Effects of dietary lysine supplementation on performance, egg quality, and development of reproductive system in egg-laying ducks

Figures & data

Table 1. Composition of the basal diet and nutrient levels.

Ingredients	Value (%)
Corn	54.48
Soybean meal	19.7
Wheat bran	9.49
Corn gluten	5.0
Limestone	8.485
Calcium hydrogen phosphate	1.33
DL-methionine	0.13
Zeolite powder	0.085
Sodium chloride	0.3
Premix^a	1.0
Total	100.0
Nutritional value
AME (Kcal/kg)	2500
Crude protein	17.0
Calcium	3.6
Total P	0.59
Available phosphorus	0.35
Total lysine	0.75
Total methionine	0.40

^aSupplied per kilogram of diet: retinyl palmitate, 12,000 IU; cholecalciferol, 2000 IU; DL-α-tocopheryl acetate, 38 mg; menadione sodium bisulphite, 1.0 mg; thiamin mononitrate, 3.0 mg; riboflavin, 9.6 mg; pyridoxine hydrochloride, 6.0 mg cobalamin, 0.03 mg; chloride choline, 500 mg; nicotinic acid, 25 mg; calcium-D-pantothenate, 28.5 mg; folic acid, 0.6 mg; biotin, 0.15 mg; Fe, 50 mg; Cu, 10 mg; Mn, 90 mg Zn, 90 mg; I, 0.5 mg; Se, 0.4 mg.

Table 2. Effects of dietary L-lysine on the performance of laying ducks.

Trait	Dietary Lys (%)						Contrast P-value
	0.75	0.80	0.85	0.90	0.95	SEM^b	Level	Linear	Quadratic
Egg production (%)	88.3	86.0	86.9	87.1	87.4	0.4	0.7	0.8	0.3
Egg weight (g)	65.1	66.0	66.4	65.1	66.9	0.2	0.03	0.057	0.9
Egg mass (g/d/d)	57.5	56.8	57.7	56.7	58.4	0.3	0.5	0.5	0.3
FCR^a	2.79	2.82	2.77	2.82	2.74	0.02	0.5	0.5	0.3

^aFeed conversion ratio, g of feed/g of egg mass

^bStandard error of means, n = 6.

Table 3. Effects of dietary L-lysine on egg quality.

Trait	Dietary Lys (%)						Contrast P-value
	0.75	0.80	0.85	0.90	0.95	SEM^a	Level	Linear	Quadratic
Egg shape index	72.2	73.1	73.2	73.5	72.2	0.3	0.7	0.3	0.7
Haugh units	68.2	70.0	71.9	69.5	75.3	1.6	0.6	0.2	0.8
Yolk colour	8.6	8.7	8.5	8.8	8.7	0.1	0.7	0.5	0.9
Yolk weight (g)	20.5	21.4	21.7	21.5	21.9	0.2	0.4	0.1	0.5
Yolk (%)	31.6	32.4	32.6	33.0	32.7	0.3	0.7	0.3	0.4
Albumin weight (g)	36.5	36.6	36.8	35.5	37.5	0.2	0.2	0.4	0.3
Albumin (%)	56.1	55.4	55.4	55.0	56.1	0.3	0.8	0.9	0.2
Eggshell thickness (mm)	0.324	0.323	0.322	0.312	0.299	0.003	0.01	0.002	0.4
Eggshell strength (N)	4.4	4.5	4.4	4.1	4.1	0.1	0.6	0.2	0.8
Eggshell weight (g)	8.0	8.0	7.8	7.7	7.5	0.07	0.1	0.03	0.3
Eggshell (%)	12.3	12.1	11.9	11.9	11.2	0.1	0.04	0.005	0.3

^aStandard error of means, n = 12.

Table 4. Effects of dietary L-lysine on reproductive organ indices of laying ducks.

Trait	Dietary Lys (%)						Contrast P-value
	0.75	0.80	0.85	0.90	0.95	SEM^a	Level	Linear	Quadratic
Oviduct length (cm)	52.9	51.6	54.7	51.8	49.1	0.9	0.7	0.3	0.7
Oviduct weight (g)	39.7	37.5	40.6	39.2	39.6	0.6	0.6	0.2	0.8
Ovarian weight (g)	46.3	45.8	47.9	48.1	49.7	0.9	0.7	0.5	0.9
Large follicles number	5.1	4.5	5.3	5.5	5.2	0.2	0.4	0.1	0.5
Small follicles number	32.5	31.0	33.6	44.0	28.8	1.7	0.7	0.3	0.4

^aStandard error of means, n = 12.

Table 5. Effects of dietary L-lysine on reproductive hormones of laying ducks.

Trait	Dietary Lys (%)						Contrast P-value
	0.75	0.80	0.85	0.90	0.95	SEM^a	Level	Linear	Quadratic
E2 (pg/mL)	349.3	257.6	358.4	338.3	263.5	23.5	0.5	0.6	0.6
LH (mIU/mL)	2.1	2.2	2.2	2.1	1.8	0.1	0.8	0.3	0.5
FSH (mIU/mL)	2.5	2.8	2.7	2.9	2.5	0.1	0.4	0.9	0.1
Progesterone (pg/mL)	348.3	305.0	262.5	270.8	227.5	15.6	0.1	0.01	0.7

Note: E2, estradiol-17β; LH, luteinizing hormone; FSH, follicle-stimulating hormone.

^aStandard error of means, n = 12.