Hydrolysed yeast from Kluyveromyces fragilis improves plasma antioxidant efficiency and immunoglobulin concentration, and faecal microbiota of weaned piglets

Figures & data

Table 1. Ingredient and calculated nutrient composition of the basal diet (as fed basis).

Item	Amount, %
Ingredients
Corn	16.45
Extruded corn	32
Soybean meal	14
Extruded soybean	11.5
Fish meal	5.6
Whey	15
Soybean oil	1
Dicalcium phosphate	0.4
Limestone (CaCO3)	0.75
Salt	0.3
Choline chloride (60%)	0.05
L-Lysine HCl	1.2
DL-Methionine	0.09
Threonine	0.27
Tryptophan	0.02
Phytase	0.02
Acidifier	0.35
Vitamin and mineral premix^a	1
	100
Calculated nutrient content
ME, MJ/kg	14.23
Lysine, %	1.3
Methionine, %	0.38
Threonine, %	0.76
Tryptophan, %	0.21

^aPremix supplied per kg of diet: niacin, 38.4 mg; calcium pantothenate, 25 mg; folic acid, 1.68 mg; biotin, 0.16 mg; vitamin A, 35.2 mg; vitamin B1, 4 mg; vitamin B₂, 12 mg; vitamin B₆, 8.32 mg; vitamin B₁₂, 4.8 mg; vitamin D₃, 7.68 mg; vitamin E, 128 mg; vitamin K₃, 8.16 mg; zinc (ZnSO₄ · H₂O), 110 mg; copper (CuSO₄ · 5H₂O), 125 mg; selenium (Na₂SeO₃), 0.19 mg; iron (FeSO₄ · H₂O), 171 mg; cobalt (CoCl₂), 0.19 mg; manganese (MnSO₄·H₂O), 42.31 mg; iodine (Ca(IO₃)₂), 0.54 mg.

ME: metabolizable energy.

Table 2. Analysed nutrient composition of diets (as fed basis).

	NC	PC	HK1	HK2
Crude protein, %	19.78	19.53	19.84	20.15
Calcium, %	0.80	0.83	0.86	0.82
Phosphorus, %	0.58	0.60	0.61	0.60
Fat, %	4.17	4.17	4.19	4.20
Ash, %	5.49	5.64	5.36	5.40

NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis.

Table 3. Effect of hydrolysed yeast from Kluyveromyces fragilis (HK) supplementation on body weight, growth performance and diarrhoea incidence (DI) of weaned piglets overall the experimental period (0-21d)^A.

Treat	NC	PC	HK1	HK2	SEM	P-value
BW, kg
Day 0	7.03	7.03	7.03	7.03	0.67	0.999
Day 21	10.84	10.77	10.79	10.77	1.13	0.999
ADG, g	181	178	179	178	26	0.999
ADFI, g	339	347	355	334	29	0.915
G:F ratio	0.536	0.498	0.501	0.529	0.041	0.886
DI, %	19.72^a	5.01^c	15.80^ab	14.55^b	–	<0.01
Culling/Mortality, %	4.00	0.00	4.00	4.00	–	0.794

ADG: average daily gain; BW: body weight; DI: diarrhoea incidence; G:F: gain to feed ratio;

NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis.

^An = 20 (5 replicates per treatment and 5 piglets per replicate).

^a-b\Means listed in the same row with different superscripts are significantly different (p < 0.05).

Table 4. Effect of hydrolysed yeast from Kluyveromyces fragilis (HK) supplementation on plasma antioxidant efficiency of weaned piglets^A.

Item	NC	PC	HK1	HK2	SEM	P-value
SOD, U/mL	25.33^b	31.73^a	29.82^ab	33.5^a	1.33	0.004
MDA, nmol/mL	3.15^a,x	2.36^b	2.47^ab,y	2.17^b	0.16	0.012
GSH-Px, U/mL	348	345	363	372	11	0.333

NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis; SOD: superoxide dismutase; MDA: malondialdehyde; GSH-Px: glutathione peroxidase.

^An = 20 (5 replicates per treatment and 1 piglet per replicate).

^a,bMeans listed in the same row with different superscripts are significantly different (p < 0.05).

^x,yMeans listed in the same row with different superscripts have tendency to be different (0.05 ≤ p < 0.10).

Table 5. Effect of hydrolysed yeast from Kluyveromyces fragilis (HK) supplementation on plasma immunoglobulin of weaned piglets^A.

Item	NC	PC	HK1	HK2	SEM	P-value
IgA, mg/mL	1.32^b,y	1.76^ab,x	1.41^b	1.96^a	0.10	0.003
IgG, mg/mL	33.86	46.00	44.59	46.50	4.80	0.285

NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis; IgA: Immunoglobulin A; IgG: Immunoglobulin G.

^An = 20 (5 replicates per treatment and 1 piglet per replicate).

^a,bMeans listed in the same row with different superscripts are significantly different (p < 0.05).

^x,yMeans listed in the same row with different superscripts have tendency to be different (0.05 ≤ p < 0.10).

Figure 1. OTU Venn diagram. NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis.

Table 6. Effect of hydrolysed yeast from Kluyveromyces fragilis (HK) supplementation on faecal microbiota α diversity of weaned piglets^A.

Item	NC	PC	HK1	HK2	SEM	P-value
Ace index	413^b	456 ^ab,y	481^ab	631^a,x	29	0.045
Chao1 index	418^b	455^b	493^ab	653^a	31	0.040
Shannon index	3.64	4.03	4.34	4.48	0.15	0.267
Simpson index	0.10	0.06	0.03	0.03	0.02	0.375

NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis.

^An = 20 (5 replicates per treatment and 1 piglet per replicate).

^a-bMeans listed in the same row with different superscripts are significantly different (p < 0.05).

^x,yMeans listed in the same row with different superscripts have tendency to be different (0.05 ≤ p < 0.10).

Figure 2. Faecal microbial β diversity (OTU level). NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis.

Figure 3. Relative abundance of species at the phylum (A) and genus (B) levels. The Y-axis represents the average relative abundance, the X-axis represents the different groups. NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis.

Figure 4. Significance test of difference between treatments at phylum (A) and genus (B) levels. The Y-axis represents the species names at a certain taxonomic level, the X-axis represents the average relative abundance in different groups of species, and the columns with different colours represent different groups; the far right is the p-value, *p < 0.05. NC: basal diet without additive; PC: NC + 2 g/kg zinc oxide; HK1: NC + 7.5 g/kg hydrolysed yeast from Kluyveromyces fragilis; HK2: NC + 10 g/kg hydrolysed yeast from Kluyveromyces fragilis.

Data availability statement

Datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.