PhD

A 4 x 4 factorial trial designed to study the dietary requirements of
protein and energy for caged egg type layers under the hot - humid conditions
of Kerala is presented in this thesis. Single Comb White Leghorn strain cross
pullets (IWN x IWP ) of the Mannuthy centre of AICRP on Poultry for eggs
formed the experimental subjects. The birds were randomly alloted to 16
dietary protein-energy combination groups.
The dietary protein levels
employed were 14,16,18 and 20 per cent and that of energy levels were 2400,
2500, 2600 and 2700 Kcal ME per kg diet. General observations of the
experiment were recorded over 12, 28 day periods.
The varying levels of protein and energy employed in this study did
not have any significant influenced on body weight gain. Birds fed 18 per cent
dietary protein had significantly higher hen-day egg production and it was
significantly lower for birds fed 14 percent dietary protein. Egg production
observed between 16 and 20 per cent and that between 18 and 20 per cent
protein were not statistically significant. Hen-day egg production was not
influenced by various dietary energy levels employed.
The daily feed intake per bird per day was not affect by the le4vels of
protein and energy employed in this experiment. A dietary protein levels of
16, 18 and 20 per cent showed significantly superior feed efficiency, when
expressed both in terms of feed per dozen egg as well as feed per kilogramme
egg. Feed conversion efficiency was not influenced by verying energy levels
employed. The egg weight was significantly influenced both by protein and
energy levels. However, the changes exerted due to feeding of various dietary
combinations did not show any definite trend. The ,mean shell thickness was
significantly influenced by dietary protein levels whereas energy did not have
any effect. There was a statistically significant decrease in albumen index and
Haugh unit score and albumen index was influenced significantly by the
energy level in the diet. The yolk index decreased with increase in protein
content in the ration, whereas it was inconsistent with the dietary energy
levels. Biochemical parameters such as haemoglobin, serum protein, serum
inorganic phosphorus and packed cell volume were not influenced either by
protein or energy levels. The level of dietary protein did not influence the
serum lipid levels whereas the dietary energy had influenced. The dietary-
protein-energy combinations in the diet significantly influenced liver lipid and
liver lipid and liver protein. The values obtained on carcass analysis were
well within the normal biological limits and did not show any specific effect
due to different dietary treatments . All the birds showed a positive nitrogen
balanced irrespective of the protein or energy levels in the diet.
On the basis of these results it can be inferred that the levels of
dietary protein and energy required
for optimum production for layers
raised in cages are 16 per cent and 2400 Kcal ME per kg, respectively.
However, in practical feed formulation where amino acids balancing
especially that of the critical amino acids being a problems in developing
countries it is suggested that a dietary protein level of 18 per cent can be
considered as optimal.
FINDINGS :
A 4 x 4 factor