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WELANIMAL CONFERENCE-32nd Scientific Day in Ovar- 2008 Mosonmagyarovar / HUNGARY

EFFECTS OF PULLET-STOCKING DENSITY AND POSITION ON PERFORMANCE OF LAYING HENS

FROM DIFFERENT GENOTYPES

Bozkurt, Z Bayram, İ Gücüyener, Ö Lenger, Ö.F


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In Europe, despite of the strict legal regulations that banning traditional cage systems (in 2012, 999/74/EC) and allowing hen egg production in alternative systems such as enriched cages, aviary, free-range or organic, it appears, in near future, that hens will be kept under conditions which enable them to show all behaviour in their natural behaviour repertoire and make them to be confined at various levels


The main objective of this study was to evaluate the production responses of four genotypes of leghorns reared under different cage density and cage position Thus, this paper discusses the possible interactions and effects of genotype and rearing cage density and position on production and welfare in layer hens.


MethodsRearing period : 1 day-18 weeks of age, under standart management

Top cage

Four Strain

( Two Brown,

Two White egg layer)

35 pullets/per cage

(211.8cm2 per bird)

27 pullets/per cage

(274.5 cm2 per bird)

20 pullets/per cage(370.6 cm2 per bird)

Middle cage

Four Strain

( Two Brown,


35 pullets/per cage(211.8cm2 per bird)

27 pullets/per cage


20 pullets/per cage


Bottom cage

Four Strain

( Two Brown,


35 pullets/per cage

(211.8cm2 per bird)

27 pullets/per cage

(274.5 cm2 per bird) 20 pullets/per cage



Laying period: up to 70 weeks of age

Pullets were transferred from the growing house into the environmentally controlled laying henhouse with 4 hens placed in each of the cages on the middle tiers (47 cm wide, 40 cm high and 38 cm deep) of a 4-tier cage system. From 18 to 21 wk, 21 to 44 wk and 45 to 72 wk periods considered prelayer, layer 1 and layer 2 diets, which contained 15.0, 17.5 and 16.5 % CP and 2750, 2750 and 2750 kcal ME/ kg,


Statistics

A three-factor by four genotype (G), three cage density (D) and three cage position (P) factorial arrangement of randomized design was used. The statistical model (Daniel, 1995) used for the analysis of dependent variables


Results

1. laying performance was increased in line with increased cage density and higher cage level during rearing period.

2. Genotype has been found to have an important effect on sexual maturity age

3. During the growing period the cage density did not affect to the sexual maturity of the birds.

4. The position of the rearing cage in the battery did not have an important impact on the sexual maturity of the hens

5. While pullet-stocking density increased the mortality rate of egg production phase decreased


6. The pullet-stocking cage position did not affect the mortality rate during 18-70 week

7. When the position of the growing cage in the battery changed from top to the bottom tiers the hens’ body weight increased. Hens from the white egg genotype were more effected by the cage position.

8. The egg weight of hens originating from white egg genotypes increased as the pullet-cage density increased while it decreased for hens of brown egg genotype.


9. During laying cycle feed consumption, feed utilization and total egg mass production were effected in a major by density of growing cage While the inhabited cage area increased as the hens were growing, they consumed more feed, did not utilize well and produced less total egg mass

10. While light and medium weight genotype hens benefited from rearing in high density cages, heavy genotype hens were adversely effect to some extent, hens from lively and active disposition genotypes were adversely affected in top and bottom level cages.


In Conclusion

These results showed that cage-related stress could be decreased if hens are reared/kept under proper position and density within cage systems by taking in to account of their physiologic and behavioral traits that controlled by the gene

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