Buffalo (Bubalus bubali) Late Embryo and Foetus Development: A Morphological Analysis

Many researches describe the embryonic developmental features in domestic animals; however, in farm animals, they are scarce. Most farm animal studies are related to assisted reproduction and embryos transfer techniques. But, morphological features and size measure to estimate the age gestation are rarely reported in literature. Thus, in this study, we described the developmental changes in the bubaline (Bubalus bubali) concepts from 21 to 60 days of gestation. Our results revealed that buffalo embryos similar morphological characteristics similar to other mammalian species. Also, similarities between bovine and bubaline persist; except on foetal stages when buffalos have a faster development than bovine. Therefore, buffalo's gestation period exhibits some varieties and accurate embryo age is more difficult. Yet, when we use a combination of the crown–rump, macroscopic analysis and alizarin red, it is possible to describe better the whole embryogenesis stages of the buffalo and which can contribute for future reproduction researches and applications in veterinary practice.     

The lack of effect of isoflavones on high-density lipoprotein cholesterol concentrations in adolescent boys: a 6-week randomised trial

BACKGROUND: A substantial fall in high-density lipoprotein cholesterol (HDL-C) during puberty in boys, but not girls, has been reported in Western populations. The fall in boys is believed to be due to hormonal changes - androgens have been shown to be associated with lower HDL-C, whereas oestrogens are associated with higher HDL-C. The fall in HDL-C during puberty was not observed, however, in a study of Moslem boys in Israel, nor in a group of Japanese boys. A diet high in phyto-oestrogens may account for the lack of a fall in HDL-C in these populations. OBJECTIVE: To examine the effect of dietary supplementation with phyto-oestrogens on the HDL-C concentration of adolescent boys from a Western population. We hypothesised that dietary supplementation of 50 mg of the isoflavones daidzein and genistein would produce a 12% higher HDL-C concentration than in controls at the end of a 6-week intervention period. DESIGN: A randomised controlled trial. SETTING: Hellyer College in Burnie (Tasmania, Australia). SUBJECTS: Adolescent boys (aged 16-18 years) were recruited through a letter sent to parents. A total of 132 eligible participants enrolled and five subjects withdrew from the trial. RESULTS: No significant increase in HDL-C was observed in the treatment group (-0.02 mmol l-1, standard error (SE)=0.03, P = 0.53) or the placebo group (0.05 mmol l-1, SE = 0.03, P = 0.11). CONCLUSIONS: Factors other than isolated dietary isoflavones may be responsible for the lack of fall in HDL-C during puberty in Japanese and Moslem boys.     

An antigenic comparison of three strains of infectious pancreatic necrosis virus of salmonid fishes

Three strains of infectious pancreatic necrosis (IPN) virus of salmonid fishes were found to be closely related antigenically when compared by cross plaque neutralization. They differed significantly, however, in stability during freezing and storage at ?60°C. The American reference strain VR-299, which was the most stable, required consistently less antibody for a given degree of neutralization than the other two, regardless of whether the antiserum was specific for that strain or for either of the others. The CTT strain was the most unstable of the three, and required the greatest amount of antibody for a comparable degree of neutralization. The COHO strain was intermediate both in stability and in antibody requirement.The results seem to indicate that the CTT virus required the most antibody because it contained the largest amount of non-infectious virus (to chinook salmon embryo cells), which would still bind antibody and render it unavailable for neutralizing activity. The VR-299 virus contained the least amount of non-infectious virus, and consequently required the smallest amount of antibody.It is suggested that the relative stability of viral strains and possible variation in the content of non-infectious virus should be taken into account or controlled when quantitative neutralization data are used to differentiate or identify viral serotypes.     

Is a purpose of REM sleep atonia to help regenerate intervertebral disc volumetric loss?

The nature of atonia in sleep continues to be enigmatic. This article discusses a new hypothesis for complete core muscle relaxation in REM sleep, suggesting a bottom-up recuperative perspective. That is, does the atonia in REM sleep provide a utility to help restore the mechanobiology and respective diurnal intervertebral disc hydraulic loss? By combining the effects of gravity with current compressive concepts in spinal stability, this article looks at vertebral approximation as a deleterious experience with an intrinsic biological need to keep vertebrae separated. Methods using polysomnography and recumbent MRI are discussed.     

Evidence that moxidectin is a greater risk factor than ivermectin in the development of resistance to macrocyclic lactones by Ostertagia spp in sheep in south eastern Australia

AIM: To determine associations between resistance of Ostertagia (= Teladorsagia) spp to macrocyclic lactone (ML) anthelmintics and history of use of anthelmintics, by type, on commercial sheep farms in temperate regions of southern South Australia and Victoria, Australia.

METHODS: Faecal egg count reduction tests (FECRTs) were conducted during a 2.5-year period (from August 2001 to January 2004) and records of the type of anthelmintic used in the 5 years preceding the FECRTs were collected from commercial sheep farms (n=103) in southern South Australia and Victoria, and data analysed retrospectively. ML resistance was defined as <95% reduction of Ostertagia spp 10–14 days after treatment with ivermectin (IVM), orally, at half the manufacturer's recommended dose rate. Use of anthelmintics in the preceding 5 and 10 years on each property was classified according to the nett number of years each of the following classes of drug had been used: IVM oral liquid (IVO), IVM controlled-release capsules (CRCs), abamectin (ABA), moxidectin (MOX) or a non-ML an- thelmintic. The prevalence of ML resistance, by property, was analysed for associations with prior use of anthelmintics.

RESULTS: Resistance by Ostertagia spp to ML anthelmintics was evident on 51/103 (49.5%) properties. The prevalence of resistance was lowest (23%) on properties on which MOX had not been used, and was significantly higher (64–77%) on properties on which MOX had been used for ≥2 of the preceding 5 years (p<0.001). In contrast, the prevalence of resistance was highest (70–74%) on the properties on which IVM, or IVM and/ or ABA, had not been used in the previous 5 years (on which the use of MOX was predominant), and was markedly lower (20– 42%) on properties that had used IVM or IVM and/or ABA for at least one of the preceding 5 years. Prevalence of resistance was higher for properties on which the only ML anthelmintic used was MOX (19/29=66%) than for those on which the only ML used was IVO (2/19=11%; p<0.001). Properties on which the only ML used was MOX were 2.72 times more likely to have resistance than properties on which the only ML used was IVO (95% confidence interval (CI) = 1.01–5.08).

CONCLUSION: Use of MOX for ≥2 of the preceding 5 years was associated with a higher prevalence of resistance to ML by Ostertagia spp on sheep farms in south eastern Australia than the use of IVO.     

Influence of ocean and freshwater conditions on Columbia River sockeye salmon Oncorhynchus nerka adult return rates

In recent years, returns of adult sockeye salmon Oncorhynchus nerka to the Columbia River Basin have reached numbers not observed since the 1950s. To understand factors related to these increased returns, we first looked for changes in freshwater production and survival of juvenile migrants. We then evaluated productivity changes by estimating smolt‐to‐adult return rates (SAR) for juvenile migration years 1985–2010. We found SAR varied between 0.2 and 23.5%, with the highest values coinciding with recent large adult returns. However, the largest adult return, in 2012, resulted not from increased survival, but from increased smolt production. We evaluated 19 different variables that could influence SARs, representing different facets of freshwater and ocean conditions. We used model selection criteria based on small‐sample corrected AIC to evaluate the relative performance of all two‐ and three‐variable models. The model with April upwelling, Pacific Northwest Index (PNI) in the migration year, and PNI in the year before migration had 10 times the AIC_c weight as the second‐best‐supported model, and R² = 0.82. The variables of April ocean upwelling and PNI in the migration year had high weights of 0.996 and 0.927, respectively, indicating they were by far the best of the candidate variables to explain variations in SAR. While our analyses were primarily correlative and limited by the type and amount of data currently available, changes in ocean conditions in the northern California Current system, as captured by April upwelling and PNI, appeared to play a large role in the variability of SAR.