Differential electrocardiographic study on iberica and duroc breeds of pigduring physical maturation

Sequential electrocardiograms were taken of 50 pigs (25 Iberica and 25 Duro c), from the ages of 5 days to 205 days. The records were analysed to estab lish the normal values of the different electrocardiographic intervals (RR, QRS, QT, TQ and ST intervals), the diastole/systole quotient and heart sco re in the first 7 months of life, as well as age-related electrocardiograph ic variations. In addition, it was intended to determine which of these two breeds showed the greater heart recovery capacity. Finally, positive or ne gative correlations between the RR interval and the electrocardiographic in cidents studied were analysed. The mean values obtained for the electrocard iographic parameters were similar in the two breeds and increased with thei r physical maturity. Analysis of the correlation between the duration of th e heart cycle and the different electrocardiographic incidents showed a pos itive and significant correlation, the r-values being higher for the RR int erval-TQ interval correlation. There was very little correlation between RR interval and heart score in Duroc pigs and practically no correlation betw een the RR interval and the QRS interval in either breed.