View Full Table | Close Full ViewTable 1.

Description of cattle hauled in each trailer type (fat vs. combination trailers)

 
Descriptor Class of cattle Fat Trailers1 Combination Trailers1
Number of trailers observed 129 146
Breed
Beef 99 132
Holstein 30 14
Sex
Steers 104 108
Heifers 18 26
Mixed2 7 11
Not specified 1
Average #head/trailer
Beef 34 37
Holstein 33 37
1Fat/feeder combo trailers are those which are used to haul both feeder calves and finished beef cattle. Fat trailers are usually used to haul finished cattle only. The differences between these types of trailers include the presence or absence of a “jail” or “doghouse” in the upper rear compartment of the trailer, used to contain very small calves (present in fat/feeder combo trailers, Beef Quality Assurance, 2006), the presence of a small compartment in the nose of the trailer, used as a counter-balance (also present in fat/feeder combo trailers), and the clearance height of the entrance into the “belly”, or lower compartment of the trailer (approximately 2 to 3 inches shorter in fat/feeder combo trailers). Either type of trailer can have a slide-in or fold-up ramp leading into the upper deck compartment.
2Mixed lot refers to a lot comprised of both heifers and steers.



View Full Table | Close Full ViewTable 2.

Description of lots observed for both traumatic events and carcass bruising

 
Descriptor Class of cattle Count
Total Number of lots 75
Average #head/lot 131
Breed
Beef 63
Holstein 12
Sex
Steer 54
Heifer 13
Mixed1 8
1Mixed lot refers to a lot comprised of both heifers and steers.



View Full Table | Close Full ViewTable 3.

Description of lots, including carcass characteristics, prevalence of traumatic events experienced, and prevalence of carcass bruising

 
Breed Sex Number of lots, n Average Carcass Weight, kg, SEM Average REA1, in, SEM Average Fat Thickness, in, SEM Average YG2, SEM Prevalence of Traumatic Events3, SEM Prevalence of Carcass Bruising4, SEM
Beef
Heifer 13 371.01 (+ 6.5) 14.09 (+ 0.28) 0.51 (+ 0.02) 2.62 (+ 0.08) 17.2% (+ 3.0%) 67.1% (+ 2.8%)
Mixed5 8 375.0 (+ 5.7) 14.01 (+ 0.23) 0.56 (+ 0.02) 2.73 (+ 0.10) 18.4% (+ 2.9%) 64.9% (+ 3.5%)
Steer 42 419.2 (+ 4.1) 14.12 (+ 0.17) 0.56 (+ 0.02) 2.65 (+ 0.07) 19.5% (+ 1.4%) 66.7% (+ 1.4%)
Total 63 403.7 (+ 3.1) 14.1 (+ 0.13) 0.55 (+ 0.03) 2.66 (+ 0.08) 18.9% (+ 1.1%) 66.6% (+ 2.5%)
Holstein
Steer 12 394.6 (+ 4.2) 13.85 (+ 0.32) 0.57 (+ 0.01) 2.81 (+ 0.05) 28.6% (+ 2.5%) 76.6% (+ 1.2%)
Total 75 402.2 (+ 3.6) 14.05 ( ± 0.12) 0.55 (+ 0.01) 2.68 (+ 0.04) 20.4% (+ 1.1%) 68.2% (+ 1.2%)
1REA = Ribeye area.
2YG = Yield grade.
3Prevalence of traumatic event occurrence was calculated dividing the number of traumatic events observed at unloading by the total number of cattle in the trailer.
4Prevalence of carcass bruising was calculated by dividing the number of carcasses with a bruise present over the total number of animals in the lot.
5Mixed lot refers to a lot comprised of both heifers and steers.



View Full Table | Close Full ViewTable 4.

P-values generated from univariable and multivariable analyses for the outcome traumatic events. Only 2-way interactions were evaluated in the multivariable analysis. Interaction effects are listed in the order by which they were removed from the model using backward selection at a threshold of P > 0.05

 
Independent variable Univariable P-values Multivariable P-values Final model P-values
Distance 0.7026 0.4542 N/A
Sex1 0.0091 0.1159 N/A
Breed2 0.0001 0.0042 0.0042
Trailer Type3 0.0591 0.0507 0.0507
Sex × Trailer N/A 0.8501 N/A
Distance × Trailer N/A 0.6945 N/A
Distance × Sex N/A 0.2727 N/A
Distance × Breed N/A 0.0713 N/A
Breed × Trailer N/A 0.0111 0.0111
1Sex was categorized as “Steer,” “Heifer,” or “Mixed.”
2Breed was categorized as “Beef” or “Holstein.”
3Fat/feeder combo trailers are those which are used to haul both feeder calves and finished beef cattle. Fat trailers are usually used to haul finished cattle only. The differences between these types of trailers include the presence or absence of a “jail” or “doghouse” in the upper rear compartment of the trailer, used to contain very small calves (present in fat/feeder combo trailers, Beef Quality Assurance, 2006), the presence of a small compartment in the nose of the trailer, used as a counter-balance (also present in fat/feeder combo trailers), and the clearance height of the entrance into the “belly”, or lower compartment of the trailer (approximately 2 to 3 inches shorter in fat/feeder combo trailers). Either type of trailer can have a slide-in or fold-up ramp leading into the upper deck compartment.



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Percent of carcass bruising on the left side, the dorsal midline, and the right side of beef carcasses. Equal distribution between all regions was expected

 
Bruise location Mean, % SEM, %
Left1 26.46a 1.10
Midline2 53.52b 1.12
Right3 19.98c 1.04
a–cSuperscripts indicate a significant difference between the observed values and the expected values of the bruising in each region (P ≤ 0.05).
1Bruises along the left side of the carcass were those which occurred in areas 3, 6, and 9 (see Fig. 1).
2Bruises along the left side of the carcass were those which occurred in areas 2, 5, and 8 (see Fig. 1).
3Bruises along the left side of the carcass were those which occurred in areas 1, 4, and 7 (see Fig. 1).



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Percent of carcass bruising on the front, middle, and rear thirds of beef carcasses. Equal distribution between all regions was expected

 
Bruise location Mean, % SEM, %
Front1 31.30a 1.05
Middle2 56.13b 1.02
Rear3 12.57c 0.71
a–cSuperscripts indicate a significant difference between the observed values and the expected values of the bruising in each region (P ≤ 0.05).
1Bruises along the front third of the carcass were those which occurred in areas 7, 8, and 9 (see Fig. 1).
2Bruises along the middle third of the carcass were those which occurred in areas 4, 5, and 6 (see Fig. 1).
3Bruises along the rear third of the carcass were those which occurred in areas 1, 2, and 3 (see Fig. 1).



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Percent of carcass bruising categorized as small, medium, or large bruises. Equal distribution between all sizes was expected

 
Bruise size Mean, % SEM, %
Small ( < 5cm) 28.64a 1.32
Medium (5 to 15cm) 41.77b 0.97
Large ( > 15cm) 29.58c 1.81
a-cSuperscripts indicate a significant difference between the observed values and the expected values of bruise size.



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Estimates of parameters for the fixed effects of average carcass weight and breed of cattle assessed with multiple linear regression

 
Effect Class1 Estimate2 SEM P-value
Intercept 1.0952 0.1447 < 0.001
Average Carcass Weight –0.00082 0.00035 0.022
Breed Beef –0.9515 0.03519 0.009
Holstein Ref.3
1Refers to breed of cattle.
2Parameter estimates.
3Ref. = reference category.



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Estimate of mean carcass bruise prevalence per lot by breed (cattle were categorized as either Holstein or beef breeds). Estimates with different superscripts differ significantly (P ≤ 0.05)

 
Class1 Estimate, % SEM, %
Beef 67.20a 3.0
Holstein 76.70b 4.3
a,bSuperscripts indicate a significant difference between the mean estimates.
1Refers to breed of cattle.



View Full Table | Close Full ViewTable 10.

P-values generated from univariable and multivariable analyses for the outcome carcass bruising. Only 2-way interactions were evaluated in the multivariable analysis. Interaction effects are listed in the order by which they were removed from the model using backward selection at a threshold of P > 0.05

 
Independent variable Univariable P-value Multivariable P-value Final model P-value
Traumatic Events 0.1158 0.3155 N/A
Average Carcass Weight 0.0195 0.0222 0.0222
Distance 0.2169 0.4166 N/A
Sex1 0.747 0.5208 N/A
Breed2 0.0078 0.0.0087 0.0087
Ribeye Area3 0.2375 0.1019 N/A
Average Yield Grade4 0.0786 0.4627 N/A
Fat Thickness 0.3968 0.5064 N/A
Traumatic Events × REA N/A 0.9543 N/A
Traumatic Events × Fat Thickness N/A 0.8967 N/A
REA × Distance N/A 0.8023 N/A
Average Carcass Weight × Distance N/A 0.8797 N/A
Traumatic Events × Distance N/A 0.8359 N/A
Distance × Breed N/A 0.6229 N/A
Fat Thickness × Average YG N/A 0.5394 N/A
Average YG × Distance N/A 0.3544 N/A
Fat Thickness × Distance N/A 0.7798 N/A
Average Carcass Weight × Breed N/A 0.4482 N/A
Traumatic Events × Average Carcass Weight N/A 0.3222 N/A
REA × Average YG N/A 0.3068 N/A
Average YG × Breed N/A 0.1105 N/A
Average Carcass Weight × REA N/A 0.1875 N/A
Traumatic Events × Breed N/A 0.2778 N/A
REA × Breed N/A 0.8703 N/A
Average Carcass Weight × Average YG N/A 0.1413 N/A
Average Carcass Weight × Fat Thickness N/A 0.3681 N/A
Fat Thickness × Breed N/A 0.1259 N/A
Traumatic Events × Average YG N/A 0.1139 N/A
REA × Fat Thickness N/A 0.0745 N/A
1Sex was categorized as “Steer,” “Heifer,” or “Mixed.”
2Breed was categorized as “Beef” or “Holstein.”
3Ribeye Area = REA.
4Yield Grade = YG.