Effects of broccoli stems and leaves meal on production performance and egg quality of laying hens

A total of 384 Roman brown shell laying hens were used to study the effects of increasing dietary inclusion of 0, 30, 60 and 90 g/kg of dried broccoli stems and leaves meal (BSLM) on production performance and egg quality. Hens were randomly allocated to four groups with six replicates of 16 chickens. The results showed that dietary supplementation of BSLM had no effect (P > 0.05) on production performance of laying hens. Incremental levels of BSLM linearly and quadratically increased the xanthophyll content of egg yolk, the yolk color (P < 0.05) and linearly decreased the content of cholesterol in egg yolk (P < 0.05). However, supplementation with BSLM had no effect (P > 0.05) on albumen height, haugh unit, shell thickness and shell strength of eggs. Hepatic hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase activity was decreased (P < 0.05) and concentrations of cecal short chain fatty acids were increased (P < 0.05) linearly and quadratically with increasing BSLM supplementation. The results indicate that supplementation with BSLM in laying hens improves egg quality with more yolk pigmentation and less yolk cholesterol. The decreased cholesterol of the egg fed BSLM may be partly caused by an alteration in the synthesis of cholesterol, which might result from the changes in cecal fermentation.