pH-dependent effects of procaine on equine gamete activation

Procaine directly triggers pH-dependent cytokinesis in equine oocytes and induces hypermotility in stallion spermatozoa, an important event during capacitation. However, procaine-induced hyperactivated motility is abolished when sperm is washed to remove the procaine prior to sperm-oocyte co-incubation. To understand how procaine exerts its effects, the external Ca2+ and Na+ and weak base activity dependency of procaine-induced hyperactivation in stallion spermatozoa was assessed using computer-assisted sperm analysis. Percoll-washed stallion spermatozoa exposed to Ca2+-depleted (+2 mM EGTA) procaine-supplemented capacitating medium (CM) still demonstrated hyperactivated motility, whereas CM without NaCl or Na+ did not. Both procaine and NH4Cl, another weak base, were shown to trigger a cytoplasmic pH increase (BCECF-acetoxymethyl (AM)), which is primarily induced by a pH rise in acidic cell organelles (Lysosensor green dnd-189), accompanied by hypermotility in stallion sperm. As for procaine, 25 mM NH4Cl also induced oocyte cytokinesis. Interestingly, hyperactivated motility was reliably induced by 2.5-10 mM procaine, whereas a significant cytoplasmic cAMP increase and tail-associated protein tyrosine phosphorylation were only observed at 10 mM. Moreover, 25 mM NH4Cl did not support the latter capacitation characteristics. Additionally, cAMP levels were more than 10x higher in boar than stallion sperm incubated under similar capacitating conditions. Finally, stallion sperm preincubated with 10 mM procaine did not fertilize equine oocytes. In conclusion, 10 mM procaine causes a cytoplasmic and acidic sperm cell organelle pH rise that simultaneously induces hyperactivated motility, increased levels of cAMP and tail-associated protein tyrosine phosphorylation in stallion spermatozoa. However, procaine-induced hypermotility is independent of the cAMP/protein tyrosine phosphorylation pathway

Comparison of five different methods to assess the concentration of boar semen

Both for research and practical purposes, accurate and repeatable methods are required to assess the concentration of boar semen samples. Since the method which is used may influence the results considerably, the aim of the present study was to compare 5 frequently used techniques to determine boar semen concentration. Fifty ejaculates were collected from 37 different boars at an artificial insemination centre. Subsequently, each ejaculate was analyzed for sperm concentration by means of 2 different types of colorimeters (Colorimeter 1: Model 252, Sherwood Scientific Ltd, Cambridge, UK; Colorimeter 2: Ciba-Corning, Schippers, Bladel, The Netherlands), the Burker counting chamber (golden standard), and the Hamilton Thorne Analyzer (Ceros 42.1) using 2 types of Leja chambers (the 'former' and the 'recently developed'). Each ejaculate was assessed 5 times with each of the 5 methods, and the repeatability, expressed by coefficient of variation (CV), was determined for each method. The different methods were compared using Pearson's correlations and limits of agreement. The colorimeters yielded the lowest CV's (both 3.7%), while the former Leja chamber resulted in the highest CV (12.4%). Moreover, significant (P0.71) were found between the results obtained by the different methods. The limits of agreement plots showed that none of the methods consistently over- or underestimated the sperm concentrations when compared to the Burker chamber, although there was a tendency toward higher over- or underestimation in highly concentrated sperm samples. Based on our results, there were no major differences in the assessment of sperm concentration between the evaluated methods. The choice of method used in a laboratory could therefore be based on factors such as cost, number of samples to be assessed and practical use, without thereby negatively affecting the validity of the results thus obtained

Trypanosoma equiperdum in the horse : a neglected threat?

Dourine is a contagious disease caused by Trypanosoma equiperdum that is transmitted directly from animal to animal during coitus. Dourine is known as an important disease in many countries, and it threatens equidae worldwide. It is reported to be widespread in South America, Eastern Europe, Russia, Mongolia, Namibia and Ethiopia. The disease can be carried to various parts of the world through the transportation of infected animals and semen. Since knowledge of the prepatent infectiousness of a recently infected animal is lacking, introduction of the disease is in principle an ever-present threat. Definitive diagnosis depends on the identification of the parasite by means of direct microscopy. This is rarely possible in practice and therefore, diagnosis in the field is based on the observation of typical clinical signs, together with serological tests. This paper is an endeavour to review briefly and compile information on the appearance and importance of Dourine in terms of its epidemiological and clinical features, as well as on its diagnosis, treatment and prognosis

Improving irrigation water delivery performance of a large-scale rice irrigation scheme

The availability of irrigation water and its equitable allocation in a large-scale rice irrigation scheme of Malaysia have been modeled. The model reliably estimates available water for irrigation at the intake of the main canal and simulates the recommended irrigation deliveries for 120 tertiary canals. Different water allocation and management scenarios were evaluated based on the sensitivity of the growth stages of rice to water, varying field-water demand, and perceived water shortages. The model provides a quantitative assessment not only of water allocation for irrigation but also of day-to-day or periodic irrigation delivery performances for a large-scale rice irrigation system. It provides 86% adequacy and 87% equity of irrigation delivery in the main season (August-December). The corresponding performance indicators provided by the model are 74 and 89% in the off-season (February-June). The dependability of water supply is higher in the off-season than in the main season, while the relative water supply (RWS) is the converse. RWS often becomes >1.0 in the main season, while such a RWS is rarely obtained in the off-season. The model augments the water delivery performance of the scheme and hence would serve as a useful tool for irrigation managers in decision making

Calibrated radar-derived rainfall data for rainfall-runoff modeling.

This study focuses on a technique to improve runoff modeling based on radar-derived rainfall and hydrological model for the whole watershed. GIS tools were used to provide the model parameters for the Upper Bernam River Basin (1090 km2), Malaysia. Virtual rainfall stations are created throughout the UBRB watershed. The rainfall data for these stations are estimated from raw weather radar data using newly developed program called RaDeR ver1.0. For this study, estimated radar rainfall data from Subang weather radar stations were compared and calibrated with actual rain gauge data. Radar-derived rainfall calibration model developed for Subang radar station was y=0.8772x. According to the model developed, the radar rainfall calibration factor (RCf) can be identified as 0.8772. The original estimated radar derived rainfall data should be adjusted before using the calibration factor (RCf). The model gives better correlation when adjusted radar values were used instead of the original radar rainfall values. The model calibration factor increased from 0.464 with R2 of 0.2759** to 0.8772 with R2 of 0.3655***. Finally, the virtual rainfall stations created throughout the river basin produced a more representative rainfall distribution. It is believed that watershed river flow can be better estimated by using radar-derived rainfall data

Application of NRCS-curve number method for runoff estimation in a mountainous watershed

The major problem in the assessment of relationships between rainfall and runoff occurs when a study is carried out in ungauged watersheds in the absence of hydro-climatic data. This study aims to evaluate the applicability of Natural Resources Conservation Service-Curve Number (NRCS-CN) method together with GIS in estimating runoff depth in a mountainous watershed. The study was carried out in the semi-arid Kardeh watershed which lies between 36º 37´ 17˝ to 36º 58´ 25˝ N latitude and 59º 26´ 3˝ to 59º 37´ 17˝ E longitude, about 42 km north of Mashhad, Khorasan Razavi Province, Iran. The hydrologic soil groups, land use and slope maps were generated with GIS tools. The curve number values from NRCS Standard Tables were assigned to the intersected hydrologic soil groups and land use maps to generate CN values map. The curve number method was followed to estimate runoff depth for selected storm events in the watershed. Nash-Sutcliffe efficiency, pair-wise comparison by the t-test, Pearson correlation and percent error were used to assess the accuracy of estimated data and relationship between estimated and observed runoff depth. The results showed relatively low Nash-Sutcliffe efficiency (E = – 0.835). There was no significant difference between estimated and observed runoff depths (P > 0.05). Fair correlation was detected between estimated and observed runoff depth (r = 0.56; P < 0.01). About 9% of the estimated runoff values were within ±10% of the recorded values and 43% had error percent greater than ±50%. The results indicated that the combined GIS and CN method can be used in semi-arid mountainous watersheds with about 55% accuracy only for management and conservation purposes

Crossbreeding effect of double-muscled cattle on in vitro embryo development and quality

Nowadays, several developing countries have started to breed double-muscled cattle to their autochthonous cattle to improve meat production. However, the developmental competence of the resultant crossbreeding embryos is unknown. The objective of this study was to evaluate the effect of crossbreeding double-muscled (Belgian Blue; BB) semen with beef (Limousin; LIM) and dairy (Holstein-Friesian; HF) derived oocytes on embryo development and quality, using purebred BB as a control (BB oocytes fertilized by BB sperm). A single ejaculate of a BB bull was evaluated by Computer Assisted Sperm Analysis before using for in vitro fertilization. Ovaries from each breed were collected at the local slaughterhouse (n = 1,720 oocytes). All statistical analyses were performed using R-core (P < 0.05). Embryo quality was evaluated via differential-apoptotic staining of day 8 blastocysts. Cleavage (48 h post insemination) and day 8 blastocyst rates were greater (P < 0.05) for LIM (82.9 ± 6 and 27 ± 4.3%, respectively) than for BB (69.8 ± 8.5 and 19.6 ± 3.1%, respectively) and HF (45.1 ± 10 and 12.3 ± 2.2%, respectively). Holstein-Friesian presented lower cleavage and day 8 blastocyst rates than BB (P < 0.05). Limousin blastocysts presented a higher number (P < 0.05) of inner cell mass cells (ICM; 68 ± 7.8) than HF (40.4 ± 8.2). In conclusion, crossbreeding double-muscled cattle by in vitro fertilization with LIM oocytes yielded better embryo compared with the purebred combination, while the combination with HF oocytes produced the lowest rate of blastocysts