Dietary influence on body temperature, performance, blood parameters and carcass characteristics of broiler chickens

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1 AGRICULTURE AND BIOLOGY JOURNAL OF NORTH AMERICA ISSN Print: , ISSN Online: , doi: /abjna , ScienceHuβ, Dietary influence on body temperature, performance, blood parameters and carcass characteristics of broiler chickens *Sogunle, O.M 1., Egbeyale, L.T 1., Idowu, O.M.O. 2, Bamidele, O.M 1., Sodeke, S.A 1, Sonaike, G.O 1 and Fanimo, A.O 1 1 Department of Animal Production & Health, University of Agriculture, Abeokuta 2 Department of Animal Nutrition, University of Agriculture, Abeokuta, P.M.B. 2240, Abeokuta, Ogun State, Nigeria, *Corresponding author: sogunleom@unaab.edu.ng ABSTRACT This experiment was conducted on three hundred unsexed day-old Arbor acre strains of broiler chicks for 56 days. The birds were divided into 4 dietary groups with 3 replications of 25 birds each. The diets contained 20, 15, 10 and 5%, respectively of rice offal (RO) being replaced by 0, 5, 10 and 15%, respectively of cashew nut reject meal (CNM). The data obtained were subjected to one-way analysis of variance. Significant (P<0.05) differences were observed in the mean weekly body temperature of the birds. The highest temperature of C was recorded in diet 3 (10% RO and 10% CNM). Reduced digestibility of nutrients was observed in diet 4 (5% RO and 15%CNM). Reduction in dietary fibre content and increased energy density of the diet resulted in improved performance of the birds in spite of marginal rise in body temperature of the birds. The lowest feed intake (5550g) was obtained in diet 3 with the highest birds body temperature. Highest weight gain (1790g), best protein efficiency of 1.64, comparably (P>0.05) best feed: gain of 3.27 and lowest mortality (2.90%) were obtained in diet 4 (5% RO and 15%CNM). The body temperature of C obtained in diet 3 (10% RO and 10% CNM) resulted in the highest (37%) PCV value. The Hb, WBC and RBC values of the blood were also highest at this temperature. The total protein was significantly (P<0.05) influenced by increasing CNM inclusion in the diets. Carcass characteristics were statistically similar (P>0.05) across the treatment groups except in the abdominal fat which was significantly (P<0.05) lowest in diet 1 (control). The carcass yield ranged from to 79.49% with diets 4 (5% RO and 15%CNM) and 2 (15% RO and 5% CNM) having the highest and lowest values, respectively. It was concluded that the nutritional intervention of using CNM to replace RO up to 15% in the diets of broiler chickens did not significantly reduce the bird s body temperature though, there were marked improvements in the performance of the birds. Keywords: Cashew nuts reject meal, rice offal, bird s temperature, broiler chickens, blood parameters, carcass characteristics INTRODUCTION Broiler chickens as homeotherms maintain their central body temperature within a slight range irrespective of ambient temperature. They have a thermoneutral zone that should be described as being a range in the environmental temperature in which energy needs for thermoregulation is minimum and the net energy for production is maximum (Furlan and Macari, 2002). The exposure to high temperatures early in the life of a broiler results in changes in the blood system on the one hand, to accommodate heat dissipation. This confirms earlier work (Vo et al., 1978) that demonstrated the haemodiluting effect of increased temperatures during growth. Methods are available for reducing the temperature of the environment such as the use of insulation, fans and evaporative coolers. Many authors (VanKampen, 1974; Clark et al., 1975) have reviewed these environmental interventions, all of which are based on physics and avian physiology (Richards, 1976). However, because of the costs of installing and running such systems, it is economically feasible for many broiler producers to modify the environment within the poultry house to any significant extent. Hence, a means of reducing the heat load on broiler chickens through nutritional strategies would be valuable, even if this meant having to pay more for the feed. Much of the work (Gous and Morris, 2005) on this subject has been conducted with laying hens and the results of such investigation cannot be applied to broilers because of the genetics and physiological differences that exist between the birds. The addition of fat to the feed (Bacon et al., 1981;

2 Reece and McNaughton, 1982) was attempted and failed to improve the performance of broilers at high temperatures. Thus, as a nutritional intervention for creating conditions that will assist the birds to maintain their optimal temperature, the addition of cashew nut reject meal (CNM) as a fat and energy source and rice offal (RO) as a major energy diluents is of significance. The inclusion of CNM is to possibly alleviate the growth depressing effect of heat stress as reported by Fuller (1981) because of the lower heat increment associated with fat metabolism in conditions of high ambient temperature. The study was therefore carried out to determine the dietary influence on body temperature, performance, carcass characteristics and blood parameters of broiler chickens. MATERIALS AND METHODS Experimental birds and management: A total of 300 unsexed day-old Arbor acre strains of broiler chicks were obtained from a reputable hatchery in Ogun State, Nigeria. The birds were randomly allocated to four (4) dietary treatments of three replications, each consisting of 25 birds. The birds were brooded for two weeks in a standard brooder. The litter was about 7cm deep to prevent hook burns. The pens were equipped with shallow feed trays and fountain drinkers for brooding chicks. The birds were fed and provided water ad libitum. The average environmental temperature at the time of the experiment was C (Mid-October to December). The experiment lasted for eight weeks. Experimental diets: The experimental diets were introduced to the birds at day-old and fed the birds for 8weeks. The levels of supplementation of rice offal (RO) by cashew nut reject meal (CNM) in the diets were as shown in Table 1. Diets 1 to 4 contained 20, 15, 10 and 5%, respectively of RO which had 0, 5, 10 and 15%, respectively inclusion of CNM. The soyabean meal was reduced as the maize increased at the same rate to confine the protein and energy values within the recommended range (NRC, 1994). Chemical analysis: The proximate composition of feed and faeces was carried out using the method of AOAC (1995). Moisture contents were determined at 60 0 C for 26hours. Metabolic trials and carcass evaluation: At the 7 th week, 3 birds per replicate were selected randomly and housed together in a metabolic crate for metabolic trial. Three days acclimatization period was observed followed by a day fasting before the commencement of the trial. Feed intake and total faecal output were recorded for 4 days while the wet faecal outputs were oven dried to constant weight. The procedure of VogtMann et al. (1975) was used in calculating the percentage digestibility of protein, fat, crude fibre and nitrogen-free extract. After the metabolic trials, the birds used were slaughtered via neck slit, singed, defeathered, dressed and eviscerated for carcass evaluation. The dressed weight, weights of the cut-up parts and organs were then expressed as percentages of the live weight of bird prior to slaughtering. Blood sampling: Blood samples were collected separately from 3 birds per replicate in EDTA (Ethylene diamine tetra-acetate) bottles for plasma and serum analysis, respectively. Packed cell volume (PCV), haemoglobin concentration (Hb) and red blood cell (RBC) were determined using Wintrobes microhaematocrit, colorimetry-cyanomethaemoglobin method and improved Neubauer haemocytometer, respectively. Serum total protein, albumin and globulin were analyzed colorimetrically using diagnostic reagent kit (Reanal Diagnosztikai Reagents, Keszlet, Hungary). Body temperature: The body temperature of the birds were measured once daily (8a.m) by inserting a digital clinical thermometer into the cloacae of the birds. Statistical analysis: The data obtained were subjected to Analysis of Variance in a completely randomized design using SPSS for Windows version 10.0 (Norusis, 1999). Significantly (P<0.05) different means were separated using Duncan s Multiple Range Test as contained in the statistical package. 779

3 Table 1: Composition (%) of the experimental diets Diets Ingredient Maize Rice offal Cashew nut reject meal Soyabean meal Fish meal (72% CP) Blood meal Bone meal Oyster shell *Vit./mineral premix Methionine Lysine Salt Total Determined analysis Dry matter (%) Crude protein (%) Crude fibre (%) Ether extract (%) Nitrogen-free extract (%) Energy (MJ/kg) Energy/Protein ratio Phosphorus (%) Calcium (%) *Premix (Univit, 15 Roche) contained the following: 1500IU, vit. A; 1500IU, vit. D; 3000IU, vit. E; 3.0g, vit. K; 0.3g, vit. B 2 ; 8.0mg, vit. B 6 ; 8.0g, Vit. B 12 ; 3.0g, Nicotinic acid; 50mg, Ca-Pantothenate; 10g, Fe; 0.2g, Al; 3.5mg, Cu; 0.15mg, Zn; 0.02g, I; 0.01g, Co. RESULTS The results of the proximate composition of the diets (Table 1) showed increases in all the parameters determined except in the crude fibre which decreased with increasing levels of CNM. However, the results showed that the diets contain crude protein of 22.75, 22.45, and from diets 1 to 4, respectively. The energy protein ratio ranged from n diet 1 to in diet 4. The mean weekly body temperature presented in Table 2 showed fluctuating values in the bird s body temperature across treatments. There were significant (P<0.05) differences in the values recorded across treatments. The highest mean body temperature of C was recorded in diet 3 (10%RO and 10%CNM). The nutrients digestibility presented in Table 3 revealed that the levels of supplementation of RO with CNM had no significant (P>0.05) effects on the nutrients digestibility. The highest values were observed in the control diet (20%RO and 0%CNM) which recorded a temperature of C, while the lowest values were observed in diet 4 (5%RO and 15%CNM) for digestible crude protein, digestible crude fibre and digestible ether extract, respectively. Table 4 showed the performance characteristics of the birds fed the experimental diets. The values obtained were not significantly influenced by the treatment except the protein efficiency ratio. The highest final weight and weight gain were obtained in diet 4 (5%RO and 15%CNM) while diet 1 (20%RO and 0%CNM) recorded the lowest. Feed intake fluctuated (P>0.05) with increasing CNM inclusion in the diets and decreasing fibre content at 780

4 fluctuating body temperatures. The highest feed intake recorded in diet 4 could result from increased palatability with increasing CNM level. The feed intake was lowest in diet 3 which recorded the highest body temperature of C. There were significant (P<0.05) differences in the protein efficiency ratio across treatments. The highest value (1.64) was recorded in diet 4 while the lowest value was recorded in diet 1. The best feed: gain (P<0.05) of 3.27 was recorded in diet 4. Table 5 showed that the blood parameters were significantly (P<0.05) influenced by the treatments except creatinine. The temperature (41,1 0 C) at 10% inclusion of CNM resulted in the highest value of 37% for PCV. Also, the results gave the highest Hb (12.30g/dl), WBC (32.00 x 10 3 /mm 3 ) and RBC (2.40 x 10 6 /ml) at 10% CNM inclusion in the diets. This in turn influenced the abundance (P<0.05) of globulin content. The values obtained for uric acid significantly fluctuated across the dietary treatments. The quality of proteins in the diets could be responsible for the comparable (P>0.05) creatinine levels across treatments. In all the parts considered for carcass characteristics of the birds (Table 6), there were no significant (P>0.05) differences across treatment except in the abdominal fat. The carcass yield ranged from to 79.49% in diets 4 and 2, respectively. The abdominal fat content increased with increasing levels of CNM inclusion in the diets. The lowest value of 0.53% was recorded in diet 1 (20%RO and 0%CNM). Table 2: Mean weekly body temperature ( 0 C) 0% 5% 10% 15% SEM b 40.2 a 40.3 a 39.8 b c 41.1 b 41.2 b 41.2 a c 41.1 b 41.1 b 41.2 a c 41.4 b 41.4 b 41.4 a c 41.0 c 41.3 b 41.3 a b 41.1 b 41.4 a 41.2 a 0.03 Mean body 40.8 b 41.0 a 41.1 a 41.0 a 0.10 temperature ( 0 C) a,b,c : Mean in a row with different superscripts differ significantly (P<0.05) Table 3: Nutrients digestibility of birds fed the experimental diets Parameters 0% 5% 10% 15% SEM Digestible dry matter (%) Digestible crude protein (%) Digestible crude fibre (%) Digestible ether extract (%) Digestible nitrogen free extract (%) a,b : Means in the a row with different superscripts differ significantly (P<0.05) Table 4: Performance characteristics of the experimental birds Parameters 0% 5% 10% 15% SEM Initial weight (g/bird) Final weight (g/bird) Weight gain (g/bird) Feed intake (g/bird) Feed: gain Protein efficiency ratio 1.41 b 1.62 a 1.62 a 1.64 a 0.06 Mortality (%) a,b: Means in a row with different superscripts differ significantly (P<0.05) 781

5 Table 5: Blood parameters of birds fed the experimental diets Parameters 0% 5% 10% 15% SEM Haematological indices Packed cell volume (%) c b a c 6.52 Haemoglobin (g/dl) 9.00 c 9.90 b a 9.10 bc 0.63 White blood cell (x10 3 /mm 3 ) b c a c 0.24 Red blood cell (x 10 6 /ml) 1.50 b 1.10 c 2.40 a 2.20 ab 0.06 Biochemical indices Total protein (mg/dl) c b a a 1.17 Albumin (mg/dl) b a c a 0.03 Globulin (mg/dl) d c a b 0.19 Uric acid (mg/dl) 2.10 b 2.40 a 2.10 b 1.80 b 0.03 Creatinine (mg/dl) a,b,c,d : Means in a row with different superscripts differ significantly (P<0.05) DISCUSSION The values obtained on the proximate composition of the diets were within the recommended range for broilers in the tropics (NRC, 1994). From the results of the mean body temperature, it could not be ascertained if the diets have any effect on the birds body temperature though the values agree with those reported for birds in the tropics (Smith, 2001). The results of the nutrients digestibility showed that 20% inclusion level of rice offal was a tolerable level for broiler chickens. However, lower digestibility recorded in diet 4 (5% RO and 15% CNM) could result from some anti-nutritional factors that might accompany the increasing level of CNM in the diets. The reduced crude fibre content and increased energy density with increasing level of CNM in the diets resulted in improved performance of the birds at the expense of rise in body temperature. Dale and Fuller (1979) reported an increased feed intake with increasing palatability of feed. This was observed with the increased inclusion of CNM in the diets. Also, the lowest feed intake observed in diet 3 conformed to the findings of Smith (2001) that any degree rise in temperature will result in decreased feed intake. The lowest weight gain and protein efficiency ratio and the highest feed: gain and mortality recorded in diet 1 supported the study of Oyawoye and Nelson (1999) who reported poor efficiency of feed utilization at high level of rice offal fed to young cockerels. Edosien and Switzer (1972) reported that decrease of fluid could arise from a high temperature, thereby increasing red blood concentration. Hence, the blood plasma gave the highest values with the highest body temperature while the total serum protein increased with increasing levels of inclusion of CNM in the diets. However, the value (32.00 x 10 3 /mm 3 ) obtained for WBC was above the range of 9 to x 10 3 /mm 3 reported by Mitruka and Rawnsley (1977). The fluctuations in the uric acid values obtained across the treatments could result from varying amino acid contents of the diets (Eggum, 1970). The dressing percentages of the birds were in consonance with the New York dressing percentage of 75 to 95% reported by Anonymous (1983) for broiler chickens. The low abdominal fat deposition recorded in all treatments resulted from narrow Energy: protein (Jackson et al., 1982). CONCLUSION It was concluded that the nutritional intervention of using CNM to replace RO up to 15% in the diets of broiler chickens did not significantly reduce the bird s body temperature though, there were marked improvements in the performance of the birds. 782

6 Table 6: Carcass characteristics and mean body temperature of the experimental birds Parameters 0% 5% 10% 15% SEM Carcass yield Live weight Dressing percentage Cut-up parts 1 Head Neck Breast Back Drumsticks Thighs Shanks Wings Organ weight 2 Lungs Kidneys Abdominal fat 0.53 c 0.60 b 0.74 a 0.62 b 0.15 Heart Liver Gizzard a,b: Means in a row with different superscripts differ significantly (P<0.05) 1,2 : Percentages of the live weight REFERENCES Anonymous. (1983). Appraising poultry enterprises for profitability. A manual for potential investors. World Bank Technical Paper No. 10. Washington DC. A.O.A.C. (Association of Official Analytical Chemist). (1990). Official methods of analysis.16 th edition, Washington DC. Bacon, W.L., Cantor, A.H. and Coleman, M.A. (1981). Effect of dietary energy environment and sex of market broilers on lipoprotein composition. Poultry Sci, 60: Clark, J.A., Charles, D.R., Wathes, C.M. and Arrow, J. (1975). Heat transfer from housed poultry, its implications for environmental control. World s Poultry Sci J, 31: 312. Dale, N.M. and Fuller, H.L. (1979). Effects of diets composition on feed intake and growth of chicks under heat. I. Dietary fat level. Poultry Sci, 58: Edosien, J.C. and Switzer, B.R. (1972). Effect of dietary protein, fat and energy on bloodhaemoglobin and haematocrit in the rat. J Nutr, 107: Eggum, B.O. (1970). Blood urea measurement as a technique for assessing protein quality. Brit J Nutr, 24: Furlan, R.L., Macari, M. (2002). In: Fisiologia aviaria aplicada a frangos de corte (Macari M, Furlan, R.L. and Gonzales, E. eds.) 2 nd ed. Jaboticadal: Funep- Unesp. Pp Gous, R.M. and Morris, T.R. (2005). Effects of high temeperature on broilers. World s Poultry Sci J, 61: Jackson, S., Summers, J.D., and Leeson, S. (1982). Effect of dietary protein and energy on broiler carcass composition and efficiency of nutrient utilization. Poultry Sci, 61: Mitruka, B.M. and Rawnsley, H.M. (1977). Clinical biochemical and haematological references values in normal experimental animals. Masson, N.Y. Norusis, M.J. (1999). SPSS for Windows v10.0. Chicago IL: SPSS incorporated. N.R.C. (National Research Council). (1994). Nutrient Requirements of Poultry. National Academy of Science. Washington DC. 783

7 Oyawoye, E.O. and Nelson, F.S. (1999). Optimum level of inclusion of rice offal in the diet of young cockerels. Proceedings of 26 th Annual Conference of Nigerian Society for Animal Production. pp Reece, F.N. and McNaughton, J.L. (1982). Effect of dietary nutrient density on broiler performance at low moderate environmental temperatures. Poultry Sci, 61: Richards, S.A. (1976). Evaporative water loss in domestic fowls and its partition in relation to ambient temperature. J Agric Sci (Cambridge), 87: Smith, A.J. (2001). Poultry. In: Tropical Agriculturist. CTA Macmillan Publisher. pp Vankampen, M. (1974). Physical factors affecting energy expenditure. In: Energy Requirements of Poultry (Morris, T.R. and Freeman, B.M. eds.). British Poultry Sci. pp Vo, K.V., Boone, M.A. and Johnstone, W.E. (1978). Effect of three lifetime ambient temperatures on growth, feed and water consumption and various blood components in male and female Leghorn chickens. Poultry Sci, 57: Vogtmann, H., Pfirter, P. And Prabuck, A.L. (1975). A new method for determining metabolizability of energy and digestibility of fatty acids in broiler diets. British Poultry Sci, 16: