Table 6.

Experiment 3. Effects of increasing supplementation levels of Tetradesmus obliquus on food, gross energy and nutrient intake (dry matter, DM, basis), fecal output and characteristics, apparent total tract digestibility (ATTD, %), metabolizable energy content (MJ kg⁻¹ DM), and fecal pH, concentration of ammonia-N (g kg⁻¹ DM), and concentration of volatile fatty acids (μmol g⁻¹ DM).

	Diet			SEM	p-value
	0.5%	1.0%	1.5%
Food intake
g/d (as-is)	301	301	301	0.02	0.130
g/d (DM basis)	278	277	279	0.9	0.450
Gross energy (MJ/d)	5.10	5.08	5.12	0.018	0.389
Nutrient intake
Organic matter	243	242	244	0.8	0.445
Crude protein	70.4	70.2	70.9	0.25	0.181
Neutral detergent fiber	63.4	63.1	63.5	0.21	0.450
Fecal output
g/d (as-is)	281	283	292	9.7	0.703
g/d (DM basis)	85.9	88.9	90.4	1.97	0.319
Gross energy (MJ/d)	1.21	1.27	1.29	0.036	0.362
Fecal production (%)	30.9	32.0	32.4	0.76	0.437
Defecations (n/d)	2.3	2.2	2.6	0.09	0.060
DM feces (%)	31.3	31.3	30.6	0.76	0.726
Fecal score (1–5)	3.2	3.0	3.0	0.11	0.397
ATTD
DM	69.1	68.0	67.6	0.76	0.437
Organic matter	74.8	73.9	73.5	0.59	0.326
Crude protein	72.8	70.6	69.9	1.38	0.353
Neutral detergent fiber	48.5	47.6	47.9	1.12	0.857
Gross energy	76.1	75.1	74.9	0.74	0.493
Metabolizable energy	13.0	12.8	12.8	0.13	0.622
Fecal metabolites
pH	6.72	6.75	6.77	0.050	0.709
Ammonia-N	2.51	2.54	2.57	0.112	0.940
Volatile fatty acids
Total	847	837	855	11.7	0.571
Acetate	526	522	531	8.0	0.731
Propionate	218	209	224	7.75	0.419
Iso-butyrate	8.97	11.1	9.23	0.656	0.104
Butyrate	73.7	73.3	70.6	1.78	0.454
Iso-valerate	10.8	12.2	11.1	0.80	0.443
Valerate	2.82	2.64	2.15	0.398	0.504
Iso-caproate	5.93	4.84	4.78	0.527	0.279
Caproate	1.43	1.48	1.46	0.272	0.993
Acetate:propionate	2.43	2.53	2.41	0.108	0.706