PhD

An experiment was designed and conducted to establish the requirements of protein and energy for broilers during the summer season in the hot and humid atmosphere of Kerala. Four trials were conducted in a span of two years. In each trial the following energy – protein combinations at starter, and subsequent finisher diets were tested in a completely randomised design.

Treatment Starter Finisher
Diet 1 22% CP:2900 Kcal ME/kg 19% CP: 3000 Kcal ME/kg
Diet 2 24% CP:2900 Kcal ME/kg 19% CP: 2900 Kcal ME/kg
Diet 3 26% CP:2900 Kcal ME/kg 19% CP: 3000 Kcal ME/kg
Diet 4 26% CP:2900 Kcal ME/kg 19% CP: 2900 Kcal ME/kg
Trials corresponding to the same period for the two years were pooled and the results were presented as period A (started in early summer and ended in peak summer) and period B (started in peak summer and ended in late summer). Except for the difference in nutrient intake, all the management practices followed were uniform for the different trials and treatment groups. Feed and water were given ad lib. The chicks were fed with starter diet upto six weeks of age and finisher diet upto eighth week of age.
Results of the study revealed that body weight at eighth week of age was not influenced by different energy protein levels in the diet during both Period A and Period B. But difference between periods was statistically (P < 0.01) significant. Broiler chicks reared during Period A showed significantly lower mean body weight at eight week than Period B. Dietary combination of 22:2900 in the starter and 19:3000 in the finisher stage upto eight weeks of age was found to be optimum for growth of broilers in summer months in Kerala.
Body weight gain was not influenced by the dietary treatments and by periods upto sixth week of age. Thereafter body weight gain was influenced by season. Broiler chicks reared during Period B showed higher body weight gain than Period A. Maximum body weight gain was recorded at fifth week of age in both Period A and Period B.
Feed consumption was not affected by dietary treatments in both Period A and Period B, but was significantly affected by periods at seventh and eighth week of age. Feed efficiency was also not affected by different dietary treatment upto eight weeks of age. Broiler chicks reared during Period A showed poorer feed efficiency from sixth week onwards.
Processing yields and losses, per cent abdominal fat and per cent body fat were not affected by dietary treatments or periods. Bio – chemical parameters like haemoglobin value and plasma value (g per cent) were not affected by different dietary treatments or periods. Per cent liver fat estimated as ether extract was significantly lower
(P < 0.01) during Period B than Period A. Fat constants such as lodine value and Saponification value were not affected by different energy protein levels of the diet. Mortality was not affected by different dietary treatments or periods.
From the overall results of the study it is concluded that commercial broilers grown in the climatic condition of Kerala, require 22 per cent crude protein and 2900 Kcal ME/kg in the starter diet coupled with 19 per cent crude protein and 3000 Kcal ME/kg in the finisher diets. Manipulation of dietary protein and/or energy has little effect in alleviating poor growth rate in broilers observed during summer.