Oocyte Maturation is Required for Correct Sperm Chromatin Rearrangement

Veterinary Research Communications -     

Apoptosis in Cooled Porcine Oocytes: Role of Calcium (Ca2+) and Ca2+-dependent Enzymes

Veterinary Research Communications -     

Role of VEGF in pig preantral follicles

Veterinary Research Communications -     

Frequency of trypanosomosis and gastrointestinal parasites in draught donkeys in the Gambia in relation to animal husbandry

Summary Prevalence of trypanosomosis, gastrointestinal strongyles and level of strongyle egg outputs were studied in relation to husbandry practices in the draught donkey population in The Gambia. Feeding regime, number of working hours per day and overnight penning practices of donkeys affected significantly (P<0·05) the level of gastrointestinal strongyle egg output, but not (P>0·05) trypanosomosis prevalence. Dual trypanosome and gastrointestinal strongyle infection significantly reduced the PCV (P<0·001). Animals positive for gastrointestinal strongyles alone did not show a significantly (P>0·05) lower PCV than those found negative. Husbandry practices to improve the situation are recommended.

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Frecuencia De Tripanosomosis Y Parasitos Gastrointestinales En Burros De Trabajo En Gambis En Relacion Al Manejo Animal

Resumen Se estudió la prevalencia de tripanosomosis, estróngilus gastrointestinales y su nivel de ovipostura, en relación con el manejo, en una población de burros de trabajo en Gambia. El régimen alimentario, el número de horas de trabajo por día y las prácticas de estabulación nocturnas, afectaron significativamente (P<0·05) el nivel de ovipostura de parásites estrongilus, pero no la prevalencia de tripanosomosis (P>0·05). Las infecciones duales de tripanosomas y estróngilus, redujeron significativamente el volumen corpuscular celular (VCC) (P<0·001). Los animales positivos únicamentea estróngilus gastrointestinales, no presentaron reducciones significativas (P>0·05) del VCC, comparados con aquellos encontrados negativos. Se recomiendan prácticas de manejo para mejorar la situación.

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Frequence De La Trypanosomose Et Des Parasites Gastrointestinaux Chez Des Anes De Trait En Gambie En Relation Avec L'elevage

Résumé La prévalence de la trypanosomose, des strongles gastrointestinaux et la quantité d'oeufs de strongles émis ont été étudiées en relation avec les pratiques d'élevage dans une population d'ânes de trait en Gambie. Le régime alimentaire, le nombre d'heures de travail par jour et la mise en enclos des ânes la nuit ont eu une influence significative (P<0,05) sur le taux d'oeufs de strongles émis, mais non sur la prévalence de la trypanosomose (P>0,05). La trypanosomose et la strongylose ont réduit de façon significative l'hématocrite (P<0,001). Les animaux atteints de strongylose seulement n'ont pas présenté un hématocrite significativement plus bas (P>0,05) que ceux indemnes. Des pratiques d'élevage destinées à améliorer la situation sont recommandées.

     

Production of Meiotically Competent Oocytes Using an In Vitro Folliculogenesis Culture System

Veterinary Research Communications -     

Effects of supplemental dietary vitamin C on quality of semen from Nile tilapia (Oreochromis niloticus) breeders

The objective of this study was to evaluate the effects of vitamin C on growth and quality of semen from Oreochromis niloticus breeders. One hundred and sixty males were fed with different levels of vitamin C (0, 261, 599 and 942 mg/kg diet). The higher weight values were recorded for 599 (166 g) and 942 (175 g) mg of vitamin C/kg diet. Sperm motility, vigour and concentration were higher with 599 and 942 mg of vitamin C/kg diet. The semen volume, gonadosomatic index and plasma protein data from the last week showed a direct relationship with increasing levels of vitamin C. No changes were observed in the hepatosomatic index and blood glucose. The haematocrit and erythrocyte showed higher values estimated by equations derived at 850 and 638 mg vitamin C/kg diet, respectively. The leucocytes were inversely proportional to the increasing levels of vitamin C. After 100 days of feeding, animals fed the diet containing 942 mg vitamin C/kg diet had higher sperm motility, linearity, curvilinear velocity, straight line velocity and average path velocity (p < .05). Higher values of beat cross‐frequency were observed in broodfish fed diets containing 942 and 599 mg vitamin C/kg. The different vitamin C levels did not cause differences in straightness, lateral head displacement and sperm morphology. For Nile tilapia males on intensive rearing and handling conditions, vitamin C levels between 599 and 942 mg/kg may be used for a better performance and quality of semen.     

Role of TRPV1 channels during the acquisition of fertilizing ability in boar spermatozoa

Recently, the transient receptor potential vanilloid type 1 (TRPV1) channel was shown to be involved in capacitation, the process that allows mammalian spermatozoa to acquire their fertilizing ability within the female genital tract. Unfortunately, the role of TRPV1 in this process is still unclear. Thus, the aims of the present work were to 1) investigate the function of TRPV1 in the male gamete signaling system and 2) modulate TRPV1 activity by administering a specific activator, capsaicin, or a specific inhibitor, capsazepin, to spermatozoa during in vitro capacitation. Using confocal microscopy, cellular responses were assessed in terms of changes in 1) cell membrane resting potential, 2) intracellular calcium concentrations, and 3) actin polymerization dynamics. As a result, TRPV1 channels were shown to act as specific cationic channels: their activation led to membrane depolarization and, consequently, the opening of voltage-gated calcium channels and an increase in intracellular calcium concentrations. These ionic events promote actin cytoskeletal depolymerization and a loss of acrosome structure integrity. In contrast, TRPV1 inhibition caused a slowing of the capacitation-dependent increase in intracellular calcium concentrations, a reduction in actin polymerization, and acrosome rupture. In conclusion, these results suggest that TRPV1 channels modulate the major pathways involved in capacitation.     

A survival analysis of trypanosomosis diagnostic-test performance under natural infection challenge

Little is known about the time-to-first detection and the time difference (TD) between first parasitological and first serological diagnosis of Trypanosoma spp. infections under natural infection challenge in cattle. The objective of our study was to estimate these measures of "longitudinal aspects" of diagnostic performance and to investigate potential biological factors. Emphasis was on diagnosis at the genus level (Trypanosoma spp.). Twelve N'Dama, 12 Gobra zebu and 12N'DamaxGobra (F1) crossbred cattle (all animals non-infected at the start of the experiment, six male and six female animals in each cohort) were exposed to natural high tsetse challenge in the Niamina East area in The Gambia [Acta Trop. 71 (1998) 57]. The animals were investigated parasitologically (detection of trypanosomes by buffy-coat technique), serologically (detection of T. brucei, T. congolense and T. vivax antigen by enzyme-linked immunosorbent assay (ELISA)) and clinically (packed-cell volume, PCV) over a period of 180 days. The time-to-first detection of trypanosomes, trypanosomal antigen (cut-off as suggested by test supplier) and drop in PCV (subject-based cut-off values) were recorded as outcomes of interest. Thus, incidence was both parasitologically (I(p)), serologically (I(s)) and clinically (I(c)). Recurrent events were not considered. The TD between first parasitological and first serological detection was established as I(s) time minus I(p) time. The effect of breed and sex on the time-to-first detection and on TD was investigated using Cox (proportional hazard) regression and ANOVA, respectively.We found that time-to-first parasitological detection of trypanosomosis in N'Dama animals was significantly longer than in the two other breeds (Cox regression, P=0.002). A similar but less-strong (P=0.063) effect of breed on time-to-first detection of trypanosomal antigen was found, whereas no breed effect was observed for clinical detection (P=0.432). Sex had no effect in all detection systems. The TD varied between -56 and 115 (mean 28). Marked differences among breeds and between sexes were not observed (ANOVA, P=0.8). We suggest that incidence studies are more suitable for detecting risk factors for animal trypanosomosis than prevalence-based (cross-sectional) studies because the latter often result in misinterpretation of factors that increase the survival time with infection as risk factors.