A Comparison of the Effect of Two Force Molting Methods on Performance of Two Commercial Strains of Laying Hens

Abstract

A low-sodium diet (.08% Na) was used to force molt 409 hens. Another 421 hens were force molted by conventional water and feed restrictions. Birds were 68 weeks of age at that time, and two strains were about equally represented in each treatment group. These strains were: A, DeKalb; and B, Hisex. The low-sodium diet and water were provided ad libitum to the first group for the entire period of molt (42 days). The second group received no water for 3 days, and no feed for 4 days, after which incremental amounts of whole oats were provided as the only feed until Day 18. After Day 18, incremental amounts of a regular laying mash and decremental amounts of whole oats were provided through Day 26, when laying mash only was given ad libitum. Both treatment groups were in the same building and received the same lighting program during the force-molt period. This program consisted of: Days 1 to 3, no light; Days 4 to 18, 8 hr/day; Days 19 to 25, 9 hr/day; Day 26, 10 hr; then, light was increased 30 min weekly until 14 hr daily was attained. The low-sodium group ceased laying after 28 to 31 days, lost 8.7% of their premolt body weight, reduced feed consumption by 35%, and decreased egg production from 62.3% (in the 28 days preceding the molt) to 19% in the 42 days of molt; their mortality rate was 3.4%. The feed- and water-restricted group receiving oats ceased laying after 11 to 12 days, lost 17% of their premolt body weight, reduced feed consumption by 81%, and decreased egg production from 59.3% (in the 28 days preceding the molt) to 4.0% in the 42 days of molt; their mortality rate was 5%. Nearly all of the birds assigned to the feed and water restriction lost their feathers during the first 2 weeks; in contrast, hens receiving the low-sodium treatment lost their feathers at a much slower rate. No significant differences were observed between the two treatment groups in egg production, egg weight, interior egg quality, or shell quality during 10 subsequent, 28-day postmolt periods.Strain B stopped laying earlier and had a higher mortality rate than Strain A during the force-molt period. However, Strain B had a significantly higher (P<.05) egg production rate during the postmolt period of 280 days.