Autores
Sarah Figueiredo Martins Bonilha, Renata Helena Branco, Tatiana Lucila Sobrinho Corvino, Guilherme Fernando Alleoni, Leopoldo Andrade de Figueiredo, Alexander George Razook
Resumo
Residual feed intake (RFI) is an alternative measurement of feed efficiency, which is theoretically independent of production level and body size, calculated as the difference between actual feed intake and predicted DMI based on metabolic BW and ADG. The objective of this work was to identify the relationships between RFI and size of important internal organs in Nellore bulls classified in low and high RFI levels. Thirty three young Nellore bulls, with minimum RFI -0.640 and maximum RFI 0.690, were slaughtered and had their internal organs weighted. Table bellow shows the least-square means of final BW (FBW); empty BW (EBW); liver (LIV); kidney (KID); gastrointestinal tract (GIT); KPH; and other internal organs (IOR). No differences were detected in body size between low and high RFI bulls. Low RFI bulls had smaller important internal organs (LIV, KID, and GIT) than high RFI bulls. For KPH, no differences were detected. Low RFI bulls ate less than high RFI bulls, had smaller internal organs and the same fat content.
Table 1. Internal organs of low and high RFI bulls
|
|
LOW RFI
(n=18) |
HIGH RFI
(n=15) |
P |
|
FBW, kg |
374a |
391a |
0.1148 |
|
EBW, kg |
343a |
357a |
0.1797 |
|
LIV, kg |
4.16b |
4.63a |
0.0043 |
|
KID, g |
673b |
786a |
0.0389 |
|
GIT, kg |
21.8b |
24.3a |
0.0411 |
|
KPH, kg |
5.25a |
5.38a |
0.8018 |
|
IOR, kg |
10.4a |
11.1a |
0.0711 |
Within a row, means with a common superscript letter do not differ (P < 0.05) by least-square means adjusted for Pdiff.
2009 ASAS ADSA Joint Annual Meeting
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