Heritage Large Fowl - Phase II

[3riverschick]

Still hoping someone will answer about the breed type above. In the interim, I have been studying how the different body parts interact with each other to provide symmetry and proper breed type. It's just fascinating.
I fund thee articles. Too scientific for me, will take a lot of work to study them but wanted o share them. Some are studies of indigenous poultry, some of broilers most with the same intent, to find measurement formulas to help predict production virtues.
( see the URL's below) BTW, I think #1, the Sri Lanka study with the formula is a most interesting cite:
Best,
Karen




1. Tropical Agricultural Research Vol. 26 (2): 261 – 273 (2015)
Comparative Study on Morphological and Morphometric Features of Village Chicken in Sri Lanka
R.P. Liyanage*, C.M.B. Dematawewa1 and G.L.L.P. Silva1
Postgraduate Institute of Agriculture University of Peradeni
https://www.pgia.ac.lk/files/Annual... 2/Papers/4-93. Mr. R.P. Liyanage OK_new.pdf
Live weight prediction (page 271)

Practical difficulties to measure live weight at field level have led scientists to develop prediction models
to estimate live weight using linear body measurements (Assan, 2013; Ige et al., 2006 & Momoh and Kershima, 2008).
When all breed groups were combined (overall), every linear parameter had a significantly positive (p<0.05)
association with body weight (detailed results were published elsewhere). Among them the following formula
was found to be the best predictor of body weight with coefficient of determination value of 65 percent:

Predicted body weight = -1690.4 + 5.53*Chest circ. + 10.11*Shank length

These results are in agreement with those of Ige et al. (2006) and Momoh and Kershima (2008)
that showed higher muscle deposition in breast and thigh create a strong relationship between
chest circumference or shank length with live weight.
--------------------------------
2. Scientific Journal of Pure and Applied Sciences (2015) 4(10) 200-210
ISSN 2322-2956
doi: 10.14196/sjpas.v4i10.1950
Journal homepage: www.Sjournals.com
Scientific Journal of Pure and Applied Sciences (2015) 4(10) 200-210
ISSN 2322-2956
doi: 10.14196/sjpas.v4i10.1950

Methodology and factors influencing the association of body weight,
performance parameters with linear body measurements assessment in poultry
N. Assan*
Open University, Zimbabwe.
section 5 is interesting:
5. Linear body measurements and carcass parameters in poultry
6. Implications
From the preceding review, can deduce that there is consensus among researchers working with different
poultry species that linear body measurements could serve as predictors of body weight and carcass parameters.
--------------------------
3. PHYSIOLOGY AND REPRODUCTION
Potential Relationships Between Physical Traits and Male Broiler Breeder Fertility1
S. McGary,* I. Estevez,*,2 and M. R. Bakst†
*Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland 20742; and †USDA-ARS, Beltsville, Maryland 20705
https://naldc.nal.usda.gov/download/8704/PDF
-----------------------------
4. Prospects for utilization of the relationship between zoometrical measurements and performance traits
for poultry and livestock genetic improvement in developing countries
Never Assan
http://www.sjournals.com/index.php/SJAs/article/view/2020/0
full PDF : file:///C:/Users/Bob/Downloads/2020-5541-1-PB.pdf
---------------------------
5. PeerJ. 2014; 2: e432.
Published online 2014 Jul 3. doi: 10.7717/peerj.432
PMCID: PMC4103091
Anatomical and biomechanical traits of broiler chickens across ontogeny.
Part I. Anatomy of the musculoskeletal respiratory apparatus and changes in organ size
Peter G. Tickle,1 Heather Paxton,2 Jeffery W. Rankin,2 John R. Hutchinson,2 and Jonathan R. Codd1
Academic Editor: Xiang-Jiao Yang
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103091/
---------------------------------
6. PeerJ. 2014 Jul 3;2:e473. doi: 10.7717/peerj.473. eCollection 2014.
Anatomical and biomechanical traits of broiler chickens across ontogeny.
Part II. Body segment inertial properties and muscle architecture of the pelvic limb.
Paxton H1, Tickle PG2, Rankin JW1, Codd JR2, Hutchinson JR1.
https://www.ncbi.nlm.nih.gov/pubmed/25071996
----------------
7. J Anat. 2010 Aug;217(2):153-66. doi: 10.1111/j.1469-7580.2010.01251.x. Epub 2010 Jun 14.
The effects of selective breeding on the architectural properties of the pelvic limb
in broiler chickens: a comparative study across modern and ancestral populations.
Paxton H1, Anthony NB, Corr SA, Hutchinson JR.
https://www.ncbi.nlm.nih.gov/pubmed/20557402
------------------------
8. Abstract
INTRODUCTION
THE GENETIC BACKGROUND
WELFARE, WILDNESS AND DOMESTICATION
EXAMPLES OF MAJOR WELFARE CONCERNS
ARE WELFARE CONCERNS JUSTIFIED?
SOLUTIONS TO WELFARE CONCERNS: NEW TECHNOLOGIES
SUMMARY AND CONCLUSIONS

Abstract
1. Genetic theory leads to the expectation that unexpected consequences of genetic selection for production traits will inevitably occur and that these changes are likely to be undesirable.
2. Both artificial selection for production efficiency and “natural” selection for adaptation to the production environment result in selection sweeps that increase the frequencies of rare recessive alleles that have a negative effect on fitness.
3. Fitness is broadly defined as any trait that affects the ability to survive, reproduce and contribute to the next generation, such as musculoskeletal disease in growing broiler chickens and multiple ovulation in adult broiler parents.
4. Welfare concerns about the negative effects of genetic selection on bird welfare are sometimes exaggerated but are nevertheless real. Breeders have paid increasing attention to these traits over several decades and have demonstrated improvement in pedigree flocks. There is an urgent need to monitor changes in commercial flocks to ensure that genetic change is accompanied by improvements in that target population.
5. New technologies for trait measurement, whole genome selection and targeted genetic modification hold out the promise of efficient and rapid improvement of welfare traits in future breeding of broiler chickens and turkeys. The potential of targeted genetic modification for enhancing welfare traits is considerable, but the goal of achieving public acceptability for the progeny of transgenic poultry will be politically challenging.
INTRODUCTION
The success of the poultry meat industry in providing high-quality affordable food in ever increasing quantities after the Second World War is well documented. The rapid intensification of the poultry industries was made possible by the availability of cheap grain and simultaneous changes in nutrition and housing, the control of disease, improved management and freedom from government control. The genetic improvement of feed conversion efficiency underpinned these changes and has resulted in a large reduction in the quantity of feed required to produce a unit of meat (McKay, 2009
Karabozhilova, I., Wieland, B., Alonso, S., Salonen, L. & Hasler, B. (2012) Backyard chicken keeping in the greater London urban area: welfare status, biosecurity and disease control issues. British Poultry Science, 53: 421–430.
[Taylor & Francis Online], [Web of Science

]
).
Early genetic improvement was achieved by simply selecting for increased body weight and breast width and had the effect of decreasing the time to a standard slaughter weight of 2 kg (and hence the energy costs of maintenance), while simultaneously increasing the yield of breast meat that was the more valuable part of the carcass (Hunton, 1990
Hunton, P. (1990) Industrial breeding and selection, in: Crawford, R.D. (Ed) Poultry Breeding and Genetics, 985–1028 (Amsterdam: Elsevier).
). Selection on relatively few traits, however, runs the risk of unintended negative consequences for traits that were not selected. There is ample evidence for this in the literature (Table 1), and there exist widespread concerns about the welfare of broilers and turkeys in commercial flocks. Rauw et al. (1998
Karabozhilova, I., Wieland, B., Alonso, S., Salonen, L. & Hasler, B. (2012) Backyard chicken keeping in the greater London urban area: welfare status, biosecurity and disease control issues. British Poultry Science, 53: 421–430.
[Taylor & Francis Online], [Web of Science

]
, p. 28) concluded that “selection for high production efficiency … has been accompanied by undesirable side effects for several physiological, immunological and reproduction traits and consequently for animal welfare”. The evidence for this conclusion in poultry was largely based on two long-term selection experiments for body weight in boiler chickens and turkeys (updated results from these selection lines are presented by Nestor et al. (2008
Karabozhilova, I., Wieland, B., Alonso, S., Salonen, L. & Hasler, B. (2012) Backyard chicken keeping in the greater London urban area: welfare status, biosecurity and disease control issues. British Poultry Science, 53: 421–430.
[Taylor & Francis Online], [Web of Science

]
) and Dunnington et al. (2013
Dunnington, E.A., Honaker, C.F., McGilliard, M.L. & Siegel, P.B. (2013) Phenotypic responses of chickens to long-term, bidirectional selection for juvenile body weight-historical perspective. Poultry Science, 92: 1724–1734.
[CrossRef], [PubMed], [Web of Science

]
)). Single trait selection experiments do not reflect the process of multiple trait selection that occurs in commercial breeding programmes, and experimental results must be validated in commercial environments. The evidence for undesirable consequences of genetic selection in broiler and turkey flocks and what breeders are doing to address these concerns should also be examined.
Table 1. The number of idiopathic disorders of broiler chickens and turkeys reported in the literature (from Hocking, 2010
Hocking, P.M. (2010) Genetics of metabolic diseases in poultry, in: Bishop, S.C., Axford, R.F.E., Nicholas, F.W. & Owen, J.B. (Eds) Breeding for Disease Resistance in Farm Animals (Wallingford: CABI).
----------------------------
A genetic correlation is defined as “the extent to which two measurements reflect what is genetically
the same character” (Falconer and MacKay, 1996
------------------------------

 

[CanadianBuckeye]

Regarding hoping someone can help me with this clarification on male White Chantecler breed type:
Go to:
http://www.cherrycreekcanadians.ca/chickens.html
scroll down to:
Chantecler Chicken History
by Hans L. Schippers
3rd pic ( Chantie hen) see that's a Sussex profile.
Now check out APA SOP Sussex hen:
http://www.katherineplumer.com/closeups/poultry/SOP/LLightSussex.html
Except for thr noticable Cormish influence in the head of the Chantie hen, they are th same.
So I think if I keep looking for that Sussex profile in my Chantie hens and
look for the Chantie profile in the cocks, I should be good.
The one thing I cannot figure out is the angle of the back
in the different breeds. it has me confounded and if anyone knows the answer I
would love to hear it because I can't find it.
The back on the Sussex male is level. The back on the Chantie male is angled.
Both sire hens with level backs. How can this be?
The only difference I can see is the size of the tail. Does the longer length
of the Chantie male tail have to do with creating more angle in the back?
I know the higher the elevation on the tail the shorter the back. But both breeds
are meant to have long backs. it's a conundrum.
Best,
Karen

My 1989 SOP for the white Chantecler rooster says only: Back: Long, broad its entire length, curving sharply to tail. Saddle: Abundant. Tail: Medium length, moderately well-shaped, carried at and angle of 30o above the horizontal. There's no mention of back angle for the rooster. For the hen, it says Back: long, broad at shoulders, sloping slightly downward to rear, where it curves sharply into tail. Tail is also 30o above the horizontal.
I noticed with my Cornish/Buckeye crosses, that if the back was sloping, the tail angle was low. I have that problem with my Buckeyes- the tails' angles are too low. It should be 40o for the male, 30o for the female. Even with the low tail angle, it's tricky to see that sloping back in a fully feathered bird especially with an abundant saddle.

 

[3riverschick]

My 1989 SOP for the white Chantecler rooster says only: Back: Long, broad its entire length, curving sharply to tail. Saddle: Abundant. Tail: Medium length, moderately well-shaped, carried at and angle of 30o above the horizontal. There's no mention of back angle for the rooster. For the hen, it says Back: long, broad at shoulders, sloping slightly downward to rear, where it curves sharply into tail. Tail is also 30o above the horizontal.
I noticed with my Cornish/Buckeye crosses, that if the back was sloping, the tail angle was low. I have that problem with my Buckeyes- the tails' angles are too low. It should be 40o for the male, 30o for the female. Even with the low tail angle, it's tricky to see that sloping back in a fully feathered bird especially with an abundant saddle.

Hum,
so SOP doesn't care about angle of cock's back but we see an angle. It does care about angle in hen's back but seeing many with level backs. Hum, what is the take-away from this? I wonder if the angle of the back is indicative of a shorter back? I know that White Chanties can be bred with a longer tail to make the back look longer in the males. Does a level back make a short back look longer in the females?
Hum,
Karen

 

[CanadianBuckeye]

Hum,
so SOP doesn't care about angle of cock's back but we see an angle. It does care about angle in hen's back but seeing many with level backs. Hum, what is the take-away from this? I wonder if the angle of the back is indicative of a shorter back? I know that White Chanties can be bred with a longer tail to make the back look longer in the males. Does a level back make a short back look longer in the females?
Hum,
Karen

I'm not sure about the angle being related to back length, or honestly how the judges can even tell how the back slopes. I personally have the devil of a time figuring that one out. When I look at photos, to me the back does not slope down at all.... rather up. For example, in this champion buckeye from the ABC blogspot (a Schumaker Farms cockerel) , I assume that

the back slopes downwards correctly, but I can't see it. Same for this Schumaker hen, another correct bird I assume but it looks level to me. Maybe it's something that you have to feel for...... not look for.????


But, I can easiily see the downward slope in this Meyer Hatchery Cornish rooster, and he has a high tail angle too.

I can see a downward slope in this Chantecler rooster:


But not in this hen


But maybe this one? To me the hen above seems to have a longer back. But I don't know.

 

[3riverschick]

Hi CanadianBuckeye,
The hen in the dry leaves is a superb example of Chantecler breed type. Tho I would like to see less "petticoat" fluffing out. I guess you are right about having to "feel" it. But there is usually a theoretical counterpoint to any physical exam. I wonder if back angle has a genetic correlation to girth or one of the other height or width measurements ?
Best,
Karen

 

[3riverschick]

Ok, I found this study. It's the Nigerians again, but this time with commercial birds ,
not village chickens. The Nigerians are very keen to understand how phenotype
correlates to production virtues.

Interrelationships and phenotypic correlations among body dimensions in commercial pullets
reared in the derived savannah zone of Nigeria
Simeon O. Olawumi
Department of Animal Production and Health Sciences, Ekiti State University, Ado-Ekiti, Nigeria
file:///C:/Users/Bob/Downloads/7060134.pdf
Abstract
This research work was conducted to evaluate the relationship between live body weight and
linear body measurements in three strains of commercial layers reared under intensive system
of management. Traits considered were body weight, body length, thigh length, shank length,
breast girth, while the feed variables were feed intake, feed conversion ratio and feed efficiency.
There were significant (P<0.01) phenotypic correlations between body weight and linear measurements
in all the three strains. Feed intake and feed efficiency also have high phenotypic correlations
with body weight and linear measurements, whereas the reverse was the case with feed conversion ratio.
In general, some traits had very high significant positive phenotypic correlations with body weight,
some recorded medium phenotypic correlation values while some had low correlation values with
body weight. Traits that recorded high phenotypic correlations with body weight are body length,
thigh length, feed intake and feed efficiency, those with medium phenotypic correlations are
shank length and breast girth, while trait with low phenotypic correlations was feed conversion ratio.
The obtained results indicate pleiotropic effects of genes operating on these traits. The implication
is that selection for any of the traits in these strains will lead to improvement of others.
-----
Still nothing about angle of back! Perhaps a better question to ask is ,
"Why did the APA bother to include angle of back in their breed descriptions??!??"

 

[3riverschick]

Ok It's the Nigerians again. I can't do this math so no use to me. However, maybe a math star among us can. They seem to have found a formula where using the weight of any part of the dressed bird, one can use it to calculate the live weight of the bird. Kinda neat. Weigh the dressed drumstick, find out how much the bird weighed before slaughter.

http://scienceandnature.org/IJSN_Vol4(1)M2013/IJSN-VOL4(1)13-26.pdf
PHENOTYPIC CORRELATIONS BETWEEN LIVE BODY WEIGHT AND CARCASS TRAITS IN ARBOR ACRE BREED OF BROILER CHICKEN
S. O. Olawumi Department of Animal Production and Health Sciences,
Ekiti State University, P. M. B. 5363, Ado-Ekiti, Nigeria

 

[Arielle]

Quote: Holy crap--are these your boys Wisher????? Dang I missed the boat!!!

Thanks, Arielle! I sure love them, they never fail to make me smile. Everybody loves this pic. It was taken last year and it is of the spring cockerels at about 7 months old. That is the age they look their best, but they are holding their looks more and more each year. I sure enjoy working with them, even if I never win more than BB or BV at the shows.
You have done well!!!

Still hoping someone will answer about the breed type above. In the interim, I have been studying how the different body parts interact with each other to provide symmetry and proper breed type. It's just fascinating.
I fund thee articles. Too scientific for me, will take a lot of work to study them but wanted o share them. Some are studies of indigenous poultry, some of broilers most with the same intent, to find measurement formulas to help predict production virtues.
( see the URL's below) BTW, I think #1, the Sri Lanka study with the formula is a most interesting cite:
Best,
Karen




1. Tropical Agricultural Research Vol. 26 (2): 261 – 273 (2015)
Comparative Study on Morphological and Morphometric Features of Village Chicken in Sri Lanka
R.P. Liyanage*, C.M.B. Dematawewa1 and G.L.L.P. Silva1
Postgraduate Institute of Agriculture University of Peradeni
https://www.pgia.ac.lk/files/Annual... 2/Papers/4-93. Mr. R.P. Liyanage OK_new.pdf
Live weight prediction (page 271)

Practical difficulties to measure live weight at field level have led scientists to develop prediction models
to estimate live weight using linear body measurements (Assan, 2013; Ige et al., 2006 & Momoh and Kershima, 2008).
When all breed groups were combined (overall), every linear parameter had a significantly positive (p<0.05)
association with body weight (detailed results were published elsewhere). Among them the following formula
was found to be the best predictor of body weight with coefficient of determination value of 65 percent:

Predicted body weight = -1690.4 + 5.53*Chest circ. + 10.11*Shank length

These results are in agreement with those of Ige et al. (2006) and Momoh and Kershima (2008)
that showed higher muscle deposition in breast and thigh create a strong relationship between
chest circumference or shank length with live weight.
--------------------------------
2. Scientific Journal of Pure and Applied Sciences (2015) 4(10) 200-210
ISSN 2322-2956
doi: 10.14196/sjpas.v4i10.1950
Journal homepage: www.Sjournals.com
Scientific Journal of Pure and Applied Sciences (2015) 4(10) 200-210
ISSN 2322-2956
doi: 10.14196/sjpas.v4i10.1950

Methodology and factors influencing the association of body weight,
performance parameters with linear body measurements assessment in poultry
N. Assan*
Open University, Zimbabwe.
section 5 is interesting:
5. Linear body measurements and carcass parameters in poultry
6. Implications
From the preceding review, can deduce that there is consensus among researchers working with different
poultry species that linear body measurements could serve as predictors of body weight and carcass parameters.
--------------------------
3. PHYSIOLOGY AND REPRODUCTION
Potential Relationships Between Physical Traits and Male Broiler Breeder Fertility1
S. McGary,* I. Estevez,*,2 and M. R. Bakst†
*Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland 20742; and †USDA-ARS, Beltsville, Maryland 20705
https://naldc.nal.usda.gov/download/8704/PDF
-----------------------------
4. Prospects for utilization of the relationship between zoometrical measurements and performance traits
for poultry and livestock genetic improvement in developing countries
Never Assan
http://www.sjournals.com/index.php/SJAs/article/view/2020/0
full PDF : file:///C:/Users/Bob/Downloads/2020-5541-1-PB.pdf
---------------------------
5. PeerJ. 2014; 2: e432.
Published online 2014 Jul 3. doi: 10.7717/peerj.432
PMCID: PMC4103091
Anatomical and biomechanical traits of broiler chickens across ontogeny.
Part I. Anatomy of the musculoskeletal respiratory apparatus and changes in organ size
Peter G. Tickle,1 Heather Paxton,2 Jeffery W. Rankin,2 John R. Hutchinson,2 and Jonathan R. Codd1
Academic Editor: Xiang-Jiao Yang
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103091/
---------------------------------
6. PeerJ. 2014 Jul 3;2:e473. doi: 10.7717/peerj.473. eCollection 2014.
Anatomical and biomechanical traits of broiler chickens across ontogeny.
Part II. Body segment inertial properties and muscle architecture of the pelvic limb.
Paxton H1, Tickle PG2, Rankin JW1, Codd JR2, Hutchinson JR1.
https://www.ncbi.nlm.nih.gov/pubmed/25071996
----------------
7. J Anat. 2010 Aug;217(2):153-66. doi: 10.1111/j.1469-7580.2010.01251.x. Epub 2010 Jun 14.
The effects of selective breeding on the architectural properties of the pelvic limb
in broiler chickens: a comparative study across modern and ancestral populations.
Paxton H1, Anthony NB, Corr SA, Hutchinson JR.
https://www.ncbi.nlm.nih.gov/pubmed/20557402
------------------------
8. Abstract
INTRODUCTION
THE GENETIC BACKGROUND
WELFARE, WILDNESS AND DOMESTICATION
EXAMPLES OF MAJOR WELFARE CONCERNS
ARE WELFARE CONCERNS JUSTIFIED?
SOLUTIONS TO WELFARE CONCERNS: NEW TECHNOLOGIES
SUMMARY AND CONCLUSIONS

Abstract
1. Genetic theory leads to the expectation that unexpected consequences of genetic selection for production traits will inevitably occur and that these changes are likely to be undesirable.
2. Both artificial selection for production efficiency and “natural” selection for adaptation to the production environment result in selection sweeps that increase the frequencies of rare recessive alleles that have a negative effect on fitness.
3. Fitness is broadly defined as any trait that affects the ability to survive, reproduce and contribute to the next generation, such as musculoskeletal disease in growing broiler chickens and multiple ovulation in adult broiler parents.
4. Welfare concerns about the negative effects of genetic selection on bird welfare are sometimes exaggerated but are nevertheless real. Breeders have paid increasing attention to these traits over several decades and have demonstrated improvement in pedigree flocks. There is an urgent need to monitor changes in commercial flocks to ensure that genetic change is accompanied by improvements in that target population.
5. New technologies for trait measurement, whole genome selection and targeted genetic modification hold out the promise of efficient and rapid improvement of welfare traits in future breeding of broiler chickens and turkeys. The potential of targeted genetic modification for enhancing welfare traits is considerable, but the goal of achieving public acceptability for the progeny of transgenic poultry will be politically challenging.
INTRODUCTION
The success of the poultry meat industry in providing high-quality affordable food in ever increasing quantities after the Second World War is well documented. The rapid intensification of the poultry industries was made possible by the availability of cheap grain and simultaneous changes in nutrition and housing, the control of disease, improved management and freedom from government control. The genetic improvement of feed conversion efficiency underpinned these changes and has resulted in a large reduction in the quantity of feed required to produce a unit of meat (McKay, 2009
Karabozhilova, I., Wieland, B., Alonso, S., Salonen, L. & Hasler, B. (2012) Backyard chicken keeping in the greater London urban area: welfare status, biosecurity and disease control issues. British Poultry Science, 53: 421–430.
[Taylor & Francis Online], [Web of Science

]
).
Early genetic improvement was achieved by simply selecting for increased body weight and breast width and had the effect of decreasing the time to a standard slaughter weight of 2 kg (and hence the energy costs of maintenance), while simultaneously increasing the yield of breast meat that was the more valuable part of the carcass (Hunton, 1990
Hunton, P. (1990) Industrial breeding and selection, in: Crawford, R.D. (Ed) Poultry Breeding and Genetics, 985–1028 (Amsterdam: Elsevier).
). Selection on relatively few traits, however, runs the risk of unintended negative consequences for traits that were not selected. There is ample evidence for this in the literature (Table 1), and there exist widespread concerns about the welfare of broilers and turkeys in commercial flocks. Rauw et al. (1998
Karabozhilova, I., Wieland, B., Alonso, S., Salonen, L. & Hasler, B. (2012) Backyard chicken keeping in the greater London urban area: welfare status, biosecurity and disease control issues. British Poultry Science, 53: 421–430.
[Taylor & Francis Online], [Web of Science

]
, p. 28) concluded that “selection for high production efficiency … has been accompanied by undesirable side effects for several physiological, immunological and reproduction traits and consequently for animal welfare”. The evidence for this conclusion in poultry was largely based on two long-term selection experiments for body weight in boiler chickens and turkeys (updated results from these selection lines are presented by Nestor et al. (2008
Karabozhilova, I., Wieland, B., Alonso, S., Salonen, L. & Hasler, B. (2012) Backyard chicken keeping in the greater London urban area: welfare status, biosecurity and disease control issues. British Poultry Science, 53: 421–430.
[Taylor & Francis Online], [Web of Science

]
) and Dunnington et al. (2013
Dunnington, E.A., Honaker, C.F., McGilliard, M.L. & Siegel, P.B. (2013) Phenotypic responses of chickens to long-term, bidirectional selection for juvenile body weight-historical perspective. Poultry Science, 92: 1724–1734.
[CrossRef], [PubMed], [Web of Science

]
)). Single trait selection experiments do not reflect the process of multiple trait selection that occurs in commercial breeding programmes, and experimental results must be validated in commercial environments. The evidence for undesirable consequences of genetic selection in broiler and turkey flocks and what breeders are doing to address these concerns should also be examined.
Table 1. The number of idiopathic disorders of broiler chickens and turkeys reported in the literature (from Hocking, 2010
Hocking, P.M. (2010) Genetics of metabolic diseases in poultry, in: Bishop, S.C., Axford, R.F.E., Nicholas, F.W. & Owen, J.B. (Eds) Breeding for Disease Resistance in Farm Animals (Wallingford: CABI).
----------------------------
A genetic correlation is defined as “the extent to which two measurements reflect what is genetically
the same character” (Falconer and MacKay, 1996
------------------------------

Karen, what I found is the more you spent time and effort on breeding good animals, the better you understand all the literature. Meaning read the works before working with the breed, then reread years into breeding said breed , the works have a clearer meaning with a clearer understanding of the nuances. I know you know what I mean. smile

 

[Arielle]

Ok, I found this study. It's the Nigerians again, but this time with commercial birds ,
not village chickens. The Nigerians are very keen to understand how phenotype
correlates to production virtues.

Interrelationships and phenotypic correlations among body dimensions in commercial pullets
reared in the derived savannah zone of Nigeria
Simeon O. Olawumi
Department of Animal Production and Health Sciences, Ekiti State University, Ado-Ekiti, Nigeria
file:///C:/Users/Bob/Downloads/7060134.pdf
Abstract
This research work was conducted to evaluate the relationship between live body weight and
linear body measurements in three strains of commercial layers reared under intensive system
of management. Traits considered were body weight, body length, thigh length, shank length,
breast girth, while the feed variables were feed intake, feed conversion ratio and feed efficiency.
There were significant (P<0.01) phenotypic correlations between body weight and linear measurements
in all the three strains. Feed intake and feed efficiency also have high phenotypic correlations
with body weight and linear measurements, whereas the reverse was the case with feed conversion ratio.
In general, some traits had very high significant positive phenotypic correlations with body weight,
some recorded medium phenotypic correlation values while some had low correlation values with
body weight. Traits that recorded high phenotypic correlations with body weight are body length,
thigh length, feed intake and feed efficiency, those with medium phenotypic correlations are
shank length and breast girth, while trait with low phenotypic correlations was feed conversion ratio.
The obtained results indicate pleiotropic effects of genes operating on these traits. The implication
is that selection for any of the traits in these strains will lead to improvement of others.
-----
Still nothing about angle of back! Perhaps a better question to ask is ,
"Why did the APA bother to include angle of back in their breed descriptions??!??"

Karen.....I have been muddling over this for a few minutes......perhaps the level issue is not specified because level can be deceptive. I watch my crew out and about, especially the buckeye boys. Level is fleeting. Depends on the stance of the boy at any given moment of activity. Even standing still he as many postures. Is there a way to stand up a bird like a dog is posed??

I watch my puppies run about and go into the pointer hunting pose. When moving I can see stride and tendency to run or trot. I see subtle variations between pups from the same litter. I look at level and see the effects of anglulation in front legs and positioning of the hind legs and how much the dog is leaning forward ....

Then I ask myself how a chicken on two legs could look level in one pose, then look not level a moment later. Or rather, why wouldnt he look not level most of the time. IMHO level is clear as mud. ANd remember, my dogs don't have feathers to fool the eye, just 1/2 of stiff hair.

 

[Arielle]

the back slopes downwards correctly, but I can't see it. Same for this Schumaker hen, another correct bird I assume but it looks level to me. Maybe it's something that you have to feel for...... not look for.????



I can see a downward slope in this Chantecler rooster:


But not in this hen