Dr. Tom Crenshaw - Swine Lamness and Clinical Diagnosis of Skeletal Integrity
•Download as PPTX, PDF•
5 likes•720 views
Swine Lamness and Clinical Diagnosis of Skeletal Integrity - Dr. Tom Crenshaw, Department of Animal Science, University of Wisconsin, from the 2013 Allen D. Leman Swine Conference, September 14-17, 2013, St. Paul, Minnesota, USA. More presentations at http://www.swinecast.com/2013-leman-swine-conference-material
Recommended
More Related Content
Similar to Dr. Tom Crenshaw - Swine Lamness and Clinical Diagnosis of Skeletal Integrity
Similar to Dr. Tom Crenshaw - Swine Lamness and Clinical Diagnosis of Skeletal Integrity (20)
More from John Blue
More from John Blue (20)
Recently uploaded
Recently uploaded (20)
Dr. Tom Crenshaw - Swine Lamness and Clinical Diagnosis of Skeletal Integrity
- 1. 2013 Allen D. Leman Swine Conference September 17, 2013 – St. Paul, Minnesota Clinical diagnosis of skeletal integrity in swine TD Crenshaw, JL Reichert, JR Booth, DK Schneider, and LA Rortvedt-Amundson SRTC Swine Research & Teaching Center Department of Animal Sciences University of Wisconsin Madison, Wisconsin 1
- 2. Advances in our understanding of the functional role of bone Bone- what you hitch muscle to! 4-H youth definition Bone is more than a stick. Loveridge, 1999. J Anim Sci 77:190-196 Bone as an endocrine organ. Fukumoto and Martin, 2009. Trends Endoc. Metab. 20:230-236 2
- 4. Skeletal Lameness in Swine Mineralization Osteochondrosis What’s the problem Doc? Carlson et al., 2010
- 5. Bone Callous – “beaded-ribs” in a growing pig fed a diet with marginal Ca and P
- 6. Bones must not only carry the animal to market – but also through the fabrication processes
- 7. Bone Composition Ca & P content in bone ash constant ratio = 2.1:1
- 9. Methods to assess skeletal tissues responses to nutrient inputs Method Histology Test Terminal Prospects Dynamic Pitfall Sample size/time Gravimetric Terminal Standard Accuracy Non-invasive Whole animal Ash ≠ Strength Mechanical Terminal Structural Integrity DXA Irregular shape & composite material
- 10. GE Lunar Prodigy DXA – Improved speed and accuracy Calculations: Predicted BMC from initial pig weight pBMC0 = 24.1 + 14.1*BW Bone Mineral Content Gain BMCg, g/d = (BMC56 – pBMC0)/56 Ca retention, g/d = (BMCg * 0.38)/0.964 P retention, g/d = (BMCg * 0.18)/0.80 GE Lunar Prodigy DXA – scan of ~ 60 kg pig Ash, g 1400 1200 1000 800 600 400 200 0 Ca efficiency = Ca retention / Ca intake P efficiency = P retention/ P intake Selected Scan Modes Small Animal Ash content accurately predicted with selected modes: Adult, standard Adult, thick BMC = 3.3 + 1.001 Ash, R 0 2 = 0.99 200 400 600 800 1000 1200 1400 Dissected Bone Ash, g Small animal, < 20 kg Adult Standard, 20 to 46 kg Adult Thick, > 46 kg
- 11. Recovery of Skeletal Mineral after a Period of Calcium Depletion Experimental Design Depletion Period Days 0 to 28 Recovery Period Days 28 to 71 150% NRC Ca 150% NRC Ca 70% NRC Ca 70% NRC Ca
- 12. Recovery from Ca Depletion Total Skeletal Growth and Mineralization In Recovery: Skeletal Mass not affected by prior depletion Skeletal Mineralization tended to “Catch-up”
- 13. DXA scans of the pig foot Does foot orientation affect accuracy?
- 14. Identify the threshold value for a deficiency based on percent bone ash ? Variables that affect the decision
- 15. Response to diets vary among bones and age
- 16. Percent ash varies with age and bones in pigs fed adequate diets
- 17. Decrease in % ash with age related to failure of mineral accretion to keep pace with the rapid growth of organic matrix. Vanderwerff et al., 2013
- 18. Carry-over of maternal vitamin D on nursery pigs Rortvedt-Amundson et al., 2013
- 19. Whole Body DXA: Birth and Weaning Differences among maternal diets were not detected in pig BMD at birth or weaning Rortvedt-Amundson et al., 2013 19
- 20. Whole Body DXA: End of Nursery 0 325 Sow diet, IU D3/kg 1750 BMD reduced 25% in pigs produced by gilts fed 0 vs 325 and 1750 IU D3/kg. Pigs fed –D120P nursery diets had reduced BMD if produced by gilts fed 0 or 325 IU D3/kg, but not 1750 IU D3/kg Rortvedt-Amundson et al., 2013 20
- 21. Unexpectedly, with 0 supplemental vitamin D, femur stress increased >20% if pigs were fed diets with 150% Ca & 120% P requirement. Rortvedt-Amundson et al., 2013
- 22. Femur vs Fibula “which bone is best” Femur Fibula
- 23. Femur vs Fibula “which bone is best” Femur Fibula Both have similar “fits” to P intake (R2) Femur has steeper slope than Fibula (more sensitive response to P intake)
- 24. Femur ash as a predictor of whole body skeletal ash
- 25. Fibula ash as a predictor of whole body skeletal ash
- 26. Femurs vs Fibulas as Predictors of Whole Body Bone Mineral Content Conclusions DXA accurately predicts whole body BMC (g ash/pig) Fibulas over estimate BMC at low P intakes but under estimate BMC at high P intakes Femurs accurately predict BMC over a range of P intakes Femurs offer a more accurate assessment of BMC than fibulas in young growing pigs
- 27. Which bone better predicts Pig BMC at market weight?
- 28. Development of standards for DXA femur scans DXA femur scans – pigs with lameness DXA scores for femurs ~ same in pigs with lameness
- 29. Development of standards for DXA feet scans DXA feet scans – pigs with lameness DXA scores for feet slightly lower in pigs with lameness
- 30. Stick to the facts Start early Study the records carefully Support co-workers Share information
- 31. Conclusions Accurate measures of bone ash can be rapidly completed with DXA scans of whole pigs or individual bones. Femurs are better predictors of whole body bone mineral content than fibulae or feet Percent bone ash is not a sensitive indicator of mineral adequacy ? Variables that affect the decision
- 32. Acknowledgements Cargill/Benevenga Undergraduate Research Stipend UW SRTC staff & students Swine Research & Teaching Center
Editor's Notes
- In past swine lameness was broadly grouped into either problems associated with mineralization or problems produced by lesions classified as osteochondrosis. With some digging into the kyphosis incidence in our herd, we have began to speculate on some signaling pathways that may link the two problems.
- Ribs are bones that display early responses to Ca, P (or vitamin D) deficiencies – in humans and in this slide in pigs. In this slide pig ribs display a callous (mineralized “bead” possible after ~ 6 weeks following a fracture and the normal wound-healing response. The more recent fractures show the hemorrhage responses evident within the first few days following a fracture. The rachitic rosary are present at the ends of the ribs.
- The dietary Ca:P ratio is influenced by the amounts stored in bone and soft tissue. In bone ash, Ca:P exists in a 2.1 Ca to 1 P ratio. Soft tissue contains more P and limited amounts of Ca, so in the next slide, the Ca P ratio can be calculated for the whole animal and the diet.
- To understand the functional relationships that Ca and P contribute to soft tissue and skeletal growth, need to understand a bit more about bone growth.Bones grow by modeling - change in shape as they grow in length and diameter. Bones also remodel - turnover of in small packets within the mineralized tissue.