The present study was undertaken to investigate the "Influence of varying levels of protien with constant level of energy on the performance of male and female broiler chicks". One hundred and eighty (90 male and 90 female) day old chicks were reared separately on three experimental starter and three finisher rations upto 50 days of age. The starter rations had a protien percentage 22, 23 and 24 percent while the finisher rations with 19, 20 and 21% respectively. All the starter and finisher rations had a similar metabolizeable energy of 3150 Kcal/Kg. The starter rations were fed upto 28 days of age and for the remaining 22 days finisher rations were fed.

Results revealed non-significant differences among weight gain of chicks fed different experimental starter rations. Similarly there were non-significant differences between the sexes. Experimental finisher rations had non significant differences among weight gain of the chicks. However there were highly significant differences between the weight gain of the sexes. The male chicks fed on finisher ration "B" (having 20% protien were apparently heavier as compared to ration "A" and "C" (having 19 and 21% protien respectively) while the female chicks fed on finisher ration "C" were apparently heavier as comparted to those reared on ration "A" and "B". At all the three finisher rations, male chicks were heavier than the female chicks. At the end of the experiment non significant differences were noticed amongst chicks fed on different experimental rations while highly significant differences between the total weight gain of both the sexes were observed. The male chicks fed on ration "B", (having 23% and 20% protien) were heavier as compared to those fed on ration "A", (having 22% and 19% protien) or "C" (having 24% starter and 21 finisher protien). The female chicks showed apparently highest total weight gain at ration "C" while male chicks had a highest total gain in weight at ration "B". The male chicks fed on ration A, B and C showed 18.12%, 15.94% and 13.31% more total weight gain than female chicks.

Highly significant differences in the feed consumption were noticed in chicks fed on different experimental starter rations and between the sexes. Both male and female chicks consumed highly significant more feed when fed on ration "C" (having 24% protien) as compared to those fed on ration "A" or "B" (having 22% & 23% protien respectively) while feed consumption of both the sexes was minimum when fed on ration "B". At all the three starter rations, females consumed more feed than the male chicks. There were non significant differences in the feed consumption of chicks fed on different finisher rations. However significant differences in the feed consumption of finisher rations were noticed between the sexes. At all the three finisher rations males consumed more feed than the female chicks. Apparently feed consumption showed an increasing trend with the corresponding increase in the protien percentage of a finisher ration in both the sexes. Non-significant differences in the total feed consumption were noticed amongst chicks fed on different experimental rations while the differences between the sexes were significant. Males consumed 11.25%, 12.35% and 5.91% more total feed than female chicks at rations A, B and C respectively. Feed consumption was maximum at ration "C" while minimum at ration "A" in both the sexes. There was an increase in the total feed consumption in both sexes with the corresponding increase in the protien percentage of a ration.

Apparently better feed utilization in male chicks was noticed when fed at starter ration "A" or "B" while female chicks showed better feed efficiency at ration "B". There were non-significant differences in the feed efficiency values of chicks reared on different experimental starter rations as well as the differences were non-significant between the sexes. At finisher ration "A" male chicks showed apparently better feed efficiency while ration "B" was best utilized by the female chicks. The results were non significant for chicks fed on different experimental finisher rations. However there were significant differences between the sexes. At all the three finisher rations female chicks required more feed per unit gain in weight than male chicks. At the end of experiment there were non-significant differences in the total feed efficiency amongst the chicks fed on different experimental rations. but the differences between the sexes were significant. At all the three rations A, B and C male chicks showed 7.80%, 4.02% and 7.83% better feed efficiency than the female chicks. Males showed apparently better feed efficiency at ration "A" while females at ration "B".

There were non-significant differences between the dressing percentage, weight of internal organs and abdominal fat deposition of chicks fed on different experimental rations. The differences were non-significant between the sexes also except for the weight of abdominal fat deposition. At all the three rations A, B and C males showed 16.81%, 30.96% and 25% more abdominal fat deposition than the female chicks. Increase in the dietary protien reduced fat deposition in both the sexes.

The present results indicated that male chicks can be reared economically at a starter ration having 22 percent protien and a finisher rations having 19 percent protien. While female chicks show best performance at a starter ration having 23% protien and a finisher ration having 20 percent protien. Weight gain, feed consumption and feed efficiency was better in male chicks than the female chicks. On the other hand male chicks showed more abdominal fat deposition than female chicks when fed on similar rations. Male chicks were cheaper to grow than the female chicks at all the experimental rations and the cost per Kg. of liveweight of males chicks was approximately 1 Rupee cheaper than the female chicks. This was because male chicks were 17.81 percent larger than the female chicks of the same age.