Performance And Immune Response Of Layers Among Different Production Cycles Influenced By Body Weight Losses During Molting
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: Molting is a natural phenomenon in birds to rejuvenate their potential and body reserves. Commercially molting is being practiced in most of the countries to extend the production cycle of the bird and gain more from a single birds. It also reduces the cost of rearing the replacement pullet and increase egg size. The success of molting depends on loss of body weight during molting. Genetic improvement is a continuous process and new strains of layers are being developed on regular basis. LSL Lite is one of the recently introduced strain in Pakistan. But, its optimum body weight loss during molting in different production cycles is need to be optimized. The present study was planned to compare the performance of birds after different body weight losses during molting in different production cycles of commercial LSL Lite strain. The study was conducted at a Commercial layer farm. A total of 216 uniform weight birds of three production cycles (1st Cycle = 16 Wk, 2nd Cycle = 80 Wk, 3rd Cycle = 108 wk) were placed in battery cages. The birds of 2nd and 3rd production cycles were first molted till reduction of 20, 25, and 30% body weight loss. The birds of 1st production cycle (Control group) were those having same body weight as those of 2nd and 3rd production cycle after molting. The birds used in 3rd production cycle were first molted at the age of 64 Wk. Each treatment was replicated three times with 8 birds each and placed according to Completely Randomized Designs. The parameters used were post-moult production performance, egg geometry, egg quality and immune profile of these birds. The data collected were subjected to ANOVA under Completely Randomized Design in factorial arrangement using SAS 9.1. Significant means (P<0.05) were compared using Duncan’s Multiple Range test. Results of the present study showed that birds in 1st production cycle have highest egg production %, better FCR per dozen eggs and per kg egg mass, shape index, egg surface area,
Huagh unit, yolk index, shell %, egg shell thickness. Whereas birds in 3rd production cycle have highest feed intake. Egg weight was highest in 2nd and 3rd production cycle. Similarly birds in low weight category have highest egg production %, better FCR per dozen eggs and per kg egg mass. Whereas birds heavy weight category had highest egg mass. Non-significant difference were observed regarding immunity in different production cycles and body weight loss categories. Similarly non-significant difference were observed regarding egg quality with respect to body weight loss categories throughout the experiment. Feed intake and egg production remained non-significant in case of interaction of production cycles and body weight loss categories.
From present studied it can be concluded that:
Different production cycles influence productive performance of the birds, especially 1st production cycle birds had higher production % FCR per dozen eggs and FCR per kg egg mass however the production performance of 2nd and 3rd production cycles birds is relatively comparable. Similarly 2nd and 3rd production cycle birds exhibit higher egg weight and egg mass.
Birds of low weight category (< 1400 g) of 1st production cycle and 30% body weight loss groups of 2nd and 3rd production cycles had relatively higher egg production %, better FCR per dozen eggs and FCR per kg egg mass. Whereas heavy weight category of 1st production cycle and 20 % body weight loss groups of 2nd and 3rd production cycle had higher egg weight and egg mass.
Egg quality and geometry was influenced by production cycles but no difference was observed by body weight loss categories in this regard.
Different production cycles and body weight loss categories did not influence immune parameters.
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Production Performance, Egg Characteristics And Immune Response In Commercial Layers Reared At Different Cage And House Zones During Summer
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: Recent trends in commercial layer farming is changing the production trends worldwide. The
commercial layer farming in Pakistan is shifting from open or semi controlled floor farms to
modern automatic controlled caged farms. These cage farms are megastructure having capacity of
huge bird rearing, due to large house dimensions the environment of house not remain uniform
throughout the house and difference in light intensity, air speed, temperature and humidity
horizontally and vertically have significant impacts on overall performance of layers. House and
cage zones in environment controlled house may influence productive performance, egg
characteristics and immune response in commercial layers. For this purpose, a total of 588 birds
arranged according to completely randomized design and divided in three house zones (Near pads,
middle and near fans) and four tier levels (Lower, Bottom, Middle, Upper) being replicated 6 times
with 9 birds in each cage. These birds were placed in ECO-60 caged house (4×4) having 9 birds
in each pen. These performance of birds were compared for differences in production performance,
egg geometry, egg quality and immune profile. Data were analyzed through factorial ANOVA
using PROC GLM in SAS software, means were compared through Duncan’s Multiple Range test.
The highest weigh gain was observed in birds reared near the pad zone followed by the birds reared
near middle and fan zone. Similarly, better egg production was found in the birds reared near
evaporative cooling pads and middle zone as compared to the birds reared near the fan zone. To
this end, better egg mass was found in the birds reared near pad and middle zone as compared to
the birds reared near the fan zone. FCR / kg egg mass was found in the birds reared near pad and
middle zone as compared to the birds reared near the fan. Regarding Infectious Bronchitis (IB), Avian
Influenza (H9), Avian Influenza (H7), Mycoplasma Gallisepticum (MG), Newcastle (ND),
difference in titters was observed among the birds of different housing zones and their interaction.
However, no significant effect of house zones, tier cage levels and their interaction was observed
regarding egg characteristics and immune response.
From the discussion in the previous chapter it can be concluded that:
In modern environment control layer house, different house zones influence productive
performance of the birds, especially near the pad zone birds exhibited improve body weight
and better production %. In the same way, birds reared near the middle zone showed better
egg mass, FCR / dozen eggs and FCR / Kg egg mass.
Among different house zones and tier cage levels, temperature, relative humidity and
thermal index varied throughout the experimental period.
Birds reared neat the pad zone at central tier had better body weight, while, better
production % exhibited by the birds reared near the middle zone at lower cage tier.
However, birds reared near pad zone at bottom cage tier revealed better FCR/dozen eggs
and / kg egg mass.
Different cage tier levels did not influence productive performance, egg characteristics and
immune response of commercial layers.
Improved immune response was shown by the birds reared in middle zone of the house as
compared to pad and fan zone while tier level did not influenced the antibody titer.
Suggestions and Recommendation
Behavioral studies are required to observe the response of bird at micro climate.
Further investigations are needed to fulfill the welfare issues of commercial layer.
Researchers should come forward to explore the alternative housing system of commercial
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