Influence of Different Levels of Crude Protein and Metabolizable Energy on Production Performance of Ross Broiler

The objective of this study was to estimate the suitability of recommending Ross guide requirements of crude protein (C.P) and metabolizable energy (M.E) during the starter and finisher stages as compared with low and high amount of these nutrients at basrah region. Four treatment with three of 15 ROSS broiler chicks per replicated were used. The treatment were fed diets 1, 2, 3 and 4 which were contented 22, 23 % C.P (as ross guide recommended), (24, 25) % C.P and 2864, 2990 Kcal M.E/kg (as Ross guide), (3120 and 3207) Kcal M.E/kg diets respectively for the starter and 18, 19 % C.P (as Ross guide), 20, 21 % C.P and 2886, 3041 Kcal M.E/kg (as Ross guide), (3204, 3357) Kcal M.E/kg diet for the finisher period respectively, The ratio between M.E and C.P in these diets treatments were equal to 130 the starter diets and 160 to the finisher diets. Live body weight, weight gain, feed consumption, C.P and M.E consumption, production index, dressing percentage, thigh and Brest percentage high significantly (p<0.05) and low in the feed conversation ratio, abdominal fat and the gizzared percentage were reputed in treatment 3 as compared with treatments 1, 2 and 4 it can be concluded that diet contented Ross guide requirement of C.P and M.E were not fit enough of these nutrients to give better performance in basrah region. DOI: 10.7176/JBAH/9-18-04 Publication date:September 3


Introduction
Nutrition is one of the parameters that broiler chick producers have the most influence. The two main nutrients in most livestock diets are energy and protein, it is cost about 90% of the total cost which should be utilized most efficiently for desired economy of production and formulation of poultry ration (Durunna et al ., 2005). Energy and protein are very important nutrients for broiler. Energy is required for body function and protein is essential constituent of all tissues of bird's body. Protein having major effect on growth performance of the birds is the most expensive nutrient in the broiler diets (Kamran et al., 2004).
Current commercial hybrids with high performance require suitable energy and protein diets which would enable the maximum exploitation of these genetic potential, the nutrient requirements of broiler chicken depend on its stage of growth (FAO, 2003).
Several workers have chosen to express these nutrient requirements in terms of energy and protein ratios. The energy and protein studies have been conducted with chicks by Rahimi and Hassanzadeh (2007) and Dairo et al. (2010). In poultry industry the regime of dietary energy and protein were established both in the tropics and temperature climate (NRC, 1994;Ojewaia and longe, 1999). The performance of broiler were evaluated by Olomu and Offioncy (1980) who reported that 23% protein with either 2800 or 3000 Kcal/Kg metabolizable energy and the ratio were 121.7 and 130.43 receptivity which adequate to the requirement for broiler starters. However, research evaluating the performance of commercial broiler chicks fed diets different in protein and energy lack. Therefore, this study evaluated the performance of broiler chicken fed diets containing different combinations of energy and protein to Ross hybrid at basrah region Table1:Composition of the broiler starter and finisher experimental diets  Ingredients (%)  Starter phase 0 -21 days  Finisher phase 22-35 days  T1  T2  T3  T4  T1  T2  T3  T4  Corn  43  43  43  43  63  65  63  159.8 Live body weight, weight gain, feed consumption, feed conversion ratio (FCR) and production index was calculated according to the equation of Naji, (2006) At the end of 35 day six bird (3 female and 3 male) were taken to slaughters; dressing percentage were calculated and relation weight for thigh, Brest, liver, heart, gizzard, proventriculus and the abdominal fat, the amount of crude protein and metabolizable energy consumption by each birds was calculated by the following equation Crude protein consumption = ×% .

Metabolisable energy = × /
Completely randomized design (CRD) way used to study the effect of difference treatment in all traits, The differences between the averages were also tested using the least significant difference (L.S.D) using the SPSS (2009).

Result
The date of weekly body weight and weight gain were presented in table 2 and 3 which reveal significantly differences (p<0.05) during all weeks of the experiment. The highest live weight and weight gain during all the experimental weeks were obtained by the birds fed diet 3 (1723, 1685) g whereas the lowest obtained by the birds fed diet 1 (1448, 1410) g respectively 1 st , 2 nd , 3 rd , 4 th and 5 th weeks of the experimental period showed the same pattern, while there were no significant differences in live weight and weight gain of bird fed diets 2 and 4. Table2. Influence of different levels of crude protein and metabolizable energy on body weight/g 1 to 5 weeks of age's ± SE Treatment Bird age ( It can be seen in table 4 that there were no significant differences in the mean total feed consumption of the experimental birds at 1 st and 2 nd weeks. The dietary treatment 4 had significant (p<0.05) decrease effects on the 3 rd , 4 th , 5 th and accumulated feed (446,580, 721 and 2013) g respectively consumption as compared with treatments 1, 2 and 3.  (5) indicated that the experiment diets had significant (p<0.05) effects on weekly feed conversation ratio (FCR) during the period from 1 st , 2 nd , 3 rd , 4 th , 5 th and the accumulation feed conversion ratio, during these period the birds fed diets 1 showed significant increase in FCR, whereas the birds feed on diets 3 and 4 showed significant decrease in FCR. Table 5. Influence of different levels of crude protein and metabolizable energy on feed conversation ratio (g feed /g weight gain) 1 to 5 weeks of age's ± SE Treatment Bird age (week) Cumulative 0-1 1-2 2-3 3-4 4-5 0-5 T1 1.18 ± 0.01 a 1.69 ± 0.03 a 1.43 ± 0.02 a 1.7 ± 0.04 a 1.96 ± 0.03 a 1.64 ± 0.03 a T2 1.18 ± 0.01 a 1.48 ± 0.02 b 1.34 ± 0.03 b 1.65 ± 0.03 a 1.71 ± 0.04 b 1.51 ± 0.03 b T3 1.07 ± 0.02 b 1.31 ± 0.04 c 1.34 ± 0.04 b 1.48 ± 0.02 b 1.53 ± 0.03 c 1.39 ± 0.03 c T4 1.02 ± 0.03 b 1.27 ± 0.04 c 1.32 ± 0.02 b 1.45 ± 0.02 b 1.58 ± 0.02 c 1.37 ± 0.02 c significant * * * * * * *Values within the same column with different letters are significantly (p<0.05) The weekly nutrients intake from M.E and crude protein of the experimental birds followed the same pattern of the total feed intake (table 6, 7). It can be seen that diet 3 had the highest statistically significant (p<0.05) effects consumption of the total M.E 7635 Kcal and crud protein 516.21 g intake during all weeks experimental period. The birds fed diet 1 and 4 showed the lowest M.E (6815, 6876.2) Kcal and crude protein intake (463.24, 466.08) g. the M.E and crude protein intake by the birds fed diets was slightly better over by the birds fed diet 1 and 2 but less than diet 3 The data of same carcass parameters is summarized in table 8. The highest dressing percentage, were obtained by the treatment of broiler chickens fed treatment three while the gizzard, proventriculus and abdominal fat percentage were the lower as compared with treatments 1, 2 and 4. A significant (p<0.05) percentage was obtained in production index was noticed in T3 (338.570 and the lowest in T1 (246.71). 300.05 ± 11.23 b * *Values within the same column with different letters are significantly (p<0.05)

Discussion
Ross guide 2014 which recommended that 23% C.P and 2990 Kcal/kg at the starter and 19 % C.P and 3050 Kcal/kg diet at the finisher were not enough to meet the Ross broiler chicken in basrah environment condition In this study the ratio between energy and protein values of each treatment diets was the same 130 to the starter and 160 to the finisher phase, this range of energy and crude protein ratio was not enough to meet the best requirement to the broiler performance broiler are fed different metabolizable energy and protein levels (afatab et al., 2006). The lower body weight and weight gain were showed in treatments 1, 2 and 4 as compared with treatment 3. Results in treatment 4 indicated that excess high protein and metabolizable energy content to improved native chicken has no advantage, this excess in this treatment has been reported to be dissipated after consumption usually in the order of protein (NRC, 1994;Gous and Morris, 2005).
This means there is a threshold above and below (20, 3200) which the crude protein and metabolizable energy value us a nutrient is not justifiable (Si et al., 2001) hence no positive result is expected in terms of growth and other performance indices. It has been shown that treatments 3 showed a high performance, this may be because of better diet digestibility and benefits level of energy and protein in this diet (Moravej et al., 2006). In chicks fed with high energy level fed intake decrease, it could be attributed to poor digestion in broiler chickens (Lee and summers, 2001). Danisman and Gons (2013) who also showed that broiler fed with high energy and protein had reduced feed consumption and improved feed conversion ratio. The abdominal fat deposition percentage increased in treatment 4 which agreed with result of Swennen et al. (2006). This result was in variance with the work of Sizemore and Siegel (1993) who reported no effect of dietary fat concentration on abdominal fat in broiler of constant calorie: protein ratio. Increasing abdominal fat content is a direct reflection of the energy value of treatment 4.
Dressing percentage in treatment 3 was influenced by weight of these chickens, as there is a positive relationship between body weight and dressing percentage (AL-Fayadh and Naji, 1989).

Conclusion
It can be concluded that with adequate balance of calorie and protein 3120 Kcal and 24 % C.P/kg at starter; 3204 Kcal and 20 % C.P /kg diet at finisher Ross diet at basrah region to be fed to improve the performance of the broiler chickens