Digging into copper & trace minerals M. Faulkner, PhD

Transcription

1 Digging into copper & trace minerals M. Faulkner, PhD Pop Quiz What are the trace mineral concentrations in your ration? Do you feed organic mineral sources? Any other form of trace mineral supplementation? Free choice, tubs, injections, etc..? 1

2 Discussion Outline Why are trace nutrients important Trace mineral absorption How are trace nutrient requirements determined Antagonists and safety factors Evaluating status and take home messages Math Refresher PPM = mg/kg On DM Basis Synonymous Terms Example Cow has 55lbs of DMI and diet Cu concentration is 18ppm 55lbs./2.2lbs in 1 kg = 25kg DMI I.e. For every 1 kg of feed consumed a cow consumes 18mg of Cu Total Cu consumption 25kg*18ppm = 450mg of Cu Consumed 2

3 Why are trace nutrients important? Trace Mineral Absorption TM 3

4 Trace mineral requirements factorial approach (NRC, 2001) Inputs Requirements BW (DMI) Days pregnant Age Milk yield Maintenance Gestation Growth Lactation mg/d of absorbed mineral excreted, accreted in fetus, secreted in milk, and retained in new tissue Slide From B. Weiss Maintenance requirement (BW and DMI) Inevitable Loss Copper Example: mg of absorbable Cu/kg of body weight 1,600lbs (727kg) mg * 727kg = 5.16mg Maintenance Requirement 4

5 Lactation requirement Milk Yield 0.15mg of absorbable Cu/kg of milk produced 100lbs (45.5kg) 0.15mg * 45.5kg = 6.82mg Milk Requirement Growth Body Weight Gain 1.15mg of absorbable Cu/kg of body weight gain 2.2lbs (1kg) Not likely after 1 st lactation, but let s just assume. 1.15mg * 1kg = 1.15mg Growth Requirement 5

6 Gestation Requirement Days PG Fetal Growth Less than 100d in gestation = 0.5 mg/d Last 30d = 2mg/d Trace mineral requirements factorial approach (NRC, 2001) Inputs BW (DMI) Days pregnant Age Milk yield Requirements Maintenance Gestation Growth Lactation 5.16mg 0.5mg 1.15mg 6.82mg 13.63mg Assumes 100% Efficiency? 6

7 TAS Inputs Feedstuffs Mineral concentration Absorption coefficients mg/d of mineral that is available for use Antagonists S Fe Fiber? Other TM Modified From B. Weiss Fe, Se, Zn, Mn, Cu Antagonists Fiber Sulfur (-) Cu Cu (+) (-) Cu-S(+) 7

8 Historical formulation theory If some is good More is better Inputs Feedstuffs Mineral concentration TAS Absorption coefficients mg/d of mineral that is available for use Organics/Specialty Minerals? Antagonists S Fe Fiber? Modified From B. Weiss 8

9 Absorption Coefficients AC = 4% 20ppm Cu = 500mg 500mg * 0.04% = 20mg absorbed AC = 5% 20ppm Cu = 500mg 500mg * 0.05% = 25mg absorbed AC = 0.075% 20ppm Cu = 500mg 500mg * 0.075% = 37.5mg absorbed Accuracy: Does a percentage unit or 2 really make a difference? 25% 50% 88% Historic theory + New mineral source = Concern Dairy Cu MTL = 40 mg/kg of DM Consumption over months and years Canada Dairy years Lactating 37.5mg/kg Dry cows 22.6mg/kg Hepatic Cu mg/kg DM Serum Cu of one cow 8.2 mg/kg 9 late gestation dry cow deaths 14% of herd Bradley,

10 Formulating for the unknowns: Safety Factors Example Cow = 13.63mg Assume 58 lbs DMI (26.36 kg) 18ppm Cu 474mg Intake Example Cow = 13.63mg 13.63/0.05 AC = 273mg 273/474 = 157% Hoof health and trace minerals 10

11 Response Genus relative abundance, % 12/18/2017 Trace minerals and hoof health Hoof wall keratinization Immune benefits Decreased bacterial exposure Don t forget about Biotin (20mg/cow-d) a Sulfate Traxim Sul + Gly Zn 1.80 ab Treponema 0.68 b Dietary Zn Formulation Saturation Curve Requirement MTL Intake

12 Dietary Iodine Formulation Weiss et al., 2015 Maximum supplemental I from EDDI: 50mg/hd/d Maximum legal concentration of I in Milk: 500µg/L or 0.5ppm or 500ppb 0.015mg I/1 kg of Body Weight 1650lbs (750kg) * = 11.25mg absorbed I Required EDDI AC = 90% 11.25*0.9% = 12.5mg Required Troubleshooting trace minerals status 12

13 Response 12/18/ Requirement MTL Intake Liver (Cu) Gold Standard Expensive Practical? Animal Welfare Adequate = mg/kg Wet Weight Basis ( mg/kg DM) Toxic = >110mg/kg Wet Weight Basis 13

14 MT CP CCS SOD Evaluating most mineral concentrations in blood for status is. Take home messages Feeding accurate concentrations of trace mineral is vital for animal health, production and far profitability. Organic or specialty minerals allow us to do more with less some more than others. Make sure you know what you are paying for and your return on the investment. Proceed with caution when discussing/troubleshooting trace mineral status. 14

15 Thank you Questions? 15