Calcium ions are involved in egress of Babesia bovis merozoites from bovine erythrocytes

Bovine babesiosis is a livestock disease known to cause economic losses in endemic areas. The apicomplexan parasite Babesia bovis is able to invade and destroy the host’s erythrocytes leading to the serious pathologies of the disease, such as anemia and hemoglobinuria. Understanding the egress mechanisms of this parasite is therefore a key step to develop new therapeutic strategies. In this study, the possible involvement of Ca²⁺ in the egress of B. bovis merozoites from infected erythrocytes was investigated. Egress was artificially induced in vitro using calcium ionophore A23187 and thapsigargin to increase Ca²⁺ concentration in the cytosol of the parasite cells. The increased intracellular Ca²⁺ concentration following these treatments was confirmed using live cell Ca²⁺ imaging with confocal laser scanning microscopy. Based on our findings, we suggest a Ca²⁺ signalling pathway in the egress of B. bovis merozoites.     

Long term haematological and serum protein changes following splenectomy in sheep

Splenectomy was performed on five rams since four years to study the long-term effect of the operation on blood profile and serum total proteins and paper electrophoresis.A reduction in the blood profile was accompanied with a decrease in the betta, gamma globulin and total globulin following removal of the spleen. Alpha globulin showed a slight rise. The albumin/globulin ratio was highly increased.     

Abomasal cannulation in the milk-fed calf using a 7 mm polyurethane tube

The main objective of this study was to develop a simple and effective surgical technique for abomasal cannulation in neonatal calves. General anaesthesia was induced in 12, 3-day-old male dairy calves and a polyurethane cannula surgically implanted in the abomasal body (n = 12) and pyloric antrum (n = 6) through a right paracostal incision. Fifteen cannulae remained in situ from day 3 to 34 of life (mean: 29 days), and three cannulae were extruded 13-14 days after placement. Calves were clinically healthy and gained weight during the study. Cannulae were well tolerated by the calves and abomasal contents did not leak from the cannula sites. Necropsy examination revealed firm adhesions between the abomasum and parietal peritoneum at the cannula sites with no evidence of leakage or peritonitis. We conclude that surgical placement of polyurethane tubes designed for percutaneous endoscopic gastrostomy provided a useful method for cannulation of the abomasum of neonatal calves. The cannulation technique can be used for experimental studies, as well as for nutritional and fluid support of sick calves that cannot be managed by oral treatment.     

Dietary nucleotides enhance growth performance,feed efficiency and intestinal functional topography in European Seabass (Dicentrarchus labrax)

Nucleotides, nucleosides and nucleic acids (NU) have many critical functions in supporting life and increasing evidence suggests that exogenous supply can benefit the health of mammals and fish. For these reasons, a 6‐week feeding trial was conducted on juvenile European seabass (Dicentrarchus labrax) with diets containing 0%, 0.15% and 0.3% inclusion of a NU mixture (Laltide^®) derived from the yeast Saccharomyces cerevisiae. At the end of the study no significant differences were found in fish performance, although a tendency towards better performance was indicated in fish fed the Nu0.3 diet. In relation to histological assessment, a significantly greater perimeter ratio; internal to outer (IP/OP) was observed in the posterior intestine of fish fed supplemental NU. Microvilli heights in the posterior intestine were also shown to be significantly promoted in fish fed NU diets (p < 0.05). Goblet cell abundance was shown to be unaffected by the inclusion of NU in the diet (p > 0.05). Overall, this study indicates that orally administered NU may be effective promoters of gut functional topography with marginal associated improvements to fish performance. Nonetheless, longer exposure and/or commercial scale application, and in diets that were challenging in use of high inclusion levels of plant by‐products would potentially amplify improvements in production characteristics, in turn benefiting fish culturists.     

Occurrence of on-farm risk factors and health effects of mycotoxins in dairy farms in Jordan

The aim of this study was to determine the occurrence of on-farm risk factors and health effects associated with contamination of dairy feeds with aflatoxins (AFs), zearalenone (ZEN), trichothecenes (T-2), deoxynivalenol (DON), and fumonisins (FB) in Jordan. A pre-tested and validated questionnaire was used to determine on-farm practices and health effects associated with high levels of mycotoxins. A total of 88 feed samples were collected from the 37 farms participating in the study and analyzed using commercially available ELISA kits. The mean total AF concentration exceeded the European Union (EU) limit in alfalfa (4%) and total mixed ration (TMR) (3%) samples. Similarly, levels exceeding EU limits were observed for T-2 in alfalfa (29%), TMR (30%), and corn silage (4%). The average concentrations of ZEN and FB were 300 ppb and 11,638 ppb, respectively, which were below the EU maximum limits in all feed samples examined. Intensive management system (OR?=?7.70), imported feed (OR?=?3.40), feed storage on the farm for more than 1-month duration (OR?=?7.90), and not using antitoxins (OR?=?2.30) were significantly (P?<?0.05) associated with high levels of mycotoxins in feed samples. A significant correlation (P?<?0.05) was evident between the presence of mycotoxins in dairy feed and feed refusal (R?=?0.70), low milk production (R?=?0.50), diarrhea problems (R?=?0.60), infertility (R?=?0.50), and repeated breeder problems (R?=?0.80). Results show that mycotoxin contamination in dairy feeds is a problem in Jordan, and appropriate measures need to be undertaken to reduce risks to human and animal health and improve production.

     

Pharmacokinetics of toltrazuril and its metabolites in pregnant and nonpregnant ewes and determination of their concentrations in milk,allantoic fluid,and newborn plasma

The objectives of this study were to determine the pharmacokinetics of toltrazuril and its metabolites in pregnant and nonpregnant ewes following a single oral dose and to determine the plasma concentrations of these compounds in milk, allantoic fluid, and newborn plasma. Eighteen healthy ewes were randomly divided into three groups (n = 6 each): pregnant ewes at 12–13 weeks of gestation (group A), nonpregnant ewes (group B), and pregnant ewes at 1–2 weeks before expected lambing date (group C). Ewes in all groups received a single oral dose of toltrazuril at 20 mg/kg body weight. In groups A and B, blood samples were collected at 1, 3, 5, 7, 9, 12, 15, 18 hr, every 6 hr to day 3, every 12 hr to day 7 and thereafter every 24 hr to day 14 post-toltrazuril administration. In group C, parturition was induced 24–36 hr after toltrazuril administration then milk, allantoic fluid, and newborn plasma samples were collected immediately after birth. Drug metabolites were assayed using ultra high-performance liquid chromatography–ultraviolet detection method (UHPLC-UV). The maximum concentration (C_max), area under the plasma concentration-time curve (AUC_0–t), AUC to 24 and 48 hr (AUC_0–24), and (AUC_0–48) were significantly higher in pregnant ewes. Longer apparent half-life (T_1/2), significantly higher apparent volume of distribution (Vd/F) and total clearance (Cl/F) were observed in nonpregnant ewes. The time to maximum plasma concentration (T_max), mean residence time (MRT) and elimination rate constant (K_el) were similar in both groups. The AUC_0–24 and AUC_0–48 were significantly higher in nonpregnant ewes. The AUC_0–t was significantly higher in pregnant ones. The ratio of plasma toltrazuril concentrations in ewes and toltrazuril concentrations in newborn lambs' plasma, allantoic fluid, and milk were 68%, 2.3%, and 5.3%, respectively. Results of this study showed that toltrazuril is well absorbed after a single oral dose in ewes with widespread distribution in different body tissues.     

Function, developmental genetics, and fitness consequences of a sexually antagonistic trait

Sexual conflict is thought to be a potent force driving the evolution of sexually dimorphic traits. In the water strider Rheumatobates rileyi, we show that elaborated traits on male antennae function to grasp resistant females during premating struggles. Using RNA interference, we uncovered novel roles of the gene distal-less (dll) in generating these male-specific traits. Furthermore, graded reduction of the grasping traits resulted in a graded reduction of mating success in males, thus demonstrating both selection for elaboration of the traits and the role of dll in their evolution. By establishing developmental genetic tools in model systems where sexual selection and conflict are understood, we can begin to reveal how selection can exploit ancient developmental genes to enable the evolution of sexually dimorphic traits.     

Heterochromia iridis in water buffaloes (Bubalus bubalis)

This study included 45 unaffected animals and 593 animals affected with heterochromia irides, and 85 enucleated eyeballs with heterochromia irides. The classification of heterochromia irides, morphology of normal and heterochromic irides, and the histology, ultrastructure, and scanning electron microscopy are presented. The incidence of heterochromia irides in water buffaloes was 7.62% affecting either one or both eyes. Both complete and partial heterochromia irides occurred. Complete heterochromia iridis is more frequent than the partial form in either bilateral or unilateral cases. The pupil has a dumb-bell-shape appearance. Granula iridica occurred at the upper (100%) and lower (30%) pupillary margins and originated from the posterior pigmented epithelium. In heterochromia irides, the melanocytes is absent in the anterior border and stromal layers, and iridal thickness appeared thinner than that of normal eyes.     

Evolution of the gene network underlying wing polyphenism in ants

Wing polyphenism in ants evolved once, 125 million years ago, and has been a key to their amazing evolutionary success. We characterized the expression of several genes within the network underlying the wing primordia of reproductive (winged) and sterile (wingless) ant castes. We show that the expression of several genes within the network is conserved in the winged castes of four ant species, whereas points of interruption within the network in the wingless castes are evolutionarily labile. The simultaneous evolutionary lability and conservation of the network underlying wing development in ants may have played an important role in the morphological diversification of this group and may be a general feature of polyphenic development and evolution in plants and animals.