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Comparison and relation among different estimates of residual feed intake for Japanese Black (Wagyu) bulls
Author(s) -
HOQUE Azharul,
OIKAWA Takuro
Publication year - 2004
Publication title -
animal science journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.606
H-Index - 38
eISSN - 1740-0929
pISSN - 1344-3941
DOI - 10.1111/j.1740-0929.2004.00176.x
Subject(s) - heritability , residual feed intake , statistics , zoology , linear regression , regression analysis , biology , regression , mathematics , body weight , feed conversion ratio , genetics , endocrinology
Residual feed intake (RFI) was estimated by ordinary regression (RFI ord ), linear regression (RFI reg ), and genetic regression (RFI gen ) for Japanese Black bulls, and compared among them by the magnitude of correlations, heritabilities, and empirical mean squared errors. The estimations were made for a total test periods of 140 days (77 bulls) and 112 days (663 bulls) sub‐divided each into two equal stages: first half and second half of the test periods. The means of RFI reg , RFI ord , and RFI gen for the total test periods were 1.09, −0.05, and −2.21 kg/day, respectively. The genetic variation exists for these estimates at different stages of the test period. High genetic and phenotypic correlations (>0.95) were found between RFI ord and RFI gen , confirming that these are regarded practically as the same traits. The phenotypic variance (0.714) and heritability (0.24) of RFI ord were close to those of RFI gen (0.726 and 0.25, respectively). According to the empirical mean squared errors from the result of the total test periods, RFI gen yielded better estimates of RFI. The high to moderate heritabilities for RFI ord were estimated for the three stages of the test periods, indicating that RFI ord might be an alternative estimate for genetic improvement of feed utilization.