Nitrogenous metabolism in Thoroughbred and Arabian foals from birth to five months of age / Metabolismo do nitrogênio em potros PSI e Arabe do nascimento aos cinco meses de idade

The maturation of nitrogen metabolism was studied in six Thoroughbred and six Arabian foals. Rectal temperature, heart and respiratory rates and serum concentration of several hematochemical parameters (total protein, urea, uric acid, creatinine, and albumine) were monitored from birth to 5 months of age. In both breeds, all the parameters except albumine showed significant differences over time (P<0.05). The two breeds did not differ from each other at any time point. Statistically significant decreases in urea and creatinine concentrations were related to the growth needs of foals during this critical period of development.

A maturação do metabolismo do nitrogênio foi estudada em seis potros da raça Puro-Sangue Inglês e seis da raça Arabe. A temperatura retal, batimento cardíaco e concentração sérica de várias características hematoquímicos (proteína total, uréia, ácido úrico, creatinina e albumina) foram investigadas do nascimento aos cinco meses de idade. Em ambas as raças, todas as características, exceto a albumina, mostraram diferenças significativas ao longo da maturação (P<0,05). As duas raças não diferiram uma da outra durante os períodos de vida equivalentes. Reduções significativas das concentrações de uréia e creatinina mostraram as necessidades de crescimento dos potros durante esse período crítico de desenvolvimento.

Electrocardiographic changes induced by physical exercise in the jumper horse

The authors conducted an electrocardiographic investigation on eight jumpers of Sella Italiana breed to evaluate cardiovascular changes associated with specific competitions. Electrocardiographic recordings were carried out using an electrocardiograph with a deflection of 10 mm/mV and a paper speed of 25 mm/sec. Recordings were conducted under the following experimental conditions: at rest, after warm up, after a jumping trial, and 15 and 30 minutes after the end of the trial. Significant reductions were observed in the duration of the P wave, of the P-Q interval, and of the R-R intervals immediately after the test. Significant elevations were observed immediately after the test in the range of the T and P waves of the heart rate. The observed changes can be attributed mainly to increase of the sympathetic tone connected with increase of heart rate necessary to satisfy the elevation of the cardiac range. These results are useful to plan and monitor specific training programmes.