The aim of this study was to investigate the possible effects of the seasonal and physiological variations on the Cu, Zn, Mg, Fe, Se, Ca, K, Na, Cl, and P concentrations and their relationships with the estradiol and progesterone levels in Sakiz-Ivesi sheep. For this purpose, 34 healthy Sakiz-Ivesi crossbreed sheep were divided into two groups. The first group (n=22) was mated and the second group (n=12) was not mated. They were raised under pasture conditions and without any dietary supplementation. Their serum samples were collected four times a year at each season and under each physiologic condition. The periods are 1=early pregnancy (October), 2=late pregnancy (January), 3=lactation (April), and 4=dry season (July). The results of this study indicated that (1) Mg concentrations in serum vary with seasonal variations but not physiological variations, (2) Fe and K concentrations in serum vary only with physiological variations, (3) the Cu concentration changes not only pregnancy but also through some other hormonal changes not caused by pregnancy, (4) Ca, P, and Se concentrations could vary with both physiologic and seasonal variations, (5) Zn, Na, and Cl were almost identical for both groups and altered depending on neither season of the year nor the physiologic status, (6) both increased estradiol level and increased progesterone level can raise Cu levels in serum, and (7) increased serum Ca concentrations are related with increased estradiol and decreased P and Mg levels. These observations suggest that seasonal and physiologic variations and sexual cycle have to be taken into consideration for a correct interpretation of elements status. If sheep are maintained at pasture conditions, the nutritional requirements must be supplemented during certain periods. Otherwise, it is apparent that this will cause a decline in the total performance of sheep and, consequently, economic lost.
In this study, dexamethasone-induced gastric lesions were studied in rats that had undergone sialoadenectomy. The ultrastructural changes developed during the study were detected by electron microscopically, while blood serum and stomach epidermal growth factor (EGF) concentrations were measured by RIA. The result of the study showed that gastric lesions were correlated with gastric mucus secretion and both serum and mucosa EGF levels. After the administration of dexamethasone, it was found that sialoadenectomy significantly (p<0.01) raised the incidence of stomach lesions (p<0.01), and a significant increase in mucus secretion was also found. Additionally, the serum and gastric mucosal EGF levels fell after sialoadenectomy when compared to normal rats. The most important gastric mucosal changes were observed in rats treated with dexamethasone and those both sialoadenectomised and treated with dexamethasone.
One of the most essential ingredients of AI programs is semen processing which generally needs diluents with additives that protecting to spermatozoa against to cold shock stress. Selection of cryoprotectant and composition of extenders are of great importance for sperm survival during and after freezing (Salamon & Maxwell, 2000). Although different extenders and freezing protocols have been established for ram semen, fertility outcome is not comparable to that achieved with fresh semen. Consequently, the development of more useful extenders has vital importance to increase pregnancy rates from AI in ewes (Aisen, Alvarez, Venturino, & Garde, 2000). Although significant attempts have been made to make better semen extenders, few new additives could have been revealed for ram semen (Cirit et al., 2013). The main aim of this study was to establish new extender formulations for freezing of EE ram semen. It seems that one of the most important and effective additives is trehalose, a nonpermeating disaccharide (Ahmad & Aksoy, 2012). The cryoprotectant action of trehalose on the plasma membrane is based on its capacity to form hydrogen bonds with the polar heads of the membrane phospholipids, thus preventing intracellular formation of ice crystals by replacing water molecules during the dehydration process (Aboagla & Terada, 2003; Aisen, Medina, & Venturino, 2002). It has been shown that trehalose increases the freezing ability of ram
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