The Content of Amino Acids in Pasture Vegetation and Their Apparent Digestibility in 2-year-old Horses

Ten samples of plant vegetation and 10 samples of fresh excrement were taken from the same pasture area. The excrement were collected from 10 2-year-old Old Kladruber horses that received the pasture vegetation daily. The apparent digestibility of nitrogen and amino acids in pasture vegetation was determined by using the acid-insoluble ash marker method. In comparison with excrement, the pasture vegetation contained higher levels of Ser, Ala, Leu, and His and higher levels of Pro (P ≤ .01), Met (P ≤ .01), and Arg (P ≤ .05). The mean level of Ile in pasture vegetation was lower than in excrement (P ≤ .05). The apparent digestibility of amino acids from pasture vegetation was high for Pro and Met (86.75 and 89.39%), moderate for Ser, Ala, Leu, His, and Arg (68.61%-76%), and low for Asp, Thr, Glu, Gly, Val, Leu, Tyr, Phe, and Lys (56.15%-66.03%). The digestibility of lysine and Ile was relatively low (56.39% and 56.15%, respectively). The total content of nitrogen per dry matter was 10.98 ± 2.46 g/kg for pasture vegetation and 12.12 ± 2.38 g/kg for excrement, whereas the content of protein nitrogen was 7.20 ± 0.25 g/kg and 6.89 ± 0.21 g/kg of dry matter in pasture vegetation and excrement, respectively. This means that only 65.55% and 56.90% of N is bound in proteins in pasture vegetation and excrement, respectively. Non-protein nitrogen accounts for 34.45% in pasture vegetation and for 43.10% in excrement.     

Granulocyte and granulocyte macrophage colony-stimulating factors as therapy in human and veterinary medicine

Granulocyte colony-stimulating factors (G-CSFs) and granulocyte macrophage colony-stimulating factors (GM-CSFs) are endogenous cytokines that regulate granulocyte colonies and play a major role in the stimulation of granulopoiesis (neutrophils, basophils and eosinophils) and in the regulation of microbicidal functions. There are numerous pathological conditions in which neutrophils are decreased, the most common being neutropenia associated with cancer chemotherapy, which increases the risk of serious microbial infections developing with the potential for high morbidity and mortality. New methods in molecular biology have led to the identification and cloning of CSF genes and biopharmaceutical production. Since then, CSFs have been widely used for the prevention and treatment of neutropenia associated with cancer chemotherapy, for mobilising haematopoietic cell precursors, and for other neutropenia-related pathologies. This review focuses on the use of CSFs within both human and veterinary medicine. Clinical applications, pharmacology, tolerability and the potential role of these factors in veterinary medicine are considered.     

Determination of the dry matter disappearance and the crude protein degradability of the formaldehyde treated feeds in the rumen by in situ method

Sunflower cake (SC), horse bean (HB), and alfalfa meal (AM) were treated with rising doses of formaldehyde (F) from 0.0, 0.2 ... 2.0 g F per 100 g crude protein. We have followed the differences of crude protein solubility, its degradability and disappearance of dry matter in the rumen as well as the amount of reversible bonded F from the F dose. With AM it was found a significant influence of ADF on the degradability and on the amount of acid-labile bonded F and/or on the decrease of N solubility. From the total N content the share of soluble nitrogen decreased in SC by 31%, HB by 24%, and in AM only by 12.5%. With the increase of the F dose its protective effect on proteins against the degradability mainly in SC and HB also rose significantly. The degradability of AM protein was influenced more by the incubation time than by the effect of treatment. The degradability of the SC proteins fell from 95% with untreated to 27% treated with the maximum dose. With AM it fell slowly from 84% to 74% by the determination coefficient R2 = 0.77. It was observed a marked decrease in HB only from the dose of 1.28% F. The changes in dry matter disappearance were similar to the changes in crude protein degradability and to the changes of solubility in SC and AM. The in situ method proved very suitable for the determination of the extent of degradability of the feed proteins in the rumen.     

Ixodid ticks parasitizing Iberian red deer (Cervus elaphus hispanicus) and European wild boar (Sus scrofa) from Spain: geographical and temporal distribution

Commercial hunting of Spanish wild ungulates has made them an important economic resource. Wild ungulates may have an important role in the maintenance of ixodid tick populations, and also as reservoirs of pathogens. We studied the ixodid ticks that parasitize Iberian red deer and European wild boar from Spain. Ixodid ticks (n=6,336) were collected from 431 Iberian red deer and 142 wild boar in different regions of Spain. We found 10 different ixodid tick species parasitizing Iberian red deer, mainly Hyalomma marginatum marginatum (63.7%), Rhipicephalus (Boophilus) annulatus (7.9%) and R. bursa (7.5%). R. (Boophilus) annulatus was only collected in the province of Cádiz (southern Spain). We found 8 ixodid tick species on the wild boar, mainly Hy. m. marginatum (68.7%), R. bursa (14.6%) and Dermacentor marginatus (9.3%). We found one adult Hy. marginatum rufipes and one adult Hy. anatolicum excavatum parasitizing wild boar from south-central Spain. Mean prevalence of ixodid ticks was 41.3+/-0.08% (n=475) and 31+/-0.09% (n=284) and intensity of parasitization was 13.9+/-0.2 (n=283) and 13.6+/-0.3 (n=130) ticks/animal for Iberian red deer and wild boar, respectively. Only 5 of the 13 ixodid tick species found were shared by Iberian red deer and wild boar. This finding could indicate a host preference when Iberian red deer and wild boar share common habitats. In both Iberian red deer and wild boar from south-central Spain the monthly relative frequencies of Hy. m. marginatum and R. bursa presented an inverse pattern. The highest Hy. m. marginatum relative frequencies coincided with the lowest R. bursa relative frequencies along the year. R. bursa and I. ricinus were present in areas from northern to southern Spain while Hyalomma sp. and D. marginatus were exclusively collected in the two southern thirds of Spain. Haemaphysalis sp. and D. reticulatus were collected in northern Spain. Hy. m. marginatum and R. bursa were present during the whole year in red deer and wild boar from south-central Spain, showing more than one life cycle per year. These results are important for understanding the role of wild ungulates in the maintenance of tick infestations and to improve tick control programmes.     

Survival of mouse embryos after vitrification depending on the cooling rate of the cryoprotectant solution

The aim of the study was to determine the relationship between the rate of cooling of eight-cell mouse embryos to the temperature of liquid nitrogen (-196 degrees C) and their developmental capacity after thawing on the basis of their ability to leave the zona pellucida ('hatching') during in vitro culturing. Eight-cell embryos were obtained from superovulated female mice and divided into three experimental and one control group. Embryos from the experimental groups were cryopreserved by the vitrification method using ethylene glycol as cryoprotectant. The vitrification protocols used in the study differed in the rate of cooling of the cryoprotectant solution. Embryos from the first group were frozen in conventional 0.25-ml plastic straws, those from the second group in pipetting 'tips', and embryos from the third group, placed in vitrification solution, were introduced dropwise directly into liquid nitrogen. The control group of embryos was cultured in vitro without freezing in a culturing medium in an environment consisting of 95% air and 5% CO2. The developmental capacity of thawed embryos was assessed on the basis of their ability to leave the zona pellucida ('hatching') after three days of in vitro culturing. In the control group 95.1% of embryos 'hatched'. A significantly higher number of embryos that 'hatched' after thawing was observed in the group introduced dropwise directly into liquid nitrogen (60.0%) compared to the group frozen in pipetting 'tips' (37.9%). The group frozen in straws yielded significantly the lowest proportion of 'hatching' embryos (8.1%). These results showed that increasing cooling rates during vitrification of embryos improved their survival.     

Endocrine characteristics of late pregnant hyperketonaemic ewes and their reproductive performance following the induction of ovarian cyclicity out of the breeding season

Ketosis was diagnosed in a flock of Merino ewes that conceived from synchronised oestrus in the early autumn period. On day 140 of pregnancy the ewes were sampled for determination of betaOH-butyrate (BHB), AST, glucose, non-esterified fatty acids (NEFA), total cholesterol (TCH), insulin, T4, T3, cortisol, IGF-1 and leptin. The results were evaluated according to the number of fetuses born some days later and the presence of hyperketonaemia (BHB: > or = 1.60 mmol/l). In May, about 3 months after lambing, cyclic ovarian function was induced (Cronolone + eCG), and the ewes were inseminated artificially (AI) 48 h after the removal of gestagen-containing sponge. At the time of AI and 10 days later blood samples were collected again to check the plasma levels of the same constituents as previously (in samples taken at AI), and to monitor the ovarian response by assaying progesterone (in both samples). On day 140 of gestation significantly lower BHB levels were detected in dams with single (n = 41) than in those with twin (n = 57) pregnancies. Hyperketonaemia was found only in ewes bearing twins (n = 27). These animals had higher NEFA and cortisol, and lower TCH, insulin, IGF-1, leptin and T3 levels than their normoketonaemic twin-bearing flock-mates, and those with single pregnancy. The blood glucose concentrations varied within a wide range, and the means of groups did not exhibit any significant differences. The formerly hyperketonaemic individuals were characterised by lower leptin level 3 months after lambing, and they showed a poorer response to the cycle-induction procedure than the others. The non-responders had lower IGF-1 and leptin levels than those ovulated after this treatment. It was concluded that the subclinical form of ovine ketosis is characterised by complex endocrine alterations, reflecting an obvious form of negative energy balance. If attempts to induce cyclic ovarian function outside the breeding season are made soon after lambing, the ovarian response and fertility of these ewes may also be depressed.     

Antigens from Rhipicephalus sanguineus ticks elicit potent cell-mediated immune responses in resistant but not in susceptible animals

In the present study we compared the immunological reactions between Rhipicephalus sanguineus tick-infested susceptible (dogs and mice) and tick-resistant hosts (guinea pigs), elucidating some of the components of efficient protective responses against ticks. We found that T-cells from guinea pigs infested with adult ticks proliferate vigorously in the presence of concanavalin A (ConA), whereas ConA-induced cell proliferation of tick-infested mice and dogs was significantly decreased at 43.1 and 94.0%, respectively, compared to non-infested controls. Moreover, cells from mice and dogs submitted to one or three successive infestations did not exhibit a T-cell proliferative response to tick antigens, whilst cells from thrice tick-infested guinea pigs, when cultured with either a tick extract or tick saliva, displayed a significant increase in cell proliferation. Also, we evaluated the response of tick-infested mice to a cutaneous hypersensitivity test induced by a tick extract. Tick-infested mice developed a significant immediate reaction, whereby a 29.9% increase in the footpad thickness was observed. No delayed-type hypersensitivity (DTH) reaction was detected. Finally, the differential cell count at the tick attachment site in repeatedly infested mice exhibited a 6.6- and 4.1-fold increase in the percentage of eosinophils and neutrophils, respectively, compared to non-infested animals, while a decrease of 77.0-40.9 in the percentage of mononuclear cells was observed. The results of the cutaneous hypersensitivity test and the cellular counts at the tick feeding site for mice support the view that tick-infested mice develop an immune response to R. sanguineus ticks very similar to dogs, the natural host of this species of tick, but very different from guinea pigs (resistant host), which develop a DTH reaction in addition to a basophil and mononuclear cell infiltration at the tick-attachment site. In conclusion, saliva introduced during tick infestations reduces the ability of a susceptible animal host to respond to tick antigens that could stimulate a protective immune response. As a consequence, the animals present a lack of DTH response and disturbed cellular migration to tick feeding site, which can represent a deficient response against ticks.     

Experimental vascular graft for liver transplantation

Hepatic artery thrombosis is a major cause of graft failure in liver transplantation. Use of donor interponates are common, but results are controversial because of necrosis or thrombosis after rejection. Reperfusion injury, hypoxia and free radical production determinate the survival. The aim of the study was to create an 'ideal' arterial interponate. Autologous, tubular graft lined with mesothelial cells, prepared from the posterior rectus fascia sheath, was used for iliac artery replacement in eight mongrel dogs for six months under immunosuppression. Patency rate was followed by Doppler ultrasound. Eight grafts remained patent and another two are patent after one year. The patency rate was good (median Doppler flow: 370 cm/sec) and there was no necrosis, thrombosis or aneurysmatic formation. The grafts showed viable morphology with neoangiogenesis, appearance of elastin, smooth muscle and endothelial cells. Electron microscopy showed intact mitochondrial structures without signs of hypoxia. Tissue oxygenation was good in all cases with normal (< 30 ng/ml) myeloperoxidase production. In conclusion, this autologous graft presents good long-term patency rate. Viability, arterialisation and low thrombogenicity are prognostic factors indicating usability of the graft in the clinical practice without the risk of rejection. Further investigations such as cell cultures and standardisation are necessary.     

Effects of transcutaneous electrical nerve stimulation on the fatty acid profile of rabbit longissimus dorsi muscle (preliminary report)

This study was designed to investigate whether transcutaneous electrical nerve stimulation (TENS) of the longissimus dorsi muscle (MLD) of rabbits induces specific proportional changes in the muscle fatty acid composition. Ten 4-week-old Pannon White rabbits were exposed to TENS treatment two times a day, with the following settings: 30 Hz, 20 micros impulse length, 10 mA, 2 x 20 min. After a treatment period of 50 days rabbits were slaughtered and the fatty acid composition of the MLD was determined by gas chromatography. The TENS treatment increased the proportions of linoleic (C18:2 n-6), linolenic (C18:3 n-3) and gondoic acids (C20:1 n-9), compared with the control group. The level of palmitic (C16:0), stearic (C18:0), oleic (C18:1 n-9) and eicosapentaenoic (C20:5 n-3) acids significantly decreased. The proportion of total unsaturated fatty acids significantly increased. On the basis of the results obtained, TENS may have similar effects on the muscle fatty acid profile like physical training. Based on the supposal that the composition of membrane structure was also affected, the electrical stimulation of muscles may have further consequences, e.g. on membrane properties.