Improving the health and healthfulness of beef J.M. Reecy, and D.C. Beitz Iowa State University

Overview Disease resistance –Infectious Bovine Keratoconjunctavitus –Respiratory Disease Improving the Healthfulness of Beef

Pink Eye Reported in the USA since % of Missouri herds have endemic IBK Average prevalence = 8% More common in the young – 10-60% Immunity develops with age No gender affinity

What Causes “Pink Eye” Moraxella bovis Brannamella ovis? High UV light Dust IBR infection IBR vaccination Mycoplasma infection Mycoplasma bovoculi Trauma Face flies- Musca autumnalis (since 1946)

Options For Control/ Prevention Are the technologies up to the job?

Options For Control/ Prevention Not up to the job –Vaccines –Fly control –Dust control –Pasture clipping

What are the Future Options Genetic selection Improved vaccines Better treatment

Requirements of the project Serve as a model for disease resistance/susceptibility research –Internal parasites - nematodes –Respiratory Use field records –Need to develop data collection scheme

Data Collection Two seasons –When cases are actively observed –Weaning Scoring system Data sheets

Score 2 – An active lesion involving one- third to two-thirds of the cornea. Score 1 – An active lesion involving less than one-third of the cornea.

Score 4 – An active lesion with perforation of the cornea Score 3 – An active lesion involving more than two-thirds of the cornea.

Pinkeye Data Analysis  1823 head (Indiana, Iowa, Missouri, Wisconsin)  Heritability  MTDFREML  Model Y =  + CG +animal +PE + error CG = Sex-weaning group (4) PE = permanent environmental  h 2 = 0.18

Effect of Pinkeye/Corneal Abrasion on Weaning Weight Weaning Weight (Lbs)

Additional Results  No evidence of prior exposure to bovine rhinotracheitis as having an effect  No evidence of Carrier status (M. bovis and B. Ovis) effecting incidence

Tear Film  Lipid layer : Reduces evaporation, prevents contamination  Aqueous layer : Lubrication and protection  Mucus layer : Lubricates and protect the cornea.

Ocular defense factors affecting susceptibility  sIgA and Lactoferrin (Lf) as candidate factors in the tear film influencing susceptibility  Antigen binding: protection against invading microorganisms  Hypothesis: Cattle susceptible to pink eye produce higher levels of sIgA and lower Lf

Probability of Corneal Scarring

MARC Pinkeye data  Gary Snowder ( JAS (3): )  19 years of data  Calves listed as being treated in the herd book  Number of records  907 to 10,947 head per breed  1.3 to 22.4% incidence

BreedN Incidence h 2 Angus6, Hereford4, Red Poll Charolais2, Simmental1, Limousin Gelbvieh2, Pinzgauer Braunvieh MARC I4, MARC III10,

Respiratory Disease Bovine Respiratory Disease is the most common and costly disease in the U.S. National mortality rate for bovine respiratory disease is 6% (NAHMS, 1997) Lung lesions are routinely observed in animals that exhibited no clinical signs

Respiratory Disease Use field records –Need to develop data collection scheme –Treatment data –Lung Score

Designing Beef to Produce a Healthier Product

Overview Goal of Research –Develop the tools to allow breeders to select for healthier beef What does this mean to the beef industry? –It will be able to actively address human health concerns with respect to consumption of beef

Interaction of Genetics and Environment in Causing Human Disease PRIMARILY NURTURE (Environment) PRIMARILY NATURE (Genetics) Motor vehicle accidents Heart Disease Stroke Pneumonia, influenza Nutritional deficiencies, nutritional anemias Cirrhosis of the liver Lung cancer Osteoporosis Diabetes Obesity Colon cancer Breast cancer Dwarfism

Two Leading Causes of Human Deaths in the U.S. Cause of death Rank 1 Deaths Percentage All causes--- 2,443, Diseases of heart1696, Malignant neoplasms2557, Cerebrovascular diseases3162, Chronic lower respiratory distress4124, Accidents (unintentional injuries)5106, Diabetes mellitus6 73, Influenza and pneumonia7 65, Alzheimer’s disease8 58, Nephritis, nephrotic syndrome, and nephrosis9 40, Septicemia 10 33, Rank based on number of deaths; total = 79% of all deaths. Source: National Vital Statistics Report, Vol. 15, No. 17

Obesity in U.S. in 2004 BMI > 30, or ~ 30 lbs. overweight for 5'4" person 2004

Calories from Fat SFAMUFAPUFA An Average American Diet34%16%11%7% What are Americans eating? Calories from Fat SFAMUFAPUFA American Heart Association Step I Diet 30%9%14%7% American Heart Association Step II Diet 25%7%12%6% What should Americans be eating?

How Do We Name Fatty Acids? Carbon chain length and # of unsaturated bonds (e.g. 18:0 or 18:1) Name Palmitic (16:0) or Palmitoleic (16:1)  9 Stearic (18:0) or Oleic (18:1)  9 Linoleic (18:2)  9,12

Atherogenic index The atherogenic index as proposed by Ulbricht and Southgate, 1991 =  (MUFAs) +  (PUFAs) 12:0 + 4*(14:0) + 16:0

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

How Does Beef Compare to Other Sources of Fat?

Health-promoting index of several foods Soy oil7.69 Olive oil7.14 Beef PL(Knight)3.03 Chicken2.27 Pork2.13 Lard1.92 Beef(Eichhorn)1.67 Margarine1.61 Beef(Knight)1.52 Beef(Garret)1.49 Food HPI Beef(NLMB)1.43 Beef TG(Knight)1.27 “Extreme” milk fat1.30 Beef(Beitz)1.16 Tallow1.12 “Greatest” milk0.94 “Average” milk fat0.44 “Low” milk fat0.30 Palm kernel oil0.15 Coconut oil0.06 Food HPI

Environment Genotype Phenotype

Feeding systems affecting fatty acid composition Ruminant species - Rumen biohydrogenation - Forage increases reductive potential of the rumen - Rumen can be overloaded with PUFA (CLA increase in pasture-fed cattle)

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

Triacylglcyerols Phospholipids Sample Processing 974 Steaks from beef cattle

Statistical analysis Steers and bulls slaughtered at normal finishing weight. Contemporary groups based on year, farm of origin, feedlot, and harvest date. 63 contemporary groups (1-65 cattle per group). 77 sires (1-40 progeny per sire).

Variation in Health-Promoting Index of Beef

Composite Fatty Acid Composition

Composite Fatty Acid Indexes

Does Breed to Breed Variation Exist in Fatty Acid Composition Collaborative project with Larry Cundiff at Meat Animal Research Center 588 animals –Sire Lines AngusBeefMaster HerefordBonsmara BrangusRomosinuano –Dam Lines AngusMARC III

Fatty AcidLowHighP-value 14: < : < : : < : < : Significant Differences in Fatty Acid Composition Exist Between Breeds

IndexLowHighP-value AI < :1/16: < :1/18: <.0001 x:1/x: < / < / <.0001 Significant Differences in Fatty Acid Indexes Exist Between Breeds

IndexLowHighP-value 18:1t :1c < :3n <.0001 CLAc9,t :5n :6n Significant Differences in Fatty Acids Exist Between Breeds

New Compounds Conjugated Linoleic Acid –Anti-cancer, anti-obesity, anti-diabetic Heme and non-Heme Iron –correlated positively with hematological status Spingolipids –may inhibit colon cancer in humans Creatine –improves muscle strength Vitamin E –negatively correlated with risk of prostate cancer

Are Single Nucleotide Polymorphisms Associated with Fatty Acid Composition 172 purebred American Angus Bulls and Steers ISU Meat Quality Selection Herd Stearoyl-CoA Desaturease SNPs –Enzyme responsible for desaturating fatty acids –SCD 316, SCD536, SCD1278 Amino AcidGenotype# AnimalsPercentage VVCC11567 VACT5733

Effect of a Stearoyl-CoA Desaturase DNA polymorphism Lipid 16:1/16:0 P-Value VAVV Phospholipid6.3%6.8%0.13 TAG14.5%13.9%0.02

Summary Triacylglycerol fatty acid composition is more heritable than phospholipid fatty acid composition. Fatty acid desaturation is more heritable in beef cattle than is fatty acid elongation. Health Promoting index/AI is highly heritable. Differences in fatty acid composition exist between breeds. DNA markers can be used to identify more healthful beef.

Conclusions Fatty acid composition is a heritable trait. Lipid composition can be improved with respect to human health by genetic selection.

Where Do We Go From Here? 1)Obtain Research Funding 2)Develop resource populations American Angus (have in hand) Meat Animal Research Center 3)Correlation With Other Traits 4)Identify Molecular Markers

Where Do We Go From Here? 5)Human Studies Taste Test Panels Feeding Studies 6)Identification of Novel Health Compounds 7)Development of New Analytical Techniques

Acknowledgements National Beef Cattle Evaluation Consortium USDA Center for Designing Foods to Improve Nutrition at the Iowa State University The Wise and Hellen Burroughs Endowment National Cattleman’s Beef Association Collaborators