Passing times of two types of feeds in wels (Silurus glanis) at three different temperatures

Passing times of two different types of feeds were determined in cases of wels (Silurus glanis) by measuring the body weight at three different temperatures. Fingerlings, 38.03 ± 8.04 g, were fed by an artificial dry feed (commercial catfish feed) or forage fish. The treatments were carried out (11 fish/aquaria) in 3 replicates. Fish were individually tagged by pit tags. Temperatures applied were the following: 15, 20 and 24 °C. The appetite of fish highly depended on temperature. At 15 °C, only 42.4 % of the experimental fish accepted the granulated feed, while this ratio was 90.9 % in the forage fish fed group. At higher temperatures, 100 % of the experimental fish accepted feed in both feeding groups. The daily mean value of consumed feed at 15 °C was 3.20 % of body weight in the case of forage fish and 1.36 % in the case of dry feed. At 24 °C, this ratio was 10.68 % of body weight in cases of forage fish and 4.46 % in cases of artificial feed. At low temperature (15 °C), the quantity of consumed feed met the measurement’s error threshold, which made the determination of passing time uncertain. At 20 °C, the evacuation started 20 h after feeding and lasted for 18 h, while at 24 °C, it started 11 h after feeding and lasted for another 16 h.     

Methane flux and production from sediments of a mangrove wetland on Hainan Island, China

Methane fluxes from sediments in different zones of a Bruguiera sexangula mangrove wetland were determined by closed static chamber techniques during one whole year period, at Changning River estuary, northeast of Hainan Island, China. Methane productions were also measured by anaerobically incubating sediment samples. Impacts of salinity, sulphate and temperature on methane production rates were studied in vitro. Great differences of annual methane fluxes were observed in three zones, with the values of 0.39, 0.20 and 0.12gm–2 in the outer zone, middle zone and inner zone, respectively, in part due to the differences of sediment water contents and crab bioturbation. The highest fluxes in each zone occurred in autumn and the lowest in winter. Large diurnal fluctuations in fluxes were caused by the changes of tidal conditions rather than the changes of air or sediment temperatures. The temporal and spatial patterns of methane production differed somewhat from those of methane flux. There was great seasonality for methane production and the highest productions were found in autumn and the lowest in spring. Different horizontal and vertical patterns occurred in different seasons and different zones, suggesting the complexity of factors controlling methane production. The in vitro control experiments indicated that salinity and sulphate had negative effects whereas temperature (20–50°C) had positive effects on methane production rates. However, there were different sensitivities for the different levels of the three factors.     

Estrus response and fertility after a single cloprostenol treatment in dairy cows with various ovarian structures

The objective of this study was to determine rates of estrus and conception in lactating multiparous Holstein cows given 500 μg of cloprostenol intramuscularly after detection of the following ≥ 60 d after parturition: a solid corpus luteum (CL), a CL with a nonechodense cavity ≤ 20 mm in diameter (CLcav), a luteal cyst (cavity > 20 mm in diameter and a luteinized wall > 3 mm in diameter), or a follicular cyst (cavity > 20 mm and a luteinized wall ≤ 3 mm in diameter). The estrus rates were 335/419 (80.0%), 183/223 (82.1%), 170/182 (93.4%), and 44/87 (50.6%), respectively (P < 0.0001), and the conception rates 30 to 36 d after insemination among the estrous cows with an apparently normal mucus discharge were 130/285 (45.6%), 44/141 (31.2%), 39/79 (49.4%), and 19/30 (63.3%), respectively (P < 0.002). Compared with a solid CL, a CLcav did not affect the estrus rate but significantly reduced the conception rate (P < 0.05), and the estrus rates were significantly higher and lower in cows with a luteal or follicular cyst, respectively (P < 0.05).     

Optimization of cryoprotectant treatment for the vitrification of immature cumulus-enclosed porcine oocytes: comparison of sugars,combinations of permeating cryoprotectants and equilibration regimens

Our aim was to optimize the cryoprotectant treatment for the preservation of immature porcine cumulus-oocyte complexes (COCs) by solid surface vitrification. In each experiment, the vitrification solution consisted of 50 mg/ml polyvinyl pyrrolidone, 0.3 M of the actual sugar and in total 35% (v/v) of the actual permeating cryoprotectant (pCPA) combination. After warming, the COCs were subjected to in vitro maturation, fertilization and embryo culture. In Experiment 1, trehalose and sucrose were equally effective during vitrification and warming in terms of facilitating oocyte survival and subsequent embryo development. In Experiment 2, when equilibration was performed at 38.5 C in a total of 4% (v/v) pCPA for 15 min, the combination of ethylene glycol and propylene glycol (EG + PG = 1:1) was superior to EG and dimethyl sulfoxide (EG + DMSO = 1:1) in terms of oocyte survival after vitrification and the quality of resultant blastocysts. In Experiment 3, equilibration in 4% (v/v) pCPA for 15 min before vitrification was superior to that in 15% (v/v) CPA for 5 min for achievement of high survival rates irrespective of the pCPA combination used. In Experiment 4, when equilibration was performed in 4% EG + PG for 5 min, 15 min or 25 min, there was no difference in oocyte survival and subsequent embryo development after vitrification and warming; however, the developmental competence of cleaved embryos was tendentiously reduced when equilibration was performed for 25 min. In conclusion, trehalose and sucrose were equally effective in facilitating vitrification, and the optimum pCPA treatment was 5–15 min equilibration in 4% (v/v) of EG + PG followed by vitrification in 35% (v/v) EG + PG.     

Beta-arrestin 2 mediates endocytosis of type III TGF-beta receptor and down-regulation of its signaling

beta-Arrestins bind to activated seven transmembrane-spanning (7TMS) receptors (G protein-coupled receptors) after the receptors are phosphorylated by G protein-coupled receptor kinases (GRKs), thereby regulating their signaling and internalization. Here, we demonstrate an unexpected and analogous role of beta-arrestin 2 (betaarr2) for the single transmembrane-spanning type III transforming growth factor-beta (TGF-beta) receptor (TbetaRIII, also referred to as betaglycan). Binding of betaarr2 to TbetaRIII was also triggered by phosphorylation of the receptor on its cytoplasmic domain (likely at threonine 841). However, such phosphorylation was mediated by the type II TGF-beta receptor (TbetaRII), which is itself a kinase, rather than by a GRK. Association with betaarr2 led to internalization of both receptors and down-regulation of TGF-beta signaling. Thus, the regulatory actions of beta-arrestins are broader than previously appreciated, extending to the TGF-beta receptor family as well.     

Bartonella infections in fleas (Siphonaptera: Pulicidae) and lack of bartonellae in ticks (Acari: Ixodidae) from Hungary

Fleas (95 Pulex irritans, 50 Ctenocephalides felis, 45 Ctenocephalides canis) and ixodid ticks (223 ixodes ricinus, 231 Dermacentor reticulatus, 204 Haemaphysalis concinna) were collected in Hungary and tested, in assays based on PCR, for Bartonella infection. Low percentages of P. irritans (4.2%) and C. felis (4.0%) were found to be infected. The groEL sequences of the four isolates from P. irritans were different from all the homologous sequences for bartonellae previously stored in GenBank but closest to those of Bartonella sp. SE-Bart-B (sharing 96% identities). The groEL sequences of the two isolates from C. felis were identical with those of the causative agents of cat scratch disease, Bartonella henselae and Bartonella clarridgeiae, respectively. The pap31 sequences of B. henselae amplified from Hungarian fleas were identical with that of Marseille strain. No Bartonella-specific amplification products were detected in C. canis, I. ricinus, D. reticulatus and H. concinna pools.     

Current status of farming practices of striped catfish, Pangasianodon hypophthalmus in the Mekong Delta, Vietnam

Aquaculture of catfish, Pangasianodon hypophthalmus (Sauvage), locally known as “ca tra”, and commonly referred to as striped catfish, river catfish and sutchi catfish, in Vietnam, having recorded a production of 683,000 tonnes in 2007, valued at about 645 million US$ is one of the largest single species based farming system, restricted to a small geographical area, in the world. The product is almost totally exported to over 100 countries as frozen fillets, as an acceptable alternative to white fish. Catfish is farmed mostly in earthen ponds, up to 4 m deep, in nine provinces in the Mekong Delta in South Vietnam. The results of the grow-out system of catfish farming in the Mekong Delta from a survey of 89 farms are presented. The farm size ranged from 0.2 to 30 ha with a mean of 4.09 ha. The frequency distribution of the yield in tonne/ha/crop and tonne/ML/crop corresponded to a normal distribution curve, where 75% of the farms yielded 300 tonnes/ha/crop or more. It was found that the yield per crop was significantly correlated (p < 0.05) to stocking density, pond depth and volume but not to pond surface area. Yields per crop was significantly different (p < 0.05) between upper and lower provinces of the Mekong Delta and water source (river versus channels), amongst others. It was evident that diseases and/or symptoms were observed to occur mostly in accordance with the onset of rains. In this paper the history of the catfish farming in the Mekong Delta is briefly traced, and current harvesting and marketing procedures as well as pertinent social elements of the farming community are dealt with.