Table 2.

Mean energy-corrected milk production and plasma AST, BHBA, glucose, insulin, and NEFA concentrations at 3 wk relative to treatment start

	Treatment				SED	P Value
	AF2×	AF1×	UF2×	UF1×		MF	FL	MF×FL
Energy corrected milk, kg/day	23.2	18.6	15.0	13.2	0.6	<0.001	<0.001	<0.001
AST, log10 IU/l	1.89 (81)	1.85 (73)	1.93 (91)	1.97 (107)	0.03	0.91	<0.001	0.09
BHBA, log10 mmol/l	−0.32 (0.48)	−0.41 (0.39)	0.07 (1.17)	−0.21 (0.62)	0.04	<0.001	<0.001	<0.01
Glucose, log10 mmol/l	0.62 (4.17)	0.64 (4.37)	0.53 (3.39)	0.59 (3.89)	0.01	<0.001	<0.001	<0.05
Insulin, log10 mmol/l	0.48 (3.02)	0.57 (3.72)	0.25 (1.78)	0.38 (2.40)	0.05	<0.01	<0.001	0.59
NEFA, log10 mmol/l	−0.36 (0.43)	−0.60 (0.25)	0.05 (1.12)	−0.04 (0.92)	0.04	<0.001	<0.001	<0.01

Grazing cows (n = 120) were adequately fed (AF; 14.3 ± 3.6 kg dry matter/cow/day) or underfed (UF; 8.3 ± 2.9 kg dry matter/cow/day) and milked once (1×) or twice (2×) daily for 3 wk from treatment start. Plasma measures were log₁₀ transformed and are displayed with back-transformed values in parentheses. Pretreatment measurements taken at −1 wk relative to the start of the treatment period were used as covariates.

AST, aspartate aminotransferase; BHBA, β-hydroxybutyrate; NEFA, nonesterified fatty acid; SED, standard error of the difference between the means; MF, milking frequency; FL, feeding level.