Effects of Saccharomyces Cerevisiae at Direct Addition or Pre-incubation on in Vitro Gas Production Kinetics and Degradability of Four Fibrous Feeds

Figures & data

Table 1. Chemical composition of the four fibrous feeds.

Species	OM, g/kg DM	CP, g/kg DM	ADF, g/kg DM	NDF, g/kg DM
Corn stover	959.7	62.9^a	274.4^c	476.7^b
Oat straw	923.6	37.2^b	380.0^a	537.8^a
Sugarcane bagasse	982.0	25.7^c	324.4^b	458.9^b
Sorghum straw	944.3	40.0^b	377.8^a	556.7^a
SEM	42.3	9.3	28.1	37.1

OM, organic matter; DM, dry matter; CP, crude protein; ADF, acid detergent fibre; NDF, neutral detergent fibre.

^a-cDifferent superscripts following means in the same row indicate differences at P<0.05.

Table 2. In vitro rumen gas kinetics of four low quality roughages as affected by the direct addition or 72 h pre-incubation with different levels of Saccharomyces cerevisiae.

	GP parameters			In vitro GP, mL/g DM
	b, mL/g DM	c, /h	L, /h	Gas2	Gas4	Gas6	Gas8	Gas10	Gas12	Gas14	Gas24	Gas30	Gas48	Gas54	Gas72
Effect of S
Corn stover	329.5^a	0.029^c	0.74^b	18.2^b	35.4^b	51.6^b	66.9^b	81.3^b	94.9^b	107.8^b	162.0^a	187.9^a	243.4^a	256.5^a	284.8^a
Oat straw	273.9^b	0.029^c	1.14^a	14.5^c	28.2^c	41.0^c	53.1^d	64.5^d	75.2^d	85.4^d	128.1^c	148.7^b	193.8^b	204.7^b	229.1^b
Sugarcane baggas	159.0^d	0.099^a	0.36^c	28.4^a	51.1^a	69.4^a	84.2^a	96.3^a	106.2^a	114.4^a	138.8^b	146.1^b	155.4^c	156.6^c	158.3^c
Sorghum straw	257.4^c	0.041^b	0.45^c	17.5^b	33.4^b	48.1^b	61.6^c	74.0^c	85.4^c	96.0^c	138.1^b	156.9^c	195.4^b	204.2^b	223.2^b
LSD	15.27	0.0064	0.153	1.56	2.71	3.54	4.16	4.62	4.97	5.25	6.11	6.54	8.02	8.53	9.99
P	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
Effect of application M
Direct	256.1	0.056^a	0.51^b	22.3^a	41.6^a	58.4^a	73.3^a	86.6^a	98.4^a	109.2^a	150.3^a	168.1^a	203.8^a	211.8^a	228.8^a
Pre- incubation	253.8	0.043^b	0.84^a	17.0^b	32.5^b	46.7^b	59.6^b	71.5^b	82.5^b	92.6^b	133.2^b	151.7^b	190.2^b	199.2^b	218.8^b
LSD	8.19	0.0034	0.082	0.84	1.45	1.90	2.23	2.48	2.67	2.82	3.28	3.51	4.30	4.58	5.36
P	0.5895	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
Effect of Y, mg/g DM
0	243.1^b	0.041^b	0.55^b	16.5^c	31.7^c	45.7^c	58.5^c	70.3^c	81.2^c	91.2^c	131.5^c	149.6^c	186.3^c	194.7^c	212.6^c
4	259.4^a	0.045^b	0.66^ab	19.0^b	36.1^b	51.6^b	65.8^b	78.6^b	90.4^b	101.2^b	143.7^ab	162.4^ab	200.4^ab	209.0^ab	227.5^ab
8	251.9^ab	0.056^a	0.74^a	21.0^a	39.2^a	55.1^ab	69.2^ab	81.6^ab	92.8^ab	103.0^ab	142.1^b	159.3^b	194.8^b	203.1^bc	221.1^bc
12	265.4^a	0.056^a	0.75^a	22.1^a	41.1^a	57.7^a	72.4^a	85.6^a	97.4^a	108.1^a	149.8^a	168.3^a	206.4^a	215.2^a	234.1^a
LSD	15.27	0.0064	0.153	1.56	2.71	3.54	4.16	4.62	4.97	5.25	6.11	6.54	8.02	8.53	9.99
Linear	0.0065	0.1165	0.076	0.0001	<.0001	<.0001	<.0001	<.0001	<.0001	<.0001	<.0001	<.0001	<.0001	<.0001	0.0002
Quadratic	0.006	<0.0001	0.0066	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
Interactions
S×M	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	0.0024
S×Y	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
M×Y	0.0989	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
S×M×Y	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0002

GP, gas production; DM, dry matter; b, asymptotic gas production; c, rate of gas production; L, initial delay before gas production begins; LSD, least significant difference; S, species; M, method; Y, yeast product.

^a-dDifferent superscripts following means in the same row indicate differences at P<0.05.

Table 3. In vitro rumen fermentation profile of four low quality roughages as affected by the direct addition or 72 h pre-incubation with different levels of Saccharomyces cerevisiae.

	pH	CH4, mL/g	DMD, mg/g	NDFD, mg/g	ADFD, mg/g	ME, MJ/kg	OMD, g/kg	SCFA, mmol/g	PF24, mg	GY24, mL gas/g
DM	DM	DM	DM	DM	DM	DM	DMD:mL gas	DMD
Effect of S
Corn stover	6.78^b	18.7^b	326.1^a	256.7^c	264.6^c	6.84^a	459^a	3.58^a	2.03^a	497.4^b
Oat straw	6.98^a	17.1^b	285.0^b	276.6^b	363.0^a	6.12^bc	413^bc	2.82^c	2.24^b	450.1^a
Sugarcane baggas	6.97^a	6.8^c	272.4^c	217.2^d	310.1^b	6.08^c	405^c	3.06^b	2.00^b	511.4^a
Sorghum straw	7.00^a	25.2^a	270.9^c	291.1^a	360.7^a	6.27^b	422^b	3.04^b	1.99^b	517.1^a
LSD	0.153	2.12	4.69	7.00	4.78	0.166	10.9	0.136	0.117	24.42
P	0.0006	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
Effect of application M
Direct	6.91	17.5^a	290.4^a	263.2^a	326.1	6.56^a	440^a	3.32^a	1.96^b	522.1^a
Pre-incubation	6.96	16.4^b	286.7^b	257.7^b	323.1	6.09^b	410^b	2.94^b	2.18^a	465.9^b
SEM	0.082	1.14	2.52	3.75	2.60	0.089	5.83	0.073	0.063	13.11
P	0.267	0.0467	0.0046	0.0045	0.0204	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
Effect of Y product, mg/g DM
0	6.92	17.6	290.4^a	263.3^a	325.4	6.05^c	407^c	2.90^c	2.23^a	454.5^b
4	6.97	17.0	283.9^b	255.4^b	325.3	6.38^ab	428^ab	3.17^ab	2.00^b	513.9^a
8	6.92	17.0	285.3^b	261.4^ab	323.7	6.34^b	426^b	3.13^b	2.03^b	500.0^a
12	6.93	16.3	294.8^a	261.6^ab	324.0	6.55^a	439^a	3.30^a	2.01^b	507.7^a
LSD	0.153	2.12	4.69	6.70	4.78	0.166	10.9	0.136	0.117	24.42
Linear	0.3417	0.4311	0.0005	0.0045	0.9362	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
Quadratic	0.7076	0.1493	<0.0001	0.3303	0.3932	<0.0001	<0.0001	<0.0001	0.011	0.0046
Interactions
S×M	0.1869	0.2509	<0.0001	<0.0001	0.6104	<0.0001	<0.0001	<0.0001	0.0011	<0.0001
S×Y	0.8837	<0.0001	<0.0001	<0.0001	0.0005	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
M×Y	0.8066	0.4184	0.1636	0.0001	0.4479	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
S×M×Y	0.9481	<0.0001	<0.0001	<0.0001	0.0152	<0.0001	<0.0001	<0.0001	0.0032	<0.0001

CH₄, methane emission; DM, dry matter; DMD, dry matter degraded substrate; NDFD, neutral detergent fibre degradability; ADFD, acid detergent fibre; ME, metabolisable energy; OMD, organic matter digestibility; SCFA, short chain fatty acids; PF24, partitioning factor at 24 h of incubation; GY₂₄, gas yield at 24 h; S, species; LSD, least significant difference; M, method; Y, yeast product.

^a-dDifferent superscripts following means in the same row indicate differences at P<0.05.