Table 3.

Results of simple linear regressions for in vitro fermentation characteristics and feeding values of compound feeds

	Calculated v. observed						Mash v. pelleted
	Slope	Slope CI	Intercept	Intercept CI	R 2	RMSE	Slope	Slope CI	Intercept	Intercept CI	R 2	RMSE
In vitro gas production
bGP	0.98	0.74 to 1.21	3.58	−11.95 to 19.11	0.95	1.70	0.79	0.64 to 0.93	13.80	3.87 to 23.72	0.97	1.06
cGP	0.68	0.03 to 1.33	2.67	−2.65 to 7.98	0.52	0.44	0.59	0.43 to 0.75	4.14	2.82 to 5.47	0.93	0.10
GP24	0.96	0.78 to 1.14	2.72	−8.52 to 13.95	0.97	1.19	0.82	0.67 to 0.98	11.27	1.63 to 20.91	0.97	1.00
dOM	1.10	0.73 to 1.40	−4.95	−33.43 to 23.53	0.91	1.25	0.77	0.59 to 0.94	19.84	4.66 to 35.02	0.95	0.74
ME	–1	–	–	–	–	–	0.71	0.54 to 0.87	3.82	1.61 to 6.03	0.95	0.07
uCP
k = 5%/h	0.97	0.61 to 1.33	−1.05	−70.00 to 67.89	0.88	3.73	0.37	−0.11 to 0.85	120.09	31.12 to 209.07	0.38	5.16
k = 8%/h	0.97	0.77 to 1.17	−1.26	−45.18 to 42.66	0.96	3.89	0.53	0.29 to 0.77	103.00	53.24 to 152.76	0.83	4.53
IDRUP	0.95	0.23 to 1.66	7.86	−30.08 to 45.80	0.64	5.53	1.42	0.99 to 1.85	−31.27	−56.26 to −6.28	0.92	3.94
CP fractions
A	1.37	0.79 to 1.94	−24.19	−92.26 to 43.88	0.85	23.09	0.95	0.69 to 1.20	7.15	−28.95 to 43.25	0.93	15.30
B1	1.65	0.94 to 2.35	−119.87	−237.17 to −2.56	0.84	26.55	0.94	0.64 to 1.24	−2.20	−49.96 to 45.55	0.91	20.23
B2	0.94	0.64 to 1.23	38.34	−144.37 to 221.05	0.91	19.22	0.88	0.52 to 1.24	88.96	−131.32 to 309.24	0.86	22.79
B3	1.70	1.22 to 2.18	−46.79	−82.89 to −10.69	0.93	8.71	0.94	0.57 to 1.32	−3.55	−34.68 to 27.58	0.86	12.03
C	0.71	0.13 to 1.29	2.36	−19.67 to 24.40	0.60	10.21	0.98	0.31 to 1.65	4.60	−15.84 to 25.04	0.68	10.83
EDCNCPS
k = 5%/h	1.24	−0.41 to 2.89	−12.35	−134.36 to 109.66	0.36	3.40	0.63	0.14 to 1.11	31.83	−7.02 to 70.68	0.62	2.08
k = 8%/h	1.41	−0.20 to 3.02	−20.20	−126.68 to 86.28	0.43	4.22	0.65	0.19 to 1.10	28.54	−4.71 to 61.79	0.67	2.55

bGP = potential gas production; cGP = rate of gas production; GP₂₄ = corrected gas production at 24 h; dOM = digestibility of organic matter; ME = metabolisable energy; uCP = utilisable CP for ruminal passage rates (k) of 5 and 8%/h; ID_RUP = intestinal digestibility of rumen-undegraded protein; CP fractions = crude protein fractions: A = non-protein nitrogen; B1 = rapidly degradable true protein; B2 = moderately degradable true protein; B3 = slowly degradable true protein, C = undegradable and indigestible true protein, determined using Cornell Net Carbohydrate and Protein System (CNCPS); ED_CNCPS = effective protein degradation for ruminal passage rates of 5 and 8%/h, calculated using Fox et al. (2003). Observed values refer to values for compound feeds in mash form.

¹Simple linear regressions of calculated and observed ME values are presented in Figure 1.