EFFECT OF LOCALLY EXTRACTED PHYTASE SUPPLEMENTATION ON THE PERFORMANCE OF BROILERS AND LAYERS PhD DISSERTATION

Abstract

The present study evaluated the two experiments with phytase supplementation for layers and broilers; Experiment I used white leghorn layers (paper I and paper II) whereas experiment II used Cobb 500 broilers (paper III and paper IV). Experiment I was conducted to study effect of extracted phytase supplementation on performance of white leghorn hens (paper I) and the effect of phytase on haematological, serum metabolites, phosphorus in faeces and phytase activities for evaluating animal’s health status and economics of phytase supplementation (paper II). Experiment II studied effect of phytase supplementation in diets on broiler feed intake, growth performance and carcass quality parameters (paper III) and effect of phytase supplementation in blood hematological and serum biochemistry of broiler chickens (paper IV). Experiments were arranged in a completely randomized design and each treatment was replicated three times. A total of 168 white leghorn chickens and 180-day-old Cobb 500 broilers were randomly distributed to the treatments and fed with the diets for 90 days (Experiment I) and 42 days (Experiment II). Body weight, egg mass, feed conversion ratio, body weight change, body weight gain were not affected by inclusion of phytase (p>0.05) but feed intake, hen day egg production and egg weight affected by phytase supplementation (Paper I). Phytase supplementation has impact on egg weight, albumin height, and albumin weight (p<0.05) but had no added advantage on haugh unit, yolk height, yolk weight, yolk diameter, yolk index, yolk color, shell thickness and shell weight (Paper I). Fertility, hatchability of total eggs set, hatchability of fertile eggs, chick length, chick weight, late dead embryos, pipped embryos, early dead embryos were not affected by inclusion of phytase (Paper I). There was no significant difference (p>0.05) in total serum, albumin, cholesterol, low-density lipoprotein among phytase supplementation and control diet, but HDLP there was a significant difference (p<0.01) among treatments (Paper II). Among the treatments, maximum net income was recorded at T4 (1200 FTU / Kg), followed by chickens raised at T3, T2, and T1. Phytase supplementation of diet has significant reduction on excreta of Ca and P (Paper II). It was observed that inclusion of phytase had significant effect on total feed intake, final body weight and body weight change during starter, finisher and entire phase among treatments (p<0.05). Higher (P<0.05) starter phase feed intake, final body weight and body weight change was recorded for T4 and T3 compared to T1 and xv T2. In addition, better-feed conversion was recorded in starter phase among treatments with inclusion of phytase compared with control group. The birds fed on the diet T1and T2 attained the lowest feed consumption than phytase supplementation recorded in T3 and T4. The highest (P<0.05) final body weight in finisher phase recorded in T2, T3 and T4 compared to T1. Also highest (P<0.05) body weight change was recorded in T2, T3, and T4 compared with T1. The highest (p<0.001) feed intake in entire phase were recorded in diets containing 600 (T3) and 1200 FTU/kg (T4) compared with T1 and T2. Final body weight, body weight change and average gain among treatment with phytase inclusion shown similarly significant effect (p<0.001) compared with control group. The weight of most carcasses were similar (P>0.05) among treatment except the dressed weight and breast weigh were significant effects (p<0.05) compared control group (Paper III). There were no significant differences (P>0.05) among all groups for packed cell volume (PCV), total red blood cells (RBC) count, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cells (WBC) and hemoglobin (Hb). Total protein, albumin and globulin values did not significantly (P>0.05) increased in supplemented groups as compared to the T1 control (group) at whole growth period (Paper IV). The calcium concentration ranged from 1-1.49% and 0.75-0.89% whereas phosphorus ranged from 0.37-0.52% and 0.28-0.44% in starter and finisher diets, respectively and it is within the range recommended in broiler ration (NRC, 1994). According to the present result of partial budget analysis, broiler chicken in T4 returned a higher profit than those grouped to T2, T3 and T1 respectively (Paper IV). It was concluded that the inclusion level of extracted phytase 600 and 1200 FTU/kg had a considerable impact on feed intake in layers. But in broilers diet (paper IV) had a considerable impact on feed intake, final body weight, body weight change, and carcass yield characteristics, Packed cell volume (PCV), Hb and WBC, reduce feed costs and improve the efficiency of utilization of phosphate in plant-based feed ingredients, resulting in economic and environmental benefits. Supplementation with 300, 600 and 1200 ftu/kg phytase in diets recommended improving broilers and hen day egg production performance with control level.