Carcass Composition and Yield of 1991 vs 1957 Broilers When Fed “Typical” 1957 and 1991 Broiler Diets

Abstract

Whole carcass yield and the yield of parts (i.e., wings, saddle and legs, Pectoralis major, Pectoralis minor, breast skin, rack, abdominal fat pad, heart, and lungs), as well as whole carcass analysis for fat, moisture, and ash, were measured in the 1957 Athens-Canadian Randombred Control (ACRBC) and in the 1991 Arbor Acres (AA) feather-sexable strain, when fed "typical" 1957 and 1991 diets. Using the average of both sexes, the carcass weights of the 1991 birds on the 1991 diets were 4.4, 3.9, and 3.5 times heavier than those from the 1957 ACRBC on the 1957 diet at 43, 71, and 84 d of age, respectively. Birds fed the 1991 diets had significantly heavier carcass weights than those fed the 1957 diets. Hot carcass yield of the AA broiler (mean of both sexes) was approximately 6 to 7% higher at the same age than for the ACRBC. Water uptake in the carcass (following a 60-min immersion in ice water) was approximately 2 to 2.5% higher in the ACRBC than in the AA broiler. Yield of saddle and legs as a percentage of live BW was about 4% higher in the AA than in the ACRBC. Dietary regimen did not affect the yield of saddle and legs. Males had 2 to 3% more saddle and legs than the females. The yield of total breast meat for the AA was approximately 3% higher (mean = 16.9%) than for the ACRBC over both sexes and all ages. Breast yield on the 1991 diets was approximately 1.2% higher for the AA than for the ACRBC. Females had slightly higher breast yield (1%) than males. The AA broiler had consistently heavier fat pads and higher percentage carcass fat at the same age and on the same diet than did the ACRBC. The percentage carcass fat was significantly higher on the 1991 vs the 1957 diet and in females vs males. The male-female difference in percentage carcass fat increased with age. Heart and lung size as a percentage of live BW were lower in the AA than in the ACRBC.

Effect of energy intake on performance and carcass composition of broiler chickens from two different genetic groups

“…Similar results were found by Havenstein et al (1994b) for heart and wings. The lower heart and liver relative weight of the AgRoss 308 group may indicate that genetically selected broilers are more sensitive to metabolic diseases.…”

“…As to genetic group, AgRoss 308 broilers showed higher carcass, breast, and thighs+drumsticks yields than PCLC broilers. Commercial broilers showed almost 5% better carcass yield, which difference is very similar to that described by Havenstein et al (1994b) between 1957 and 1991 broilers at 43 days of age. This was also observed for breast yield.…”

“…This was also observed for breast yield. In addition, Havenstein et al (1994b) observed that the difference between genetic groups in breast yield increased with time, an indication that selected broilers do deposit more muscular mass in the breast than the non-selected ones.…”

“…Considering the precocity of the improved line, an opposite behavior was expected. In fact, Havenstein et al (1994b) found that genetically improved broilers deposited abdominal fat at a higher rate than the non-selected until 85 days of age. Nevertheless, after this time, total carcass fat was the same between genetic groups.…”

Breeding for efficiency in the broiler chicken: A review

“…This is reflected in the higher carcass yield (i.e. the proportion of the edible carcass of the total slaughter weight) of modern birds compared to old-type breeds (Havenstein et al 1994b(Havenstein et al , 2003a. This might be expected, as maintaining the digestive system requires a high level of metabolic energy (see section 4).…”