YOLK:ALBUMEN RATIO IN EXPERIMENTAL HYBRID LAYERS WITH DIFFERENT PATERNAL GENOTYPE (RELACIÓN YEMA:ALBUMEN EN HÍBRIDOS EXPERIMENTALES DE GALLINAS PONEDORAS CON DIFERENTE GENOTIPO PATERNO)

Dottavio A.M.

Description

Abstract
Egg weight and major egg components, with special emphasis on yolk:albumen ratio, were studied in three experimental hybrids of laying hens with Barred Plymouth Rock maternal genotype and either Fayoumi (F), White Leghorn (L) or Rhode Island Red (R) sires. Data were collected from eggs laid in the first (37 weeks of age) and in the second (85 weeks of age) laying cycle. Asymptotic body weight ranked following the same order as paternal genotypes (F < L < R) and, at both ages, mean egg weight ranked following the same order as hens? average body weight. F birds, with the lightest eggs, showed the highest shell and yolk proportions, the lowest albumen percentage and the highest yolk to albumen ratio, in both laying cycles. Significant genotype and laying cycle effects and a nonsignificant interaction between them were observed for all traits. The joint variation of the three major egg components - yolk, albumen and shell - expressed as a percentage of egg weight was analysed using a multivariate principal component technique. The two first principal components explained almost all the generalized variance (99.93 percent) grouping hens by the paternal genotype. The first principal component discriminated birds for their yolk and albumen percentages while the second one was correlated with percent shell values. Fayoumi genes diminished body weight, food intake and egg weight and augmented yolk to albumen ratio. These modifications could be considered suitable in terms of the human target population with unsatisfied nutritional requirements to whom these hens are provided. They are also remarkable because the introgression of Fayoumi genes in commercial populations would be useful to enhance yolk production.
Resumen
Los pesos del huevo y sus componentes mayores, con especial énfasis en la relación yema:albumen, se estudiaron en tres híbridos experimentales de gallinas ponedoras resultantes del cruzamiento del genotipo materno Plymouth Rock Barrado con tres genotipos paternos: Fayoumi (F), White Leghorn (L) y Rhode Island Red. Los datos se obtuvieron de huevos puestos en el primer (37 semanas de edad) y en el segundo (85 semanas de edad) ciclo de postura. En ambas edades, el peso corporal asintótico de cada grupo se ordenó de la misma manera que el genotipo paterno (F < L < R), al igual que el peso promedio de los huevos de cada híbrido. Los híbridos con padre F mostraron las proporciones más elevadas de cáscara y yema, el porcentaje de albumen más bajo y la relación yema:albumen más elevada, en ambos ciclos. El genotipo paterno y el ciclo de postura fueron efectos estadísticamente significativos, mientras que la interacción entre ambos caracteres no fue significativa. La variación conjunta de los tres componente mayores ?yema, albumen, cáscara- expresados como porcentajes del peso del huevo se analizaron con la técnica multivariada de componentes principales. Los dos primeros componentes principales explicaron casi toda la variación (99,3 p.100) agrupando a las aves por el genotipo paterno. El primer componente principal discriminó a las aves por los porcentajes de yema y de albumen de sus huevos, mientras que el segundo estuvo correlacionado con el porcentaje de cáscara de los mismos. Los genes Fayoumi disminuyeron el peso corporal, el consumo de alimento y el peso del huevo y aumentaron la relación yema:albumen. Estas modificaciones se consideran deseables en relación con la población humana con requerimientos nutricionales insatisfechos a los que se destinan estas aves. También resultan de importancia en términos de la posibilidad de introgresión de genes Fayoumi en las poblaciones comerciales y de la identificación de QTLs para el carácter y su utilización en programas de selección asistida por marcadores.

Sujets

• Egyptian Fayoumi
• Multivariate analysis

Informations

• Publié par: erevistas
• Publié le: 01 janvier 2005
• Nombre de lectures: 19
• Langue: English

Extrait

YOLK:ALBUMEN RATIO IN EXPERIMENTAL HYBRID LAYERS
WITH DIFFERENT PATERNAL GENOTYPE
RELACIÓN YEMA:ALBUMEN EN HÍBRIDOS EXPERIMENTALES DE GALLINAS
PONEDORAS CON DIFERENTE GENOTIPO PATERNO
1,3 1,4 1 1 2,3 1,2,3Dottavio, A.M. , Z.E. Canet , C. Faletti , M. Álvarez , M.T. Font and R.J. Di Masso *
1Cátedra de Genética. Facultad de Ciencias Veterinarias. UNR. Ovidio Lagos y Ruta 33. 2170 Casilda.
República Argentina.
2Instituto de Genética Experimental. Facultad de Ciencias Médicas. UNR. Santa Fe 3100. 2000 Rosario.
3Consejo de Investigaciones de la Universidad Nacional de Rosario. CIC-UNR. Programa Pro-Huerta.
*Corresponding author. E-mail: [e-mail]
ADDITIONAL KEYWORDS PALABRAS CLAVE ADICIONALES
Major egg components. Fayoumi. Multivariate Componentes del huevo. Fayoumi. Análisis
analysis. Laying hens. multivariado. Gallinas ponedoras.
SUMMARY
Egg weight and major egg components, with three major egg components - yolk, albumen and
special emphasis on yolk:albumen ratio, were shell - expressed as a percentage of egg weight
studied in three experimental hybrids of laying was analysed using a multivariate principal
hens with Barred Plymouth Rock maternal component technique. The two first principal
genotype and either Fayoumi (F), White Leghorn components explained almost all the generalized
(L) or Rhode Island Red (R) sires. Data were variance (99.93 percent) grouping hens by the
collected from eggs laid in the first (37 weeks of paternal genotype. The first principal component
age) and in the second (85 weeks of age) laying discriminated birds for their yolk and albumen
cycle. Asymptotic body weight ranked following percentages while the second one was correlated
the same order as paternal genotypes (F < L < R) with percent shell values. Fayoumi genes
and, at both ages, mean egg weight ranked diminished body weight, food intake and egg
following the same order as hens’ average body weight and augmented yolk to albumen ratio.
weight. F birds, with the lightest eggs, showed the These modifications could be considered suitable
highest shell and yolk proportions, the lowest in terms of the human target population with
albumen percentage and the highest yolk to albu- unsatisfied nutritional requirements to whom these
men ratio, in both laying cycles. Significant hens are provided. They are also remarkable
genotype and laying cycle effects and a non- because the introgression of Fayoumi genes in
significant interaction between them were commercial populations would be useful to
observed for all traits. The joint variation of the enhance yolk production.
Arch. Zootec. 54: 87-95. 2005.DOTTAVIO, CANET, FALETTI, ÁLVAREZ, FONT AND DI MASSO
RESUMEN INTRODUCTION
Los pesos del huevo y sus componentes The hen's egg has been traditionally
mayores, con especial énfasis en la relación considered an important source of
yema:albumen, se estudiaron en tres híbridos nutrients for humans. Nowadays it is
experimentales de gallinas ponedoras resultan- widely recognized that eggs are more
tes del cruzamiento del genotipo materno than a source of dietary nutrients and
Plymouth Rock Barrado con tres genotipos pater- extensive studies identifying and
nos: Fayoumi (F), White Leghorn (L) y Rhode characterizing their biologically acti-
Island Red. Los datos se obtuvieron de huevos ve components have been carried on
puestos en el primer (37 semanas de edad) y en (Mine and Kovacs-Nolan, 2004). The
el segundo (85 semanas de edad) ciclo de postu- egg size as well as the weight of its
ra. En ambas edades, el peso corporal asintótico major components is influenced by
de cada grupo se ordenó de la misma manera que genetic and nongenetic factors (Sáinz
el genotipo paterno (F<L<R), al igual que el peso
et al., 1983). The egg yolk contains
promedio de los huevos de cada híbrido. Los
several substances of nutritional and
híbridos con padre F mostraron las proporciones
therapeutic relevance (Hartmann andmás elevadas de cáscara y yema, el porcentaje
Wilhelmson, 2001). The relatively highde albumen más bajo y la relación yema:albumen
level of cholesterol in the avian eggmás elevada, en ambos ciclos. El genotipo pater-
has become of increasing interest be-no y el ciclo de postura fueron efectos esta-
cause of concern about the effect ofdísticamente significativos, mientras que la
dietary cholesterol on health (Washburn,interacción entre ambos caracteres no fue signi-
1990). This statement could be re-ficativa. La variación conjunta de los tres compo-
nente mayores –yema, albumen, cáscara- expre- lativized both in terms of new information
sados como porcentajes del peso del huevo se available on this issue (Stadelman, 1999)
analizaron con la técnica multivariada de compo- and also regarding the nutritional status
nentes principales. Los dos primeros componen- of the human target population.
tes principales explicaron casi toda la variación In Argentine, a national program of
(99,3 p.100) agrupando a las aves por el genotipo social assistance that includes the
paterno. El primer componente principal discrimi- distribution of layers to low resources
nó a las aves por los porcentajes de yema y de families has been developed. These
albumen de sus huevos, mientras que el segundo hens are bred in a public institution
estuvo correlacionado con el porcentaje de cás- (EEA INTA Pergamino) by crossing
cara de los mismos. Los genes Fayoumi disminu-
local strains of Rhode Island Red as
yeron el peso corporal, el consumo de alimento y
sire line and Barred Plymouth Rock as
el peso del huevo y aumentaron la relación
dam line, thus generating an autosexingyema:albumen. Estas modificaciones se consi-
hybrid. One-day-old female chickensderan deseables en relación con la población
are allotted to these families jointlyhumana con requerimientos nutricionales insa-
with technical and educational assis-tisfechos a los que se destinan estas aves. Tam-
tance. As a genetic alternative to redu-bién resultan de importancia en términos de la
ce the feeding costs of the program aposibilidad de introgresión de genes Fayoumi en
new set of experimental crosses waslas poblaciones comerciales y de la identificación
proposed using Fayoumi (ultralight)de QTLs para el carácter y su utilización en
or White Leghorn (light) breeds withprogramas de selección asistida por marcadores.
Archivos de zootecnia vol. 54, núm. 205, p. 88.EGG COMPONENTS IN EXPERIMENTAL HYBRIDS
the aim of diminishing maintenance age, and a standard laying ration (16
costs by reducing the mean body weight percent CP) from 141 days of age on.
of the progeny (Dottavio et al., 2001). At 18 weeks of age, 30 birds randomly
Among other traits, the Egyptian sampled from each genetic group were
Fayoumi breed is characterized by a moved to the laying house and allocated
low body weight and eggs of high shell to individual laying cages (40 cm high,
strength and high yolk to albumen ratio 25 cm wide, and 35 cm deep). The
(Amer, 1972). lighting program used was one with an
The purpose of this study was to evenly decreasing day length from 24
compare the major components of eggs hours the first week to 13 hours at 18
laid by experimental hybrids layers weeks of age. Day length was then
obtained by crossing Barred Plymouth increased by 30 minutes per week up
Rock hens to sires belonging to three to the limit of 17 hours per day.
breeds with different adult body weight
(Fayoumi, White Leghorn and Rhode MAJOR EGG COMPONENTS
Island Red), in two laying cycles. The Three eggs of each of twenty hens
body weight-egg weight relationship and of each genetic group were chosen at
the effect of introducing Fayoumi genes random at 37 weeks of age (first laying
as an alternative to improve yolk:al- cycle) and at 85 weeks of age (second
bumen ratio was particularly emphazied. laying cycle). A third group of eggs
was studied at 124 weeks of age to
determine the mature values of all traits.
MATERIAL AND METHODS Eggs were gathered early in the
morning and kept at room temperature
BIRDS until evaluation on the afternoon of the
Data were collected on hybrid layers same day. Individual eggs were
sampled from the respective popu- weighed, then broken and whites and
lations produced at the Facultad de yolks carefully separated manually.
Ciencias Veterinarias, Universidad Most of the albumen was discarded
Nacional de Rosario, Argentina. Three upon initial separation from the yolk.
experimental F1 crosses with Barred Further separation of the adhering al-
Plymouth Rock as maternal genotype bumen was made by carefully rolling
and either Fayoumi (F), White Leghorn the yolk several times on a paper towel.
(L) or Rhode Island Red (R) as pater- The egg shells, including membranes,
nal genotypes were produced via arti- and yolks were weighed separately
ficial insemination. Chicks from the with an accuracy to the nearest 0.1 g.
three genetic groups were obtained Albumen weight was determined by
from only one hatch in Spring subtracting fresh yolk weight plus fresh
(October) and were reared intermingled shell weight from the original egg
on the floor. Birds were fed a standard weight. Using the individual weight of
starter rat