The effects of starter period length and crude protein level of diets on performance, carcass traits and intestinal morphology of broilers

Abstract

Introduction: This study was conducted to investigate the effects using different levels of
dietary crude protein starter period length on performance, carcass characteristics and
intestinal morphology of broilers.
Materials & Methods: 288 Rass 308 broilers were used as factorial arrangement (2×3)
included 2 levels of dietary cured protein (Rass company recommended and 5% more than
it) and 3 starter period length included (7, 10 and 16 days) in a completely randomized
design.
Results: Reduce the starter period length to 7 days reduced the amount of feed intake and
weight gain, whereas increase the starter period length to 16 increased the amount of feed
intake, weight gain and final live weight (P<0.05 Reduce or increase of the amount of feed
intake and weight gain were observed in interaction between starter period length and crude
protein levels (P<0.05). Starter period length and crude protein levels had not significant
effect on feed conversion ratio and carcass traits (P>0.05). Starter period length and crude
protein level had significant effects on intestinal morphology (P<0.05). Reduce the starter
period length to 7 days increased the intestinal villi width and length, whereas using crude
protein 5% more than Ross recommendation reduce them.
Conclusion: In broilers reduce the length of using stater period diet via reduce of the
amounts of daily feed consumption and weight gain, reduce the final weight, whereas
increase of the use of starter period via increase the amounts of daily feed intake and weight
gain, increase the final weight.