Winery by-products as a feed source with functional properties: dose–response effect of grape pomace, grape seed meal, and grape seed extract on rumen microbial community and their fermentation activity in RUSITEC

Table 3 Nutrient degradation and fermentation efficiency as affected by dietary treatment^a

Item	Treatment						SEM	Overall P-value	Contrast P-value
Item	CON	EXT	GP-low	GP-High	GS-low	GS-high	SEM	Overall P-value	EXT vs. GP	EXT vs. GS	GP vs. GS
Nutrient degradation, %
Dry matter	65.03	62.49^*	62.61^*	61.32^*	63.95⁺	62.78^*	0.66	< 0.001	0.190	0.032	< 0.001
Organic matter	63.08	60.33^*	60.65^*	59.27^*	62.04	60.91^*	0.72	< 0.001	0.380	0.009	< 0.001
Crude protein	69.43	66.93^*	69.34	67.19⁺	71.24	70.75	0.99	< 0.001	0.107	< 0.001	< 0.001
Ether extract	45.58	39.52⁺	52.82^*	50.99	41.03	43.12	3.21	< 0.001	< 0.001	0.221	< 0.001
Neutral detergent fiber	47.24	46.24	39.74^*	42.29^*	46.51⁺	45.11	2.50	< 0.001	< 0.001	0.558	< 0.001
Acid detergent fiber	36.88	33.70	32.44	34.48	35.89	34.79	1.31	0.157	0.995	0.210	0.219
Fermentation efficiency
Short-chain fatty acids, mmol/g degraded organic matter	9.60	9.41	8.87⁺	9.55	9.29	9.04	0.28	0.042	0.356	0.266	0.811
Methane, mL/g degraded organic matter	12.33	11.22	12.59	11.70	12.10	11.78	1.21	0.243	0.077	0.170	0.623
Ammonia, mmol/g degraded crude protein/d	4.88	4.08^*	4.10^*	4.01^*	4.19^*	4.15^*	0.28	< 0.001	0.838	0.422	0.221

Values in the same row with * significantly differ from CON (P < 0.05) or with + tend to differ from CON (0.05 < P ≤ 0.10) according to Dunnett’s test
^aDiets without (CON) or with different inclusion levels of grape pomace (GP-low and GP-high) or grape seed meal (GS-low and GS-high) or supplemented with grape seed extract (EXT)

ISSN: 2049-1891