Feed Efficiency in Bull Testing Programs Dr. Lisa Kriese-Anderson Associate Professor/ Extension Animal Scientist Auburn University 2007 NBCEC Brown Bagger
Feed Efficiency Measures • More than two dozen measures of feed efficiency in the literature – Gross Feed Efficiency • Gain per unit of DMI – Feed Conversion Ratio (FCR) • DMI per unit of gain • BIF Guidelines adjust to MBW – Feed Intake – Residual Feed Intake 2007 NBCEC Brown Bagger
Feed Efficiency Measures • Most are moderately heritable – h 2 = 0. 20 to 0. 40 • Many are ratio based • Many are specific to a stage of animal growth or production • Most measures of efficiency are highly correlated with other economically important traits 2007 NBCEC Brown Bagger
Review of Literature • Phenotypic correlations between FCR and ADG Phenotypic Author Correlation -0. 74 Arthur et al. (2001 ) -0. 63 -0. 60 2007 NBCEC Brown Bagger Nkrumah et al. (2004) Carstens and Tedeschi (2006)
Review of Literature Author FCR-USFAT 0. 21 Arthur et al. (2001) FCR-USFAT 0. 21 Nkrumah et al. (2004) 0. 11 Carstens and Tedeschi (2006) FCR-USREA 0. 03 Arthur et al. (2001 ab) FCR-USREA -0. 08 Nkrumah et al. (2004) FCR-USREA 2007 NBCEC Brown Bagger Phenotypic Correlation FCR-USFAT • Phenotypic correlations involving FCR Traits 0. 11 Carstens and Tedeschi (2006)
Review of Literature • Phenotypic correlations between FCR and ADG Phenotypic Author Correlation -0. 74 Arthur et al. (2001) -0. 63 -0. 60 2007 NBCEC Brown Bagger Nkrumah et al. (2004) Carstens and Tedeschi (2006)
Review of Literature Genetic Correlation Author FCR-TG -0. 34 Woldehawariat et al. (1977) -0. 53 Koots et al. (1994 ab) FCR-FT -0. 24 Koots et al. (1994 ab) FCR-USFAT 0. 03 Arthur et al. (2001 ab) FCR-SC -0. 10 Arthur et al. (2001 ab) FCR-USREA 2007 NBCEC Brown Bagger Traits FCR-TG • Genetic correlations involving FCR -0. 12 Arthur et al. (2001 ab)
Review of Literature Traits • Genetic correlations involving FCR-Mature Weight FCR-FI 2007 NBCEC Brown Bagger Genetic Correlation Author -0. 14 Koots et al. (1994) 0. 92
Need to Use Caution With Ratio Traits • A favorable decrease in FCR (due to selection) does not necessarily correspond to improvements in efficiency of feed utilization – Could be due to change in growth rate 2007 NBCEC Brown Bagger
Phenotypic Trends of FCR at Auburn 2007 NBCEC Brown Bagger LSMeans Adjusted for Weight
Phenotypic Trends of YWT at Auburn 2007 NBCEC Brown Bagger
Comparison of Trends 2007 NBCEC Brown Bagger
Residual Feed Efficiency • Measure of efficiency talked about in beef research and industry circles for the past 5 years – Actual Feed Intake – Expected Feed Intake • Not correlated to ADG – “Independent” measure of efficiency 2007 NBCEC Brown Bagger
How Do We Get at Measures of Efficiency • Many require collection of feed intake data – States with access to individual feed intake (University based) • • • Alabama (capacity of 96) Florida (Grow. Safe System) Illinois Iowa Texas (Grow. Safe System) West Virginia (Grow. Safe System) 2007 NBCEC Brown Bagger
Feed Efficiency Traits • Many require collection of feed intake data – Some private companies/producers are putting in systems to measure individual feed intake • Model Predicted Feed Conversion – 2 primary software programs are available • Cornell/Cattle Value Discovery System (CVDS) • DECI (MARC) • Validation of software shows both are robust 2007 NBCEC Brown Bagger
Efficiency and Bull Tests • What is needed at traditional bull tests to measure efficiency? – Buy in from purebred producers (consignors) and commercial producers (buyers) that efficiency is important • They need reassurance from academic community that efficiency in growing animals will correspond to efficiency in the cowherd 2007 NBCEC Brown Bagger
Efficiency and Bull Tests • What is needed at traditional bull tests to measure efficiency? – Need the capacity to measure entire contemporary groups – How do we report the data? 2007 NBCEC Brown Bagger
Can Differentiate Animals • Carstens and coworkers – Used index (Crews et al, 2006) to sort bulls involved in a Texas Bull Development Center • RFI, ADG, YWT • Higher index bulls (>105) – 17% ADG – 9% less intake – 22% lower FCR 2007 NBCEC Brown Bagger
LSMEANS for breed effect on ADG of central test bulls adjusted for weight a a ab ab bc c ab c Columns with different letters differ at P < 0. 05 2007 NBCEC Brown Bagger
LSMEANS for breed effect on FCR of central test bulls adjusted for weight a ab ab abc bc c Columns with different letters differ at P < 0. 05 2007 NBCEC Brown Bagger
LSMEANS for breed effect on FI of central test bulls adjusted for weight a ab bc bcd cd d Columns with different letters differ at P < 0. 05 2007 NBCEC Brown Bagger
LSMEANS for breed effect on RFI of central test bulls adjusted for age a bc ab abc cd cd bcd d Columns with different letters differ at P < 0. 05 2007 NBCEC Brown Bagger
Where Do Large Breeders Come In? • Need to encourage large producers to think about efficiency – On farm evaluations – Cooperator herds 2007 NBCEC Brown Bagger
Some Closing Thoughts • This is hard • Need buy in from both sides of industry – They probably need more information • Mass educational effort 2007 NBCEC Brown Bagger
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