Stocker Programs, Feedlot Performance and Carcass Merit Jim Oltjen University of California, Davis...

Stocker Programs, Feedlot Stocker Programs, Feedlot Performance and Carcass MeritPerformance and Carcass Merit

Jim OltjenUniversity of California, Davis

April 10, 2008

UC Sierra Foothills Research & Extension Center

UC Davis Feedlot

OutlineOutline• Compensatory growth • Using Davis Growth Model for performance and carcass traits• Growing phase feed quality effects• Growing phase length effects• Previous nutrition effects on carcass merit and maintenance• Physiology of growth and fat development• Latest Research on:

– Patterns of marbling– Length of stocker phase effects on fat distribution– Length of stocker phase effects on rate of marbling and subQ fat gain– Residual feed intake relationship with maintenance requirements

• New model to predict fat distribution

Compensatory growth in beef cattleCompensatory growth in beef cattle

200

250

300

350

400

450

500

0 50 100 150 200 250 300

Days on feed

Em

pty

body

wt,

kg

CA-CACL-CACL-CLFA-CAFA-CL

From: Sainz et al., 1995

Sainz et al., 1995

Compensatory gain in feedlot steersCompensatory gain in feedlot steers

Davis Growth ModelDavis Growth Model

Net energy

Protein

Maintenance Fat (kg)TtrtrttrRtrttr

r

Davis Growth Model (Oltjen et al. 1986)Davis Growth Model (Oltjen et al. 1986)

DNABody

fatBody

ProteinBody

accretionDNA

accretionFat

SynthesisProtein nDegradatioProteinMetabolizable Energy Intake

Heat production

Biological processes: Biological processes: Cell proliferation and hypertrophyCell proliferation and hypertrophy

Homeorrhetic controlHomeorrhetic control

Biological processes: Biological processes: Synthesis and degradationSynthesis and degradation

Biological processes: Biological processes: maintenancemaintenance

Efficiency of conversion into net energy is related to both quantity and concentration of metabolizable energy in the diet

Effect of diet quality in growing phase to a constant BW endpoint

(327 kg)

Stocker cattle’s rate of gain is linear from 2 to 3 Mcal ME/kg DM

assuming cattle are fed ad libitum or have adequate available forage.

(growing phase to 327 kg BW)

Finishing daily gain is inversely and nearly linearly related to previous growing phase performance.

This hardly varied whether cattle were fed to equal body weight or fat content endpoints.

Steers fed to an equal body weight endpoint were more sensitive to previous growing phase ration energy compared to steers fed to a constant fat endpoint.

Those fed higher energy diets as calves reached acceptable carcass fatness at much lighter weights.

Effect of growing phase length(MEC = 1.87 Mcal/kg)

(growing phase MEC 1.87 Mcal/kg)

Finishing period performance

(growing phase MEC 1.87 Mcal/kg)

Steers fed to an equal body weight endpoint were more sensitive to the length of the growing period compared to a constant fat endpoint.

Calf fed’s Calf fed’s reach carcass reach carcass fatness before fatness before desirable desirable slaughter slaughter weights, weights, confirming confirming previous work previous work that medium or that medium or small frame small frame steers require steers require a growing a growing period before period before slaughter, slaughter, particularly if particularly if

not implanted.not implanted.

Calf fed’s Calf fed’s reach carcass reach carcass fatness before fatness before desirable desirable slaughter slaughter weights, weights, confirming confirming previous work previous work that medium or that medium or small frame small frame steers require steers require a growing a growing period before period before slaughter, slaughter, particularly if particularly if

not implanted.not implanted.

Conversely, if we use longer growing Conversely, if we use longer growing periods due to increased cost of grain, periods due to increased cost of grain, cattle will have to be fed to larger weights cattle will have to be fed to larger weights for acceptable fatness, further for acceptable fatness, further exacerbating the progressive trend to exacerbating the progressive trend to larger carcasses in the industry.larger carcasses in the industry.

Intermuscular Fat Subcutaneous Fat Intramuscular Fat


0

5

10

15

20

25

30

Carcass fat, % Backfat, mm Abdominal fat, kg

CA-CA CL-CA CL-CL FA-CA FA-CLFrom: Sainz et al., 1995

aa

a

b b

a ab

c cb

ab

a a

b


0

2

4

6

8

10

KPH, % Marbling score Slight=7,Small=10

% LD fat

CA-CA CL-CA CL-CL FA-CA FA-CL From: Sainz et al., 1995

a

aba

ab

babab

a

b

b

ab ab ab

b

Sainz et al., 1995


Sainz et al., 1995


SEM

a

bb

Growth curves Growth curves

0

100

200

300

400

500

0 5 10 15 20 25 30 35

Age, months

Bod

y w

t, kg

Allometric growthAllometric growth

0

20

40

60

80

100

0 50 100 150 200 250 300

Carcass wt, kg

Wt,

kg

Muscle

Fat

Bone

Frame score and total body fatFrame score and total body fat

Growth gradients among adipose depots Growth gradients among adipose depots

Perirenal

Intermuscular Intramuscular

Subcutaneous

From: Bruns et al. (2004) J. Anim. Sci. 82:1315-1322

From: Sainz & Vernazza-Paganini, 2004

Gain in 12Gain in 12thth rib fat gain (BF. µm/day) in high and low growth rib fat gain (BF. µm/day) in high and low growth cattle backgrounded at two ME levelscattle backgrounded at two ME levels

Gain in intramuscular fat gain (IMF. %/day) in high and low Gain in intramuscular fat gain (IMF. %/day) in high and low growth cattle backgrounded at two ME levelsgrowth cattle backgrounded at two ME levels

UC Davis Feedlot

Residual Feed Intake• More efficient steers with negative RFI ate less (12%). • RFI was related to maintenance energy requirements

(r=0.42). • No ‘significant’ association with carcass traits. • Myofibrillar protein degradation rates were positively

related to maintenance energy requirements (r=0.76), but were not related to RFI (r=-0.14).

A genetic trait related to RFI should be used in prediction models to account for differences in maintenance.

Eventually adjust for protein synthesis/degration rate differences which are explicitly represented in the Davis Growth Model.

Intermuscular Fat Subcutaneous Fat Intramuscular Fat

Net energy

Protein

Maintenance Fat

Visceral(kg)

Sub(kg)

Intra(kg)

Inter(kg)

12/13th

Rib fat(mm)

Carcasscharacteristics

Davis Growth Model

KPH(kg)

KPH(%)

IMF(%)

First order differential equation

FatdtdS

s

Example: Subcutaneous fat (S; kg)

Constraint 14

1jj

Where j = 1 to 4 for each fat depot

d

dt

a proportional variable is a function of DNA and maximum

adipocyte size

s

Cell number (hyperplasia) ~ DNA

Cell size (hypertrophy) ~ maximum adipocyte size

Proportion of total fate.g. subcutaneous (S; kg) proportional fat

variable

14

1jkFatj

4

1jj

ADSMAX*DNAS

1DNA*kFats

ss

s

Constraint

ADSMAX – Maximum adipocyte size = 4.5 x 105 kg TG/kg DNA

Days on feed

Proportion )( of total body fat

Subcutaneous

Visceral

Intramuscular

Intermuscular

Grid of fat depot parameter values

Breedtype

Implanted n kFs kFm kFv

1 No 5 0.3 0.4 0.2

2 No 29 0.1 0.4 0.0

3 No 9 0.2 0.3 0.1

1 Yes 24 0.2 0.3 0.1

2 Yes 70 0.2 0.4 0.1

3 Yes 2 0.3 0.4 0.1

Grid of fat depot parameter valuesBreedtype

Implanted n kFs kFm kFv

1 No 5 0.3 0.4 0.2

2 No 29 0.1 0.4 0.0

3 No 9 0.2 0.3 0.1

1 Yes 24 0.2 0.3 0.1

2 Yes 70 0.2 0.4 0.1

3 Yes 2 0.3 0.4 0.1

Growth of four body fat depotsGrowth of four body fat depots

0

20

40

60

80

100

120

0 200 400 600 800

Age, d

Wei

gh

t, k

g

Intermuscular

Subcutaneous

Visceral

Intramuscular

Model Summary

• Good starting point for predicting–12/13th rib fat (mm), IMF (%), and KPH

(%) for breed type and implant status• More data is required to develop fat

depot parameters e.g. serial slaughter data. But data is scarce!

• Model needs to be evaluated

12/13th ribfat, mm

Su

bcu

tan

eo

us

fat,

kg

0 10 20 30 40 50 60

02

04

06

08

01

00

Frame size = Small (< 4)Frame size = Medium (>= 4 & <7)3.70 + 1.86 x ribfat (SE = 9.11)

Obs

erve

d s

ubcu

taen

ous

fat,

kg

0

10

20

30

40

50 (a)

0 10 20 30 40 50

-10

-5

0

5

10

Predicted subcutaneous fat, kg

Obs

erve

d -

pred

icte

d, k

g

(b)

From: Garcia et al., 2007

Body protein

Angus-Hereford steers

Salers heifers

Charolais bulls

DGM INRA

From: Garcia et al., 2007

Angus-Hereford steers

Salers heifers

Charolais bulls

Body fat

DGM INRA

Ingredient¹ Low Moderate Finishing

Chopped Oat Hay² 75.0 50.0 5.0

Chopped Alfalfa Hay ----- ----- 5.0

Steam-Flaked Corn³ 15.0 40.0 80.0

Yellow Grease 3.0 3.0 2.5

Molasses 2.0 2.0 4.0

Trace Mineral Salt 2.0 2.0 0.5

Oyster Shell Flour 1.0 1.0 0.5

Monosodium-Phosphate 1.0 0.75 -----

Sodium- Bicarbonate ----- ----- 1.25

Ammonium- Chloride ----- ----- 0.25

Potassium- Chloride ----- ----- 1.0

Urea (45% N) 1.0 1.25 1.0

Rumensin ----- ----- Per label

Formulated Values

DM % 73 80 80

NEm. Mcal/kg DM 1.32 1.59 2.22

Crude Protein.%DM 11.06 11.06 14.75

Composition of growth and finishing dietsComposition of growth and finishing diets

Weight gains in high (BX) and low (GX) growth cattle Weight gains in high (BX) and low (GX) growth cattle backgrounded at two ME levelsbackgrounded at two ME levels

200

250

300

350

400

450

500

550

600

250 300 350 400 450 500 550 600 650

Age, d

Bod

y w

t, k

g

BX-Low

BX-Moderate

GX-Low

GX-Moderate

1 2 3

The arrows show the beginning of the finishing phase for the BX-M (1). GX-M and BX-L (2) and GX-L (3) groups.

High growth Low growth P Values¹

Measurement² Low Moderate Low Moderate SEM³ Genotype Group

Hot carcass wt, kg 325.0 320.4 365.6 349.2 9.38 0.006 0.294

Ribeye area, cm² 74.91 73.77 84.26 78.14 3.30 0.071 0.303

Backfat,mm 12.46 13.34 12.71 12.81 0.495 0.789 0.354

KPH³. fat % 1.16 1.57 1.82 1.87 0.230 0.071 0.343

Marbling score 4 3.77 3.96 3.80 3.65 0.207 0.529 0.913

Quality grade 5 6.34 6.63 6.38 6.30 0.249 0.564 0.689

Yield grade 2.97 3.16 3.00 3.18 0.152 0.848 0.253

Backgrounding effects: carcass traitsBackgrounding effects: carcass traits

1 Probability of a Type 1 error2 Standard error of the mean (n=3/group)3 Kidney.pelvic and heart fat4 Marbling Score: ; 3 = Small 0; 4 = Modest 0.5 Quality Grade: 0-2=Standard; 3-5=Select; 6-8= Choice; 9-11= Prime


100

200

300

400

500

600

700

800

1.0 1.2 1.4 1.6 1.8 2.0

Empty body wt gain, kg/day

Gai

n, g

/day


Fat

Protein


3

6

9

12

15

1.0 1.2 1.4 1.6 1.8 2.0


Bac

kfat

, mm


CL-CA


6.5

7.0

7.5

8.0

8.5

9.0

9.5

1 1.2 1.4 1.6 1.8 2


Mar

blin

g sc

ore


Slight = 7-9, Small = 10-12

Backfat, mm

Growing MEC, Mcal/kg

BW 1.87 3.06 3.06 limited MEI237 1.0 1.0 1.0

327 2.0 6.1 3.3

481 9.9 12.6 11.6

Growing phase to 327 kg BW

Marbling Score1

Growing MEC, Mcal/kg

BW 1.87 3.06 3.06 limited MEI237 0.9 0.9 0.9

327 2.6 5.2 3.7

481 8.7 8.0 8.9

Growing phase to 327 kg BW

10, devoid; 1, practically devoid0; 2, practically devoid50 3, practically devoid100; 4, traces0; 5, traces50; 6, traces100; 7, slight0; 8, slight50; 9, slight100

Table 1. Growth performance of finishing steers previously fed a forage diet (1.87 Mcal ME/kg DM) ad libitum (FA) or a high concentrate diet (3.06 Mcal ME/kg DM) at intake levels (CL) to achieve similar growing phase gains (Sainz et al., 1995).

CL FA

------------------------------------------------------------------------------------------------------------------

Period length, d 89 111

Intake, kg DM/d 10.98 11.73

Gain, kg/d 2.01 1.82

Feed/Gain 5.47 6.45

Viscera, kg 28.8 32.8

Relative maintenance BW-.75 .83 1.21

Residual feed intake, kg/d -.63 1.05

------------------------------------------------------------------------------------------------------------------

What about limit feeding concentrate in growing period?

Stocker Programs, Feedlot Performance and Carcass Merit Jim Oltjen University of California, Davis...

Documents

Transcript of Stocker Programs, Feedlot Performance and Carcass Merit Jim Oltjen University of California, Davis...