Vol. 12, Issue 4 (2023)

Author(s):
Hariharan T and Gangadevi P

Abstract:
An experiment spread over a period of eight weeks was carried out to study the effect of citric acid and microbial phytase (Natuphos^®-5000G) on growth performance in broiler chicken. One hundred and ninety-two, day-old broiler chicks (Vencobb) were divided into four identical groups having four replicates in each group with 12 birds in each replicate and allotted randomly into four dietary treatments viz., T₁, T₂, T₃ and T₄. The treatments consisted of a standard broiler ration (SBR) with 0.5 per cent available P (T₁), low available P broiler ration having 0.3 per cent available P (LAPBR) and 3.0 per cent citric acid (T₂), LAPBR supplemented with 700 U of phytase/kg feed (T₃) and LAPBR with 1.5 per cent citric acid and 350 U of phytase/kg feed (T₄). All the rations were formulated as per BIS specifications except in the level of available P. Body weight and weight gain of the experimental birds were significantly influenced by the dietary treatments. The highest weight gain and body weight being observed in T₄ with significant difference both at sixth week (p<0.01) and eighth week (p<0.05), indicating the synergistic effect of citric acid and microbial phytase on nutrient utilization and growth performance. The mean daily, fortnightly and cumulative feed intakes differed significantly between treatments. The birds fed on all the experimental rations (T₂, T₃ and T₄) consumed more feed, than control (T₁) group. The highest cumulative feed consumption was observed in T₄ at sixth week (p<0.01) and in T₂ as well as T₄ at eighth week (p<0.01). The results indicate that inclusion of citric acid or phytase improve feed intake and can cause further improvements in feed intake when these additives were added together (T₄). Cumulative feed conversion ratios recorded by the birds were 2.09, 2.02, 2.07 and 2.01 at sixth week and 2.36, 2.30, 2.30 and 2.29 at eighth week for T₁, T₂, T₃ and T₄, respectively. Though the birds maintained on different dietary treatments registered no significant difference in cumulative feed conversion ratio, an increasing trend in feed efficiency was noticed in T₂, T₃ and T₄ over the control group (T₁) in the sixth week and almost similar feed efficiency for the various groups during eighth week, indicating that citric acid or phytase favours the nutrient utilization. The percent livability was not influenced by the different dietary treatments, even though the birds maintained on low P diet in T₂, T₃ and T₄. Over all evaluation of the present study revealed that combination of citric acid and microbial phytase in low available P diet could synergistically improve growth performance in broiler chicken.