Dietary supplementation of active dry yeast (Saccharomyces cerevisiae) to finishing bulls: effects on growth performance, blood hormones, fatty acid concentrations in the gastrointestinal tract and trace mineral elements utilisation

Figures & data

Table 1. Ingredient and nutritional composition of basal diets (%, dry matter basis).

Ingredient composition	Content, % of DM	Nutritional composition^a	Content, % of DM
Corn silage	42.00	Dry matter, DM	86.45
Corn meal	40.00	Crude protein	11.95
Soybean meal	8.00	Ether extract	3.60
DDGS	3.10	Neutral detergent fibres	26.60
Corn germ meal	3.00	Acid detergent fibres	14.61
Bacterial protein feeds	1.00	Calcium	0.39
Sodium bicarbonate	1.00	Phosphorus	0.32
Soybean oil	0.50	Sodium chloride	0.40
Salt	0.40	Fe, mg/kg	71.89
Compound premix^b	1.00	Cu, mg/kg	15.01
Total, %	100.00	Zn, mg/kg	52.59
		Mn, mg/kg	22.03
		Se, mg/kg	0.49
		C8:0–C12:0, mg/kg	427.80
		C13:0–C14:1, mg/kg	619.92
		NEg^c, Mcal/kg DM	1.24

^aConventional nutrients in feed were calculated based on the actual content of feed ingredients and trace mineral elements were measured by a service corporation (Beijing Sino-UK of Biological Technology, Beijing, China).

^bSupplied per kilogram of product. Ca: 200 g; P: 50 g; Fe: 500 mg; Cu: 1000 mg; Zn: 2400 mg; Mn: 1500 mg; I: 10 mg; Co: 7 mg; Se: 45 mg; vitamin A: 500,000 IU; vitamin D: 150,000 IU; vitamin E: 400 mg.

^cNEg (net energy for growth) was estimated from the analysed value of the dietary ingredients [based on Ministry of Agriculture of P.R. China (2018)].

Table 2. Effects of active dry yeast (ADY) supplementation on growth performance of finishing bulls.

Items	CON	ADY	SEM	p-Value
Initial BW, kg	485.70	485.09	8.400	0.964
Final BW, kg	591.41	597.78	7.840	0.427
ADG, kg/d	1.18	1.24	0.087	0.451
DMI, kg/d	10.03	11.01	0.316	0.042
Gain:Feed, G:F	0.12	0.11	0.006	0.620

BW: body weight; ADG: average daily gain; DMI: dry matter intake; CON: the control group cattle fed control diets; ADY: the treatment group cattle fed control diets containing active dry yeast; SEM: standard error of the means.

Table 3. Effects of active dry yeast (ADY) supplementation on blood intake-related hormones of finishing bulls.

Items	CON	ADY	SEM	p-Value
AG, pg/mL	57.38	89.05	37.840	0.053
TG, pg/mL	147.29	173.35	12.450	0.308
AG/TG	0.39	0.52	0.039	0.092
POMC, pg/mL	705.96	523.52	40.060	0.180
NPY, ng/mL	9.42	10.08	0.800	0.692
CRH, pg/mL	692.72	402.87	49.580	0.001
Orexins, pg/mL	572.30	733.07	51.520	0.121
AGRP, ng/mL	7.44	7.72	0.370	0.173
GOAT, ng/mL	1.70	2.62	0.197	0.018

AG: acyl ghrelin; TG: total ghrelin; POMC: proopiomelanocortin; NPY: neuropeptide Y; CRH: corticotropin-releasing hormone; AGRP: agouti-related protein; GOAT: ghrelin O-acyl transferase; CON: the control group cattle fed control diets; ADY: the treatment group cattle fed control diets containing active dry yeast; SEM: standard error of the means.

Table 4. Effects of active dry yeast (ADY) supplementation on selected fatty acids content in rumen fluid and duodenal digesta of finishing bulls.

Items	CON	ADY	SEM	p-Value
Rumen fluid
C8:0, μg/mL	/	/	/	/
C10:0, μg/mL	/	/	/	/
C12:0, μg/mL	0.50	0.60	0.041	0.243
C13:0, μg/mL	0.19	0.25	0.021	0.136
C14:0, μg/mL	4.06	4.97	0.360	0.215
C14:1, μg/mL	0.52	0.53	0.033	0.908
Duodenal digesta, DM
C8:0, μg/g	/	/	/	/
C10:0, μg/g	0.85	0.90	0.082	0.746
C12:0, μg/g	11.16	13.52	0.590	0.042
C13:0, μg/g	2.94	4.17	0.320	0.054
C14:0, μg/g	53.52	58.61	4.600	0.596
C14:1, μg/g	3.08	4.03	0.400	0.249

CON: the control group cattle fed control diets; ADY: the treatment group cattle fed control diets containing active dry yeast; SEM: standard error of the means.

Table 5. Effects of active dry yeast (ADY) supplementation on apparent digestibility of trace mineral elements of finishing bulls.

Items	CON	ADY	SEM	p-Value
Fe, %	35.66	32.79	3.27	0.673
Cu, %	60.15	61.31	2.49	0.823
Zn, %	14.79	23.64	2.25	0.045
Mn, %	67.55	70.51	2.24	0.525
Se, %	66.57	66.23	2.68	0.952

CON: the control group cattle fed control diets; ADY: the treatment group cattle fed control diets containing active dry yeast; SEM: standard error of the means.

Table 6. Effects of active dry yeast (ADY) supplementation on intake, absorption, and excretion of trace mineral elements of finishing bulls.

Items	CON	ADY	SEM	p-Value
Intake
Fe, mg/d	721.43	791.32	19.000	0.064
Cu, mg/d	150.64	165.24	3.970	0.064
Zn, mg/d	527.81	578.94	13.900	0.064
Mn, mg/d	221.09	242.51	5.820	0.064
Se, mg/d	4.88	5.35	0.128	0.064
Absorption
Fe, mg/d	255.47	260.92	26.040	0.920
Cu, mg/d	90.90	102.75	5.730	0.314
Zn, mg/d	78.76	137.80	13.950	0.027
Mn, mg/d	149.28	171.45	7.060	0.119
Se, mg/d	3.26	3.58	1.920	0.421
Excretion
Fe, mg/d	465.96	523.22	28.620	0.331
Cu, mg/d	59.75	60.99	3.420	0.861
Zn, mg/d	449.05	434.88	12.710	0.591
Mn, mg/d	71.81	68.85	5.440	0.794
Se, mg/d	1.62	1.72	0.120	0.684

CON: the control group cattle fed control diets; ADY: the treatment group cattle fed control diets containing active dry yeast; SEM: standard error of the means.

Table 7. Effects of active dry yeast (ADY) supplementation on serum trace mineral elements content of finishing bulls.

Items	CON	ADY	SEM	p-Value
Fe, μg/L	643.92	691.52	30.16	0.446
Cu, μg/L	355.21	423.81	16.63	0.035
Zn, μg/L	594.17	676.07	20.89	0.047
Mn, μg/L	17.55	19.72	0.78	0.171
Se, μg/L	58.30	56.23	4.27	0.817

CON: the control group cattle fed control diets; ADY: the treatment group cattle fed control diets containing active dry yeast; SEM: standard error of the means.

Table 8. Effects of active dry yeast (ADY) supplementation on trace mineral elements contents in tissues of finishing bulls.

Items	CON	ADY	SEM	p-Value
Liver
Fe, μg/g	31.49	28.00	2.370	0.480
Cu, μg/g	26.92	37.58	2.510	0.030
Zn, μg/g	60.62	64.91	2.810	0.464
Mn, μg/g	3.62	3.44	0.090	0.345
Se, μg/g	0.19	0.18	0.011	0.763
Hair
Fe, μg/g	217.32	293.57	24.960	0.133
Cu, μg/g	8.16	8.12	0.710	0.982
Zn, μg/g	118.79	134.99	9.380	0.407
Mn, μg/g	5.23	4.73	0.350	0.499
Se, μg/g	0.71	0.58	0.063	0.323
Muscle
Fe, μg/g	30.06	14.45	2.690	0.001
Cu, μg/g	0.79	1.12	0.130	0.210
Zn, μg/g	50.76	42.46	2.490	0.099
Mn, μg/g	4.08	3.87	0.130	0.435
Se, μg/g	0.22	0.18	0.012	0.144
Overall deposition (liver + hair + muscle)
Fe, μg/g	278.87	336.01	23.030	0.228
Cu, μg/g	35.87	46.82	2.810	0.049
Zn, μg/g	230.17	242.37	9.520	0.541
Mn, μg/g	12.92	12.05	0.400	0.288
Se, μg/g	1.12	0.95	0.063	0.182

CON: the control group cattle fed control diets; ADY: the treatment group cattle fed control diets containing active dry yeast; SEM: standard error of the means.

Data availability statement

The data analysed during the current study are available from the corresponding author on reasonable request.