Use of 25hydroxyvitamin D3 to improve tenderness of beef from distillers coproduct supplemented past

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Use of 25-hydroxyvitamin D3 to improve tenderness
of beef from distillers co-product supplemented
pasture- and feedlot-finished beef steers

• Abstract 23032
• R. C. Knock1, A. H. Trenkle1, E. J.
  Huff-Lonergan1, S. M. Lonergan1, J. R. Russell1,
  P. M. Dixon1, K. M. Carnagey2, and D. C. Beitz1
• Iowa State University, Ames, IA, USA1,
• Wake Forest University School of Medicine,
  Winston-Salem, NC, USA2

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Introduction

• Interest in pasture-fed beef is increasing
• Distillers grains availability is on the rise
• Beef tenderness is a critical palatability trait
• 25-hydroxyvitamin D3 supplementation may improve
  beef tenderness
• Increased calcium to activate the calpains

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Synthesis of Vitamin D
7-dehydrocholesterol
UV light
Previtamin D3
Vitamin D3
LIVER
25-hydroxylase
25-hydroxyvitamin D3
KIDNEY
24-hydroxylase
1a-hydroxylase
24,25-dihydroxyvitamin D3
1,25-dihydroxyvitamin D3
ACTIVE
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Objective

• to evaluate effects of distiller's co-product and
  VITD supplementation on performance and carcass
  traits of feedlot- and pasture-finished beef
  steers
• To evaluate beef tenderness and beef color of
  steaks from feedlot- and pasture-finished beef
  steers supplemented with VITD

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Materials and Methods

• British-breed beef steers
• Pasture finished (n 24)
• Feedlot finished (n 24)
• Implanted with a combination TBA/estradiol
  implant
• Monitored 12th rib fat thickness by ultrasound
• Designated for harvest
• 3 harvest dates
• 112, 133, 154 days on feed
• 0 or 500-mg of 25(OH)D3 via oral bolus
• Given at 7 d prior to harvest

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Diets
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Sample Collection

• Collected strip loins (IMPS 180) and inside
  rounds (IMPS 168) after 48 h chill
• Longissimus (LM), gracilis (GR), and
  semimembranosus (SM)
• Processed into steaks at 3 d
• Aged 3, 7, or 14 d
• PROC Mixed of SAS
• Harvest date as a random variable
• VITD, diet, muscle and aging in the model of
  appropriate analyses

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Data Collected

• Beginning weight, end weight, and ADG
• HCW, REA, 12th rib fat, KPH
• FYG
• Marbling score and quality grade
• Calpastatin activity
• Warner-Bratzler shear force
• Instrumental color

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Results

• Steers had similar weights upon diet assignment
• Feedlot steers were heavier at their respective
  harvest dates
• 584 kg vs. 563 kg (P 0.04)
• Feedlot steers had greater ADG
• 1.74 kg/d vs. 1.51 kg/d ( P 0.0001)
• Feedlot steers and pasture-finished steers
  averaged 133 and 130 days on feed (P 0.51)

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Carcass characteristics of pasture- and
feedlot-finished steers
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Calpastatin Activity

• Calpastatin activity was not affected by diet or
  by VITD supplementation

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Calpastatin Activity
a
P lt 0.05
b
c
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Instrumental color comparisons between pasture-
and feedlot-finished beef steers
b
P lt 0.05
a
a
b
b
a
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Conclusions

• VITD did not affect calpastatin activity
• VITD was not effective at decreasing WBSF
• Muscles responded differently to aging
• Steaks from pasture-finished steers were less red
  than those from feedlot-finished steers
• Supplementing co-products to pasture-finished
  steers resulted in reasonable gains and time to
  reach market weight

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Implications

• Dose-response to 25-hydroxyvitamin D3 needs
  further investigation
• Supplementing pasture-finished cattle with
  distillers grains products may provide more
  viability to grass-based systems

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Acknowledgements

• National Cattlemens Beef Association is
  acknowledged for funding of this research

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Use of 25-hydroxyvitamin D3 to improve tenderness
of beef from distillers co-product supplemented
pasture- and feedlot-finished beef steers

• Abstract 23032
• R. C. Knock1, A. H. Trenkle1, E. J.
  Huff-Lonergan1, S. M. Lonergan1, J. R. Russell1,
  P. M. Dixon1, K. M. Carnagey2, and D. C. Beitz1
• Iowa State University, Ames, IA, USA1,
• Wake Forest University School of Medicine,
  Winston-Salem, NC, USA2

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Diets

• Feedlot
• Dry rolled corn, corn silage, WDGS, chopped hay
• RumensinTM (monensin 35.2 mg/kg DM)
• Pasture
• Continuously grazed 24 ac predominantly
  bromegrass
• Supplemented with a pellet of DDGS, wheat midds
  and soy hulls
• Supplemented initially at 4.5 kg/d and then at
  6.8 kg/d
• Vitamin/Mineral block to provide 80-200 mg
  monensin/d