The Journal of Poultry Science : 3 **0 Research Note Haq Nawaz Tariq Mushtaq and Muhammad Yaqoob Institute of Animal Nutrition and Feed Technology University of Agriculture Faisalabad** Pakistan Department of Livestock Management University of Agriculture Faisalabad** Pakistan An experiment involving * straight run onedayold Hubbard broiler chicks was conducted on floor pens to investigate the e#ect of di#erent levels of energy and protein on live performance and carcass responses of broilers chicks Six broiler starter diets with two levels of metabolizable energy (ME) ie ** and *** kcal kg each with three levels of crude protein (CP) ie * and were o#ered to birds from hatching to d of age Similarly six broiler finisher diets with two levels of ME ie *** and ** kcalkg and levels of CP ie 0 and and 3 and * respectively were o#ered during 3 d of age The chicks were randomly divided into replicate of chicks each and there were replicates under each diet Feed intake was significantly (p **) high in diet having low ME during both phase with * and CP during starter phase whereas all CP levels showed nonsignificant e#ects on feed intake at finisher phase Low ME and high CP diets showed high feed intake (p **) during starter and finisher phases Higher weight gains (p **) were observed at low ME diets during the experiment Dietary CP contents at low ME did not a#ect the weight gain during starter phase whereas high CP with low ME showed high weight gain in finisher phase The response of CP and ME was similar for good feed conversion ratio (FCR) as was observed for feed intake and weight gain No significant di#erences of dietarytreatments were observed on any of the carcass characteristics From the recent study it is obvious that low ME and high CP diets promised optimum performance for broiler chicks at both starter and finisher phases Key words : broilers carcass metabolizable energy performance protein J Poult Sci : 3 **0 Introduction Energy and protein are very important nutrients for broilers like other living creatures Energy is required for body functioning and protein is an essential constituent of all tissues of animal body Protein having major e#ect on growth performance of the bird is the most expensive nutrient in broiler diets (Kamran et al **) Energy levels suitable for raising broilers in temperate zones need revision as compared to tropical zone as environmental conditions modify these values (Ho#mann 3) High energy broiler starter diets result in extra deposition of fat (Holsheimer and Jensen 33) pointing the wastage of dietary energy To ensure maximum utilization of each and every nutrient of the diet a right proportion of these nutrients is necessary to optimum growth of the birds and to minimize the surplus use of vital dietary component The ratio of energy to protein established for broiler is for Received : December ** Accepted : June **0 Correspondence to : T Mushtaq Institute of Animal Nutrition and Feed Technology University of Agriculture Faisalabad** Pakistan Tel : 3 ** 0**3 Email : tmmirza@fsdpaknetcompk
Nawaz et al : Energy and Protein for Broilers 389 Table 4 Percent composition of broiler starter diets Ingredients A B C D E F Maize Wheat Wheat bran Rice seed covering Cotton seed meal (decorticated) Rapeseed meal Sesame meal Corn gluten meal 0* Fish meal Blood meal Meat meal Molasses Vitamin & mineral premix Calculated analysis ME kcalkg CP ( ) Ca ( ) Av4 P( ) 4 * *4 4 4 4 * 4* * 4 * 4* 4* 4 * * 4 4 *** *4 *43 0 4 * * 4 4 ** 4 4* 0 * * 4 4 ** 4* 4* 0 Each kg of premix provided : vitamin A **** IU ; vitamin D ** IU ; vitamin K 4 mg ; vitamin E IU ; biotin *4 mg ; folic acid 4* mg ; niacin mg ; calcium pentothenate 4 mg ; pyridoxine 4* mg ; riboflavin mg ; thiamin 4 mg ; vitamin B mg ;Fe mg ; Mn mg ; Cu 4 mg ; Se *4*3 mg ; Zn 0* mg ; choline chloride 4 mg4 USA for Canada 0 for Western Europe for Eastern Europe for Middle East and * for Asia Likewise di#erent ratios of energy to protein for broiler finisher are 0 for USA 0* for Middle East and for Asia (Barque et al 33) The standard for Asia may be applicable to conditions in Pakistan However it is advisable to compare the existing standards used in various countries regions to recommend guidelines for broilers diet formulation The study was therefore conducted to investigate the e#ect of di#erent levels of energy and protein on weight gain feed consumption feed e$ciency and carcass responses of broilers Materials and Methods A total of * straight run onedayold broiler chicks were used to evaluate the e#ect of di#erent levels of energy and protein on live performance and carcass characteristics of broilers The birds were randomly divided into 0 treatments and replicates of chicks each Room temperature was maintained at during first week and it was decreased each week till it reached at fifth week Feed and fresh water was supplied ad libitum during the experiment A hours light was made available to the chicks throughout the experiment Six broiler starter diets were formulated having two levels of metabolizable energy (ME) ie ** and *** kcalkg each with three levels of crude protein (CP) ie * and (Table ) Similarly six broiler finisher diets having ME *** kcalkg with 0 and CP and ME ** kcalkg with 3 and * CP were formulated (Table ) The starter and finisher diets were fed from * dand3 d respectively Feed intake and weight gain was recorded at th and nd day and feed conversion ratio (FCR) was calculated On nd day of the experiment two birds from each replicate were randomly selected slaughtered and defeathered to get carcass responses to the dietary treatments The data on carcass weight shank and keel lengths abdominal fat and organ weights ie heart liver and gizzard were also recorded at this stage The experimental design was completely randomized with 0 treatments in each phase and three replicates for each treatment and was analyzed statistically using ANOVA technique In case of significance (p **) Duncan s Multiple Range Test was used to compare the means (Muhammad **) Results and Discussion Data on feed intake weight gain and FCR during di#erent phases of experiment are presented in Table Maximum feed intake was observed in birds fed
390 J Poult Sci () Table 4 Percent composition of broiler finisher diets Ingredients A B C D E F Maize Wheat Wheat bran Rice polishing Cotton seed meal (decorticated) Rape seed meal Sesame meal Corn gluten meal 0* Fish meal Blood meal Meat meal Molasses Dicalcium phosphate Vitamin & mineral premix Calculated analysis ME kcalkg CP ( ) Ca ( ) Av4 P( ) 0 4 333 043 *43 *40 0 ** 4 *43 *40 34 4 0 * 4 *43 *40 4 4 4 ** 4* *40* 04 4 * 34* *40* 4 4 *3 *4* *40* Each kg of premix provided : vitamin A **** IU ; vitamin D ** IU ; vitamin K 4 mg ; vitamin E IU ; biotin *4 mg ; folic acid 4* mg ; niacin mg ; calcium pentothenate 4 mg ; pyridoxine 4* mg ; riboflavin mg ; thiamin 4 mg ; vitamin B mg ;Fe mg ; Mn mg ; Cu 4 mg ; Se *4*3 mg ; Zn 0* mg ; choline chloride 4 mg4 on diet containing ** kcal MEkg and CP during the starter phase (* d) and on *** kcal MEkg and CP during the finisher phase (3 d) Feed consumption was low (p **) with high energy (*** kcal MEkg) than with low energy (** kcal MEkg) The feed consumption also increased with the increase in protein concentration of the diet ie feed consumption increased in diets A to C and D to E as well (Table ) The results of the present study are in close agreement with those of Holsheimer and Veerkamp (33) who found that feed intake was a#ected chiefly by energy and protein content of the feed The results of the present experiment are in line with the findings of Onwudike (3) who reported a decreased feed intake as ME of the diets increased beyond 3** kcalkg The increased feed intake is probably due to greater energy requirements of the broiler birds to cope with the high growth rate which is achieved by high intake in low energy diets The results were also in accordance with those of Leeson et al (330) who reported a decrease in feed intake with increasing ME contents of the diets However the results of the present study did not agree with the findings of Bregendahl et al (**) who reported a decrease in feed intake as the CP contents of the diets increased Han et al (33) however reported no di#erences in feed intake of broilers when the CP content of the diet was decreased from to * They however supplemented the low protein diets with crystalline amino acids The results of the present study showed that the birds mainly eat for calories and CP or more precisely amino acids have an addition e#ect on increased feed intake Maximum weight gain was observed in birds fed on diet containing ** kcal MEkg and CP during the starter phase and *** kcal MEkg and CP during the finisher phase It was noted that birds fed on diets containing *** kcal MEkg with CP had higher weight gain than the birds fed on diet containing ** kcal MEkg with CP during finisher phase It was also observed that birds fed on low ME and high CP diets gained more weights as compared to those fed high ME and low CP diets The results of this study were supported by Holsheimer and Veerkamp (33) who reported significantly higher body weight of broilers raised on diets containing normal CP than that of high The results were also in accordance with those of Onwudike (3) who reported an increased daily weight gain with ** kcal MEkg when dietary protein was increased from * to in broiler
Nawaz et al : Energy and Protein for Broilers 39 Table 4 Feed intake weight gain and feed conversion ratio (FCR) of broiler chickens as a#ected by various metabolizable energy (ME) and crude protein (CP) levels of the diets Diets A B C D E F Pooled SEM Feed Intake (g) Weight gain (g) FCR (gg) * 3 * * 3 * * 3 * days 4 ab 04 b 04 a 4 c *4 b *4 b 34* 4 ab 04 bc 3**4 a 040 c *43 bc 043 bc 34 4 ab *4 ab 4 a *43 b 4 ab 40 ab 04* 0343 b 4 b *34 a 4 c 04 c 40 b 4 *40 ab 304 ab 040 a *4 b 43 ab 4 ab 04 43 b *43 ab 4 a *34* c 340 bc 34 b 4 4 bc 4* d 4* d 40 ab 4 a 40 cd *4*0 4 ab 43 bc 4 c 4 a 430 bc 4*0a bc *4* 40 ab 40 bc 4* c 4 a 40 bc 4 abc *4* Mean of replicates having birds in each replicate4 ad Means within a lacking common superscripts di#er significantly (p *4*) Treatment codes are AC has ME ** kcalkg and CP * respectively and DF has ME *** kcalkg and CP * respectively during the starter phase (* d) whereas AC has ME *** kcalkg and CP 0 respectively and DF has ME ** kcalkg and CP 3 * respectively during the finisher phase (3 d)4 The data during * d represent the combined e#ect of starter and finisher diets4 chickens The findings of this study were in close agreement with those of Leeson et al (330) who found that high energy and low protein diets (*** kcal MEkg and * CP) depressed growth of broilers They also reported significantly higher body weight gains with and CP than that of * However Leeson et al (33) reported that body weight gain and growth rate were una#ected by level of the energy in diet of broiler chicks The poor response to low CP and high ME diets in finisher phase may be due to carry out e#ects of starter diets where these diets resulted in poor responses Han et al (33) observed no di#erence in body weight gain in low protein diets for broilers when they fortified the low CP diets with essential amino acids So it seems that growth depression due to low protein diets may be due to low amino acid profile of such diets Improved FCR was observed in birds fed diets containing ** kcal MEkg with or CP during starter phase and diet containing *** kcal MEkg and CP during the finisher phase It was observed that during finisher phase either very low CP ie 0 or high CP ie 3 and * significantly depressed FCR The results of the present study are in agreement with those of Holsheimer and Veerkamp (33) who reported that feed e$ciency was a#ected significantly by energy content of the diet The results are in agreement of the findings of Onwudike (3) and Temim et al (3) who observed that feed e$ciency was improved with increasing dietary CP levels for broiler chicks The results were also in accordance with those of Jackson et al (3) who noted that feed e$ciency increased with increasing levels of dietary protein or energy The finding of the present study are supported by Leeson et al (330) who reported improved feed e$ciency with and CP and *** kcal MEkg as compared with diets with * CP and 0** kcal MEkg Ferguson et al (33) reported an increase in FCR when CP was reduced from to 30 in a 0 week broiler growth trial Similarly Si et al (**) also reported a significant e#ect of dietary CP on FCR Carcass gizzard heart and liver weight and shank and keel length as a#ected by dietary treatments are presented in Table Nonsignificant di#erence of dietary treatments were observed on all of the carcass performances The results of the present study are agreed with those of Moran and Etches (3) who reported similar results when they fed varying protein levels to finishing broiler toms up to weeks of age However the findings of the present study are not in agreement with those of Zarate et al (**) who observed significant decrease in carcass responses of broiler fed on low CP diets Waldroup et al (33*) reported no significant e#ect of ME on dressing weight of male broilers Kamran et al (**) however reported higher carcass weights at * CP than that of when low protein diets were supplemented with essential
39 J Poult Sci () Table 4 Carcass gizzard liver and heart weights abdominal fat and shank and keel lengths of broiler chickens as a#ected by various metabolizable energy (ME) and crude protein (CP) levels of the diets Diets A B C D E F Pooled SEM Carcass weight 043 04 04 04 04* 04 *40 Gizzard weight (g) *4 34 34 4 34 4 4 Liver weight (g) Heart weight (g) 4 4 4 4 04 4* 4* Abdominal fat 4 34 *4* *4 4 4 43 4 4 4 4 4 34* 4* Shank length (cm) 4** 43 4 4* 4 43 *40 Keel length (cm) 34* 4 34 4 4 4 *4 Mean of 0 observation from each treatment i4e4 two from each replicate4 Means within a column without any superscripts do not di#er significantly (p *4*) of live weight of carcass weight Treatment codes are AC has ME ** kcalkg and CP * respectively and DF has ME *** kcalkg and CP * respectively during the starter phase (* d) whereas AC has ME *** kcalkg and CP 0 respectively and DF has ME ** kcalkg and CP 3 * respectively during the finisher phase (3 d)4 amino acids in a ideal amino acid pattern In conclusion it is obvious that the energy contents of ** kcalkg and CP in typical Pakistani starter diets (* d) whereas energy contents of *** kcalkg and CP during finisher diets (3 d) promised optimum production and better economical yields as compared to high energy and low CP diet References Barque AR Koirala PK Gilani AH Nawaz H and Ahmed G E#ect of varying levels of protein and energy on the carcass characteristics of broilers Journal of Agriculture Research and Science : * *3 33 Bregendahl K Sell JL and Zimmerman DR E#ect of lowprotein diets on growth performance and body composition of broiler chicks Poultry Science : 0 0 ** Ferguson NS Gates RS Taraba JL Cantor AH Pescatore AJ Ford MJ and Burnham DJ The e#ect of dietary crude protein on growth ammonia concentration and litter composition in broilers : 33 Han Y Suzuki H Parsons CM and Baker DH Amino acid fortification of a low protein corn and soybean meal diet for chicks Poultry Science : 0 33 Ho#mann L E#ects of factors of nutrition and husbandry on the heat production of rats and broilers Heat production of growing broiler chicks kept in groups depending on the environmental temperature Archiv fur Tierernahrung : 3 3 Holsheimer JP and Jensen WM Limiting amino acids in low protein maizesoyabean meal diets fed to broiler chicks from to weeks of age British Poultry Science : 33 Holsheimer JP and Veerkamp CH E#ect of dietary energy protein and lysine content on performance and yields of two strains of male broiler chicks Poultry Science : 3 33 Jackson S Summers JD and Leeson S E#ect of dietary protein and energy on broiler performance and production costs Poultry Science 0 : * 3 Kamran Z Mirza MA Haq AU and Mahmood S E#ect of decreasing dietary protein levels with optimum amino acids profile on the performance of broilers Pakistan Veterinary Journal : 0 0 ** Leeson S Summers JD and Caston LJ Diet dilution and compensatory growth in broilers Poultry Science * : 0 33 Leeson S Caston L and Summers JD Broiler response to energy or energy and protein dilution in the finisher diet Poultry Science : 330 Lopez PL Chavez MA and Luis ES The energy protein requirements of broilers in di#erent seasons in Philippines during the cold dry months Philippine Agriculturist 0 : 0 3 Moran ET Jr and Etches RJ Finishing broiler toms using an estradiol beta implant together with a high energylow protein final feed Poultry Science 0 : ** ** 3 Muhammad F Statistical Methods and Data Analysis ** ** Edition pp Kitab Markaz Bhawana Bazar Faisalabad Pakistan ** Onwudike OC Energy and protein requirements of broiler chicks in humid tropics Tropical Animal Production : 3 3 Si J Fritts CA Burnham DJ and Waldroup PW Extent to which crude protein may be reduced in corn soybean meal based broiler diets through amino acid supplementation International Journal of Poultry Science : 0 * **
Nawaz et al : Energy and Protein for Broilers 393 Temim S Chagneau AM Guillaumin S Michel J Peresson R and Tesseraud S Does excess dietary protein improve growth performance and carcass characteristics in heatexposed chickens? Poultry Science 3 : *** Waldroup PW Tidwell NM and Izat AL The e#ects of energy and amino acid levels on performance and carcass quality of male and female broilers grown separately Poultry Science 03 : 33* Zarate AJ Moran ET Jr and Burnham DJ Reducing crude protein and increasing limiting essential amino acid levels with summer reared slow and fast feathering broilers Journal of Applied Poultry Research : 0* 0 **