The Benefits of Adding Sulfur and Urea to a Concentrate Mixture on the Utilization of Feed, Rumen Fermentation, and Milk Production in Dairy Cows Supplemental Fresh Cassava Root

Table 3

Effect of sulfur and urea levels on rumen ecology in dairy cows.

Items	Sulfur-1		Sulfur-2		SEM	value
	Urea-1	Urea-2	Urea-1	Urea-2		Sulfur	Urea	Sulfur  urea
Ruminal pH
0 h prefeeding	6.65	6.67	6.67	6.57	0.071	0.606	0.582	0.376
4 h postfeeding	6.47	6.41	6.39	6.32	0.094	0.064	0.474	0.896
Mean	6.56	6.54	6.53	6.44	0.047	0.244	0.306	0.495
Ammonia-nitrogen, mg/dl
0 h prefeeding	8.51^a	10.60^b	8.92^a	11.52^b	0.128	0.151	0.001	0.108
4 h postfeeding	18.61^a	23.61^b	19.22^a	24.11^b	0.156	0.165	0.001	0.964
Mean	13.56^a	17.14^b	14.09^a	17.85^b	0.118	0.189	0.001	0.432
Protozoa, ×10^6 cells/mL
0 h prefeeding	8.80	9.00	8.90	8.80	0.081	0.457	0.880	0.117
4 h postfeeding	12.80	12.90	12.80	12.90	0.049	0.805	0.231	0.463
Mean	10.83	10.95	10.87	9.31	0.787	0.329	0.375	0.308
Bacteria, ×10^9 cells/mL
0 h prefeeding	31.00	31.00	30.50	30.50	0.549	0.381	1.000	1.000
4 h postfeeding	41.75^a	41.25^a	41.50^a	42.25^b	0.295	0.164	0.836	0.038
Mean	36.38	36.06	36.00	36.38	0.354	0.931	0.931	0.352

Sulfur-1 and sulfur-2 = sulfur addition into concentrates at 10 g/kg DM and 20 g/kg DM. Urea-1 and urea-2 = urea addition into concentrates at 10 g/kg DM and 20 g/kg DM; SEM = standard error of mean; sulfur  urea = interaction effect between sulfur and urea; ^a,bmeans in the same row with different superscript letters are accepted as significantly different ().