Publication Date


Advisor(s) - Committee Chair

Gordon Jones, Jodie, Pennington, James Worthington

Degree Program

Department of Agriculture

Degree Type

Master of Science


The purpose of this study was to compare the performance and carcass characteristics of swine of four different phenotypes and three USDA grades.

Hogs were placed into phenotypic groups of 24 each and penned by group. These pens were ideal, cutability, light muscled, fat, VS US and US The hops were fed a 16% corn and soybean meal ration fortified with appropriate minerals and vitamins. They were housed in a total confinement curtain-sided Kentucky plan building with a partially slatted floor. The hogs were weighed at 6-week intervals throughout the project to monitor average daily gain and pen feed efficiency. Twelve hogs from each pen were slaughtered at approximately 2(0 pounds and the remaining twelve pigs at approximately 230 pounds to determine if differences in performance and carcass characteristics remained consistent or became greater at heavier weights. Carcass weight, backfat at the tenth rib and last rib, length and loin eye area were obtained on each carcass. Data were adjusted to the group means for the heavy and light groups using least squares analysis. The mean for the heavy group was 255 pounds and the mean for light group was 229 pounds.

Results of the study showed the ideal pen to have significantly higher (P<.01) average daily gain than all other pens at 229 pounds and significantly higher (P<.01) average daily gain than the cutability, US #2, and US #3 pens at 255 pounds. The two leanest and heaviest muscled pens were cutability and US #1. These two pens had significantly (P<.01) lower fat and larger loin eye area than the light muscled. US #3 and fat pens at 229 pounds. The fat pen had significantly (P.-01) greater backfat, smaller loin eye area, and lower percent muscle than all other pens in the heavy group. The cutability and US #1 pens had significantly higher (P<.01) percent muscle than the light muscled, US #3, and fat pens. The ideal, US #1, and cutability pens had significantly (P<.01) higher lean gain per day on test than all other pens with the exception of the light muscled pen taken to the heavier slaughter weight.

The ideal, cutabilitv, and US #1 hogs had the lowest average values for feed per unit of lean gain. The fat pen required 2.5 pounds more feed to produce a pound of loan gain than ideal. cutability or US #1 pens. The US #1 group required 1.50 fewer pounds of feed per pound of lean growth than US #2 and #3 groups.

These results indicate that the ideal pen was superior in terms of performance and lean growth. The cutabilitv and US #1 pen were the leanest and heaviest muscled. The fat group was extremely high in backfat, low in loin eye area and the most inefficient in converting feed into lean tissue.


Agriculture | Animal Sciences | Life Sciences | Meat Science