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Table 1 Trait definition and estimates of variation coefficients, heritability, and genetic correlations with tibia density and strength

From: Genetic markers associated with bone composition in Rhode Island Red laying hens

Method

Tibia

Phenotypic

Genetic correlation with

Bone

Trait name

Definition

Variation coefficient

h2 ± SE

Tibia density

Tibia breaking strength

FTIR

Cortex

Cortical PO4/Amide I

Calcium-phosphate (PO4) relative to organic matter (Amide I); calcium-phosphate and organic matter measured as FTIR area at main peak 900–1200 cm−1 and 1640 cm−1, respectively; this measurement indicates the degree of mineralization

13.43

0.08 ± 0.04

− 0.14 ± 0.04

− 0.11 ± 0.04

Cortical CO3/PO4

Carbonate relative to calcium-phosphate(PO4); carbonate and calcium-phosphate measured as FTIR area at main peak 1415 cm−1 and 900–1200 cm−1, respectively. Carbonate peak represents carbone contribution from crystalized and non-crystalized minerals excluding carbone contribution from organic matter phase; this measurement refers to carbonate substitution and is an indicator of carbonate weight % [19]

9.13

0.07 ± 0.04

0.18 ± 0.04

0.14 ± 0.04

Cortical CO3/Amide I

Carbonate relative to organic matter (Amide I); carbonate and organic matter measured as FTIR area at main peak 1415 cm−1 and 1640 cm−1, respectively; CO3/Amide I and PO4/Amide I together refer to bone mineralization process

6.85

0.09 ± 0.04

− 0.05 ± 0.04

− 0.04 ± 0.04

Cortical CO3 1450/1415

Ratio of secondary carbonate and organic matter peak (1450 cm−1) to the main carbonate peak (1415 cm−1)

3.43

0.06 ± 0.04

− 0.07 ± 0.04

− 0.07 ± 0.04

Cortical collagen maturity

Mature relative to immature collagen cross-links; mature and immature collagen measured as the FTIR area at main peak 1660 cm−1 and 1690 cm−1, respectively; this measurement is used as an indicator of the collagen maturity

60.04

0.09 ± 0.04

− 0.08 ± 0.04

− 0.10 ± 0.04

Cortical lipid

Carbonyl group from the lipid; measured as the FTIR area at main peak 1710 cm−1

69.26

0.19 ± 0.05

− 0.20 ± 0.04

− 0.19 ± 0.04

Medulla

Medullary PO4/Amide I

As in cortex. Note Amide I in medulla come from medulla bone organic matter and bone marrow as well

40.14

0.05 ± 0.03

0.08 ± 0.04

0.10 ± 0.03

Medullary CO3/PO4

As in cortex

31.07

0.06 ± 0.04

− 0.04 ± 0.04

− 0.05 ± 0.03

Medullary CO3/Amide I

As in cortex

29.67

0.07 ± 0.03

0.13 ± 0.04

0.15 ± 0.03

Medulla CO3 1450/1415

As in cortex

23.41

0.02 ± 0.03

− 0.05 ± 0.04

− 0.07 ± 0.03

Medullary collagen maturity

As in cortex

57.44

0.05 ± 0.03

− 0.02 ± 0.04

− 0.02 ± 0.03

Medullary lipid

As in cortex

91.9

0.01 ± 0.03

− 0.02 ± 0.03

− 0.05 ± 0.03

TGA

Cortex

Cortical water %

Water weight% measured by TGA

8.51

0.00 ± 0.08

0.00 ± 0.03

0.00 ± 0.04

Cortical OM %

Organic matter weight% measured by TGA

6.43

0.10 ± 0.04

− 0.15 ± 0.06

− 0.16 ± 0.04

Cortical CO3%

Carbonate weight% measured by TGA

16.3

0.00 ± 0.03

0.01 ± 0.03

0.00 ± 0.04

Cortical phosphates %

Phosphate weight% measured by TGA

2.35

0.09 ± 0.04

0.10 ± 0.04

0.11 ± 0.03

Cortical mineral %

Minerals weight%; calculated as the sum of carbonate % and phosphate % measured by TGA

2.47

0.07 ± 0.04

0.14 ± 0.05

0.15 ± 0.04

Cortical phosphates/OM

Phosphate weight % relative to organic matter weight % measured by TGA

7.91

0.13 ± 0.04

0.15 ± 0.04

0.15 ± 0.04

Cortical CO3/phosphates

Carbonate weight % relative to organic matter weight % measured by TGA

16.57

0.00 ± 0.03

0.00 ± 0.03

0.00 ± 0.04

Medulla

Medullary water %

As in cortex

16.49

0.03 ± 0.04

0.10 ± 0.04

0.08 ± 0.04

Medullary OM %

As in cortex

19.12

0.23 ± 0.04

− 0.25 ± 0.04

− 0.20 ± 0.04

Medullary CO3 %

As in cortex

35.72

0.04 ± 0.03

0.13 ± 0.03

0.14 ± 0.05

Medullary phosphates %

As in cortex

31.37

0.22 ± 0.04

0.24 ± 0.04

0.20 ± 0.04

Medullary mineral %

As in cortex

32.39

0.22 ± 0.04

0.25 ± 0.04

0.20 ± 0.04

Medullary phosphates/OM

As in cortex

52.79

0.24 ± 0.05

0.26 ± 0.04

0.21 ± 0.04

Medullary CO3/phosphates

As in cortex

33.41

0.04 ± 0.03

− 0.11 ± 0.03

− 0.06 ± 0.04

XRD

Cortex

Crystal scattering

Scattering degree of mineral crystals orientations within bone mineral; measured as the angular breadth of bands displayed in the intensity profile along the Debye–Scherrer ring associated with the 002 reflection of apatite mineral (Gamma scan [53]); the wider the band, the greater the scattering (less organization) in the orientation of the c-axis of apatite crystals; this is the most accurate XRD measurements

11.58

0.02 ± 0.03

0.03 ± 0.03

− 0.02 ± 0.03

Crystal orientations

Degree of crystal orientation; it ranges from 0 (random) to 1 (completely oriented)

15.67

0.01 ± 0.03

− 0.06 ± 0.04

− 0.04 ± 0.03

Crystal oriented fraction

Ratio of orientated to non-orientated mineral crystals; greater value means well organized crystals and smaller values means less organized crystals

25.98

0.00 ± 0.02

0.02 ± 0.03

0.02 ± 0.03

  1. FTIR: Fourier transform infrared spectroscopy; TGA: thermogravimetry; XRD: X-ray diffraction; OM: organic matter; heritabilities (h2) and genetic correlations are estimated by multi-trait genomic restricted maximum likelihood; SE: standard error of the estimates; \({h}^{2}\) for tibia density: 0.50 ± 0.05; \({h}^{2}\) for tibia breaking strength: 0.46 ± 0.05
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Genetics Selection Evolution

ISSN: 1297-9686