15% of C. suppressalis females called and mated within 3?m of the site of eclosion, and approximately 5% of C. suppressalis males mated within 5?m of the site of eclosion. These results suggest that random mating is likely to occur between S. incertulas eclosing in Bt rice fields and nearby refuge fields. Although a small proportion of C. suppressalis did not move far before mating, random mating of moths from Bt and nearby refuge fields is also likely to occur in this species if Bt-resistant moths are rare.     

Assessment of Vascular Perfusion Kinetics Using Contrast‐enhanced Ultrasound for the Diagnosis of Prostatic Disease in Dogs

Vascular perfusion was assessed in 10 dogs without prostatic abnormalities and 26 dogs with prostatic disease using contrast‐enhanced ultrasound. The time to reach peak contrast intensity (TTP) and peak perfusion intensity (PPI) were measured, and histological biopsies were collected from each dog. Biopsies confirmed normal prostate (n = 10), benign prostatic hyperplasia (n = 11), mixed benign pathology (n = 9), prostatitis (n = 1), prostatic malignancy [adenocarcinoma (n = 4); leiomyosarcoma (n = 1)]. In normal dogs, mean PPI was 16.8% ± 5.8 SD, and mean TTP was 33.6 ± 6.4 s. Benign conditions overall were not statistically different from normal dogs (p > 0.05); for benign prostatic hyperplasia, mean PPI was 16.9 ± 3.8%, and mean TTP was 26.2 ± 5.8 s; for mixed benign pathology mean PPI was 14.8 ± 7.8%, and mean TTP was 31.9 ± 9.7 s; for prostatitis, PPI was 14.2%, and TTP was 25.9 s. The malignant conditions overall had perfusion values that differed from the normal dogs (p < 0.05), although evaluation of the data for individual malignancies did not demonstrate a consistent trend; for adenocarcinomas, the PPI was numerically higher with a mean of 23.7 ± 1.9%, and the mean TTP was 26.9 ± 4.8 s, whilst for the dog with leiomyosarcoma values were numerically lower with a PPI of 14.1% and TTP of 41.3 s. Contrast‐enhanced ultrasound appears to offer some ability to document differences in perfusion that may differentiate between malignant and benign lesions, although studies with larger numbers of animals are required to confirm this contention.     

Introduction and elimination of Bovine Viral Diarrhoea Virus in a commercial beef herd: a case study

Routine Bovine Viral Diarrhoea Virus (BVDV) monitoring of a commercial beef herd in southern New South Wales over a 10-year period provided an opportunity to assess the impact of the introduction of BVDV on that herd. BVDV antibody testing provided strong evidence that the herd was initially free of BVDV (2009–2011). Testing from 2012 suggested BVDV had been introduced into the herd and this was confirmed in 2015 with the identification of persistently infected (PI) animals. Having become established in the herd, the owners then set out to eliminate BVDV from the herd. Antigen testing aimed at identifying PI animals revealed BVDV was already absent from the herd. Subsequent antibody testing confirmed that the herd was now free from BVDV. Despite the incursion of BVDV in this herd, there was little measurable impact on reproductive performance (pregnancy rates), although suspected increased calf losses from birth to calf marking were reported. This is the first time such self-clearance has been documented as part of a longitudinal study under Australian conditions.     

THE EFFECT OF NITROGEN APPLICATION AND AUTUMN MANAGEMENT ON AUTUMN GROWTH, WINTER 'BURN' AND SPRING GROWTH OF LOLIUM PERENNE L. AT ABERYSTWYTH, EDINBURGH AND CAMBRIDGE.

A trial was carried out to find management practices which would permit the best discrimination for winter performance of erennial ryegrass cultivars. Due to the mild winter experienced only a few of the plants were killed outright. The cultivars were therefore assessed for percentage of green herbage and for spring growth. There were four sites: an upland and lowland site at Aberystwyth and one site each at Edinburgh and Cambridge. At all sites two N rates (totals of 125 or 550 kg/ha in the first year after sowing) and 5 autumn cutting treatments were used to give differences in the amounts of herbage remaining at the onset of winter. The last dates of defoliation in the autumn were: C₁ end of August; C₂ end of September; C₃ end of October; C₄ mid-November; C₅ was cut on all these dates. Four cultivars (Grasslands Ruanui, S321, Premo and Argo) which differed in their autumn growth potential, frost susceptibility and degree of winter dormancy were grown. The autumn yield of S321 was, in general, higher than that of the other cultivars but there were interactions with N, management and location. The data on percentage of herbage remaining green in February illustrated differences due to the siting of the trial. In the conditions prevailing the two Aberystwyth sites facilitated greater discrimination between cultivars than those at Edinburgh and Cambridge. In three of the four sites the management which produced most winter ‘burn’(including both that due to natural senescence and that due to winter damage) involved accumulation of herbage in the autumn but there were considerable sites × managements interactions. For example at Cambridge management produced no significant effect whereas at the Aberystwyth lowland site frequent defoliation in the autumn had more effect than allowing herbage to remain uncut after the end of August. High N significantly decreased the percentage of green herbage only at the two Aberystwyth sites. Over five-fold differences in spring yield were obtained, the heaviest yields being recorded at Edinburgh and Cambridge. However, there were large interactions between environments and cultivars; for example the higher N rate reduced spring yield at Aberystwyth but increased spring yield at Edinburgh and Cambridge. Premo and S321 had similar yields in spring at the Aberystwyth lowland and Cambridge sites but Premo was higher yielding than S321 at the Aberystwyth upland site and at Edinburgh. The large environmental effects and their interactions with cultivars illustrate the difficulties of cultivar assessment and the dangers inherent in national recommendations for grass cultivars.