feed additives and feed efficiency in the pork industry
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Feed additives and feed efficiency in the pork industry
F.R. Dunshea1,2
1CRC for High Integrity Pork; 2Department of Agriculture and Food Systems, Melbourne School of Land and Environment,
The University of Melbourne, Parkville, VIC 3010;
We need technology
https://www.elanco.com/Content/pdfs/2011_11068_Three-Rights-White-Paper-Revision_AI11224.pdf
Some technologies
Porcine somatotropin (pST, Reporcin)
β-agonists (ractopamine, Paylean)
Dietary additives
Cysteamine
Chromium
Betaine
Neuroleptics
Immunization against GnRF (Improvac)
Beta agonists (ractopamine, Paylean)
Orally active metabolic modifier
Metabolic modifiers
Porcine somatotropin (pST, Reporcin)Recombinant peptide hormone
Daily (or less frequent) injectable
Beta agonists (ractopamine, Paylean)Orally active metabolic modifier
Introduction
Wray-Cahen et al. 1998
Daily pST injections increases daily gain (data 16 farms across Australia)
0
200
400
600
800
1000
Gilt Gilt Boar Boar
Dai
ly g
ain
(g
/d)
ControlpST
Dunshea 2005
Daily pST injections decreases FCR(data 16 farms across Australia)
Dunshea 2005
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Gilt Gilt Boar Boar
Fee
d:g
ain
(g
/g)
ControlpST
MWF pST injections decreases FCR
Hellams et al 2000
2.00
2.20
2.40
2.60
2.80
3.00
0 20 40 60 80
Dose of pST (mg/week)
FC
R
Daily
MWF
Metabolic modifiers
Beta agonists (ractopamine, Paylean)Orally active metabolic modifier
Ractopamine increases daily gain (5 ppm for 14 d followed by 10 ppm for 17 d)
0
200
400
600
800
1000
1200
Gilt Gilt Boar Boar
Dai
ly g
ain
(g
/d)
ControlRactopamine
Rikard-Bell et al. (2009a)
Ractopamine decreases feed:gain (5 ppm for 14 d followed by 10 ppm for 17 d)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Gilt Gilt Boar Boar
Fee
d:g
ain
(g
/g)
ControlRactopamine
Rikard-Bell et al. (2009a)
2.0
2.2
2.4
2.6
2.8
Boars Gilts
Fee
d co
nver
sion
rat
io
Control Ractopamine Ractopamine + pST
Effect of feeding ractopamine for 4 weeks without or with daily pST for last 2 weeks on FCR
Rikard-Bell et al. (2009b)
Paylean for 4 weeks plus 4 pST injections over last 2 weeks decreases feed:gain
Paylean for 4 weeks plus 4 pST injections over last 2 weeks decreases feed:gain
van Barneveld et al. (2009)
Introduction
Wray-Cahen et al. 1998
Introduction
Wray-Cahen et al. 1998
Cysteamine
Cysteamine
• Cysteamine hydrochloride (CSH) increases ST secretion in rats
• Mechanism appears to be through inhibition of somatostatin (SRIF) secretion
• Responses are not as pronounced as pST and may be transitory
• Further work is required to optimise the dose and timing as high doses may blunt the response more rapidly through inhibition of gherelin
Cysteamine at 70 ppm increases ADG
600
700
800
900
Control 70 ppm CSH
Dai
ly g
ain
(g
/d)
Dunshea 2007
Liu et al 2009
Response to Cysteamine (70 ppm) is not as great as pST
600
800
1000
1200
Control Cysteamine pST
Dai
ly g
ain
(g
/d)
Dunshea 2007
Cysteamine (70 ppm) and pST decrease fat
Dunshea 2007
0
3
6
9
12
15
P2 Shoulder fat
mm
or
% Control
Cysteamine
pST
Cysteamine
• Cysteamine hydrochloride (CSH) increases ST secretion in rats
• Mechanism appears to be through inhibition of somatostatin (SRIF) secretion
• Responses are not as pronounced as pST and may be transitory
• Further work is required to optimise the dose and timing as high doses may blunt the response more rapidly through inhibition of ghrelin
Introduction
Wray-Cahen et al. 1998
GRF (GHRH) and other neonatal manipulations
0.400.450.500.550.600.650.700.750.80
Untouched 0.25nmol GHRH 0.50nmol GHRH Handled
Neonatal Treatment
AD
G fr
om d
ays
0-15
0 (k
g/da
y)
Female Male
Gallagher 2000
Dunshea (unpublished)
0
2
4
6
8
Saline pST/GHRH pST
Liv
ewei
gh
t (k
g)
Weaning
Weaning + 7 d
Neonatal treatment with pST can increase weaning weight and subsequent growth
Dunshea (unpublished)
Neonatal treatment with pST can increase slaughter and carcass weight
60
70
80
90
Saline pST/GHRH pST
Wei
gh
t (k
g)
Carcass
Slaughter
Introduction
Wray-Cahen et al. 1998
Chromium
Chromium
• Chromium is an essential element that improves insulin activity
• The digestibility and availability of Cr is low and variable (0.5-2% for inorganic Cr and 10-25% for organic)
• Responses to dietary Cr have been variable, possibly because of poor and variable digestibility
Dietary Cr increases ADG but the response is variable (31 studies)
Sales and Jancik 2011
Nano- and micro- chromium
• Chromium is an essential element that improves insulin activity
• The digestibility and availability of Cr is low and variable (0.5-2% for inorganic Cr and 10-25% for organic)
• Responses to dietary Cr have been variable, possibly because of poor and variable digestibility
• Reducing the Cr particle size may improve responses
Dietary Cr increases carcass weight
60
62
64
66
68
70
72
Control CrPic micro CrPic nano CrPic
Carc
ass w
eig
ht
(kg)
Hung et al. 2011
Dietary Cr reduces backfat in very lean pigs
6.0
7.0
8.0
9.0
Control CrPic micro CrPic nano CrPic
P2
bac
k fa
t (m
m)
Hung et al. 2011
Dietary nano CrPic increases the expression of muscle PI3K (an insulin signalling gene)
0
50
100
150
200
Control nano CrPic
Rel
ativ
e ex
pre
ssio
n (
%)
Low fatHigh fat
Hung et al. 2011
Betaine
• Betaine is an osmoregulator that reduces maintenance energy requirements
• Improved pigs can be limited by DE intake
• Responses to metabolic modifiers may be limited by DE intake
• Betaine may provide additional energy for protein deposition in pigs
Betaine and pST have additive effects on daily gain in boars fed 80% ad libitum
0
200
400
600
800
1000
1200
1400
Control Betaine
Dai
ly g
ain
(g
/d)
Control
pST
Betaine P=0.049
pST P<0.001
ab
cc
Suster et al. (2006)
Betaine and xylanase have additive effects on daily gain in gilts fed 80% ad libitum (2.7 kg/d)
700
800
900
Control Betaine
Dai
ly g
ain
(g
/d)
Control
Xylanase
Dunshea (unpublished)
Dietary neuroleptics may improve growth of boars
• Performance of group-housed entire males over the late finishing period is less than potential, possibly because of aggressive and sexual behaviours
• Dietary neuroleptics (and immunization against GnRF) offer a means of reducing sexual and aggressive behaviours
Dietary neuroleptics may increase carcass growth
Dunshea et al. 2011
• Physical castration of male pigs results in reduced feed efficiency and lean deposition and excess deposition of fat
• Performance of group-housed entire males over the late finishing period is less than potential, possibly because of aggressive and sexual behaviours
• Immunization against GnRF offers a means of reducing boar taint and negative behaviours and improving growth performance over that of both entire and physically castrated males
Immunological castration (Improvac)
0
200
400
600
800
0 30 60 90 120 150
Lea
n t
issu
e d
epo
siti
on
(g/d
)
Age (days)
Suster et al. (2006)
Entire males deposit more lean than physically castrated barrows during finishing
Entire
Barrow
0
10
20
Fat mass (kg) Fat % P2 (mm)
kg, %
or
mm
Entire
Barrow
Physically castrated barrows are fatter than entire males at 150 days of age
Suster et al. (2006)
0
1
2
3
4
Study 1 Study 2 Study 3 Study 4
Fee
d:g
ain
Entire
Barrow
Physically castrated barrows are less efficient than entire males (ca. 11%) from weaning to market
I Smell Boar Taint!
GnRFHypothalamus
Pituitary
LH & FSH
steroids such astestosterone & androstenone
boar taint & sexual & aggressive activities
Testes
Sexual development in the boar
GnRFHypothalamus
Pituitary
LH & FSH
steroids such astestosterone & androstenone
boar taint & sexual & aggressive activities
Anti-GnRF
Testes
Immunization against GnRF (with Improvac) arrests/reverses sexual development in the boar
Immunocastration reduces testes size
60.0
80.0
100.0
120.0
140.0
14 16 18 20 22 24
Age (weeks)
Tes
tes
wid
th (
mm
)
Boar Improvac Dunshea et al. (2001)
Primary Secondary
0
2
4
6
8
10
12
0 2 4 6 8
Weeks after secondary immunization
Tes
tost
ero
ne
(ng
/mL
)Boar
Improvac
Dunshea et al. (2008)
Plasma testosterone declines rapidly and remains low for upto 8 weeks
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 2 4 6 8
Weeks after secondary immunization
Fat
an
dro
sten
on
e (µ
g/g
)Boar
Improvac
Dunshea et al. (2008)
Fat androstenone declines rapidly and remains low for upto 8 weeks
0.0
0.1
0.2
0.3
0.4
0.5
0.0 0.5 1.0 1.5 2.0 2.5
Androstenone (µg/g fat)
Ska
tole
(µ
g/g
fat
)Boar ImprovacBarrow
Castration and immunocastration eliminate boar taint
Dunshea et al. (2001)
Dunshea et al. (2011)
Moore et al. (2011)
Immunization agaisnt GnRF decreases the lysine requirement beyond 3 weeks after secondary immunization
0
200
400
600
800
1000
1200
1400
1600
Boar Boar + pST
Dai
ly g
ain
(g
/d)
Control
Improvac
pST and Improvac combine to increase daily gain
Oliver et al. (2001)
0
200
400
600
800
1000
1200
Boar Boar + Ractopamine
Dai
ly g
ain
(g
/d)
Control
Improvac
Ractopamine and Improvac combine to increase daily gain
Moore et al. (2008)
Conclusions
• We have some excellent metabolic modifiers (eg. pST and ractopamine) and we need to advocate their use while we continue to identify other technologies
• Dietary additives offer a means of manipulating growth performance but can be variable and inconsistent and further research is needed to identify the circumstances under which they are most effective.
• There may be opportunities to manipulate the somatotrophic/IGF/insulin axis with dietary additives (although responses will likely not match pST)
• Immunization against GnRF offers a means of improving feed efficiency through making use of entire males without the risk of boar taint
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