<b>Evaluation of residual feed intake in young bulls of the Polled Nellore breed in a performance test</b> - DOI: 10.4025/actascianimsci.v30i4.6464

Abstract

This study evaluated the characteristics: age, weight, daily weight gain (DWG), dry matter intake (DMI), feed conversion (FC), feed efficiency (FE) and residual feed intake (RFI) of young bulls of the Polled Nellore breed in a performance test. Thirty bulls, with initial age of 243.6±30.4 days were used. Dry Matter Intake (DMI) was quantified daily for each animal. The animals were classified by the performance test index (PTI). RFI did not show differences (p > 0.05) among the averages of the groups. The variables weight and DWG were not correlated with RFI. There was high correlation between RFI and FC. FE and FC showed correlation with RFI. The PTI showed high correlation with DMI (r = 0.75). When comparing mean RFI among the bulls, it was observed that less efficient animals showed a DMI 27.7% superior to the most efficient animals. The variable PTI did not identify the most efficient animals in dry matter utilization, because there were low correlations with FC, FE and RFI. It can be concluded that the bull selection for PTI selects those that shows more weight gain; however, they have more DMI. It is possible to improve the methodology for selection with the inclusion of RFI.