High prevalence of mycoplasmas in the genital tract of asymptomatic stallions in Austria

Mycoplasma equigenitalium and M. subdolum have been implicated in genital disorders and infertility of horses. The reported cytopathic effects of M. equigenitalium observed in vitro underscore its potential pathogenic role in reproductive dysfunction in mares. This study was initiated to determine the prevalence of mycoplasmas in the genital tract of stallions in relationship to age, clinical signs, geographic location and semen quality. For this purpose the mycoplasma flora of the genital tract of 116 stallions of the Noric breed was determined by isolation and colony immunoblotting and by polymerase chain reaction (PCR) assays. Of 438 swabs from the genital tract, pre-ejaculatory fluid and semen samples, 352 (80%) samples were positive by PCR and 125 (29%) were positive by culture. Mycoplasmas were isolated predominantly from the fossa glandis and urethra and less frequently from the penis shaft and from semen. M. equigenitalium (89 isolates) and M. subdolum (70 isolates) were the predominant species identified. M. equirhinis and M. felis were detected in 27 and 8 samples, respectively. Comparison of these isolations with clinical signs, semen quality, and age of the stallions revealed no significant correlation. However, geographical location of the stallion significantly correlated with mycoplasma detection. These results suggest that mycoplasmas are present as commensals in the genital tract of stallions. Thus, clinically healthy stallions may present a permanent reservoir for infection of mares via venereal transmission.     

Animal welfare aspects regarding the raising of breeding ostriches in Germany

The commercial housing of African Ostriches in Germany for the breed and meat production still represents a disputed topic under the criterion of the animal's welfare. Above all critics state that the frequently wet-cold weather in Germany impairs the well-being and health of the animals. So far however there are just a few scientifically documented data about requirements for housing conditions of ostriches in Central Europe and thus hardly answers whether housing in Germany is possible under the criteria of the animal's welfare. This study tried to evaluate ostrich housing under South German climatic conditions (Rhine level), on the basis of behavioral observations of breeding ostriches. The use of the stable and the influence of different climatic parameters on the behavior were considered. In addition the behavior of 18 adult animals in 5 breeding groups from January to December 2002 was observed. Parallel various climatic data were raised. The housing of the animals took place in open stables with unrestricted pasture possibility. The ostriches reacted in their behavior to different climatic conditions. Particularly at cold weather and adverse soil conditions they used the open stable increasingly as weather protection. In addition, with increased wind velocities the animals spent more time in the stables. The daily amount of precipitation showed no influence on the frequency or duration of the stable use. Rainfall did not animate the animals to look for protection within the stable, but more to set itself on the ground in the external enclosure. The locomotion activity of the animals was strongly in dependence to the reproduction time and the territorial behavior and therefore highest in spring. On cold days the animals performed their reproduction behavior mainly in the stable. For the comfort behaviour distinct weather dependence was seen particularly for sand bathing. Warm temperatures and dry sand were the preconditions for it. Regarding the results it seems, that with the conditions existing on the examined farm, housing of ostriches under respect of animal welfare in Germany is possible. New regulations are to be demanded, adjusted to the newest level of knowledge about ostrich husbandry, with requirements for care, support, accommodation and nutrition of the animals as well as about the qualification of the owners. An occasional hobby animal husbandry limited to few single ostriches is to be rejected. Further scientific investigations at other farms, possibly also under variable climatic conditions are however necessary.     

Testicular blood flow and plasma concentrations of testosterone and total estrogen in the stallion after the administration of human chorionic gonadotropin

The goal of this study was to investigate for the first time a possible association between plasma concentrations of testosterone and total estrogen and testicular blood flow in the stallion. Correlations between these variables were calculated before and after administration of human chorionic gonadotropin (hCG). Eight mature warmblood stallions received 5,000 IU hCG intravenously, and four stallions received solvent only. Testicular blood flow in the left and right testicular arteries was assessed using colour Doppler sonography by measuring blood flow volume (BFV) and pulsatility index (PI) immediately before (time 0) and 1, 3, 6, 12, 24, 72, 120 and 168 h after hCG administration. EDTA blood samples were collected after each examination from a jugular vein to measure plasma testosterone and total estrogen concentrations. After treatment, the BFV increased and was elevated at 1 h and between 12 and 24 h. The profile of the PI was contrary to that of the BFV throughout the study period. Following hCG, there was a biphasic increase in testosterone concentration with maxima between 1 and 3 h and between 24 and 72 h, and there was a monophasic increase in the total estrogen concentration with a maximum between 6 and 24 h. At time 0, the total estrogen concentration correlated significantly with BFV (r=0.90; P<0.05) but the testosterone concentration did not (P>0.05). The testosterone and total estrogen concentrations did not correlate with PI (P>0.05). The total estrogen concentration, but not testosterone, correlated well with BFV after injection of hCG (P<0.05). The results of this study indicated that the testicular blood flow volume of the stallion may be regulated by estrogens, but additional studies are necessary to investigate whether there is a causal relationship.