2010 Goat Carcass Evaluation
One of the goals of the Western Maryland Pasture-Based Meat Goat Performance Test is to characterize and compare carcass characteristics of meat goats consuming a pasture-only diet. This year, ten bucks from ten different consigners were selected for harvest and deboning.
The bucks were transported from the test site at the University of Maryland’s Western Maryland Research & Education Center on October 7. They were humanely harvested (on the same day) by LambCo, LLC, a USDA/custom abattoir in New Windsor, Maryland.
The goats were weighed immediately before harvest. Live weight (LW) ranged from 50.0 to 72.0 pounds and averaged 57.2 lbs. (26 kg). Hot carcass weights (HCW) were determined soon after harvest. They ranged from 24.7 to 38.1 lbs. and averaged 27.4 lbs. (12.5 kg).
For the ten goats, dressing percentage (hot carcass weight divided by live weight) ranged from 44.0 to 52.9 percent and averaged 48.1 percent. Dressing percentage (DP) for goats varies considerably and is affected by many factors, including sex, age, gut fill, and fat content. The dressing percentages observed in these goats were within the expected range.
After chilling overnight, cold carcass weights (CCW) were determined. Weights ranged from 24.0 lbs. to 37.2 lbs and averaged 26.8 lbs. (12.2 kg). Cold carcass weights were 1.2 percent less than hot carcass weights, as carcasses lose moisture during chilling. Cold carcass weights were used to calculate carcass yields.
Rib eye area
Jeff Semler measured rib eye area (REA, between the 12th and 13th rib) using a grid. Each dot on the grid represents 0.1 square inches of measurement. There is a degree of subjectivity when using a grid to measure rib eye area. To reduce the subjectivity, each side of the rib eye was measured and an average value was used.
Rib eye measurements ranged from 0.70 to 1.80 square inches and averaged 1.04 square inches. With the exception of two goats, the actual rib eye measurements were very close to the ultrasound measurements taken on September 9. The goat with the biggest rib eye was from a 72-lb. Kiko buck consigned by Warren & Liz Barnes. Its rib eye area was an impressive 1.8 in2 (11.6 cm2).
Kidney and heart fat (KH) was removed from each carcass and weighed. While fattened goats are known for depositing more internal fat than other livestock species, these goats had very minimal internal fat. Kidney and heart fat ranged from less than 0.1 to 0.3 lbs. (per carcass) and averaged 0.21 lbs. (0.1 kg). Percent KH fat ranged from less than 0.1% to 1.14% and averaged 0.76% of cold carcass weight.
Back fat (as determined by ultrasound on Septebmer 9) was very minimal (less than 0.05 inches) and could not be differentiated between carcasses. In goats and lambs, body wall thickness (BWT) is considered to be a better indicator of fat cover. It was measured by Jeff Semler. It ranged from 0.1 to 0.4 inches and averaged only 0.20 inches.
The carcasses were completely deboned. Fat and lean were separated from the bones, resulting in separate “piles” of bones, fat, and lean, which were weighed (by Jeff Semler and David Gordon) to determine carcass percentages.
Fat trim ranged from 0.5 to 0.9 lbs. (per carcass) and averaged 0.53 lbs. (0.24 kg). Percent fat ranged from 0.8 to 2.8 percent and averaged only 2.0 percent of cold carcass eight. These goats were incredibly lean as they subsisted on drought-ravaged pastures throughout most of the testing period. By way of comparison, the carcasses from the goats that were harvested last year had an average fat percentage of 6.06.
Bones ranged in weight from 7.5 to 10.9 lbs. (per carcass) and averaged 8.7 lbs. (4.0 kg). Bones comprised from 29.3 to 35% of cold carcass weight, for an average of 32.7 percent. Lean tissue ranged from 13.0 to 23.2 lbs. (per carcass) and averaged 15.5 lbs. (7.0 kg). Percent lean ranged from 54.2 to 62.4 percent and averaged 57.5 percent.
As a percentage of live weight, lean ranged from 22.0 to 30.9 percent and averaged 25.3 percent. The buck with the highest percentage of lean (carcass and live weight basis) was the Kiko buck consigned by Warren & Liz Barnes (Leatherwood Kiko Goat Ranch) from Summersville, Missouri.
Next year, we would like to harvest more goats from the test and incorporate a carcass contest into the performance testing program. For information about the goat carcass evaluation and/or Western Maryland Meat Goat Performance Test, contact Susan Schoenian at (301) 432-2767 ext. 343 or firstname.lastname@example.org. Information can also be found on the blog at http://mdgoattest.blogspot.com.