Effects of Inclusion of Selenium-Enriched Yeast in the Diet of Laying Hens on Performance, Eggshell Quality, and Selenium Tissue Deposition

Figures & data

Figure 1. Average selenium content of eggs produced by laying hens fed sodium selenite vs Se-enriched yeast at the beginning of the trial and during the 56-day experimental period. Data in columns represent the means of 8 replicates (2 hens per replicate) ±SE. Two eggs per replicate were analysed at Days 0, 18, 36 and 56 during the experimental period. C, Control group; SS, Sodium selenite; SY, Se-enriched yeast. A,B,C, Values with no common superscript are significantly different (P<0.01).

Figure 2. Selenium serum concentration in laying hens fed sodium selenite vs Seenriched yeast at the end of a 56-day supplementation period. Data are expressed as means ±SE. C, Control group; SS, Sodium selenite; SY, Se-enriched yeast. A,BC, Columns with no common superscript differ significantly (P<0.01).

Table 1. Composition of the basal diet.

	Ingredients, %
Corn ground	54.00
Soybean meal^°	29.00
Calcium carbonate	9.50
Soybean oil	4.54
Monocalcium phosphate	1.40
Vitamin and mineral mix^#	1.00
Salt	0.40
DL-methionine	0.16
Analysed composition
Dry matter, %	88.81
Metabolisable energy, kcal/kg	2835.00
Crude protein, %	17.30
Ether extract, %	7.27
Neutral detergent fibre, %	8.78
Lysine, %	0.92
Methionine, %	0.43
Methionine+cysteine, %	0.74
Ash, %	14.37
Calcium, %	4.40
Phosphorus, %	0.62
Non-phytate phosphorus, %	0.35
Selenium, ppm^§	0.11

Selenium sources were added in vitamin and mineral mix.°44% crude protein.

^#Provided per kilogram of diet: vitamin A (retinyl acetate), 12,500 U; vitamin D3, 2000 U; vitamin E (DL-α-tocopheryl acetate), 67 U; choline, 750 mg; niacin, 39.40 mg; pantothenic acid, 10.00 mg; pyroxidine, 5.10 mg; riboflavin, 5.00 mg; menadione, 4.40 mg; thiamin, 2.00 mg; folacin, 0.80 mg; biotin, 0.10 mg; vitamin B12, 0.02 mg; manganese, 125.00 mg; zinc, 76.00 mg; iron, 60.00 mg; copper, 10.00 mg; iodine, 1.00 mg; cobalt, 0.30 mg.

^§Analysed Se content of the basal diet.

Table 2. Analysed content of selenium in the experimental diets.

Treatment	Selenium content, ppm as fed
C	0.11
SS	0.46
SY	0.47

C, control group; SS, sodium selenite; SY, selenium-enriched yeast.

Table 3. Performance of laying hens fed different sources of selenium.

		Treatment
	C	SS	SY	SE
ADFI per cage, g/d	215.04	222.50	216.16	1.69
Feed:egg mass ratio, kg:kg	2.22	2.39	2.30	0.08
Egg production, %	87.50	83.59	85.49	2.64
Egg mass, g/week/hen	354.77	352.10	354.68	11.50

Data represent the means of 8 (2 hens per replicate) replicates. Data refer to the 56-day supplementation period for 22-week old laying hens at the beginning of the trial. C, control group; SS, sodium selenite; SY, selenium-enriched yeast; ADFI, Average daily feed intake.

Table 4. Eggshell quality of laying hens fed different sources of selenium.

		Treatment
	C	SS	SY	SE
Egg weight, g	57.66^b	59.74^a	59.36^a	0.53
Eggshell weight, g	5.39^b	5.62^a	5.68^a	0.08
Egg surface area, cm^2	69.77^b	71.47^a	71.14^a	0.42
Eggshell, %	9.37	9.44	9.65	0.10
Eggshell index, g/100 cm^2	7.72^b	7.87^ab	8.04^a	0.09
Eggshell stiffness, N/mm	148.50	156.40	159.70	5.23
Eggshell elastic modulus, N/mm^2	14.305	14.754	14.525	461.00
Eggshell breaking strength, N	35.64^B	35.89^B	39.03^A	0.77
Eggshell fracture toughness	423.5	420.9	442.2	7.23
Eggshell thickness, mm	0.359	0.361	0.369	0.003

Data represent the means of 128 samples per treatment. Data refer to a 56-day supplementation period. C, control group; SS, sodium selenite; SY, selenium-enriched yeast.

^A,BMeans within a row with different superscript are significantly different (P<0.01).

^a,bMeans within a row with different superscript are significantly different (P<0.05).

Table 5. Selenium content of breast muscle, liver, skin, and kidneys in laying hens fed different sources of selenium.

		Treatment
	C	SS	SY	SE
Breast muscle, ppm	0.42^B	0.39^B	1.22^A	0.19
Liver, ppm	1.36^b	1.69^ab	1.84^a	0.12
Skin, ppm	0.22^B	0.31^AB	0.40^A	0.04
Kidney, ppm	0.90^b	1.45^a	1.31^ab	0.15

Data represent the means of 8 (1 hen per replicate) samples collected 56 days after supplementation in 30-week old laying hens. Selenium content values are expressed on a dry matter basis. C, control group; SS, sodium selenite; SY, selenium-enriched yeast.

^A,BMeans within a row with different superscript are significantly different (P<0.01).

^a,bMeans within a row with different superscript are significantly different (P<0.05).

Table 6. Blood metabolites of laying hens fed different sources of selenium.

		Treatment
	C	SS	SY	SE
Total protein, g/L	47.63	46.00	51.13	1.66
Albumin, g/L	22.13	20.75	22.38	0.81
Glucose, mmol/L	11.78	11.95	12.05	0.51
Cholesterol, mmol/L	2.59	3.17	3.22	0.43
Total bilirubin, μmol/L	3.76	5.09	5.45	0.71
ALAT, U/L	4.13	3.88	3.75	0.53
ASAT, U/L	177.88	189.75	169.88	14.21
ALP, U/L	1029.50	1224.71	935.63	354.94
GSH-Px, U/mL	375.34^b	1309.43^a	1119.97^a	216.80

Data represent the means of 8 (1 hen per replicate) samples collected after 56 days of supplementation from 30-week old laying hens. C, control group; SS, sodium selenite; SY, selenium-enriched yeast. ALAT, Alanine transaminase; ASAT, Aspartate transaminase; ALP, Alkaline phosphatase; GSH-Px, Serum glutathione peroxidase activity.

^a,bMeans within a row lacking a common superscript are significantly different (P<0.05).