TABLE 1.

Cellulose digestion and changes in bacterial and fungal concentrations during the fermentation of purified cellulose by rumen contents without (control) and with added antibiotics^a

Time (h)	Cellulose digestion (%)b		No. of bacteria/ml (107)c		No. of fungi/ml (102)d
	Control	Antibiotics	Control	Antibiotics	Control	Antibiotics
0	0	0	9.4 ± 3.1	9.4 ± 3.1	11.9 ± 4.1	11.9 ± 4.1
24	37.5 ± 4.6e	1.2 ± 0.7	1,000 ± 489	0.0004 ± 0.0001	0.01 ± 0.01	15.5 ± 9.7
30	51.2 ± 8.7	3.1 ± 1.0	451 ± 231	0.0023 ± 0.0011	0.02 ± 0.01	50.3 ± 33.4
48	56.8 ± 8.3	16.6 ± 1.9	290 ± 214	0.0044 ± 0.0010	0	229.8 ± 86.1
72	70.0 ± 1.7	47.2 ± 0.8	38.2 ± 4.8	0.0029 ± 0.0014	0	510.0 ± 80.0

^aPenicillin and streptomycin. 

^bAt all time periods, cellulose digestion in the control was higher than with antibiotics (P < 0.02). 

^cBacterial concentrations higher in the control tubes at 24 h (P < 0.13), 30 h (P < 0.15), at 48 h (P < 0.27), and 72 h (P < 0.01). 

^dFungal concentrations higher in the antibiotic tubes at 24 h (P < 0.21), 30 h (P < 0.23), and 48 and 72 h (P < 0.01). 

^eMean ± standard error.