Dr. L.E. Chase

Department of Animal Science

Cornell University

A number of New York dairymen will be short of forage this year. A minimum quantity of coarse forage is needed to maintain cud chewing, rumination and normal rumen function. One option for dairy producers is to purchase additional forage to meet their needs. Another option is to purchase some nonforage fiber sources (NFFS). These feeds can be used as partial replacements for forages in the ration. The following points should be evaluated when considering the use of NFFS in dairy rations.

1. Nutrient composition – Typical analyses are in Table 1. These values are only guidelines since variation will exist both within and between suppliers. Forage analyses of the specific feed to be used is suggested.

 

 

Table 1. Dry matter and nutrient composition of fibrous byproduct feeds^a

Feed	Dry Matter	Crude Protein	Protein Fractionsb			ADF	NDF	Fat	Ash	NSC	Starch	NE1
			SIP	DIP	UIP
	(%)	(% DM)	- - -(% of CP) - -			- - - - - - - - - - (% of DM) - - - - - - - - - -						Mcal/lb DM
Apple pomace	19.5	7.0	21.9	80	20	43.9	51.9	5.1	2.2	33.8	--	.71
Beet pulp	91.0	10.8	26.4	70	30	27.8	50.1	1.0	4.9	33.2	.4	.81
Brewers grain, dry	92.4	30.3	11.4	47	53	2135	49.2	7.8	5.3	7.4	3.8	.68
Brewers grain, wet	21.6	28.7	10.5	66	34	22.4	47.0	7.9	4.6	11.8	3.8	.73
Citrus pulp	89.0	7.5	41.3	80	20	(22)	(23)	2.9	7.0	59.4	.2	.80
Corn gluten feet	88.0	24.2	47.7	70	30	12.4	37.6	4.2	6.1	27.9	23.3	.87
Cottonseed, hulls	89.0	9.6	21.9	--	--	61.0	75.6	6.0	3.3	5.5	1.0	.45
Cottonseed, whole	89.0	25.4	22.6	55	45	42.7	54.7	15.6	4.2	0.1	.3	1.01
Distillers grain, dry	88.7	29.0	14.6	38	62	20.3	41.1	10.2	4.6	15.1	2.4	.93
Distillers grain, wet	30.1	27.0	12.4	--		16.3	33.8	12.6	5.0	21.6	2.4	.93
Oat hulls	92.0	3.9				42.0	78.0	1.8	7.0	9.3	5.0	.34
Soy hulls	90.2	14.1	30.8			43.9	60.3	3.0	4.9	17.7	5.3	.80
Wheat midds	86.7	18.1	32.8	80	20	13.0	39.6	4.5	3.2	34.6	29.0	.71

aDerived from references 1, 2, 11, 12, 13, 14

bSIP = soluble intake protein, DIP = degradable intake protein, UIP = undergraded intake protein

 

 

 

2. Economic evaluation – The cost of NFFS sources needs to be evaluated on a nutrient content basis. This will provide an index of the relative cost of energy and protein in these feeds. One approach is to use feed evaluation factors based on the price of shelled corn and 44% CP soybean meal. Feed evaluation factors for some NFFS are:

 

 

 

 

Feed	DM, %	Corn Factor	44% SBM Factor
Apple pomace	89	.871	-.073
Beet pulp	91	.913	.018
Brewers grains, dry	92	.293	.497
Brewers grains, wet	22	.065	.124
Corn gluten feed	90	.657	.331
Cottonseed, whole	88	.781	.313
Soyhulls	90	.829	.08.
Wheat midds	89	.549	.249

 

The above factors are from the Penn State Dairy Reference Manual 91995). They can provide a quick evaluation of economic feasibility of a specific product. A number of computer programs are available which provide a more in-depth economic evaluation.

 

3. Minimum forage feeding – The following guidelines are suggested to determine the minimum quantity of forage to be fed when using NFFS. The combination of NFFS and forage should maintain rumen function.

1. Forage intake should be at least 1.3 – 1.4% of bodyweight.

 

2. Forage NDF intake should be at least 0.65-0.75% of bodyweight. This is similar to a minimum of 14-15% of the total ration DM as forage NDF.

1. Effectiveness of fiber in NFFS – The effective fiber value of NFFS feeds will vary due to other ration characteristics. As an example, work at Michigan State indicated the effective fiber value of whole cottonseed was 41% of NDF when replacing alfalfa silage with a mean particle length of 9.5 mm. However, this value was 78% of total NDF when the mean particle length of the alfalfa silage was 4.8 mm. In another study at Florida, the effective fiber of distillers grains was 68% when the ration contained 70% concentrate. The effective fiber value was 21% when the ration contained 55% concentrate. Table 2 contains estimates of the effective fiber value for some NFFS feeds.

 

2. Ruminal NDF digestion – Table 2 contains estimates of ruminal NDF digestion of selected feeds. As a comparison, ruminal NDF digestion of alfalfa may vary from 30-65% depending upon maturity.

 

 

Table 2. Effective fiber and ruminal NDF digestion of NFFSa
Feed	Ruminal NDF Digestion %	Effective NDF, % of NDF
Beet pulp	68.9	40
Brewers dried grains	50.2	35
Cottonseed hulls	33.1	80
Corn gluten feed	45.7	50
Distillers grains	71.6	30
Soyhulls	90.7	20
Wheat midds	52.1	50
Whole cottonseed	-	85
a Firkins, S.L., 1995. Proc. 2nd National Alternative Feeds Symposium, St. Louis, MO. p. 221.

 

3. Feeding guidelines – The quantity of NFFS fed will vary with each ration. The key factor determining feeding level will be the quantity of forage to be replaced and price. However, there is an upper limit to the quantity of a specific NFFS which should be fed. The following guidelines can be used in making this evaluation.

Overall, the NFFS feeds may be very useful to us in New York this year to assist in stretching the forage supplies. The specific NFFS source to be used will depend upon availability, price and the other nutrient characteristics of the feed.