The Effect of Animal Disposition on Carcass Traits Eric Berg Meat-Animal Scientist

Introduction Livestock Welfare and Temperament Genetic Potential Physiological Function Environmental Stimuli Quantification of Temperament and Stress

Introduction Project Animals Materials and Methods Results and Discussion Summary Implications

Welfare and Temperament “Quality of Life” Behavioral Needs Health Needs Stress Alteration from Homeostasis Response – “Fight or Flight” Activation Mediation

Welfare and Temperament Stress Physiological Psychological Temperament Response Excitable Animals Hormone Profile

Genetic Potential Selection Criteria Phenotype Performance Carcass Characteristics Reproduction Expected Progeny Differences Marker Assisted Selection 1960 Model Hereford Steer 1969 Model Hereford Steer

Genetic Potential Marker Assisted Selection Bovine Genome Evaluation Commercial DNA Test Single Nucleotide Polymorphs (SNPs)

Physiological Function Stress Disruption of Homeostasis Sympathetic Nervous System Activation (Fight) Mobilization (Flight) Vigilance (Fright) Arousal (Sex)

Physiological Function Stress Response Increased Heart Rate Blood Pressure Respiration Metabolism

Physiological Function Stress Response Inhibited Energy Storage Digestion Growth Immune Function Reproduction

Quantifying Temperament Temperament Evaluation Exit Velocity Chute Score Pen Score

Quantifying Temperament Exit Velocity Separation of Animal from Human Contact Infrared Sensors (1.82 m)

Quantifying Temperament Chute Score Subjective Evaluation Five Point Scale (Grandin, 1993) 1) Calm, no movement 2) Slightly restless 3) Squirming, occasionally shaking chute 4) Continuous, very vigorous movement 5) Rearing, twisting of body, violently struggling

Quantifying Temperament Pen Score Subjective Small Group/Small Pen Five Point Scale (Hammond, 1996) 1) non-aggressive, walks slowly upon approach 2) slightly aggressive, pace fences 3) moderately aggressive, run along fences 4) aggressive, avoids humans, run into gates/fences 5) very aggressive, runs over anything in path

Project EVALUATION OF THE PHYSIOLOGICAL RESPONSE OF FEEDLOT CATTLE TO WORKING CHUTE ENVIRONMENT RELATIVE TO TEMPERAMENT, GROWTH RATE, CARCASS COMPOSITION, BEEF QUALITY, AND TENDERNESS

Temperament Project Central Dakota Feeder Calf Club Steers (n = 183) Blocked by Weight (275 kg) Weighed Periodically (28 d) Temperament Evaluation

Temperament Project Temperament Evaluation Exit Velocity Chute Score Catch Score

Temperament Project Exit Velocity Infrared Sensors (FarmTek, Inc.) Placed at 0.5 m and 2.32 m (1.82 m) Measured at 7 weigh periods

Temperament Project Chute Score Subjective Visual Evaluation Measured at 6 weigh periods Five Point Scale (Grandin, 1993) 1) Calm, no movement 2) Slightly restless 3) Squirming, occasionally shaking chute 4) Continuous, very vigorous movement 5) Rearing, twisting of body, violently struggling

Temperament Project Catch Score Resistance to Head Restraint Measured at 3 weigh periods Five Point Scale (Grandin, 1993) 1) Calm, no movement 2) Slightly restless 3) Squirming, occasionally shaking chute 4) Continuous, very vigorous movement 5) Rearing, twisting of body, violently struggling

Temperament Project Commercial DNA Testing with IGENITY™ Ear Tissue and Hair Sample IGENITY™ Profile including: Docility Tenderness Ribeye Area Fat Thickness Percent Choice Marbling

Materials and Methods Carcass Data Hot Carcass Weight 45 min pH Ribeye Area 12th Rib Fat Kidney, Pelvic Fat Marbling Yield Grade

Materials and Methods Carcass Data – Longissimus Sample 36 hr pH Color Scores L* (light / dark) a* (red / green) b* (yellow / blue) Warner-Bratzler Shear Force

Materials and Methods Statistical Analysis Correlation Coefficients Temperament Carcass Least Squares Means Exit Velocity (Slow, Medium, Fast) Docility Potential (Low, Moderate, High) Carcass Composition Carcass Quality Tenderness

Results and Discussion Exit Velocity Over Time of Study a, b, c Means with different superscripts within rows were different (P < 0.05)

Adjustments to Working Chute

Results and Discussion Subjective Chute Scores Over Time a, b, c, dMeans with different superscripts within rows were different (P < 0.05)

Results and Discussion Exit Velocity Correlation Fat Parameters Final Yield Grade 12th Rib Fat Kidney, Pelvic Marbling Tenderness Warner-Bratzler Shear Force

Results and Discussion Exit Velocity with Carcass Parameters Slower Exit Velocity = Fatter Variable FYG HCW Dress 12thFT REA KPH Marb First Exit Velocity -0.0516 (0.495) 0.068 (0.367) -0.051 (0.504) -0.0479 (0.528) 0.0731 (0.335) 0.0818 (0.279) 0.1282 (0.089) Last Exit 0.1938 (0.011) 0.0711 (0.354) -0.0465 (0.545) 0.1495 (0.051) -0.0799 (0.299) 0.1919 (0.012) 0.1466 (0.054) Average Exit 0.1231 (0.099) 0.0833 (0.265) -0.0332 (0.658) 0.0608 (0.418) -0.0429 (0.567) 0.1853 0.1107 (0.138)

Results and Discussion Exit Velocity with Carcass Parameters Faster 1st Exit Velocity = Tougher Meat Variable Marb WBS pH45 pH36 h L* a* b* First Exit Velocity 0.1282 (0.089) -0.1992 (0.008) 0.1379 (0.069) -0.1133 (0.134) 0.0554 (0.465) 0.0276 (0.716) 0.0385 (0.612) Last Exit Velocity 0.1466 (0.054) -0.0763 (0.320) -0.0226 (0.769) -0.1449 (0.058) 0.1079 (0.159) 0.1347 (0.078) 0.1621 (0.034) Average Exit Velocity 0.1107 (0.138) -0.1450 (0.052) 0.0703 (0.350) -0.1709 (0.022) 0.0806 (0.282) 0.1071 (0.152) 0.1315

Results and Discussion Exit Velocity with Carcass Parameters b b a a, b Means with different superscripts within rows were different (P < 0.05)

Results and Discussion Catch Score Correlation Quality Parameters Marbling Color Scores L* (Lightness / Darkness) a* (Red / Green) b* (Yellow / Blue) 36 hour pH

Results and Discussion Catch Score with Carcass Parameters Higher Catch Score = Less marbling Higher pH Darker meat Variable Marb pH36 h L* a* b* First Catch Score -0.1078 (0.149) 0.3032 (< 0.001) -0.1957 (0.009) -0.1509 (0.043) -0.1672 (0.025) Last Catch Score -0.1327 (0.075) 0.1916 (0.010) -0.0853 (0.255) -0.1119 (0.135) -0.1158 (0.122) Average Catch Score -0.1959 0.2033 (0.007) -0.1359 (0.073) -0.1447 (0.056) -0.1485 (0.050)

Results and Discussion Catch Score with Carcass Parameters a, b Means with different superscripts within rows were different (P < 0.05) 1Marbling Score numeric designation: 100 = traces; 200 = slight; 300 = small; 400 = modest; 500 = moderate.

Results and Discussion IGENITY® Tenderness vs. Shear Force b a a P < 0.0001

Results and Discussion IGENITY® Docility vs. Shear Force b b a P = 0.012

Summary Temperament Slower Exit Velocity Higher Catch Score Fatter More Tender Higher Catch Score Lower Marbling Higher 36 hour pH Darker Color

Implications Beef Temperament Possible Effects Measurement Fat Deposition (Marbling $) Tenderness Lean Color (Dark Cutter?) Measurement Catch Score