united states department of agriculture heifer stocking ......assuming this is a 1200- lb (pregnant,...

U.S. Dairy Forage Research Center, USDA Agricultural Research Service

United States Department of Agriculture

Four-State Dairy Nutrition and Management Conference

June 15-16, 2016

Wayne Coblentz, USDA-ARSUS Dairy Forage Research Center

Marshfield, WI

Matt S. Akins and Nancy M. EsserUniversity of Wisconsin-Madison

Heifer Stocking Density and Performance

Background

Nonlactating Beef Cow, TDN = 47%Lactating Beef Cow, TDN = 61%

Dairy Heifer, TDN = 63%

Jersey Dairy Cow, TDN = 75%

Assuming this is a 1200-lb (pregnant, nonlactating) beef cow wandering aimlessly in

the Ozarks, the required energy density of her diet should be about 47% TDN.

well-managed cool-season pasture corn silage

alfalfa haylage

Key Points● Management programs for replacement heifers prioritize rearing animals at low economic and environmental cost, without compromising their performance as lactating cows (Hoffman et al., 2007).

● Generally, diets for replacement dairy heifers are forage-based but may be too energy dense, especially if significant proportions of corn silage are included.

● Dairy heifers will consume approximately 1% of their bodyweight daily in NDF (Hoffman et al., 2008).

● Heifers consuming diets containing inadequate NDF are susceptible to excessive DM intake, further compounding the risk of over-conditioning.

● Generally, there are two approaches to combating these problems:a) precision or limit-feedingb) dietary dilution with low-energy forages

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A Non-Straw Option: Eastern Gamagrass (EGG)

● perennial warm-season bunchgrass

● adapted to moist sites, swales, stream banks

● distant relative of corn

● responsive to N fertilization

● suitable for ensiling

● very palatable (ice cream cone grass)

● high yield potential

● maintains typical nutritional characteristics of a warm-season grass

Yield and quality responses for eastern gamagrass at Marshfield, WI (2010-2013)

Harvest Date Yield NDF TDN

lbs/acre ------- % of DM -------1 Aug 5079 75.8 53.215 Aug 6201 75.8 52.21 Sep 5509 76.5 49.215 Sep 6642 76.3 50.51 Oct 6614 77.8 48.815 Oct 6122 80.6 44.41 Nov 5966 82.0 43.9SEM 226.0 0.41 0.79

Contrast ----------------- P > F ---------------Linear < 0.01 < 0.01 < 0.01

Quadratic < 0.01 < 0.01 0.15Cubic 0.73 0.94 0.54

Coblentz et al. (2014)

2011 Eastern Gamagrass Feeding Trial(Experiment 1)

• 105-day feeding trial• 120 Holstein heifers• 5 diets, 15 pens• heifers blocked by weight

• light, 714 ± 49.3 lbs• medium, 813 ± 26.1 lbs• heavy, 934 ± 35.1 lbs

• heifers housed in sand-bedded freestalls

• no overstocking (freestalls or feedbunk)

Coblentz et al. (2012) 7

Composition of Diets (Experiment 1)-------------------- Diet ---------------------

Item EGG0 EGG10 EGG20 EGG30 LIMIT*

Ingredient, % DM

Corn Silage 53.2 44.7 36.7 28.7 53.2

Alfalfa Haylage 46.8 46.1 44.9 43.7 46.8

EGG Haylage 0 9.2 18.4 27.6 0

Nutrients, % DM

NDF 39.6 43.0 45.6 48.7 39.6

CP 12.9 13.0 13.1 12.9 12.9

TDN 68.2 65.3 63.2 61.3 68.2

* Offered at 85% of EGG0.


Nutrient Intakes and Performance (Experiment 1)

-------------------- Diet ---------------------

Item EGG0 EGG10 EGG20 EGG30 LIMIT*

Intake, lbs/d

DM 20.7 19.8 19.7 19.7 17.8

NDF 8.2 8.5 9.0 9.6 7.0

NDF, % BW 0.88 0.92 0.97 1.04 0.77

TDN 14.1 12.9 12.4 12.1 12.1

Performance

Gain, lbs 251 236 221 196 203

ADG, lbs/d 2.40 2.27 2.09 1.87 1.94

Feed:Gain, lbs/lbs 8.6 8.8 9.4 10.5 9.2

* Offered at 85% of EGG0. Coblentz et al. (2012)

Key points:

1) Caloric intake was limited by reducing the energy density of the diet, and by reducing voluntary intake.

2) Unique observation: eastern gamagrassdiets were non-sortable.

Assessment of Dilutants(Experiment 2)

• 118-day feeding trial• 128 Holstein heifers• 4 diets, 16 pens• heifers blocked by weight• heifers housed in freestalls

with mattresses with a light layer of organic solids

• over-stocking at the feedbunk (133%), but not in the freestalls

• automatic alley scrappers

Coblentz et al. (2015) 11

Composition of Diets (Experiment 2)------------------------------ Diet ---------------------------------

Item Control EGG Wheat Straw Corn Fodder

Ingredient, % DM

Corn Silage 55.8 26.7 25.2 32.6

Alfalfa Haylage 44.2 47.2 53.5 52.5

EGG 0 26.2 0 0

Wheat Straw 0 0 21.3 0

Corn Fodder 0 0 0 14.9

Nutrients, % DM

NDF 43.3 50.9 53.3 50.4

CP 13.9 13.7 13.6 13.8

TDN 66.8 58.9 59.7 59.1


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Assessment of Sorting Behaviors (Experiment 2)

• heifers fed once daily at 10:00 am• feedbunks were scored daily, and

daily diet distributions were adjusted to limit orts (2.1%)

• feedbunks sampled in three week-long periods during the trial

• feedbunks sampled at 1:00 pm, 5:00 pm, 9:00 pm, 1:00 am, 6:00 am, 8:30 am (orts)

• particle size determined at each sampling time with a Penn State Particle Separator

• bunks also assessed for NDF, CP and TDN concentrations at all sampling times


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Diets (Experiment 2)

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• because of limited orts (2.1%), diets were essentially fully consumed

• sorting factor = [time x]/[initial] x 100%

• >100% indicates discrimination

• <100% indicates preference


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• because of limited orts (2.1%), diets were essentially fully consumed

• sorting factor = [time x]/[initial] x 100%

• >100% indicates discrimination

• <100% indicates preference


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Simple Counts of Other Behaviors (Experiment 2)


Intake and Performance (Experiment 2)------------------------------ Diet ---------------------------------

Item Control EGG Wheat Straw Corn Fodder

Intake, lbs/d

DM 24.4 23.3 20.9 22.1

NDF 10.6 11.8 11.1 11.2

NDF, % BW 0.89 1.02 0.97 0.96

TDN 16.3 13.7 12.5 13.2

Performance

Gain, lbs 309 258 209 256

ADG, lbs/d 2.56 2.16 1.74 2.14

CV, % 10.4 11.5 14.4 15.5

Feed:Gain, lbs/lbs 9.6 10.8 12.1 10.5


Key points:

1) Again, caloric intake was limited by reducing the energy density of the diet, and by restricting voluntary intake via NDF (gut fill).

2) The EGG diet was sorted minimally compared to the (alfalfa/corn silage) control, but straw (intermediate) and corn fodder (worst) were sorted more aggressively.

3) Feeding management resulted in nearly 100% consumption of all dietary components within 24 hours, which is consistent with current recommendations for management of straw in TMR diets (Shaver and Hoffman, 2010).

4) Sorting behaviors could not be linked directly to heifer growth performance.

Dilution with Straw and Over-Stocking(Experiment 3)

• 90-day feeding trial• 240 Holstein heifers• 2 diets, 3 stocking densities, 24 pens• over-stocking at the feedbunk and in

freestalls at 100 (8 heifers/pen), 125 (10 heifers/pen), and 150% (12 heifers/pen) of capacity

• diets were formulated identically, except that one contained well-processed straw, and the other poorly processed straw

• heifers blocked by weight• heifers housed in freestalls with

mattresses with a light layer of organic solids

• automatic alley scrappers

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Composition of Diets (Experiment 3; partial)

---------- Straw Diet ------------

Item Well Processed

Poorly Processed

Ingredient, % DM

Corn Silage 33.4 33.4

Alfalfa Haylage 52.1 52.1

Wheat Straw 14.5 14.5

Nutrients, % DM

NDF 46.5 47.5

CP 13.0 12.6

TDN 60.5 59.5

Well Processed Straw

Poorly Processed Straw

Performance (Experiment 3; partial)-------- Diet ---------- --------------- Stocking Rate -------------

Item Good Poor 100% 125% 150%

Performance

Gain, lbs 183 184 189 181 181

ADG, lbs/d 2.02 2.02 2.07 1.99 1.99

CV, % 18.7 14.3 13.3 17.3 18.9

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Assessment of Heifer Behaviors (Experiment 3; partial)

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Assessment of Heifer Behaviors (Experiment 3; partial)

Behavior* (Experiment 3; partial)------ Diet ------ ------------ Stocking Rate --------------


Lying Time, min/d 840 838 865 829 823

Standing Time, min/d 600 602 575 611 617

Bouts, #/d 11 11 11 11 11

Lying Time/Bout, min 80 83 82 83 80

Standing Time/Bout, min 58 62 56 62 63

*Lying and standing behaviors determined by data logger (Hobo Pendant® G Acceleration Data Logger, Onset Computer Corp., Bourne MA) as calculated based on Ledgerwood et al. (2010).

Hygiene Score (Experiment 3; partial)------ Diet ------ ------------ Stocking Rate --------------


Flanks 1.9 2.1 1.7 2.0 2.2

CV Flanks, % 32.5 26.2 18.0 30.6 39.5

Legs 2.2 2.5 2.1 2.4 2.5

CV Legs, % 13.6 15.0 9.4 13.9 19.7

*Hygiene scores based on a scale of 1 (cleanest) to 5 (soiled) as described by Cook (2007).

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Summary

● Dilution of heifer diets with low-energy forages will control weight gains by reducing the energy density of the diet, and by limiting voluntary intake.

● Heifers are generally limited to about 1% of their bodyweight daily in NDF intake.

● Although heifers will exhibit different sorting behaviors with various diluting agents, these behaviors have not (yet) been linked directly to growth performance in our trials.

● Variability in daily weight gains within each pen have trended greater with more sortable diets, but (to date) this has not been statistically significant.

● Feeding management in these trials was consistent with current University of Wisconsin recommendations for including straw in TMR diets (minimal orts).

● Over-stocking resulted in poorer hygiene scores, and a greater percentage of heifers lying in alleys or inactively standing during night hours. Within-pen variability of hygiene scores also increased sharply with over-stocking.

Q U E S T I O N S ?

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U.S. Dairy Forage Research Center

www.ars.usda.gov/mwa/madison/dfrc

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united states department of agriculture heifer stocking ......assuming this is a 1200- lb (pregnant,...

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