Selecting broilers for low or high abdominal fat: Initial observations

1. Two lines of broiler breeders were selected for three generations using a high (fatty line) or a low (lean line) ratio of abdominal fat to live weight as criterion in males at 9 weeks of age.

2. The heritability of this character remained high in both lines.

3. By the third generation, the progress achieved was much more marked in males than in females. The difference between the females of both lines was nevertheless significant.

4. The differences between the two lines were already discernible at 4 weeks of age.

5. Selecting for low or high abdominal fat content was accompanied by a better food conversion ratio in males of the lean line.

6. Selecting for the amount of abdominal fat produced similar effects on the other fatty deposits.