0393 Analysis of genetic residual feed intake in Danish Holstein cows by covariance functions using random regression models

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 190-191
Author(s):  
C. Pfeiffer ◽  
B. Li ◽  
P. Lovendahl ◽  
J. Lassen
Author(s):  
Hadi Esfandyari ◽  
Just Jensen

Abstract Rate of gain and feed efficiency are important traits in most breeding programs for growing farm animals. Rate of gain (GAIN) is usually expressed over a certain age period and feed efficiency is often expressed as residual feed intake (RFI), defined as observed feed intake (FI) minus expected feed intake based on live weight (WGT) and GAIN. However, the basic traits recorded are always WGT and FI and other traits are derived from these basic records. The aim of this study was to develop a procedure for simultaneous analysis of the basic records and then derive linear traits related to feed efficiency without retorting to any approximations. A bivariate longitudinal random regression model was employed on 13,791 individual longitudinal records of WGT and FI from 2,827 bulls of six different beef breeds tested for own performance in the period from 7 to 13 months of age. Genetic and permanent environmental covariance functions for curves of WGT and FI were estimated using Gibbs sampling. Genetic and permanent covariance functions for curves of GAIN were estimated from the first derivative of the function for WGT and finally the covariance functions were extended to curves for RFI, based on the conditional distribution of FI given WGT and GAIN. Furthermore, the covariance functions were extended to include GAIN and RFI defined over different periods of the performance test. These periods included the whole test period as normally used when predicting breeding values for GAIN and RFI for beef bulls. Based on the presented method, breeding values and genetic parameters for derived traits such as GAIN and RFI defined longitudinally or integrated over (parts of) of the test period can be obtained from a joint analysis of the basic records. The resulting covariance functions for WGT, FI, GAIN and RFI are usually singular but the method presented here do not suffer from the estimation problems associated with defining these traits individually before the genetic analysis. All results are thus estimated simultaneously, and the set of parameters are consistent.


animal ◽  
2009 ◽  
Vol 3 (2) ◽  
pp. 181-188 ◽  
Author(s):  
H. Hüttmann ◽  
E. Stamer ◽  
W. Junge ◽  
G. Thaller ◽  
E. Kalm

2004 ◽  
Vol 44 (5) ◽  
pp. 405 ◽  
Author(s):  
J. H. J. van der Werf

Residual feed intake is a linear function of feed intake, production and maintenance of liveweight, and as such is an attractive characteristic to use to represent production efficiency. The phenotypic and genetic parameters of residual feed intake can be written as a function of its constituent traits. Moreover, selection indices containing the constituent traits are equivalent with an index that includes residual feed intake. Therefore, definition of the term residual feed intake may be useful to interpret variation in production efficiency, but it does not help in obtaining a better selection response than selection on constituent traits alone. In fact, multiple trait genetic evaluation of constituent traits rather than residual feed intake is likely to be more accurate as this more appropriately accommodates different models for the constituent traits and missing data. For residual feed intake to reflect true biological efficiency in growing animals, it is important that feed intake and liveweight are accurately measured. Accounting for growth and body composition would significantly help in revealing between-animal variation in feed utilisation. Random regression models can be helpful in indicating variation in feed efficiency over the growth trajectory.


2004 ◽  
Vol 82 (1) ◽  
pp. 54-67 ◽  
Author(s):  
J. A. Arango ◽  
L. V. Cundiff ◽  
L. D. Van Vleck

animal ◽  
2007 ◽  
Vol 1 (3) ◽  
pp. 325-334 ◽  
Author(s):  
C.M.R. de Melo ◽  
I.U. Packer ◽  
C.N. Costa ◽  
P.F. Machado

2013 ◽  
Vol 96 (12) ◽  
pp. 7991-8001 ◽  
Author(s):  
G. Manafiazar ◽  
T. McFadden ◽  
L. Goonewardene ◽  
E. Okine ◽  
J. Basarab ◽  
...  

2009 ◽  
Vol 123 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Annaiza Braga Bignardi ◽  
Lenira El Faro ◽  
Vera Lucia Cardoso ◽  
Paulo Fernando Machado ◽  
Lucia Galvão de Albuquerque

2018 ◽  
Vol 162 ◽  
pp. 69-76 ◽  
Author(s):  
Davoud Ali Saghi ◽  
Ali Reza Shahdadi ◽  
Fatemeh Kazemi Borzelabad ◽  
Kourosh Mohammadi

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