Ankara Üniv Vet Fak Derg, 65, 51-55, 2018

Some egg quality traits of two laying hybrids kept in different cage
systems*

Esin Ebru ONBAŞILAR1, Necmettin ÜNAL1, Evren ERDEM2

1Ankara University, Faculty of Veterinary Medicine, Department of Animal Husbandry, Ankara; 2Kırıkkale University, Faculty of
Veterinary Medicine, Department of Animal Husbandry, Kırıkkale, Turkey.

Summary: Interest has been increasing about enriched cages affecting the laying hens and the producers. Egg quality traits are
important for economic impact. Whence, the purpose of this study was to determine the differences in egg quality traits of two laying
hybrids reared in conventional and enriched cages at different ages. 532 Lohmann Brown Classic (LB) and 532 Lohmann LSL Classic
(LW) hens were kept from 16 to 73 weeks in either conventional cages or enriched cages. Twenty eight eggs were selected randomly
from each hybrid and cage group at 20, 30, 40, 50, 60 and 70 wk of ages at from 08.00 to 10.00 o’clock to evaluate egg quality traits.
For this aim, a total of 672 eggs were used. Egg weight, shape index, breaking strength, shell thickness, albumen index, yolk index and
Haugh Unit were determined. Yolk index, albumen index and Haugh Unit in eggs of hens were reared in conventional cages were
lower than those of in enriched cages. Egg weight, shape index and shell thickness were higher in eggs laid by LB hens. Layer age was
affected all examined egg quality parameters. Consequently, albumen index, yolk index and Haugh Unit were enhanced by the
enrichment of the cages and interactions among cage type, hybrid and layer age should be taken for the egg quality traits.
Keywords: Age, cage type, egg quality, hybrid.

Farklı kafes sistemlerinde barındırılan iki yumurtacı hibritte bazı yumurta kalite özellikleri

Özet: Yumurtacı tavukları ve üreticileri etkileyen zenginleştirilmiş kafeslere olan ilgi artmaktadır. Yumurta kalite özellikleri
ekonomik öneme sahiptir. Bu nedenle bu araştırmanın amacı geleneksel ve zenginleştirilmiş kafeslerde barındırılan iki yumurtacı
hibritte farklı yaşlarda yumurta kalite özelliklerini araştırmaktır. Toplam 532 Lohmann Kahverengi (LB) ve 532 Lohmann Beyaz (LW)
yumurtacı tavuk 16 haftalık yaştan 73 haftalık yaşa kadar geleneksel ve zenginleştirilmiş kafeslerde barındırıldı. Yumurta kalite
özelliklerinin incelenmesi için 20, 30, 40, 50, 60 ve 70 haftalık yaşlarda saat 8.00-10.00 arasında her bir genotip ve kafes grubundan
28 yumurta rastgele seçildi. Bu amaçla toplam 672 yumurta kullanıldı. Yumurta ağırlığı, şekil indeksi, kırılma mukavemeti, kabuk
kalınlığı, ak indeksi, sarı indeksi ve Haugh birimi belirlendi. Geleneksel kafeste yetiştirilen tavukların yumurtasında sarı indeksi, ak
indeksi ve Haugh birimi zenginleştirilmiş kafeste yetiştirilenlerinkine göre daha düşük bulundu. Yumurta ağırlığı, şekil indeksi ve
kabuk kalınlığının kahverengi yumurtacılardan elde edilen yumurtalarda daha yüksek olduğu görüldü. Yumurtacı tavukların yaşı,
incelenen tüm yumurta kalite özelliklerini etkiledi. Sonuç olarak, zenginleştirilmiş kafesler ak indeksi, sarı indeksi ve Haugh birimini
arttırmıştır ve kafes tipi, hibrit ve yaş arasındaki interaksiyonlar yumurta kalitesi bakımından dikkate alınmalıdır.
Anahtar sözcükler: Hibrit, kafes tipi, yaş, yumurta kalitesi.

Introduction these parameters, egg quality traits are also important for
Cage systems of laying hens have been changed from consumers and producers. Egg quality is influenced by
conventional to enriched cages due to the welfare of hens’ genotype, age, rearing system, diet and environmental
and consumers’ demands. Enriched cages have more factors (8, 10, 19, 25). Also interactions of genotype, cage
space per hen and supply the hen’s behavioural needs such system and age probably play an important role in egg
as nest, perch, scratch-pad and nail shortener. In quality determination. However, there are limited studies
commercial egg production, different hybrids are used including these interactions. Therefore, this study was to
according to the culture. However, production parameters determine the effect of cage type on the egg quality
vary according to the hybrids (12). Egg production, feed obtained from brown and white layers and interaction of
conversion, external appearances, bone and liver health cage type (conventional and enriched), genotype
and also some blood parameters of hens kept in different (Lohmann Brown Classic and Lohmann LSL Classic) and
cage systems were examined (4, 12, 22, 23, 27). Besides layer age on some egg quality traits.

* This research was supported by Ankara University BAP-10A3338005.

52 Esin Ebru Onbaşılar - Necmettin Ünal - Evren Erdem

Materials and Methods were weighed and their shape indexes were determined as
Animal care protocols and experimental procedures (egg width (cm)/egg length (cm)) × 100. A quasi-static
were certified by Ankara University Animal Experiments compression device was used to determine the eggshell
Ethics Committee (Number: 201057/285). A total of 532 breaking strength. A tripod micrometer was used to
brown (Lohmann Brown Classic; LB) and 532 white determine the albumen and yolk heights. Digital caliper
(Lohmann LSL Classic; LW) laying hybrids aged from 16 was used to specify the length and width of the albumen
to 73 wk of age were used in the study. These hybrids were and diameter of the yolk. Indexes of albumen and yolk
kept in two caging systems (conventional and enriched) in were calculated as: Albumen index (%): [(albumen height
the same poultry house. Each system had 3 rows. (mm)/average of albumen length (mm) and albumen
Conventional cages were 192 cm width, 62.5 cm depth width (mm)] × 100 and Yolk index (%): [(yolk height
and 57 cm height and 20 hens were kept in this cage type. (mm)/yolk diameter (mm)] × 100. Haugh unit (%) was
Enriched cages were 240 cm width, 62.5 cm depth and 57 reckoned as 100 × log (albumen height + 7.57 − 1.7 egg
cm height and 18 hens were kept in this cage type. weight0.37). Eggshell thickness was measured with using a
Enriched cages also included the nest (48 cm width x 62.5 micrometer in 3 different parts of the shell (28).
cm depth), scratch-pad (35 cm width x 35 cm length), Statistical analysis: A minimum sample size of 26
perch and claw shortener (12 cm width x 3 cm length). The eggs achieves 80% power to detect an effect size of 0.8
nesting area was separated from the other areas with blue with a significance level (alpha) of 0.05. However, 28 eggs
plastic strips. Two plastic perches were used with 190 and were examined in the study depending on the number of
137 cm in length. Each cage had 8 nipple type drinkers. cages. Sample size estimation was carried out using the
Each hybrid and cage system groups consisted of 14 cages. PASS 11. Distribution the homogeneity of variance of the
The ingredients and the nutrient compositions of the diets data was analysed. Differences among cage type, hybrid
by period were reported in Table 1. The lighting program and layer age groups as well as their interactions with
was 16 L:8 D during the laying period. respect to the egg quality traits were determined with
28 eggs (2 eggs of each cage) were selected from three-way ANOVA with SPSS for Windows (SPSS Inc.,
each hybrid and cage group at 20, 30, 40, 50, 60 and 70 Chicago, IL). P < 0.05 was taken into the account
week of ages at from 08.00 to 10.00 o’clock to evaluate statistically significant (3).
egg quality traits. A total of 672 eggs were used. They

Table 1. Ingredients and chemical composition of the experimental diets.

Tablo 1. Deneme rasyonlarının içeriği ve kimyasal bileşimi.
Laying periods (weeks of age)
Ingredient, %
16-17 18-31 32-45 46-59 60-73
Maize 51.6 52.0 53.4 54.0 54.8
Wheat 7.6 7.80 6.80 6.90 6.90
Soybean meal, 47% 17.4 17.3 17.3 17.1 16.2
Full-fat soy 8.00 6.52 6.09 4.34 4.10
Sunflower seed meal 5.50 5.70 5.10 6.20 6.40
Limestone 8.00 8.50 9.10 9.40 9.60
Dicalcium phosphate 1.20 1.50 1.50 1.40 1.30
Sodium chloride 0.21 0.21 0.21 0.21 0.21
DL-Methionine 0.17 0.15 0.15 0.15 0.14
Vitamin mineral premixes 0.25 0.25 0.25 0.25 0.25
Sodium bicarbonate 0.10 0.10 0.10 0.10 0.10

Analysed value
ME, MJ/kg 11.6 11.4 11.4 11.3 11.3
CP, % 17.8 17.3 17.0 16.6 16.2
Ca, % 3.40 3.70 3.95 4.05 4.12
Total P, % 0.58 0.61 0.60 0.58 0.55
Methionine, % 0.44 0.41 0.41 0.41 0.39
Lysine, % 0.87 0.84 0.83 0.80 0.77
 Ankara Üniv Vet Fak Derg, 65, 2018 53

Table 2. Egg quality traits of two different laying hybrids kept in conventional and enriched cages.
Tablo 2. Geleneksel ve zenginleştirilmiş kafeslerde barındırılan iki farklı yumurtacı hibritin yumurta kalite özellikleri.
Cage type Hybrid Layer Egg weight Shape Breaking Shell Yolk Albumen Haugh
age (g) Index (%) strength thickness Index index Unit
(wk) (kg/cm2) (µm) (%) (%)
Conventional 61.45 76.15 2.96 38.53 41.44 8.39 78.96
Enriched 61.69 76.00 2.95 38.44 42.84 8.55 79.75
LB 61.83 76.35 2.93 38.77 42.21 8.52 79.58
LW 61.31 75.80 2.98 38.20 42.07 8.42 79.13
20 47.41a 78.13b 3.37c 41.82c 48.14e 10.06e 88.98d
30 58.75b 78.22b 3.18b 41.92c 42.61d 9.38d 83.51c
40 63.67c 75.26a 2.94a 37.34b 40.89bc 8.52c 78.16b
50 65.38d 75.40a 2.72a 36.87ab 38.53a 8.22c 77.60b
60 66.76e 74.40a 2.81a 36.83ab 40.77b 7.50b 74.37a
70 67.45e 75.03a 2.72a 36.14a 41.89cd 7.14a 73.53a
Pool SEM 0.124 0.102 0.015 0.113 0.102 0.036 0.187
P-value
Cage type 0.335 0.477 0.772 0.705 0.000 0.022 0.035
Hybrid 0.038 0.006 0.132 0.011 0.472 0.161 0.225
Layer age 0.000 0.000 0.000 0.000 0.000 0.000 0.000
Cage type X Hybrid 0.630 0.585 0.084 0.672 0.009 0.724 0.408
Cage type X Layer age 0.152 0.684 0.005 0.867 0.003 0.013 0.008
Hybrid X Layer age 0.056 0.110 0.193 0.394 0.000 0.195 0.109
Cage type X Hybrid X Layer age 0.984 0.218 0.727 0.843 0.689 0.011 0.302
a–eValues within the same column with no common superscripts are significantly different, P < 0.05.
a–e Aynı sütunda farklı harfleri taşıyan değerler istatistiksel olarak farklıdır, P < 0.05.

Results enriched cages. However, Jones et al. (6) found that eggs
Effects of cage type, hybrid and age on egg quality from furnished cages were significantly heavier than those
traits were given in Table 2. In conventional cages, egg produced in conventional cages. Egg weight was affected
weight, shape index, breaking strength and shell thickness by hybrid and layer age. The egg weight of LB hens was
were 61.45 g, 76.15 %, 2.96 kg/cm2 and 38.53 µm, while heavier (P<0.05) than that of LW hens throughout the
in enriched cages 61.69 g, 76.00 %, 2.95 kg/cm2 and 38.44 laying period. LB laying hens were heavier and this trait
µm, respectively. Cage type didn’t influence these correlated with egg weight (21). Similarly, Ledvinka et al.
parameters (P>0.05). In LB hens, egg weight, shape index, (10) reported that egg weight increased with advancing
breaking strength and shell thickness were 61.83 g, 76.35 hen age in different 3 genotypes. Egg weight increased
%, 2.93 kg/cm2 and 38.77 µm, while in LW hens, 61.31 g, with the layer age (P<0.001) from 47.41 to 67.45 g.
75.80 %, 2.98 kg/cm2 and 38.20 µm, respectively. Egg Silversides and Scott (20), Johnston and Gous (5), Peebles
weight (P<0.05) and shape index (P<0.01) and shell et al. (15) and Dikmen et al. (4) found similar results.
thickness (P<0.05) were affected by hybrid groups. Egg Interaction is important to understand impact of the cage
weight increased, while shape index, breaking strength type, hybrid and layer age together in more details.
and shell thickness decreased with layer age. Cage type However, there were no significant interactions among
and layer age affected the yolk index, albumen index and examined parameters for egg weight.
Haugh unit. Interactions were important for breaking No significant differences on egg shape index of
strength, yolk index, albumen index and Haugh unit. hens reared in different cage type were detected. Similarly
some researchers (1, 11) reported that egg shape index was
Discussion and Conclusion not affected by rearing systems. The result of the present
Results of this study didn’t reveal differences in egg study indicated that shape index was significantly
weight according to the cage type. Egg weights of hens (P<0.01) affected by the hybrid, because shape index
reared both conventional and enriched cages were similar. depends on the anatomical structure of the hen. Width was
Also, Tactacan et al. (22) showed that no differences were longer and length was shorter in brown eggs than those in
found in the egg weight of reared in conventional and white eggs. Therefore shape index was higher of brown
54 Esin Ebru Onbaşılar - Necmettin Ünal - Evren Erdem

eggs than that of white eggs. Similarly, Küçükyılmaz et al. of eggs laid in enriched cages in all examined period was
(8) showed that shape index for eggs from brown layers higher than that in conventional cages. And also, yolk
was higher than that for eggs from white layers. Egg shape index of egg laid of brown hybrids was lower than that of
index decreased (P<0.001) and longer eggs being white hybrids in 70th wk of age.
produced from older hens. Because anatomical structure Albumen index and Haugh unit in eggs of hens
particularly of the shape of the pelvic bone changes with reared in enriched cages were higher than that in
layer age and egg shape might be affected by this situation. conventional cages (P<0.05). Similarly Ahammed and
However, no significant interaction among cage type, Ohh (1) reported that Haugh Units of eggs laid in barn and
hybrid and layer age was found. cage were significantly different. However Küçükyılmaz
Shell breaking strength is important for producers. et al. (8) showed that hens reared in organic and
However enrichment didn’t affect the breaking strength. conventional cages didn’t affect the Haugh Unit. It is
Similarly Valkonen et al. (26) and Kalmendal et al. (7) known that albumen index and Haugh Unit values directly
reported that modifying some details of cage design didn’t depend on the albumen height. And also these traits differ
have an effect on shell strength parameters. Brown eggs significantly (P<0.001) between different layer age of
have thicker egg shells as compared to white eggs. The measurement and the highest albumen index and Haugh
results of our experiment were in accordance with the Unit were observed at 20th weeks of layer age. The internal
findings of Ledvinka et al. (9) and Zita et al. (29) who quality of eggs is measured by means of the Haugh Unit
found a thicker eggshell in brown eggs. Poggenpoel et al. that associated the height of with the functionality of
(16) indicated that genetic selection programs can affect albumen (25). 90% of the inner thick albumen is
the eggshell quality. Genotypes of layers influenced egg composed of ovomucin and is the most important
shell traits more than the cage type. component in determining the height of the inner thick
Layer age had an important role (P<0.001) on albumen (24, 25). Decrease in albumen height as the age
breaking strength and shell thickness. Significant advances also reported some researchers (10, 13, 17, 24,
interaction of cage type and layer age (P<0.01) was found. 29). Significant interaction between cage type and layer
Breaking strength and shell thickness decreased with layer age in albumen index and Haugh Unit. And also
age. This result might correspond with results of interaction among cage type, hybrid and layer age was
Rodriguez-Novorro et al. (18) who described the effect of significant for albumen index.
age on shell microstructure like crystal size. Egg shells As a conclusion enrichment of the cages was
composed of larger crystals obtained from older hens than enhanced to the yolk index, albumen index and Haugh
those from young hens. Ahmed et al. (2) stated that small Unit. Also enrichment was interacting with hybrid and
crystal size was more solid and this was stronger shells. layer age separately or together some egg quality traits.
However, Ledvinka et al. (10) indicated that there was no Hybrid, only affected the egg weight, shape index and
significant effect of age on shell strength. This difference shell thickness. All examined egg quality traits were
from our study might be a result of examined period. Cage influenced by layer age. Cage type, hybrid and layer age
type and layer age interaction was important (P<0.01) for interactions should be taken into account when
breaking strength. considering the egg quality.
Cage type and layer age were significant (P<0.001)
factors, clearly affecting the yolk index. Yolk index of References
eggs laid in enriched cages was higher than that in 1. Ahammed M, Ohh SJ (2013): Effect of housing systems-
conventional cages. Different results were obtained from barn vs cage on the first phase egg production and egg
previous studies. Ahammed and Ohh (1) and Pavlouski et quality traits of laying pullet. Korean J Poult Sci, 40, 67-73.
al. (14) informed that housing system did not affect any 2. Ahmed, AMH, Rodriguez-Navarro AB, Vidal ML, et al.
(2005): Changes in eggshell mechanical properties,
significant difference on yolk index. This might be related
crystallographic texture and in matrix proteins induced by
to the different housing system. The yolk index was high
moult in hens. Br Poult Sci, 46, 268-279.
value in the 20th wk of the layer age, and then this index 3. Dawson B, Trapp RG (2001): Basic and clinical
started to decrease to 50th wk of layer age. Similar results biostatistics, 3rd ed. Lange medical books. McGraw-Hill
with Zita et al. (30) who reported the decreasing yolk Medical Publishing Division, New York.
index with increasing age. Hybrid didn’t affect the yolk 4. Dikmen BY, İpek A, Şahan Ü, et al. (2016): The egg
index. Cage type and hybrid interaction was important production and welfare of laying hens kept in different
(P<0.01) for yolk index due to the differences in hybrid housing systems (conventional, enriched cage, and free
reared in enriched cages. Brown layers reared in the range). Poult Sci, pew082.
5. Johnston SA, Gous RM (2007): Modelling the changes in
enriched cages had eggs with higher yolk index.
the proportions of the egg components during a laying
Significant interactions were also seen cage type and layer
cycle. Br Poult Sci, 48, 347-353.
age and also hybrid and layer age (P<0.001). Yolk index
 Ankara Üniv Vet Fak Derg, 65, 2018 55

6. Jones DR, Karcher DM, Abdo Z (2014): Effect of 20. Silversides FG, Scott TA (2001): Effect of storage and
commercial housing system on egg quality during extended layer age on quality of eggs from two lines of hens. Poult
storage. Poult Sci, 93, 1282-1288. Sci, 80, 1240-1245.
7. Kalmendal R, Johansson F, Wall H (2013): Effects of 21. Siegel PB (1962): Selection for body weight at eight weeks
fiber supply in furnished cages on performance, egg quality, of age 1. Short term response and heritabilities. Poult Sci,
and feather cover in 2 egg-laying hybrids. J Appl Poult Res, 41, 954-962.
22, 109-117. 22. Tactacan GB, Guenter W, Lewis NJ, et al. (2009):
8. Küçükyılmaz K, Bozkurt M, Herken EN, et al. (2012): Performance and welfare of laying hens in conventional and
Effects of rearing systems on performance, egg enriched cages. Poult Sci, 88, 698707.
characteristics and immune response in two layer hen 23. Tauson R (2005): Management and housing systems for
genotype. Asian Australas J Anim Sci, 25, 559-568. layers – effects on welfare and production. World's Poult
doi:10.5713/ajas.2011.11382. Sci J, 61, 479-492.
9. Ledvinka Z, Tůmová E, Arent E, et al. (2000): Egg shell 24. Toussant MJ, Latshaw JD (1999): Ovomucin content and
quality in some white-egg and brown egg cross composition in chicken eggs with different interior quality.
combinations of dominant hens. Czech J Anim Sci, 45, 285- J Food Sci, 79, 1666-1670.
288. 25. Tůmová E, Gous RM (2012): Interaction of hen
10. Ledvinka Z, Tůmová E, Englmaierová M, et al. (2012): production type, age, and temperature on laying pattern and
Egg quality of three laying hen genotypes kept in egg quality. Poult Sci, 91, 1269-1275.
conventional cages and on litter. Arch Geflűgelkunde, 76, 26. Valkonen E, Venäläinen E, Rossow L, et al. (2010):
38-46. Effects of calcium diet supplements on egg strength in
11. Lewko L, Gornowicz E (2011): Effect of housing system conventional and furnished cages, and effects of 2 different
on egg quality in laying hens. Ann Anim Sci, 11, 607-616. nest floor materials. Poult Sci, 89, 2307-2316.
12. Onbaşılar EE, Ünal N, Erdem E, et al. (2015): Production 27. Wall H, Tauson R, Elwinger K (2002): Effect of nest
performance, use of nest box, and external appearance of design, passages and hybrid on use of nest and production
two strains of laying hens kept in conventional and enriched performance of layers in furnished cages. Poult Sci, 81,
cages. Poult Sci, 94, 559-564. 333-339.
13. Padhi MK, Chatterjee RN, Haunshi S, et al. (2013): 28. Yalçın S, Özsoy B, Erol H, et al. (2008): Yeast culture
Effect of age on egg quality in chicken. India Int J Poult Sci, supplementation to laying hen diets containing soybean
48, 122-125. meal or sunflower seed meal and its effect on performance,
14. Pavlovski Z, Masic B, Josipovic S, et al. (1992): The effect egg quality traits, and blood chemistry. J Appl Poult Res,
of system of housing on the laying performance of hens in 17, 229-236.
small flocks. Biotech U Stocarstvu, 8, 57-63. 29. Zita L, Tůmová E, Štolc L (2009): Effects of genotype, age
15. Peebles ED, Zumwalt CD, Doyle SM, et al. (2000): Effects and their interaction on egg quality in brown-egg laying
of breeder age and dietary fat source and level on broiler hens. Acta Veterinaria Brno, 8, 85-91.
hatching egg characteristics. Poult Sci, 79, 698-704. 30. Zita L, Ledvinka Z, Klesalová L (2013): The effect of the
16. Poggenpoel DG, Ferreira GF, Hayes JP, et al. (1996): age of Japanese quails on certain egg quality traits and
Response to long‐term selection for egg production in their relationships. Veterinarski Arhiv, 83, 223-232.
laying hens. Br Poult Sci, 37,743-756.
Geliş tarihi: 15.07.2016 / Kabul tarihi: 26.01.2017
17. Rajkumar U, Sharma RP, Rajaravindra KS, et al.
(2009): Effect of genotype and age on egg quality traits in Address for correspondence:
naked neck chicken under tropical climate from India. Int J Prof. Dr. E. Ebru ONBAŞILAR
Poult Sci, 8, 1151-1155. Ankara University,
18. Rodriguez-Navarro A, Kalin O, Nys Y, et al. (2002): Faculty of Veterinary Medicine,
Influence of the microstructure on the shell strength of eggs Department of Animal Husbandry,
laid by hens of different ages. Br Poult Sci, 43, 395-403. 06110, Ankara, Turkey.
19. Svobodova J, Tůmová E, Englmaierová M (2014): The e-mail: onbasilar@ankara.edu.tr
effect of housing system on egg quality of Lohmann white
and Czech hen. Acta Fytotechn Zootechn, 17, 44-46.