| dc.description.abstract | The effects of two feed enzymes, Allzyme SSF and Nutrase Xylla (NX) and dietary energy level on broiler chicken performance were studied. Three main diets, high energy (HE), medium energy (ME) and low energy (LE) were formulated to provide 100, 95 and 90%, respectively of metabolizable energy requirements of broiler chicken, based on Kenya Bureau of standards. The high energy diet contained 3000 kcal/kg metabolizable energy, while the ME and LE diets contained 2850 and 2700 kcal/kg metabolizable energy, respectively. From the three main diets, nine experimental diets were made by adding or omitting the feed enzymes.
Diets 1, 2 and 3 were HE, ME and LE, respectively, without enzyme addition. Diets 4,5 and 6 were HE, ME, and LE, all with the enzyme Nutrase Xylla added, while diets 7, 8 and 9 were HE, ME and LE, respectively, to which the enzyme Allzyme SSF was added. Both enzymes were included in the feed at the rate of 0.1 gmJ kg of diet. A total of 360 day-old chicks of Arbor acres (unsexed) were randomly divided into the nine dietary treatments each comprising 40 chicks, with four replicates of ten birds per replicate. The design was 3 x3 Factorial Design. The birds were reared, in deep litter pens each measuring 1m2, from 0-49 days post-hatch. Feed and water were provided at libtum.
Data on feed consumption, weight gain, feed conversion ratio and cost of feed was collected. The data was analysed using Genstat Discovery Edition 3. The results showed that from 0-21 days, 22-49 days and for entire feeding phase (0-49 days), feed intake was significantly (P<0.05) improved with birds fed non-supplemented diets compared to supplemented diets with both Nutrase Xylla and Allzyme SSF, except birds fed low energy Allzyme added diets which tended to have significant (P<0.05) feed intake.
Feed conversion ratio during starter, finisher and for entire feeding phase, was significantly (P<0.05) improved at low energy of non-supplemented diets, while it was significantly improved in birds fed Nutrase Xylla throughout of growing period. The addition of exogenous enzymes was effective in overcoming anti-nutritive effects of NSPs on broiler performance only at low energy levels. Body weight gain during starter, finisher and for entire feeding phases, was not affected by enzymes inclusion as body weight gains of non-supplemented diets were higher compared to diets supplemented with exogenous enzymes at high and medium energy levels. The energy level of the diet affected the performance of the birds fed low Allzyme SSF, except FeR where low energy diets added to enzyme did not have any effect. The highest return was obtained from birds fed diets supplemented with Allzyme SSF, while Nutrase Xylla added diets resulted to loss of money.
Keywords:- Allzyme ﾮ SSF, Nutrase Xylla, broiler chickens performance, energy levels, nonstarch polysaccharides (NSPs), economic returns. | en_US |
