TABLE 1.

Effect of feeding essential oils to cattle on the subsequent breakdown of proteins, peptides, and amino acids in rumen fluid in vitro

Treatment or parameter	Amt (mg) of substrate degraded mg of protein−1 h−1					Amt (nmol) of peptide degraded mg of protein−1 h−1					Amt (nmol) of NH3 produced mg of protein−1 h−1
	Casein	Lacto- globulin	Hide powder azure	Albumin	Elastin Congo red	Ala2	Ala5	Arg Lys Asp Val Tyr	Ala2- pNA	GlyArg- MNA	No monensin	5 μM monensin
Control	0.46	0.21	0.048	0.033	0.0056	0.60	1.03	0.33	1.64	0.36	410	280
Essential oils	0.49	0.24	0.049	0.035	0.0054	0.69	1.22	0.35	1.58	0.40	372	287
SEDb	0.038	0.032	0.0035	0.0016	0.00092	0.088	0.230	0.035	0.056	0.060	9.8a	10.9

^aP < 0.05.

^bSED, standard error of the difference.