1 Investigating Opportunities Available in Genetic Selection for Healthy Beef J R Tait and James Reecy Iowa State University

2 Product Branding

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4 Fatty Acids Fatty acid concentrations determine healthfulness of the lipid Fatty acid concentration is influenced by: Nutrition (Duckett et al., 1993) Breed (Pitchford et al., 2002) S. K. Duckett et al J. Anim. Sci. 71: W. S. Pitchford et al J. Anim. Sci. 80:

Triacylglcyerols Phospholipids Sample Processing Steaks from beef cattle

16:018:0 16:118:1 Fatty acid synthesis 14:1 14:0 Fatty Acid Synthesis and Modification

Atherogenic index The atherogenic index as proposed by Ulbricht and Southgate, 1991 =  (MUFAs) +  (PUFAs) 12:0 + 4*(14:0) + 16:0 Ulbricht, T.L.V., and D.A.T. Southgate Lancet 338:8773

Health Promoting Index =  (MUFAs) +  (PUFAs) 12:0 + 4*(14:0) + 16:0

Variation in Health-Promoting Index of Beef

< Number of Cattle Percentage C14:0 Variation in C14:0 Concentration of Beef

11 Variation in Iron Content of Beef MenFemale

12 Genetic Analysis Estimate h 2 of fatty acids in Angus beef: 14:0, myristic acid 14:1, myristoleic acid 16:0, palmitic acid 16:1, palmitoleic acid 18:0, stearic acid 18:1, oleic acid 18:2, linoleic acid

13 Data Description Data collected from Angus-sired bulls and steers 87 sires with 1 to 41 progeny Calf-fed management Corn-based finishing rations

14 Data Description Longissimus dorsi sample External connective tissue was removed Fatty acids evaluated by gas chromatography

15 Data Descriptors Fatty Acid Mean % of lipid SD % of lipid Min % of lipid Max % of lipid 14: : : : : : :

16 Genetic Analysis MTDFREML Sire model Contemporary group definition: Herd of origin Sex Feedlot management treatment Harvest date

17 Genetic Analysis Model: Y = Xb + Zu + e Fixed effects (b): Model I: Contemporary group only Model II: Cont group & lipid covariate Random effects (u & e): Sire Error

18 Heritability Estimates (% of lipid) Fatty Acid h 2 Model I SE Model I 14: : : : : : :

19 Heritability Estimates (% of lipid) Fatty Acid h 2 Model I SE Model I h 2 Model II SE Model II 14: : : : : : :

20 Heritability Estimates (% of lipid) Fatty Acid h 2 Model I SE Model I h 2 Model II SE Model II Δ h 2 Model II - I 14: : : : : : :

21 Discussion Generally, little change in h 2 estimates with Model II Short-chain, saturated fatty acids are heritable 14:0 (0.49) 16:0 (0.43) Monounsaturated fatty acids are heritable 16:1 (0.49) 18:1 (0.38)

22 Genetic Correlation Estimates Fatty Acid HCW12 FatREAMARBW-B Shear 14: : : : :

23 Conclusions Opportunities exist to select for fatty acid composition of beef Genetic correlations? Fatty acid relationships to consumer acceptability need to be investigated

24 Where do we go from here? Genetic variability exists for fatty acids Very expensive traits to measure Are there other characteristics which make beef “healthful” to consumers? Jan release of BovineSNP50

25 Where do we go from here? Iowa State University, in collaboration with NBCEC, proposed a Healthfulness of Beef study utilizing the BovineSNP50 Discovery and Validation both in the experimental design Pfizer Animal Genetics chose to invest in this project and vision for the beef industry

Used for Beef Cattle Seed Stock Populations Longissimus Dorsi Samples Nutrient Composition Data Tenderness / Taste Data Develop Guidelines for Selection of New Breeding Stock EPDs/DNA Markers Collection of Used for Bulls and/or Genotypes with Superior Genetic Merit for Beef Healthfulness National Cow Herd Management Selection Genetic Evaluation Carcass Data Collection of Used for

27 Acknowledgements ISU – Center for Designing Foods to Improve Nutrition ISU – Burroughs Endowment National Cattlemen’s Beef Assoc. U.S. Meat Animal Research Center NBCEC – National Beef Cattle Evaluation Consortium Pfizer Animal Genetics Jim Reecy Research Group – Mary Sue Mayes, Matt Schneider Don Beitz Research Group – Travis Knight, Shu Zhang, Jon Schoonmaker, Grace Duan, Matt O’Neil Dorian Garrick Rohan Fernando