Comparative Study Ofthe Effects Of Season On Physiological Responses And Productivity Of Local And Exotic Breeds Of Layers
Comparative Study Ofthe Effects Of Season On Physiological Responses And Productivity Of Local And Exotic Breeds Of Layers
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Date
2015-04-18
Authors
Elsadig, Walieldin
Journal Title
Journal ISSN
Volume Title
Publisher
University of Khartoum
Abstract
The aim of this study was to evaluate the effects of season and
breed on thermoregulation, blood constituents, blood metabolites, blood
minerals, blood enzymes, egg production performance and egg quality in
local and exotic breed (White Hisex) laying hens.
The rectal temperature (Tr
) was significantly higher during the
summer than the winter in both birds. The exotic breed showed
significantly higher Tr
than the local breed during summer and winter.
The packed cell volume (PCV) was significantly lower during summer
compared with winter in both breeds, and it was significantly higher in
exotic breed than in local breed during summer. The haemoglobin
concentration (Hb) was significantly higher in the exotic breed than the
local breed in both seasons. The heterophil/lymphocyte ratio (H/L) was
significantly higher during summer than the winter in both breeds.
The plasma glucose level decreasedsignificantly during summer
compared to winter in both breeds. The concentration of serum
cholesterol was significantly higher during summer compared to winter in
both breeds and it was significantly lowerin the local breed compared to
the exotic breed during summer. Serum total protein concentration was
significantly higher in exotic breed compared to the local breed only
during summer.
The serum Ca level decreased significantly during summer than the
winter in both breeds and it was significantly lower in the local breed
compared to the exotic breed in both seasons. Serum Na concentration
was significantly lower in the local breed compared to the exotic breed
during the summer and winter. Serum K concentration increased
significantly during the summer compared to the winter in both breeds
iv
and was significantly lower in the local breed compared to the exotic
breed during winter.
The feed intake, egg production, egg weight and eggshell weight
decreased significantly during the summerthan the winter in both breeds.
These parameters also were significantly lower in the local breed
compared to the exotic breed during summer and winter. The eggshell
thickness was significantly greater in the exotic breed compared to the
local breed in both seasons. Also the eggshell thickness was significantly
lower during the summer compared to the winter in the exotic breed.
The results indicated that the thermoregulation, haematological
values, blood metabolites and blood electrolytes were affected by thermal
load during summer inboth breeds. The summer hot environment was
associated with decreased production performance (feed intake, egg
production, egg weight and egg quality) in both breeds. These results
have implications in environmental physiology and poultry industry
under tropical conditions, were discussed critically in the light of the
information previously reviewed in the literature
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Keywords
Comparative Study,Effects,Season, Physiological, Responses,Productivity , Local,Exotic Breeds, Layers