Effects of the dietary nonfiber carbohydrate content on lactation performance, rumen fermentation, and nitrogen utilization in mid-lactation dairy cows receiving corn stover

Table 3 Lactation performance in dairy cows fed 3 experimental diets

Items	Treatment^d			SEM	P-value
Items	AH	L-NFC	H-NFC	SEM	P-value
DM intake, kg/d	21.9^a	21.5^a	20.1^b	0.44	< 0.01
Milk yield, kg/d	24.8^a	23.2^b	22.8^b	0.76	< 0.01
ECM^e, kg/d	27.7	27.0	26.4	1.01	0.20
Milk composition, %
Fat	3.90^b	4.25^a	4.11^a	0.12	< 0.01
Protein	3.48	3.52	3.50	0.06	0.56
Lactose	5.00	4.95	4.98	0.06	0.11
Total solid	12.6^b	12.9^a	12.8^ab	0.17	< 0.01
Milk urea nitrogen, mg/dL	18.1^b	20.3^a	18.3^b	0.72	< 0.01
Feed efficiency, kg/kg
Milk/DM intake	1.15^a	1.08^b	1.15^a	0.03	< 0.01
ECM/DM intake	1.28	1.27	1.32	0.04	0.16
Somatic cell count, ×10³/mL	94.8	64.2	70.6	20.6	0.26
Feed cost per kg milk, $/kg	0.342^a	0.331^b	0.319^c	0.01	< 0.01

^a-cLeast squares means within a row with different superscripts differ significantly (P < 0.05)
^dAH = Total mixed rations containing alfalfa hay. L-NFC = Total mixed rations containing corn stover with a low content of non-fiber carbohydrates; H-NFC = Total mixed rations containing corn stover formulated to have similar non-fiber carbohydrate concentrations as the AH diet
^eECM = Energy-corrected milk. ECM (kg) = 0.3246 × milk yield (kg) + 13.86 × fat yield (kg) + 7.04 × protein yield (kg) [39]

ISSN: 2049-1891