Effects of different sources of carbohydrates on intake, digestibility, chewing, and performance of Holstein dairy cows

Table 1 Ingredients and chemical composition of three total mixed rations containing three different sources of non-fiber carbohydrates

Item	Treatments¹			SEM	P value
Item	B	BC	BB	SEM	P value
Ingredients, % of DM²
Alfalfa hay	23.41	23.69	23.57
Wheat straw	15.53	15.84	15.8
Barley grain	34.91	18.87	18.86
Corn grain	…	15.89	…
Beet pulp	…	…	15.89
Cotton seed meal	11.19	8.88	8.90
Soybean meal	3.01	2.99	3.01
Wheat bran	8.01	9.68	9.69
Sunflower meal	2.69	2.99	3.01
Calcium carbonate	0.43	0.4	0.5
Calcium phosphate	0.25	0.20	0.20
Salt	0.10	0.10	0.10
Vitamin supplement³	0.25	0.25	0.25
Urea	0.22	0.22	0.22
Chemical compositions, % of DM
CP	16.2	15.9	15.9	0.232	0.321
NDF	36.2	36.9	37.7	0.864	0.079
ADF	23.1	22.6	24.6	0.541	0.092
NFC	38.9	38.9	37.9	0.682	0.061
Starch	22.2^a	20.2^a	14.5^b	0.792	0.001
Sugar	3.1	2.8	3.3	0.432	0.213
NDSC⁴	13.6^c	15.9^b	20.1^a	0.232	0.001
EE	2.3	2.4	2.4	0.219	0.212
Ash	6.4	5.9	6.1	0.672	0.431
NEl⁵, Mcal/kg of DM	1.58	1.59	1.58	0.232	0.452

^{a, b, c}Means within a row with different subscripts differ (P < 0.05).
¹Treatments were diets containing barley + basal diet (B), barley and corn + basal diet (BC), and barley and beet pulp + basal diet (BB).
²Alfalfa, wheat straw, barley grain, corn, beet pulp, cotton seed meal, soy bean meal, wheat bran, and sun flower meal (DM basis) were chemically composed of 89.1%, 50.9%, 18.7%, and 15.3%; 91.2, 75.2, 10.4, and 3.4; 93.2, 22.1, 55.4, and 10.5; 96.7, 11.0, 78.3, and 8.5; 93.4, 44.4, 41.0, and 9.0; 90.7, 45.2, 16.3, and 27.3; 90.3, 17.8, 24.7, and 42.5; 90.3, 52.3, 24.4, and 16.5; and 92.0, 55.7, 17.3, and 16.1 for OM, NDF, NFC, and CP, respectively.
³Contained 40% NaCl, 25% Dyna mate, 10% K, 7% Mg, 12% S, 1,000 mg Fe/kg, 2% ZnSO₄.H₂O, 2% MnSO₄.4H₂O, 0.01% CoSO₄.6H₂O, 0.009% Na₂SeO₃, 0.012% ethylenediamine dihydroiodide, 0.8% CuSO₄.5H₂O, 680,000 IU/kg of Vitamin A, 160,000 IU/kg of Vitamin D, and 2,000 IU/kg of Vitamin E.
⁴NDSC = Neutral detergent soluble carbohydrate.
⁵NEl was calculated based on NRC [4].

ISSN: 2049-1891