ASI 105 Beef (Bovine) Exam
Young
Calf
To give birth
Calving
Female after giving birth
Cow
Finish (Fatness)
FT .20 - .60 in
Female before giving birth
Heifer
Type of digestive tract
Herbivore (Ruminant)
Dressing Percent
(hot carcass weight/live weight) x 100
Bos Indicus Beef Breeds
- American Brahman - Beefmaster - Brangus - Santa Gertrudis - Simbrah - Belgian Blue
British Beef Breeds
- Angus - Red angus - Hereford (horned) - Polled Hereford - Shorthorn
3 types of beef breeds
- British - Continental - Bos Indicus
Continental Beef Breeds
- Charolais - Chianina - Gelbvieh - Limousin - Maine-Anjou - Salers - Simmental
Purebred vs Fullblood
- Fullblood is 100% original genetics of that breed - Purebred designation is determined by each breed
Traits of Importance - Beef Cattle
- calving ease - growth - carcass traits - maternal traits - adaptability to environment and resources
Dressing Percent Factors
- fill - finish (fatness) - muscling - sex - type - pregnancy - hide weight - mud, horns, etc.
F1 Cross
- first generation cross between two purebred animals
USDA Quality Grades
- grades of quality categorize meat on the basis of its acceptability for consumer cuts. Variables uses in assigning quality grades include factors related to palatability of the product.
Economically Important Traits
- live weight - dressing percent - quality grade - muscling - finish (fatness) - yield grade
Maternal Traits
- milking ability - mothering instincts
Growth
- pre-weaning and post-weaning - feed efficiency
Carcass Traits
- quality (marbling) - yield (trimness and muscle)
Calving Ease
- size of calf - shape of calf - position of calf
Hybrid Vigor or Heterosis
- the ability of crossbred livestock to outperform the average of their purebred parents (free growth)
Evaluating Maturity
- there is no concrete way to determine age of every slaughter animal - physiological age has a much stronger correlation with tenderness traits than does chronological age - graders will evaluate bone characteristics and ossification of cartilage in certain areas (with age bone whites and cartilage ossifies)
Live Weight
1100-1500 lbs.
Age to breed
14 to 15 months
Yield Grade
2.5 - 3.5
Gestation length
283 to 285 days
Dressing Percent
60-64%
Reproductive Efficiency
70 to 80%
Puberty
8 to 12 months
Palatability
= taste, tenderness, juiciness and flavor attributes
Intact male
Bull
Muscling
REA 12.0 - 16.0 in^2
Castrate male
Steer
Beef Quality Grades
Two major factors: - degree of maturity - degree of marbling Other factors: - color - texture - firmness
Maturity Score - B
approximate age: 30-42 months
Maturity Score - C
approximate age: 42-72 months
Maturity Score - D
approximate age: 72-96 months
Maturity Score - A
approximate age: 9-30 months
Maturity Score - E
approximate age: > 96 months
Visual Appraisal - Fatness
decreased Meat Yield, improves Quality
Visual Appraisal - Performance
high daily gain, efficient conversion of feed
Visual Appraisal - Muscling
increases Meat Yield
Visual Appraisal - Weight
optimum size of carcass
Quality Grade
select/choice
Visual Appraisal - Conformation
structural soundness, balance
