Formulating Rations in Dairy Herds

James D. Ferguson, VMD, MS
Section Animal Production Systems
ferguson@vet.upenn.edu

Groups to consider in a dairy herd
	Calves on liquid diets (milk, milk replacer)			birth to (1.5) 2 months of age
				Isometric mammary growth

	Heifers 2 months to 6 months of age			developing rumen and growth
				Isometric >> allometric mammary growth

	Heifers 6 months to puberty and breeding			growth rate
				allometric to 10-12 months (puberty)
				Isometric growth to 3 m of gestation

	Heifers pregnant to 2 months prior to calving continued growth			allometric 3 m gestation to calving

	Lactating cows			production grouping
		Age grouping		first versus 2 lactation
		Production grouping
			Lactating cows	high production (150 days)
			Lactating cows	mid to low production (>150 days)

	Dry cows – far off			210 to260 days gestation

	Dry cows – close-up			three weeks prior to calving
				Springing heifers

	Transition cows			3 weeks prior to 4 weeks postcalving

Feeding Methods
	Total Mixed Ration (TMR)	all feed ingredients mixed together
	Cafeteria style	most feed ingredients fed separately
	TMR top dress	TMR formulated to a moderate production level
		top dress grain depending on production above moderate level

TMR – group fed rations
	Blended delivery of feed ingredients
		Each mouthful is “balanced”
	Feed groups of cows efficiently

	Cannot handle long dry material (hay) without chopping to mix in TMR
		Moisture level ideally 40% to 60%

	Challenge is to formulate for representative production levels (milk and growth)

	Feeding sheet for amounts of feeds to add

	Sensitivity of mixing scales for amounts added for group
		1, 5, 10 lb sensitivity is typical for most scales

		lbs/cow x number of cows = lbs to add
			amount to add by front end loader, skid steer or bucket

	How many production groups are being fed and managed depends on housing system

Cafeteria style – individual cow feeding systems

	All ingredients fed separately
		Weigh each ingredient for each cow

	Feeding sequence is important
		Forage before concentrate
		Feed energy concentrate with protein concentrate

	Feed to milk production
		Often a feed chart from 40/50 lbs to 120 lbs of milk in 10 lb increments
		“Floating” forage which is fed free choice

	Older systems would offer forage free choice from a bunk, or graze cattle and then offer grain at milking from parlor feeders. A conveyor belt would run forage out to a feed manger.
	Calibrate feed offered per time of unloading. Hay offered free choice from a hay feeder. Cattle on pasture.
	Forage intake free choice. Then supplement in parlor at milking.
		Maximum intake in parlor about 10 lbs of grain at a milking

Combination – base TMR formulated to a moderate milk level
	Top dressed with energy and protein supplements to a higher production level

Housing system influences feeding method
	Tie stall barn – individual cow feeding or a TMR or combination

	Group system – need to feed a TMR or forage from a manger
		Production levels and age groups
		Physical facility determines group possible

Water – one waterer per 20 cows
	Consumption greatest after milking
		- 30% to 50% of daily water intake within 1 hour of milking
		- Daily drinking time is as little as 7 minutes to 40 minutes a day
			>>Depends on flow rate: 1.2 to 6.5 gallons/minute
	4 to 5 lbs of water/lb of milk
		- 8.34 lbs/gallon; 7.48 gallons/cubic foot
	9 to 13 gallons to support maintenance (1.08 to 1.56 lbs)
		- 3.785 liters/gallon
	influenced by temperature, milk production, dry matter intake, and Na content
		- 1.45 l / kg of milk (1.45 lb/lb milk)
		- 4.39 l / kg dmi (4.39 lb/lb dmi)
		- 1.20 l / C increase in minimum temp
		- 0.11 l / g Na in diet
	1 water bowl per 10 to 20 cows
	2 waterers / loafing area
	Rate - 4 - 15 l /min consumption rate
	Adequate linear feet and refill rate
		- waterers - 5 cm/cow length with a 90 cm height
		>>1.2 to 3.6 linear inches/cow (2 inches/cow)
			2 feet of tank space/20 cows
		>>Height of waterer 24 to 32 inches
		>>Water depth a minimum of 3 inches
		>>Waterer within fifty feet of feed bunk and milking parlor exit

Energy density of lactating diets

	You typically balance a TMR ration to an energy density to support a level of production

		This will be represented as what level of production is this ration balanced to?
			For example select a production level: 90 lbs, 70 lbs,
			A representative animal description is used to describe the cow
				An average body weight
			Production is described by milk production and average milk composition

			A target days in milk and days of gestation is described
			An age, a representative lactation number, is chosen
				1^st or 2^nd usually

	How to choose a target milk production to formulate to

	Challenge what to select for high milk production
		You don’t want to underfeed and diminish peak milk production
		You don’t want to overfeed or supply excessive NFC and low NDF

			Maintain adequate forage and NDF and provide sufficient energy

		Some strategies to select production target
			Lead factor
				Mean production of cows in the group and add one SD
			Balance group to average production at third test day
			Peak production minus 20 lbs
			Choose 80 to 95 lbs as target
	Middle to low group
		20 to 25 lbs lower than high group

Protein density will depend on the level of production balanced for

Ranges in NDF, NFC, SP

NDF	Minimum	NRC 26 to 28%
	- Rather low when chopped forages are in diet
	- We target 30 to 32% as minimum with chopped forages
	Maximum	34 to 36% to high producers

	Maximum NDF intake is expressed as a % of body size by some

Guidelines outlined by Chase
Production level (4% FCM, lb)	Max NDF % of BWT	Dietary NDF (% DM)
Nonlactating	1.12	59
0 to 31	1.10	47
31 to 46	1.10	40
46 to 64	1.10	35
64 to 80	1.10	31
>80	1.10	28

Dietary NDF based on 75% NDF from forage

Maximum will vary with level of production and other cow groups

Other considerations to ensure adequate fiber
	% forage NDF in ration – usually at least 75% of NDF from forage
		21% of forage NDF in DM
	% physically effective NDF (peNDF) – 22% of DM
		% NDF retained on a 1.18 mm sieve
			Considered size at which material passes from the Rumen (Mertens JDS 80:1463-1481; 1997)

Retained on
	Feed		NDF (%)	1.18 sieve	peNDF

	Standard		100	1.00	100.0
	Grass hay		65	0.98	63.7
	Legume hay		50	0.92	46.0
	Legume hylg		50	0.82	41.0
	Legume hylg
		Fine Chop	50	0.67	33.5
	Corn Silage		51	0.81	41.5
	Brewers grain		46	0.18	8.3
	Corn, ground		9	0.48	4.3
	SBM		14	0.23	3.2
	Soybean hulls		67	0.03	2.0

	No standard method of measurement is a problem


	peNDF and % fat in milk
	(from Mertens JDS 1997)
	3.4% fat corresponds to a peNDF of 18.6% peNDF

	Rumen pH of 5.9 is associated with a peNDF of 18.5%

	Forage % of DM – another method to ensure adequate rumen mat
		40% to 65% of total ration DM
		Depends on forage quality how high forage inclusion may be

NFC – nonfiber carbohydrate in the ration

	Calculated value by difference
		(100-NDF-EE-CP-Ash)

	Starch, sugars, water soluble fiber, and silage acids
		Except silage acids, all are rapidly fermented in rumen

			Maximum	typically 40% of DM to reduce risk of rumen upset
				May go up to 45% under certain conditions

			Minimum	typically 35% in lactating rations
				Need sufficient NFC to drive rumen microbial synthesis

Processing – as for NDF the processing of NFC is important
	In general finer not coarser increases rumen digestion
	Steam processing can improve rumen fermentation
	Depends on source of grain what is appropriate process

In addition to NFC, consider starch and sugar content
	Starch	23 to 28% of DM
	Sugar	3 to 10% of DM

Protein

	Goal is to provide sufficient metabolizable protein and minimize wastage from excess ammonia produced in the rumen

	Protein needed in the diet will depend on efficiency of carbohydrate fermentation in the rumen
		Rumen degradable protein
			Soluble protein plus “B” protein fraction
				“B” fraction has a moderate rate of protein degradation
			Soluble protein 25% to 35% of CP
				Below 25%, may not have sufficient rapidly available ammonia
				Above 30%, may have too much excess ammonia

		Rumen undegradable protein
			Sufficient amount to complement microbial protein production

		Essential amino acids: methionine and lysine as percent of MP
			Methionine: 2.05% of MP or higher
			Lysine: 6.57% of MP 0r higher

		CPMDairy
			Rumen ammonia and peptide N balance 115% to 125%
			Can cover over 125%, but wastage of Nitrogen will be increased
			Check urea cost on the metabolism page in CPMDairy

Least cost formulation
	Allow the computer program to determine feed inclusion
	Limit the amount of certain feed ingredients to a maximum based on palatability and availability

	for example, maximum amount of silage may depend on feed inventory suggestions

			minimum	maximum

		DMI ranges	95	105	% of requirement
		ME	100	100	% of requirement
		MP	100	100	% of requirement
		NDF	30	34	% of DM
		Starch	23	28	% of DM
		Forage	45	60	% of DM
		Peptides	110	125	% of requirement
		Ammonia	110	125	% of requirement
		Methionine	85	100	% of Rulquin ratio
		Lysine	92	100	% of Rulquin ratio

Minerals and vitamins

	Provide sufficient content: % and ppm of diet

	When formulating, include “vitmin” as a feed ingredient to allow room to add minerals when other ingredients have been accounted for to supplement needed minerals and vitamins

	Supplement macro minerals after feed ingredients have been calculated to meet requirements and ration content

	Add trace minerals and vitamins as if no amounts from feed ingredients

	always add .5% DM salt
	always offer white salt free choice either as a block or loose from a tub

Additives

	This is always a difficult choice – what additive should you use

	Always
		Sodium bicarbonate: 0.5% of total ration dry matter
		Magnesium oxide: 1/3 of bicarbonate addition

	Strong consideration
		Ionophore such as rumensin 350 mg/cow/day
			Especially in close-up and transition cows
		Yeast – improve NDF digestibility

	Others – you’re on your own



As target milk increases, NDF (and ADF) decreases, energy density and RUP both increase, starch and CP change in a nonlinear fashion. Keeping DMI to model prediction and limiting NFC to 40%.
At 85 lb of millk, fat sources must be allowed to enter solution, or NFC increased to 43.9% and starch to 30.8% of ration DM. At 105 lb of milk, MP must be overfed; at 115 lb of milk, NFC and starch must be allowed to go above limits and rumen N balance to drop to 100%. This is with good to excellent forages.

Target energy density – suggested high group targets:

Lactation 1		Lactation 2		milk, lb

15,000	0.73	18,000	0.76	75
18,000	0.76	21,000	0.78	85
20,000	0.78	23,000	0.80	100
22,000	0.80	25,000	0.81	105
24,000	0.81	27,000	0.82	115

Over	0.77 mcal/lb, need to include fat
	0.81 mcal/lb, need to include fat and increase NFC and starch, or overfeed RUP

These were calculated with excellent forages