Feedlot Nutrition: Moving the Boundaries P. H. Henning & F. M. Hagg SAFA Cattleman’s Conference 2011

Feedlot Nutrition: Moving the Boundaries

P. H. Henning & F. M. Hagg

SAFACattleman’s Conference

2011

Feedlot Nutrition: Moving the Boundaries

• Introduction

• The boundaries

• Dietary adaptation (step-up)

• Promising new technology

• Parting thoughts

Introduction (1)

“Change is the only certainty”

Introduction (2)

• Changing numbers– human population ↑– food / beef requirement ↑– agricultural land ↓

• Changing views (consumer)– global village; competitiveness– sustainability– animal welfare– natural / organic

Introduction (3)

• “For the Feedlot Industry change is not a

choice but a matter of survival”

• Initiative rather than defensive

• Need to move boundaries

– 4-minute mile

The boundaries (1)

• Feedlot objectives– produce desired carcass in most cost-effective

manner– maximize carcass weight per unit feedlot (people,

facilities, overheads)– maximize price / value per kg carcass

• FCR (F:G)• Feed cost per kg gain

The boundaries (2)

The boundaries (3)

Dietary adaptation (1)

• Definition: Gradual (sequential) increase in diet grain concentration, over 2 to 4 week period

• USA 65 → 94% concentrate in 28d• SA 80 → 92% concentrate in 14d• Substantial variation !!!


• Elements of adaptation

– microbiological change

– physiological change

– behavioral change

• Change in rumen microbial population is the

rate-limiting step ?!


• Change from high-forage to high-concentrate diets → marked changes in rumen environment– rapidly fermentable carbohydrate (RFC) ↑– fibrolytic bacteria ↓– amylolytic bacteria ↑– pH ↓

• Time is required to establish a stable microbial population


• Typical step-up strategies

– sequential (concentrate ↑, roughage ↓)

– restricted feeding of finishing diet

– limited maximum feeding of step-up diets

– Two-diet blending

• starter-finisher



• Implications of dietary adaptation

– higher roughage use

• manure ↑

• methane ↑

• handling ↑

• risk ↑

– delay of desired high energy intake

Promising new technology (1)

• Dietary adaptation = change in rumen

microbial population

– Megasphaera elsdenii – key lactic acid utilizer

– numbers low on high roughage diets

– slow growing → requires time to reach adequate

levels in rumen

• Postulated (1975) to use M. elsdenii as DFM to

facilitate adaptation

• Thwarted by

– loss of viability during freeze-drying

– sensitivity to oxygen (strict anaerobe)



• Concept received new impetus with isolation

of M. elsdenii NCIMB 41125

– fast-growing

– wide pH optimum

– tolerant of ionophores and in-feed antibiotics

– novel approach to its application

Megasphaera elsdenii NCIMB 41125


• Novel application– give live M. elsdenii as a single oral dose to cattle

on the first day of the adaptation period

• Hypothesis 1: live M. elsdenii, given as a single oral dose, will:– rapidly colonise in the rumen– prevent accumulation of lactic acid– improve rumen pH


• Trials to test hypothesis– rumen-fistulated cattle / sheep– changed from high-roughage to high-concentrate

diet– given single oral dose of M. elsdenii NCIMB 41125

to coincide with diet change– ca ≥10IO viable cells per animal– McDaniel et al (2008a,b); Henning et al (2010);

Aikman et al (2011)


P < 0.05


P < 0.05


P < 0.05

Rumen pH

5

5.5

6

6.5

7

08:45 10:45 12:45 14:45 16:45 18:45 20:45 22:45 00:45 02:45 04:45 06:45Time

Ru

men

pH

Placebo

NCIMB 41125

P<0.1 at this time pointAnimals

fed

Animals fed


• Hypothesis 2: Live M. elsdenii, given as a single oral dose at start of concentrate feeding, will allow more rapid step-up

• Trials to test hypothesis– Kansas State University (Thompson et al, 2010)– ARC-Irene (Henning et al, 2009)

KSU trial• Objective:

– To evaluate the effect of a single oral dose of Megasphaera elsdenii NCIMB 41125 on performance of cattle fed either a traditional or an accelerated diet step-up regime

• The study was conducted as a 2 x 2 factorial

design with dietary step-up rate (traditional or accelerated) and addition of M. elsdenii or placebo as treatment factors

Dietary treatments

Diet Traditional 5-step Accelerated 3-step

55% concentrate/45% roughage Days 1 to 4 Days 1 to 3

65% concentrate/35% roughage Days 5 to 8 ---


85% concentrate/15% roughage Days 13 to 16 ---


No Tylan included

Experimental

• 80 crossbred beef cattle• Animals were kept in individual pens• 95-day experimental period• Me-treated animals received a single oral

dose of M. elsdenii NCIMB 41125 (1011 viable cells) on Day 1 (first day of step-up) whilst each control animal received a placebo

Results

Item5 – step (16d) 3 – step (7d)

Control Me-treated Control Me-treated

No of head 20 20 20 20

Start LW (kg) 408 408 408 408

FCR (kg DM / kg LW) 4.82 4.53 4.75 4.74

Carcass weight (kg)(P < 0.10)

334 338 324 335

Liver abscess (%) 4.7 5.5 20.1 9.7

ARC-Irene trial• Hypothesis: Orally dosing cattle with M.

elsdenii at start of feeding period will allow them to go onto the top diet sooner

• Objective: To determine how rapid newly-arrived feedlot cattle may be stepped-up when they are orally dosed with M. elsdenii

• Approach: followed a regression approach with 6 step-up rates, increasing with equal increments

Treatmentnumber

Starting roughage level on Day 1

Roughage level ofTop Diet

Day reaching Top Diet

1 17.5 5.0 21

2 15.0 5.0 17

3 12.5 5.0 13

4 10.0 5.0 9

5 7.5 5.0 5

6 5.0 5.0 1

Dietary treatments with different starting roughage levels (% of DM) and subsequent different number of days required to reach the Top Diet containing 5% roughage.

Ingredient Starter Grower

Eragrostis curvula hay 17.5 5.0Ground maize (corn) 56.4 73.4Wheat bran 10.0 6.0Commercial HPC 8.5 8.0Molasses meal 5.0 5.0Feed lime 1.0 1.0Salt 0.5 0.5Urea 1.0 1.0Vit-min premix 0.1 0.1

Ingredient composition (% A-F) of the basal diets used in the trial.

Nutrients Starter Grower

CP 14.7 14.6

Starch 40.8 52.0

NDF 30.2 19.8

ADF 16.6 9.9

EE 3.4 3.4

ME (MJ/kg DM)(calculated) 11.1 12.1

Nutrient composition of the experimental diets (%DM).

Experimental• 36 Bonsmara steers (W = 231 ± 9.9 kg)• No previous exposure to concentrate diets• Kept in single pens• Fed ad libitum at 08:00 and 15:00 • Roughage for 2 weeks, fast for 18h, feeding of

experimental diets from Day 1 to Day 35• 100 ml oral dose of M. elsdenii NCIMB 41125

(1011 cfu) at 08:00 on Day 1, just prior to feeding concentrate diets for the first time

The effect of diet step-up rate on performance (Days 1 to 35) of feedlot steers receiving a single oral dose of M. elsdenii.

1Feed conversion ratio2Animals showing symptoms of digestive or respiratory health problems

Day reaching Top Diet Regression

21 17 13 9 5 1 P-value

DMI (kg/d) 4.94 5.19 5.07 4.43 5.43 5.32 0.57

ADG (kg/d) 1.04 1.05 1.21 1.27 1.14 1.25 0.09

FCR1 5.25 5.23 4.31 3.54 4.91 4.28 0.28

No. of pulls2 1 0 1 1 1 1 .

Conclusions1. In cattle dosed with M. elsdenii it was

possible to increase step-up rate, without compromising performance

2. Higher energy intake plus M. elsdenii benefitted performance

3. Increasing step-up rate reduced the need for roughage


• M. elsdenii is a promising tool to move boundaries in feedlot nutrition

• Further trials currently in progress– large experimental pen trial at KSU– large-pen commercial feedlot trials


• Important considerations– applying M. elsdenii with current step-up =

defeating the object; greatest advantage expected when used in conjunction with accelerated step-up

– need to adjust revised starter diet(s) for content of other critical nutrients and therapeutic agents

– concern about early finishing

Parting thoughts

• Awareness of the need to move boundaries, and willingness to try new technologies

• Step-up is a very real boundary, and one which may be moved

• Megasphaera elsdenii is a promising new tool in the hand of the Feedlotter

• As with other tools it requires strategic application to be beneficial

Thank you

Documents

Feedlot Nutrition: Moving the Boundaries P. H. Henning & F. M. Hagg SAFA Cattleman’s Conference 2011