Selenium, Micro and Macromineral levels and Supplementation Strategies

at Pasture, and Their Impact on Backgrounder Cattle Performance

Christoph Wand1 and Peter Kotzeff2

Ontario Ministry of Agriculture and Food - Guelph, ON Kotzeff Veterinary Services & Chesley Veterinary Management – Chesley, ON

Background • More effort to match CP & P allowances to

actual requirements, especially in feedlot

• Mineral supplementation on pasture in other jurisdictions (NZ, Michigan) is done using trace-mineralized salt, as opposed to complete vitamin-mineral premix as used in confinement

• Selenium is considered deficient in Great Lakes Basin

• Vitamins largely not required due to combination of sun and fresh forage

Objectives: 1. Determine the effectiveness of selenium

pellets,TM resin boluses, and feeding of trace-mineralized (TM) salt on pasture as the sole Se, mineral and Vitamin E sources

2. Pasture monitoring (feed anaylsis) for TMs was undertaken to explain the conditions cattle experience

3. Sampling of pastures of other producers, properties and sward types in 2012

Also referred to as Iron: Selenium pellets as they contain 90% iron to give the product weight to prevent it from being regurgitated. Last as

©FARMRITE

Also referred to as Iron: Selenium pellets

Composed of 90% Fe to give them adequate weight

Slowly dissolved in the reticulorumen to release a continual supply of Se

Advised to administer every 12-18 months

TM Bolus

‘Customer Formulation’ TM Salt

North Farm, June 9th 2011

Kuepfer June 9th, 2011

Lockerby August 8th, 2011

14 Farms Sampled, Bi-weekly 2012

% Calcium 2012requirement = 0.35%

0

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1

1.5

2

2.5

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Paisley

Knapw

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May June Week 1 June Week 2 July Week 1

July Week 2 August Week 1 August Week 2 August Week 3

% Phosphorus 2012requirement = 0.2%

0

0.1

0.2

0.3

0.4

0.5

0.6

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May June Week 1 June Week 2 July Week 1July Week 2 August Week 1 August Week 2 August Week 3

% Potassium 2012requirement = 0.6%

0

0.5

1

1.5

2

2.5

3

3.5

4

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May June Week 1 June Week 2 July Week 1

July Week 2 August Week 1 August Week 2 August Week 3

Conclusions • Macro-minerals minerals (Ca, P, K, Mg) are at

sufficient levels in the 2011 and 2012 forage samples on these farms

• Several micro-minerals are also sufficient with some even well above the recommendations of NRC 1996 (Fe, Mo)

• Copper is widely deficient, with likelihood of increased effective deficiency due to ample Molybdenum on these farms

• Zinc is also widely deficient

Conclusions • Patterns of sufficiency and insufficiency are

widely conserved in this geographic area

• Salt (Na) universally deficient

• Trace mineralized salt is an adequate form of supplementation provided it is formulated to address shortfalls. In this case:

– copper, zinc and selenium shortfalls

– localized concerns eg manganese

River Ridge Sept 7th, 2011

Procedure: Animal Performance • Cattle were purchased from various sources

including Western Canada, Ottawa Valley and local sales

• Weights were taken at turn-out and off-grass processing, and through the feedlot

• In spring of 2011 approximately 750 head: – 1/3 of animals allocated to each Se pellets, TM resin

boluses, and neither. All animals offered free choice custom TM salt

• In spring of 2013 approximately 550 head: – 1/2 of animals allocated to either TM resin boluses,

or not. All animals offered free-choice custom TM salt

Results: 2011 ADG

Treatment ADG LSMEAN

Standard Error P

Control 1.58a,b 0.057 <.0001

Se Pellet 1.53a 0.053 <.0001

TM Bolus 1.71b 0.060 <.0001

1.25

1.35

1.45

1.55

1.65

1.75

Control Se Pellet TM Bolus

2011 and 2012 Combined Pasture Performance (ADG)

Treatment

ADG

LSMEAN Number LSMEAN

TM Salt 1.750 1 Se Pellet 1.718 2 TM Bolus 1.747 3

Least Squares Means for effect Treatment

Pr > |t| for H0: LSMean(i)=LSMean(j)

i/j 1 2 3

1 0.6001 0.9935

2 0.6001 0.6728

3 0.9935 0.6728

2011 Results: ADG by Pasture Pasture

Farm ADG

LSMEANS Standard

Error P

Value

Kuepfer 1.40 0.116 <.0001

Lockerby 1.70 0.083 <.0001

North Farm 1.83 0.215 <.0001

Paisley 1.86 0.083 <.0001

River Ridge 1.29 0.093 <.0001

Stonewall 1.51 0.168 <.0001

Twin Pine 1.67 0.127 <.0001

Willowdale 1.59 0.217 <.0001

11.11.21.31.41.51.61.71.81.9

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2011 and 2012 Feedlot Performance Data

Treatment

ADG Feedlot

LSMEAN

LSMEAN Number

TM salt 3.424 1

Se Pellet 3.453 2

TM Bolus 3.423 3

Least Squares Means for effect Treatment

Pr > |t| for H0: LSMean(i)=LSMean(j)

i/j 1 2 3

1 0.8789 1

2 0.8789 0.8778

3 1 0.8778

Other Observations

• No treatment impact on finishing weight in 2011 or 2012

• No treatment impact on carcass weight in 2012 (manner of settlement different)

• No difference in gain at pasture vs. feedlot (compensation) due to treatment

• Large difference in both years by pasture location and purchase groups (interactions, unbalanced effects)

Conclusions

• TM supplementation strategy (Bolus vs TM salt) had no effect on pasture ADG

• TM supplementation strategy had no effect on subsequent feedlot performance

• TM supplementation strategy had no effect on slaughter end point and/or carcass merit

Implications

• TM salt at pasture was an effective mineral supplementation approach; forage analysis ensured macro-mineral sufficiency

• TM salt as the sole mineral supplement at pasture had no negative impact on gain, subsequent feedlot performance or carcass merit

• Ontario producers should consider forage sampling for macro-minerals (micros?) and adjust their supplementation protocol accordingly for potentially significant savings

Thank You!

• Pasture Farm Cooperators • PKW Feedlot & Staff • Summer Students & Staff • Peter Kotzeff • OCA/BFO

– Farm Innovation Program