Effect of two thermal regimes on the muscle growth dynamics of sea bass larvae,Dicentrarchus labrax L

Muscle growth was studied in larvae of sea bass, Dicentrarchus labrax L., reared at two temperatures: real ambient temperature ( congruent with 15 degrees C during vitelline phase and increased gradually) and 19 degrees C from fertilization until the end of larval development. Muscle cellularity, body length and body weight were measured. Early temperature influenced larval development and so, pre-larval phase finished earlier at 19 degrees C than at ambient temperature (4 and 6 days, respectively). Temperature also affected muscle growth such that at hatching and at mouth opening hypertrophy of muscle fibres was greater at 19 degrees C (P < 0.05), whereas hyperplasia was similar in both groups. After 25 days, the cross-sectional area of the white muscle was greater at 19 degrees C (P < 0.05), which was mainly associated with a higher proliferation of new white muscle fibres. At this stage the body length was also higher at 19 degrees C. Metamorphosis finished earlier in fish reared at 19 degrees C (52 days) than at natural temperature (82 days). At this developmental stage body length and cross-sectional area of the myotome were similar in both groups. However, muscle cellularity differed between groups. Thus, hypertrophy of muscle fibres was higher in fish reared at ambient temperature (P < 0.05), whereas proliferation of new muscle fibres was higher at 19 degrees C (P > 0.05).     

The seroprevalence of canine respiratory coronavirus and canine influenza virus in dogs in New Zealand

Abstract

AIM: To determine whether canine respiratory coronavirus (CRCoV) and canine influenza virus (CIV) are present in dogs in New Zealand.

METHODS: Serum samples from 251 dogs of varying age, breed and clinical histories were tested for the presence of antibodies to CRCoV and CIV, using indirect fluorescent antibody (IFA) analysis. The population sampled represented a wide geographic area but principally encompassed the central and lower North Island of New Zealand.

RESULTS: Seventy-three of the 251 samples (29%) were seropositive for CRCoV. Dogs <2 years old were less likely to be seropositive for CRCoV than older dogs. None was seropositive for CIV.

CONCLUSIONS: This study revealed the presence of antibodies to CRCoV in dogs in New Zealand. Young dogs are less likely to be seropositive than older dogs, probably due to increased opportunity for exposure to CRCoV over time. Serum antibodies to CIV were not detected in any of the dogs sampled, suggesting that this virus is unlikely to be present in dogs in New Zealand.

CLINICAL RELEVENCE: Canine respiratory coronavirus is present in New Zealand. Although the role of this virus in canine infectious tracheobronchitis has not been fully elucidated, evidence suggests that it may have a causal role in this disease. Veterinarians should consider CRCoV as a differential diagnosis in cases of respiratory disease in dogs in New Zealand. While CIV appears not to be currently present in New Zealand, veterinarians should consider infection with this virus as a differential diagnosis in dogs presenting with respiratory signs.     

Effect of Overnight Staining on the Quality of Flow Cytometric Sorted Stallion Sperm: Comparison with Tradtitional Protocols

Flow cytometry is considered the only reliable method for the separation of X and Y chromosome bearing spermatozoa in equines. The MoFlo SX DP sorter is highly efficient, allowing the production of foals of the desired sex. However, to achieve acceptable pregnancy rates the currently used protocol requires working with fresh semen obtained close to, or at, the sorting facility. An alternative protocol was tested during two consecutive breeding seasons. Fresh stallion semen was cooled for 20 h, during which staining with Hoechst 33342 took place. On the following day, this sample was flow sorted and compared with spermatozoa from the same ejaculate that had been sexed on the previous day. All sperm parameters evaluated remained unchanged when fresh sorted and refrigerated sorted semen were compared. Pre‐sorting storage at 5°C did not alter sperm velocities nor kinetics, viability or membrane permeability, production of reactive oxygen species, mitochondrial membrane potential or DNA fragmentation index of the sorted sample. The findings open for the possibility of using semen from stallions housed far from the sorting facilities. Processed and stained sperm could be shipped refrigerated on the previous day, sorted and inseminated on the next day.     

Standing Laparoscopic Peritoneal Flap Hernioplasty of the Vaginal Rings does not Modify the Sperm Production and Motility Characteristics in Intact Male Horses

Laparoscopic hernioplasty techniques have been developed in the recent years to avoid the recurrence of inguinal hernias and to spare the testicles for breeding purposes in stallions. However, there have been no previous comprehensive and systematic studies of the reproductive outcomes and prognoses for stallions after inguinal hernioplasty. Therefore, the objective of this study was to assess the possible effects of one of these techniques (standing laparoscopic peritoneal flap hernioplasty) on the sperm production and motility characteristics of six healthy stallions that received this procedure based on 1‐year follow‐ups. There were no significant differences in the measured sperm variables (assessments based on the DSO, MOT, PMOT, VSL, VCL and VAP) during 1‐year follow‐ups.     

Quantitative analysis of the resorption and osteoconduction of a macroporous calcium phosphate bone cement for the repair of a critical size defect in the femoral condyle

Clinical orthopaedic use of calcium phosphate cement has been limited due to its slow resorption rate, but a new macroporous alpha-tricalcium phosphate (alpha-TCP) bone cement has been designed to accelerate resorption and to increase bone ingrowth. To assess its clinical potential, the in vivo behaviour of alpha-TCP was evaluated in a critical-size defect drilled in the femoral condyles of 36 adult female New Zealand rabbits. Macroporous or standard cement was injected immediately after preparation of the defect. The foaming agent was albumen, which gave up to 75% porosity. The rabbits were divided into three groups and the lesions examined histopathologically at 1, 4 and 12 weeks. No inflammatory reaction was detected at any time period following implantation with either macroporous or standard cement. At 12 weeks, the area of the implanted macroporous cement was approximately 35% of the initial lesion size. Bone growth and revascularisation was observed inside the central pores of the macroporous cement, not only at the margins, as was found with standard calcium phosphate cement. The results indicated that both cements were osteoconductive, biocompatible and biodegradable but their different physicochemical and biological properties had a marked influence on their post-implant behaviour.     

Uptake Studies on a Fluorescein-Labelled Seed Oil Adjuvant in Abutilon theophrasti, Sinapis arvensis and Beta vulgaris

Though adjuvants are abundant in almost every pesticide solution, their mode of action is still not completely clear. Studies on their way through the cuticle are quite difficult due to a lack of radiolabelled surfactants. In this study we want to present the results of an experiment conducted to evaluate the mode of action of an ethoxylated soybean oil (ESBO) adjuvant. To evaluate the route of ESBO through the cuticle it was labelled with fluorescein and applied to one leaf of different test species (Abutilon theophrasti, Sinapis arvensis and Beta vulgaris). Treated leaves were harvested and rinsed with either deionised water, methanol/water or chloroform. The fluorescein content of washed leaves and the solution in which they were washed were analysed with High-Performance Liquid Chromatography (HPLC) coupled with an UV detector. Results lead to the assumption that ESBO passed through the cuticle. If this holds true, ESBO was able to reach the underlying cell tissue where it might have been metabolised or even translocated to other plant parts. Though a lot of research has to be conducted on the mechanism and mode of action of adjuvants, this study gives an approach to investigate the behavior of foliar applied adjuvants.     

Resistance to Wheat streak mosaic virus– a survey of resources and development of molecular markers

Wheat streak mosaic virus (WSMV) has been newly documented in Australia. The vulnerability of contemporary Australian elite wheat germplasm prompted a survey for effective resistance against an Australian isolate, WSMV‐ACT. This study confirms the effectiveness of previously reported sources of resistance and shows that new sources of resistance also confer protection. The resistance derived from Thinopyrum intermedium (Wsm1) as a 4D translocation and a new 4A translocation, and two bread wheat resistances, Wsm2 and the new source c2652, were effective against WSMV‐ACT in glasshouse experiments. Wsm1 was effective at lower temperatures but ineffective above 20°C, a temperature sensitivity shared with many of the derivatives of Wsm2 except for one new selection which was effective at 26°C. True wheats c2652 and Wsm2 selection CA745, and amphiploids Zhong1, Zhong2, Zhong4, Zhong5, TAF46, Summer1, Ot38 and OK7211542 were uniformly resistant at 20, 25 and 28°C. New sources of resistance were identified in a Th. scirpeum‐wheat amphiploid, B84‐994, and in chromosome addition lines Z2, Z6 and TAi27, derived from wheat‐Th. intermedium partial amphiploids. Several new, tightly linked SSR, RAPD and EST‐ILP PCR markers were developed for tracking the various Th. intermedium translocations associated with Wsm1, including the smaller translocations on wheat chromosome 4AS and 4DS. Three markers for the 4A‐Wsm1 translocation were validated on a segregating breeding population.     

Detection of antibodies to Brucella ovis in sheep milk using B. ovis and B. canis antigen

The diagnostic techniques most widely used for detecting brucellosis caused by Brucella ovis are serological tests such as complement fixation (CFT), agar gel immunodiffusion (AGID), and ELISAs. However, to our knowledge, milk tests, with the advantage that samples may be taken in a non invasive manner, have not been investigated as diagnostic tools. We studied 144 samples of milk and sera from lactating ewes, comparing bacteriological studies, serological and milk tests using Brucella canis and B. ovis antigens. A group of 75 ewes in an uninfected flock were serologically negative to rapid slide agglutination test (RSAT), indirect ELISA (IELISA)-B. canis, AGID and IELISA-B. ovis. The milk of these ewes had an IELISA-B. canis mean (%P) value of 16.18 (S.D. 5.63), while the IELISA-B. ovis had a mean (%P) value of 12.52 (S.D. 4.94). A cut-off value of (%P) 27.44 (+2 S.D.) or (%P) 33 (+3 S.D.) was determined by milk-ELISA-B. canis and (%P) 22.4 (+2 S.D.) and (%P) 27.34 (+3 S.D.) by milk-IELISA-B. ovis. These cut-off values were adjusted by receiver-operator characteristics (ROC) analysis using 23 positive samples from infected ewes, which indicated a milk-IELISA-B. canis cut-off value of (%P) 33 and milk-IELISA-B. ovis of (%P) 26 with 100% sensitivity and specificity. Based on our results, we propose that, following a study of a larger number of samples, the milk-IELISA-B. canis could be considered a suitable test for the diagnosis of B. ovis brucellosis in lactating ewes.     

Prevalence and spatial distribution of cattle herds infected with Theileria orientalis in New Zealand between 2012 and 2013

AIM: To describe the prevalence and spatial distribution of cattle herds infected with Ikeda and non-Ikeda types of Theileria orientalis in New Zealand between November 2012 and June 2013.

METHODS: Pooled serum samples collected historically between November 2012 and June 2013 were obtained from cattle herds throughout New Zealand. Each pooled sample consisted of approximately 20 individual cattle samples from that herd, and was provided with details of the spatial location of the herd (n=722). DNA from all samples was tested using two quantitative PCR assays for the detection of T. orientalis (all types) and the Ikeda type. The proportion of herds that were positive for T. orientalis and Ikeda type, or that were positive for T. orientalis but negative for Ikeda type (non-Ikeda positive) was determined for different regions of New Zealand.

RESULTS: The highest prevalence of herds infected with Ikeda type was detected in the Northland (33/35; 94%) and Auckland and the Waikato (63/191; 33%) regions. Only 2/204 (1%) herds were positive for the Ikeda type in the South Island. A high percentage of herds that were positive for non-Ikeda types was detected in the Gisborne and Hawkes Bay (23 (95%CI=13–37)%), Auckland and Waikato (22 (95%CI=16–29)%) and Bay of Plenty (24 (95%CI=10–44)%) regions.

CONCLUSIONS AND CLINICAL RELEVANCE: The high prevalence of Ikeda type detected in cattle herds in the Northland, Auckland and Waikato regions represents a risk to naive cattle being introduced into these regions. There is also the potential for resident cattle herds in the Gisborne and Hawkes Bay, Auckland, Waikato and Bay of Plenty regions to experience increased infection with the Ikeda type.

The overall impact experienced by regions will depend on other factors such as the number of herds present and the predominant type of farming, as well as the interplay between tick ecology, cattle immunity and movement patterns of cattle.