Autores
Tatiana Lucila Sobrinho Corvino, Renata Helena Branco, Angelo Polizel Neto, Sarah Figueiredo Martins Bonilha, Leopoldo Andrade de Figueiredo, Alexander Geoge Razook
Resumo
Residual feed intake (RFI) is the difference between DMI observed and predicted; based on metabolic BW and ADG. Feeding behavior influences RFI, however the relationships between there traits are not well known. The objective of this research was to evaluate the differences in feeding behavior of low and high RFI Nelore bulls selected for post weaning weight. The experiment was conducted at CAPTA Pecuária de Corte – Instituto de Zootecnia, Sertãozinho - São Paulo/Brazil. Thirty nine Nelore bulls had RFI evaluated (112 d in individual pens) and were classified in: low RFI (<0.5 SD; more efficient; n=21) and high RFI (>0.5 SD; less efficient; n=18). Feeding behavior was evaluated at 10 min intervals, during 24 h, in two random d, to determine feeding and chewing categories. Measured traits were daily feed duration (DFD), chewing time (CHT) and daily feed attendance (DFA). DFD/DMI had significant difference for RFI levels, being more efficient bulls (low RFI) those with lesser intake and greater time spent on feeding than less efficient ones (high RFI). Low RFI bulls used food with higher efficiency, ingesting slowly and retaining more nutrients than high RFI bulls.
Table 1. Feeding behavior of low and high RFI Nelore bulls
|
LOW RFI |
HIGH RFI |
P |
n |
|
|
--- |
RFI |
|
|
|
DMI, kg/d |
|
|
|
DFD, min |
|
|
|
DFD/DMI, min/kg DM |
|
|
|
DFA, event |
|
|
|
DMI/event, kg DM/event |
|
|
|
DFD/event, min/event |
23.6ª |
|
0.440 |
CHT, min |
478ª |
|
0.125 |
CHT/DMI, min/kg DM |
85.9ª |
|
0.093 |
Within a row, means without a common superscript letter differ (P < 0.05) by Student Newman-Keuls test.
2009 ASAS ADSA Joint Annual Meeting
Íntegra (PDF)