Biomedical subjects
Publications and source records attributed to H Merkt.
A stallion got fatal injuries by kicks of a maiden mare because a so called "panic hook" untied spontaneously. The use of such hooks to secure mares during mating should therefore not be recommended.
The purpose of this study was to examine the influence of an eight day starvation period on semen characteristics and some endocrine parameters of young bulls. The experiments were performed with 18 bulls in two trials showing the following set-up: pre-treatment period (7 or 20 days), starvation period (8 days), realimentation period (3 days) and control period (64 days). During the pre-treatment period and the control period the bulls obtained a well-balanced food-ration, during the period of starvation only 2 kg straw daily. During the starvation period the bulls lost 6% of their bodyweight. No influence on general health could be noticed. The concentrations of testosterone, LH, bovine growth hormone, insulin and insulin-like growth factor decreased significantly during or after the period of starvation. There was no clear influence in volume, sperm density and total number of sperm due to the metabolic stress during the hunger period. The initial progressive motility of sperm was not affected. The percentage of morphological abnormal spermatozoa increased 45-55 days after the hunger period. Simultaneously the semen freezability was decreased. An influence on the acrosomal morphology of frozen/thawed spermatozoa could not be obtained. The concentration of fructose, citric acid and glycerylphosphorylcholine (GPC) of the seminal plasma was insignificantly influenced during the period of starvation. The realimentation caused a stimulating effect on the secretion mainly of GPC.
A reduction in the motility of the spermatozoa in stallion semen stored in pellet form for 23 years in liquid nitrogen at -196 degrees C could not be seen after thawing. The insemination of a mare with this semen resulted in a normal pregnancy. A normally developed, healthy male foal was born after a gestational period of 321 days.
A malpractice caused a reduction in the value of a 15 years old mare, however the owner of the mare had not given the veterinarian the chance to reduce the injury and his claim of damages was unrealistically high.
The rules for the minimal requirements in health and genital potency for stallions formulated by GOTZE (1950) are reformulated, taking into consideration the results achieved by KLUG (1982) and KENNEY (1983). A stallion must be free of phenotypic hereditary faults. Furthermore he has to be in general and genital health and must be fit in both, potentia coeundi and generandi. The figures are based on the examination of thoroughbred and so called "warmblood" stallions. However, they can be adapted to other breeds like draughthorses and ponys.
The newborn guanaco (Lama quanaco e ) is covered by an extra fetal membrane. It shares this characteristic with the newborns of old-world camelids. This membrane, which is lubricated by the watery amnionic fluid typical for camelids, facilitates the delivery of the conceptus. the newborn gets rid of this membrane itself, since in camelids mothers do not lick their offsprings.
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Over the last years the percentage of foals lost by EHV at term or close to term seems to be higher than in former years. Furthermore, the pathological findings seem to shift from liver to lung. So far there has been no explanation for this phenomenon.
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Excessive iodine supply of at least 700 mg inorganic iodine in foals and of more than 350 mg iodine in pregnant and lactating mares cause a high incidence of goitres in the newborn and disorders in the long leg bones of foals. Elevated phosphorus and alkaline phosphatase content in the blood may indicate a severe disturbance in the bone metabolism. Of 39 pregnant mares 17 aborted and some of the mares also showed goitres. After withdrawal of the iodine supply normalization took place. Foals born more than 6 weeks later showed normal conditions. The goitres in the mares and the high blood levels of iodine decreased.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.