Serological responses of specific pathogen-free foals to equine herpesvirus-1: primary and secondary infection, and reactivation.

Serum antibody (virus neutralisation, complement fixation, IgM and IgG) responses to equine herpesvirus-1 (EHV-1) infection were measured in six foals which were initially free from EHV-1 and EHV-4 infection and maternally-derived antibodies. Following primary infection, high titres of virus neutralisation and complement fixation antibodies were detectable against EHV-1, however, corresponding antibody levels against EHV-4 were low or inapparent, although the two viruses share a number of cross-reactive epitopes. In addition, following the primary infection with EHV-1, IgM levels increased before those of IgG, virus neutralisation and complement fixation antibodies, peaked sooner and thereafter declined. Stimulation of IgM levels was observed on secondary infection with EHV-1 given 61 days later. In contrast, IgG, virus neutralisation and complement fixation antibodies following primary infection were more sustained and no increase in their levels was observed on secondary infection. No consistent changes in IgM or IgG levels were seen after administration of dexamethasone to reactivate latent virus.     

The effect of repeated administration of carbetocin (Depotocin, Spofa) in the first days postpartum on levels of thyroxine, triiodothyronine, 17 beta-estradiol, progesterone and on fertilization]

Application of new procedures in the sphere of the control of sexual functions requires an extension of present knowledge of postparturient endocrinium or endogenic factors comprised in postparturient physiology of sexual activity. According to recent data, oxytocin, besides its uterotonic and luteolytic activity, acts as an ovarian factor in the local intrafollicular regulation of stereidogenesis and as a modulator of uterine secretion of prostaglandines. Based on present knowledge of oxytocin effects, this study was aimed at investigation of the influence of repeated carbetocin (Depotocin inj. Spofa) administration on the dynamics of changes in thyroxine (T4), triiodothyronine (T3), 17 beta-estradiol (E2), progesterone (P4) concentrations and their mutual correlations from the 36th hour till the 51st day after parturition. Simultaneous study of a possible delayed influence of applied carbetocin on conception of ewes after oestrus evocation on day 51 after lambing was carried out. Nineteen ewes of the Slovak Merino breed, lambed in the first decade of February, were assigned to the experimental (n = 9) and to the control group (n = 10). Experimental ewes were subjected to repeated postparturient carbetocin treatment at the dose 0.07 mg per animal. The first dose was applied i. m. in 24 hours, and the second in 72 hours after parturition. On day 51 oestrus was induced in nine ewes of each group by combined treatment with chlorsuperlutin (Agelin, vaginal pessaries, Spofa) and PMSG (500 I.U./animal). On the day of PMSG application ewes were housed together with rams for the period of the next six days. Samples of blood were taken 24 hours before parturition (-1st day), up to 36 h after parturition and on days 4, 7, 14, 17, 21, 25, 34, 42 and 51 after parturition. Concentrations of T4, T3, E2 and P4 were determined by commercial kits RIA-test-T4; RIA-test-T3; RIA-test-ESTRA and RIA-test-PROG (URVJT Kosice). Animal of the control group showed variations of T4 concentrations (Tab. I, Fig. 1) at the level of original values (59.4 +/- 9.69 nmol.l-1) up to the 21st day with the exception of temporary drop on day 4 and rise on day 7, insignificant compared to the -1st day. T4 concentrations of the control group displayed an intermittent increasing trend with the statistically insignificant peak after 36 h and on day 17, compared to the -1st day. After the 21st day controls revealed a sustained moderate increase while the experimental ewes displayed a decline of its concentrations until the 51st day.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of milk sampling techniques on milk composition, bacterial contamination, viability and functions of resident cells in milk.

Three different milk sampling techniques were evaluated during milk sampling: a direct aseptic collection from the udder through a sterile cannula was used as the reference technique, compared with either a manual or a mechanical sampling method. In this study 30 high-yielding Holstein-Friesian dairy cows at different stages of lactation and free of udder infection were used. For each milk sample, the influence of milk sampling techniques was determined for the following parameters: somatic cell count, milk composition, bacterial contamination, viability, in vitro phagocytosis and overall killing of Staphylococcus aureus Newbould 305, and cellular chemiluminescence. Because milk sampling occurred throughout lactation, the differences between early, mid- and late lactation were estimated. It was concluded that bacterial contamination was not significantly different in manual milking samples and the reference technique; bacterial contamination was, however, significantly (P < 0.001) higher in machine milking samples than in the reference technique. Among the different sampling techniques, no significant effects on SCC, milk composition, viability and functions of the cells isolated from milk were observed. It was found that viability, intracellular killing and cellular chemiluminescence of milk PMN were significantly lower (P < 0.05) in early lactation compared to mid-lactation. Phagocytosis was significantly (P < 0.05) higher in early lactation compared to mid- and late lactation, and no significant differences were observed between mid- and late lactation. From this study, it can be concluded that despite a higher bacterial contamination obtained with the mechanical sampling method, the 3 milk sampling techniques described in this study can be used for the evaluation of milk cell functions.     

Estradiol-17beta in the blood of boars with disorders of sexual potency

The levels of oestradiol-17 beta (E2) in the blood plasma were evaluated in 15 boars exhibiting signs of sexual potency disorders and in 20 boars with no such disorders before and after i. v. administration of chorion gonadotropin (HCG). No significant difference (P greater than 0.05) was found in the E2 levels in the blood plasma of the boars of the two groups before HCG administration. Two hours after the i. v. injection of 500 I. U. of HCG, an insignificant increase in the basal levels of E2 was recorded, reaching on the average 28.9% in the boars with potency disorders and 38.8% in those with no potency changes. Neither were there any significant differences in the E2 levels determined after HCG treatment between the boars with and without sexual potency disorders. It is inferred from the results that deviations in E2 concentration in the blood obviously do not contribute significantly to disorders in the sexual potency of boars.     

Relationship between blood iron parameters and trichinellosis in swine

Reduced levels of total iron binding capacity and unsaturated iron binding capacity were observed in the blood of trichinous and iron-injected trichinous pigs. No change was observed in their serum iron and saturation concentration levels. Also, reduced iron concentration levels were observed in the livers of trichinous pigs, while increased iron concentration levels were observed in the spleens of trichinous pigs and the livers and spleens of iron-injected pigs. No difference was found with regard to weight gains, number of larvae per gram of tissues, or histologic characteristics of 'nurse cells'.     

Salinity Tolerance of Rice (Oryza sativa L.) with Reference to Endogenous and Exogenous Abscisic Acid

Experiments conducted m a phytotron on three rice varieties of different salinity tolerance revealed an increase in the content of endogenous abscisic acid (ABA) with increasing NaCl salinity in IR20 (semi salt-tolerant), but in Pokkali (salt-tolerant) and IR28 (salt-sensitive) the increase in ABA content was marginal. Under sahnity stress, in general, 5 weekly sprayings of ABA (10^-4 mol L^-1) decreased Na and K concentrations in the shoot to the extent of 29.5 % and 3.3 %, respectively. However, ABA application significantly improved the K/Na ratio as well as the chlorophyll fluorescence decrease ratio (Rfd, indicator for potential photosynthetic activity), the number of green leaves per plant and the shoot dry weight. The response of IR20 and IR28 to ABA application was significantly better than that of Pokkali. Increasing salinity caused marked nutrient imbalances, decreased Rfd values and shoot dry weight. The results are discussed in relation to possible mechanism of salinity tolerance.