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Summary Six electrocardiograms have been taken of a beef cow exhibiting both the normal ECG and the W-P-W syndrome. These electrocardiograms have been illustrated, the cardiac electrical axes calculated, the vector loops constructed, and the cardiac intervals graphed to obtain data for the 7 Figures and table presented. The P-wave has the same configuration in both normal and W-P-W recordings. The P-R interval is decreased in the W-P-W syndrome and remains constant over a wide range of R-R intervals. The QRS duration is increased 50% during W-P-W episodes. The P-QRS (W-P-W) interval seldom equals the P-QRS (normal) interval. Duration of the T-wave remains the same whether W-P-W or normal. The QRS and T wave axes exhibit similar relationships to each other whether normal or W-P-W patterns are calculated even though the orientations are markedly different. Zusammenfassung Das W-P-W-Syndrom in einer Hereford-Kuh Bei einer Kuh der Hereford-Rasse wurden zu verschiedenen Zeiten EKG aufgenommen. Diese waren zeitweise normal, zeitweise zeigten sie ein Wolff-Parkinson-White-Syndrome. Die P-Zacke wies sowohl in den Normal- als auch in den WPW-Schlaagen eine normale Konfiguration auf. Das PR-Intervall war wahrend der Phasen des W-P-W-Syndroms verkurzt und ziemlich konstant. Die QRS-Dauer wahrend den WPW-Episoden war um 50% verlangert. Das P-QRS-Intervall der WPW-Schlage war selten gleich lang wie das P-QRS-Intervall der Normalschlage. Die Dauer der T-Zacke bei den Normal- und WPW-Schlagen war gleich lang. Die QRS- und T-Achse weicht bei den WPW-Schlagen stark von der normalen Richtung ab. Dessen ungeachtet ist aber der Winkel, den die QRS- und T-Achse einschliesk bei den Normal- und WPW-Schlagen der gleiche. Resume Le syndrome de Wolff-Parkinson-White chez une vache de race Hereford Six electrocardiogrammes ont ete enregistres chez une vache presentant alternativement un Ecg normal et le syndrome de Wolff-Parkinson-White. Ces electrocardiogrammes ont ete photographies, on calcula les axes electriques du coeur, on construisit les courbes vectorielles et les intervalles cardiaques ont ete representes graphiquement de maniere a obtenir les donnees necessaires pour les 7 figures et tables presentees dans ce travail. L'onde P a la meme configuration dans les traces normaux et dans le syndrome de W-P-W. L'intervalle P-R est diminue dans le syndrome W-P-W et reste constant pendant une longue serie d'intervalles P-R. La duree QRS est accrue de 50% durant les episodes W-P-W. L'intervalle P-QRS dans le syndrome W-P-W egale rarement l'intervalle P-QRS du trace normal. La duree de l'onde T reste la meme dans les deux traces. Les axes des ondes QRS et T montrent des relations semblables les unes aux autres tant dans le type normal que dans le type W-P-W, bien que leur orientation soit nettement differente. Resumen El sindrome W-P-W en una vaca Hereford En una vaca de engorde se tomaron seis electrocardiogramas, mostrando normales el ecg y el sindrome W-P-W. Estos electrocardiogramas han sido ilustrados, calculados los ejes cardiacos electricos, construidas las asas vectoriales y dibujados los intervalos cardiacos para obtener los datos precisos de las 7 figuras y la tabla reproducidas. La onda P tiene la misma configuracion tanto en los registros normales como en los W-P-W. El intervalo P-R disminuye en el sindrome W-P-W y permanece constante a lo largo de una amplia serie de intervalos R-R. La duracion QRS aumenta en un 50% durante los episodios W-P-W. El intervalo P-QRS (W-P-W) raras veces iguala al intervalo P-QRS (normal). La duracion de la onda T permanece igual tanto en los W-P-W como en los normales. Los ejes de onda QRS y T muestran relaciones similares para con cualquier otros modelos normales o W-P-W calculados, aunque las orientaciones sean senaladamente diferentes.

CONTRIBUTIONS to the knowledge of the influence of reproduction, especially that of the individual reproductive hormones upon the growth rate in the female, have not been numerous. In most of these investigations the effects of ovariectomy or of pregnancy were generally studied. Evidence that ovariectomized rats grow more rapidly than virgin controls has been presented by Stotsenburg (1913), Slonaker (1930), Freudenberger and Billeter (1935), Freudenberger and Howard (1937), Freudenberger and Hashimoto (1937–38 and 1939) Bogart et al. (1940), and Tang (1941). Pronounced differences in the rate of growth were shown to exist between pregnant and virgin female rats of the same age by Slonaker (1927), Cole and Hart (1938) and Bogart et al. (1940). The effects of pregnancy, pseudopregnancy (Hart and Cole, 1939) and ovariectomy upon growth indicate that the reproductive hormones may be directly or indirectly involved.

Much of the material on the genetics of the horse and donkey is either old or has been done in Europe and Asia. This is because horse breeding has become relatively unimportant in the United States since the replacement of horses by tractors, trucks, and automobiles. Recently, however, horse breeding has gained importance in the United States because of the pleasure horse assuming an important role in our leisure society.

Published October 1951. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

Summary and Conclusions1. Testosterone injected intramuscularly at the rate 1 mg/kg of body wt per week in beef heifers and steers from 500 to 800 lb live wt had the following effects: a) Increased average daily gain and decreased feed requirements per unit gain, b) Increased weight of the thyroid glands, c) Increased secretory activity of the thyroid gland, d) Decreased stores of thyroxine in the thyroid gland. 2. Correlations between thyroid gland activity and growth rate are suggested as indicating a possible mode of the action of testosterone in affecting growth of beef cattle. 3. A method is described using the time of asphyxiation of thiouracil-treated mice as a measure of thyroxine content of the thyroid gland.

The potash method of clearing specimens for bone studies has been in use for some time. This method is particularly valuable in studies of bone development or in determining the relation of nutrition to bone structure. The relation of the bones to one another and, also, finer details, can be seen better by this method than is possible by dissection. One disturbing factor is that the large amount of fat in most specimens obscures vision to such an exte'nt that little can be seen in some regions. No solvent has been found effective in eliminating the masses formed by the combination of the potash with the fat (Strong, 1925). Regarding the extraction of fat from specimens prior to clearing with potash, Dawson (1926) states that leaving the specimens in acetone for a considerable period after fixation in 95 percent alcohol is the most satisfactory method. However, we have found from experience that this method is not entirely satisfactory. All the fat is not removed from larger specimens and there is considerable waste of the solvent, due to frequent changing. For these reasons an apparatus which keeps the specimens in a purified solvent is desirable, and one of this type is described. The effectiveness of various solvents in removing the fat from specimens is also reported. The apparatus keeps the specimens in a purified solvent by continuous distillation and intermittent siphoning (fig. 1). The solvent in a pyrex flask (A) is boiled in a steam bath (B). The vapor passes up the tube and is condensed in the condenser (C). The extraction cup (D) is made by cutting the bottom from a large round bottle. A tin lid (E) covers the cup and is packed with cloth around the edges (G). A stopper (F) over the lower end of the condenser, fits closely against the lid to prevent escape of the solvent. A piece of screen wire (H) is placed in the bottom of the cup to prevent specimens from stopping up the siphon tube. The cork (J), through which the siphon tube passes, is sealed with gelatin glue. The siphon tube is flattened at (K) so that the surface tension of the liquid will start the siphoning action. Otherwise there is a tendency for the solvent merely to trickle over. The solvent should siphon over every 20 to 60 minutes. The following method has been followed in preparing the specimen for clearing. Immediately after killing, the hair is removed with sodium sulfide. The specimen is fixed in 95 percent alcohol for at least 3 days. If trichlorethylene,2 alone or in a mixture, is used as a solvent, it is necessary to dehydrate the specimens before extracting the fat, because water and trichlorethylene do not mix. The fat is extracted by the method of continuous purification of the solvent for five days. In case ether or trichlorethylene, alone