Comparative Evaluation Of The Nutritive Value Of Different Feed Energy Sources With And Without Enzyme Supplementation On The Performance Of Broiler Chickens
Two experiments were carried out to determine the nutritive value of sorghum, millet, cassava and sweet potato with or without enzyme supplementation in broiler chickens production. The growth performance, nutrient digestibility, heamatological parameters and characteristics of broiler chickens were evaluated. In the experiment 1, diets were not supplemented with enzyme while in the second, the diets were supplemented with Maxigrain® enzyme. Five isonitrogenous and isocaloric diets (23.17 % CP; 2831 Kcal/kgME) and (21.73 % CP; 2929 Kcal/kgME) for the broiler starter (0 – 4 weeks) and finisher phases (5-8 weeks) respectively were formulated. Diet T1 maize based diet served as the control while diets T2, T3, T4 and T5 were sorghum, pearl millet, cassava and sweet potatoes based diets, respectively. A total of 225 day- old NAPRI X broiler chicks were randomly allotted to the five treatments. Each treatment consisted of 45 birds with three replicates of fifteen birds each in a completely randomized design. Feeds and water were provided ad libitum. Data collected were analysed using the general linear model procedures of S.A.S. 9.0 and significant difference (P<0.05) in means among the dietary treatments was separated using a tukey test. The result of the first experiment 1 showed that final body weights of 503.44 g and 2302.77 g, feed intake of 819.67 g and 3073.70 g and weight gain of 453.61 g and 1892.07 g were significantly (P<0.05) higher in birds fed the millet based diet (T3) for starter and finisher broiler respectively than the other dietary treatments. The broiler chickens in T3 (millet based diet) recorded significantly (P<0.05) the best feed conversion ratio of 1.62 and the cheapest feed cost per kg weight gain of ^145.90 for finisher phase. Birds fed diet T5 the sweet potatoes based diet gave significantly (P<0.05) poorest values in in FCR, feed cost, weight gain and mortality rate at the starter phase. At the finisher phase, the sweet potato based diet also gave the poorest performance in FCR and feed cost per kg weight gain. The result of carcass showed significant differences (P<0.05) within the treatments in all the parameters measured with the exception of heart and length of intestine. Digestibility trial showed significant (P<0.05) difference in the percent ether extract digestibilities across dietary treatments. Dietary treatments had significant (P<0.05) effect on white and red blood cells. In experiment 2, enzyme with different energy feed sources had significant (P<0.05) effect on all the parameters. Final weight, weight gain, feed conversion ratio, water intake, water:feed ratio and feed cost per kilogramme weight gain with the exception of mortality rate at starter phase. Birds fed the sorghum based diet had the best performance at starter phase with final weight of 627 g, weight gain of 576.85 g and cheapest feed cost/kg gain of ^ 187.95 k. At the finisher phase, sorghum supplemented with enzyme also had the highest final bodyweight, best feed conversion ratio (1.96) and feed cost/kg gain; ^ 171.15 k. The haematological and digestibility results showed significant (P<0.05) differences across dietary treatments. However, based on the results of the studies, dressing percentage was not significantly (P>0.05) difference. It was concluded that millet based diet without enzyme and sorghum based diets with enzyme supplementation can be suitable and effective as an alternative dietary energy source replacement for income in broiler Chicken production.
Nigeria like most other developing countries, suffers greatly from a constant shortage and increasing cost of protein and energy feed resources for livestock (F.A.O., 2000). This situation has become highly magnified due to high competition between livestock and the ever growing human population for the same source of food, particularly energy feed such as maize, sorghum etc. Whereas these feeds form the basic constituents of the ration for the monogastric animals, it also form the major sources of human food (F.A.O., 2002). Feed remains the most expensive input in poultry production with cereal grains constituting more than 40 % of the feed cost. Oyedeji et al. (2003) observed that cost of feeding accounts for about 70 % of cost of production in poultry business. Several workers have emphasized the need for utilizing alternative feed ingredients which have no competition for human (Durunna et al., 1999; Fanimo et al., 2007; Nsa et al., 2010). There is therefore, a dire need for the animal nutritionists to seek for alternatives to the inadequate and expensive alternative feedstuffs to forestall an impending serious food crisis. Some researchers (Kwari et al., 2004; Okah, 2004) have stressed the need for utilization of alternative feed ingredients.
Energy feed sources (maize, sorghum, millet and cassava) are expensive feedstuff, constituting about 50-55% of the formulated poultry diets. Maize a major component of feed is expensive, its productivity is low which means it does not meet its demand for both human and animal needs (Agbede et al., 2002; Hamzat et al., 2003 and Okereke et al., 2006). Maize most often constitutes the highest proportion of ingredient in diet formulation of any poultry ration. Maize is the major source of energy in poultry production accounting
for 45-65% of poultry feeds (Ijaiya et al., 2012). Worldwide, guinea corn (Sorghum bicolar Linn.) and millet grain crops (finger millet (Eleusine coracam) and pearl millet (Pennisetum typhoids) are very important ingredients in poultry diets. Millet is reported to have lower metabolizable energy, higher crude protein, crude fibre and ash than maize and sorghum (Medugu et al., 2011; Ijaiya et al., 2012). Cassava (Manihot esculenta), a high energy crop is available throughout the year in Nigeria. Both cassava and sweet potato have starch as the major component with low protein (2.7-7.9 %) hence obviously needs adequate protein supplementation (Apata and Babalola, 2012). Cassava contain toxic/anti-nutritional factors such as cyanogenic glycosides (cyanide, linamarin, lotaustralin and hydrocyanic acid) which cause bitter taste and reduce palatability of the roots. Sweet potato, (Ipomoea batatas) belongs to the morning-glory family Convalvuceace. It is cultivated primarily in tropical areas and ranked fifth among the most important food crop in the tropics (An, 2004). The few available reports agreed that sweet potato can be incorporated into diets of chicken but should not be made the main source of energy (Afolayan, 2010).
There is a need to evaluate different energy sources so as to make better choices of which to use depending on prevailing circumstances of cost, scarcity and/or abundance. Therefore, information on their use in poultry diets. When prices of the alternative energy sources such as maize is high, information on other possible alternative sources become necessary to keep production on. There is a need to evaluate the effect of enzyme on these sources of energy for optimum poultry production. This study was therefore conducted to evaluate the
effect of some energy sources on the performance of broiler chickens, with and without enzyme supplementation.
1.2 Objectives of the Study
1.2.1 Main Objective To determine the performance of broiler chickens when fed diets containing different energy sources. 1.2.2 Specific Objectives: These were to:
1. Compare the growth performance, nutrient digestibility, haematological parameters and carcass characteristics of broiler chickens fed maize, sorghum, millet, cassava and sweet potatoes as energy sources.
2. Compare the growth performance, nutrient digestibility, haematological parameters and carcass characteristics of broiler Chickens fed maize, sorghum, millet, cassava and sweet potatoes as energy sources with enzyme supplementation.
Ho: There is no significant difference in growth performance, nutrient digestibility, haematological parameters and carcass characteristics of broiler chickens fed maize, sorghum, millet, cassava and sweet potatoes as energy sources, with or without enzyme supplementation.
Ha: There is a significant difference in growth performance, nutrient digestibility, haematological parameters and carcass characteristics of broiler chickens fed maize,
sorghum, millet, cassava and sweet potatoes as energy sources, with or without enzyme supplementation.