Long-term effects of feeding flaxseed-based diets. 1. Egg production parameters, components, and eggshell quality in two strains of laying hens.

We used a split-plot design of five diets: control (corn-soy) with 3.8% Ca, 10% flaxseed with 3.8% Ca, 10% flaxseed with 4.5% Ca, 10% flaxseed with 3.8% Ca and 22,000 IU vitamin D3/kg, and 10% flaxseed with 4.5% Ca and 22,000 IU vitamin D3/kg, and two strains of birds, DeKalb Delta (DD) and Hy-Line W-36 (HL), to evaluate long-term effects of flaxseed supplementation on egg production parameters. Each of the five treatments was randomly assigned and replicated six times with five hens per replicate pen from 21 to 57 wk of age. Phase I was from 21 to 39 wk, Phase II was from 40 to 48 wk, and Phase III was from 49 to 57 wk. Feed consumption was significantly (P < 0.04) greater for the hens fed 10% flaxseed diets (100.9 g) when compared to the corn-soy controls (99.3 g). Overall average egg production (P < 0.05) was 87.8, 87.1, 86.0, 87.1, 84.8, for diets 1, 2, 3, 4, and 5, respectively. Average hen weights during the study were significantly lower for the flaxseed-fed hens (1.559 kg) compared to the controls (1.616 kg). Egg weight was significantly affected by diet during Phase III with heavier eggs from flaxseed fed hens (62.6 g) compared to controls (61.44 g), but overall egg weight was not significantly affected. Average egg mass was not significantly affected by dietary treatments, but DD hens had a decrease in egg mass with Ca supplementation (Diet 2 vs. Diet 3), whereas HL egg mass increased with Ca supplementation. Percentage albumen had a significant strain effect and strain by diet interactions. Overall, significantly less albumen (P < 0.001) was produced by HL (59.4%) compared to DD (61.3%). Supplemental Ca increased albumen percentage in DD (interaction effect P < 0.03) and decreased albumen percentage in the HL strain. Flaxseed supplementation significantly increased albumen percentage (P < 0.02) when compared to the corn-soy control, 60.5 and 59.9%, respectively. An interaction effect (P < 0.01) was noted for percentage wet yolk, in which increasing Ca decreased wet yolk percentage in DD but increased yolk percentage in HL. Wet yolk percentage was also significantly (P < 0.001) less in DD (25.0%) when compared to HL (26.9%). Addition of flaxseed decreased yolk percent when compared to controls (P < 0.03) during Phase II. Ca supplementation significantly (P < 0.03) increased yolk solids in both strains. Grams of yolk solids per egg were affected by flaxseed supplementation (P < 0.06). Flaxseed eggs contained 7.18 g per egg yolk solids compared to 7.3 g in corn-soy control group. Wet shell percentage was significantly lower in the flaxseed diets (12.4%) when compared to the controls (12.6%). Addition of flaxseed to the diet of laying hens did not have any adverse effects on egg production parameters, but flaxseed supplementation can significantly alter weight of yolk solids and yolk and albumen percentages.