Copper and MolybdenumCopper and Molybdenum
• Copper deficiency is 2nd most common in world
• Much work in UK has surrounded distillery by-products – pot-ale/pot-ale syrup/dark grains
• Can be primary or secondary (Fe/S/Mo)
• Controversy over mechanisms;-– Molybdenum toxicity – Telfer (Black)– Copper deficiency & Laboratory anomalies (Suttle)
Weeks on treatment Phillippo et al., (1987)
Pla
sma
Cu
con
cen
trat
ion
(mm
ol/l
)
Effect of dietary molybdenum and iron on plasma copper concentration in heifers
Effect of dietary molybdenum and iron on plasma copper concentration in heifers
0
5
10
15
20
0 8 16 24 32
Control
Iron
Molybdenum
Weeks on treatment Phillippo et al., (1987)
Liv
er C
u c
once
ntr
atio
n
(mm
ol/l
)
Effect of dietary molybdenum and iron on liver copper concentration in heifers
Effect of dietary molybdenum and iron on liver copper concentration in heifers
0
40
80
120
160
0 8 16 24 32
Control
Iron
Molybdenum
Weeks on treatment Phillippo et al., (1987)
Cu
mu
lati
ve d
aily
wei
ght
gain
(kg)
Effect of dietary molybdenum and iron on cumulative daily weight gain in heifers
Effect of dietary molybdenum and iron on cumulative daily weight gain in heifers
0
100
200
300
0 8 12 16 20 24 28 32
Control
Iron
Molybdenum
Age
at
pu
ber
ty (
day
s)
Phillippo et al., (1987)
250
270
290
310
330
1
Control
Iron
Molybdenum
Restricted fed
Treatment
Puberty = Plasma progesterone >1 ng/ml for >6 days
Effect of dietary molybdenum and iron on age at reaching puberty in heifers
Effect of dietary molybdenum and iron on age at reaching puberty in heifers
Significant findings from Phillippo et al 1987Significant findings from Phillippo et al 1987
Compared with controls and Fe groups Mo supplementation has marked effects;-
• Reduced LWG (P<0.05 expt 1, P<0.1 expt 2) (reduced food conversion efficiency)
• Delayed onset of puberty (P<0.05) • Lowered basal LH levels (peak levels P<0.1) • Decreased frequency of LH release (P<0.01) • Increased incidence of ovulation failure (P<0.05) • Reduced conception rate (P<0.05 (if expressed as those
that ovulated))
Copper and MolybdenumCopper and Molybdenum
• Assessment of copper status is problematical– Liver main storage organ and most accurate?– Plasma copper levels can be maintained– TCA – Cu-thiomoybdate complex – unavailable
• <22% of cattle have TCA in blood – Leeds Univ. (<68%)
– Caeruloplasmin – 6 Cu atoms per molecule• Attack by Mo – rendered inactive• NB – is an acute phase protein
– CP:PlCu ratio• Low < 1.6 Marginal 1.6 to 1.8 Normal > 1.9
The Relationship Between ‘Calving-pregnancy’ Intervals and Variables.The Relationship Between ‘Calving-pregnancy’ Intervals and Variables.
Variable Rate Ratio 95% Confidence Interval
Wald Test P-value
LRS P-value
Treatment
Model 1 Injection 1.00
Glass Bolus 1.84 1.39 – 2.44 <0.001 <0.001
Model 2 Matrix Bolus 1.00 Glass Bolus 1.53 1.16 – 2.01 0.002 <0.001
0 50 100 150 200 250 300 350 400 450
Time in days post calving
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0C
umul
ativ
e pr
obab
ility
of c
once
ptio
n
Matrix bolusInjectionGlass bolus
110 136 160
0 50 100 150 200 250 300 350 400 450
Time in days post calving
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0C
umul
ativ
e pr
obab
ility
of c
once
ptio
n
Matrix bolusInjectionGlass bolus
0.65
0.42
0.47
Copper and MolybdenumCopper and Molybdenum
• Mechanisms of Cu deficiency/Mo toxicity– LH pulsatility reduced size and frequency
• Cu-histidine complexes required for GnRH release
• ACTH release blocked
• Possibly associated with PAM
• Possible associated with cytochrome c-oxidase which is required for oxidative phosphorylation and energy production in the cell
Control 500 mg/kg DM Iron
2 mg/kg DM Molybdenum 10 mg/kg DM Molybdenum(Williams, 2004)
Effect of Molybdenum and Iron on ACTH accumulation in pituitary glands of sheepEffect of Molybdenum and Iron on ACTH accumulation in pituitary glands of sheep
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