Red clover-rich grassland increases equol concentration in eggs from free-range laying hens

Figures & data

Table 1. The balanced feed for outdoor production offered ad libitum to laying hens during all the study: ingredients and chemical composition (calculated values)

	Feed
Ingredient, g/kg DM
Wheat	340
Maize	300
Soybean meal	200
Crushed limestone	60
Soybean oil	40
Bran	25
Chalk	23
Vitamins and minerals	12
Chemical composition
DM, g/kg	890
Crude protein, g/kg DM	160
Fat, g/kg DM	53
Ash, g/kg DM	120
Starch, g/kg DM	430
Calcium, g/kg DM	35
Phosphorus, g/kg DM	4

Table 2. Impact of grassland species and time on laying rate (egg/hen/day) and egg weight (g)

	Grassland species					P-value
Item	RC^1	WC^2	CH^3	RG^4	SEM^5	G^6	T^7	G*T
Laying rate (egg/hen/day)	0.816	0.871	0.880	0.906	0.039	0.273	< 0.001	0.094
Egg weight (g)	60.3	60.1	58.9	59.8	0.54	0.171	< 0.001	0.770

¹RC, red clover; ²WC, white clover; ³CH, chicory; ⁴RG, ryegrass; ⁵SEM, standard error of the mean; ⁶G, grassland species, ⁷T, time.

Table 3. Impact of grassland species and time on concentrations of target compounds in fresh grassland cover and in egg yolk

	Grassland species					P-value
Item	RC^1	WC^2	CH^3	RG^4	SEM^5	G^6	T^7	G*T
Fresh grassland cover, µg/g DM
Daidzein	85^a	41^b	< LOQ^8,c	5^c	10	< 0.001	0.177	0.988
Formononetin	996^a	282^b	< LOQ^d	20^c	78	< 0.001	0.774	0.948
Egg yolk, ng/g DM
Equol	1,154^a	282^b	109^d	229^c	41	< 0.001	0.081	0.365
Daidzein	661^a	228^b	59^d	175^c	41	< 0.001	0.004	0.883

¹RC, red clover; ²WC, white clover; ³CH, chicory; ⁴RG, ryegrass; ⁵SEM, standard error of the mean; ⁶G, grassland species, ⁷T, time; ⁸LOQ, limit of quantification. ^abcdIn the same row, means with different superscript letters indicate a significant difference between grassland species.