Dried distillers grains with solubles in laying hen diets

A study was conducted to test the inclusion rate of corn dried distillers grains with solubles (DDGS) in laying hen diets on egg production (EP) responses for a full production cycle. A total of 288 Bovan Single Comb White Leghorn laying hens were fed diets containing 0, 5, 10, 15, 20, or 25% DDGS from 24 to 46 wk (phase 1) and 47 to 76 wk (phase 2) of age. The diets were formulated to be isocaloric at 2,775 and 2,816 kcal/kg of ME and isonitrogenous at 16.5 and 16.0% CP for phases 1 and 2, respectively. Nutrient retention of both N and P were determined by the indicator methods during phase 2. Diets were replicated with 8 pens/treatment and 6 hens/pen in an unbalanced randomized complete block design. Average daily feed intake, EP, and overall weight gain were similar (P = 0.08 to 0.1) among treatments during the study. Egg weight was affected (P = 0.064) by DDGS treatment during phase 1. Hens fed 0, 5, 10, 15, 20, or 25% DDGS had an average egg weight of 60.6, 60.4, 60.8, 60.0, 59.0, and 59.0 g, respectively; however, no differences were detected in egg weight during phase 2. During phase 1, diets were formulated based on TSAA, allowing Met to decrease as DDGS increased, but during phase 2, diets were formulated to keep Met equal across DDGS treatments, allowing TSAA to increase as a result of high Cys in DDGS. Yolk color increased with increasing DDGS level; the highest Roche score (P = 0.001) was 7.2 for hens fed 25% DDGS. Nitrogen and P retention was greater (P = 0.003) in hens fed 25% DDGS. Also, N and P excretion decreased (P = 0.007) linearly as DDGS increased. In summary, feeding DDGS up to 25% during EP cycles had no negative effects on feed intake, EP, Haugh units, or specific gravity, and improved yolk color at the highest levels. Increasing DDGS level beyond 15% caused a reduction in egg weight during phase 1 of egg production, though no differences were observed in egg weight during phase 2. Nitrogen and P excretion were lower at higher inclusion rate of DDGS. Hens fed 25% DDGS had the highest N and P retention.