PERFORMANCE OF STARTER BROILER CHICKENS FED ON A BLEND OF PHYTOBIOTICS AS IN-FEED ANTIBIOTIC REPLACERS

Abstract

The performance of starter Cobb 500 broiler chickens fed on stinging nettle leaf meal (NLM) or whole coriander seed meal (CSM) as feed additives singly and as a blend was investigated. The National Research Council (NRC) (1994) guidelines were followed in formulating the experimental diets. Each of the experiment lasted for 17 days. In experiment one, seven diets were prepared as follows: Control (0%), NLM at 1%, 1.5% and 2% and CSM at 0.5%, 1% and 1.5% dietary inclusion levels. A total of 84 unsexed chicks were weighed and randomly allocated the experimental diets with 4 replicates of 3 chicks each. The aim of the experiment was to get the level with highest Growth rate (GR) for each of the phytobiotic. For experiment two, three diets were utilised; basal diet supplemented with a blend of NLM at 1.5% and CSM at 0.5% inclusion levels (Blend), basal diet supplemented with oxytetracycline hydrochloride powder at the rate of 0.05g/kg of feed (Cox; the positive control) and the Control diet (negative control). A total of 36 unsexed chicks were weighed and randomly allocated to the experimental diets with 4 replicates of 3 chicks each. For both experiments, feed intake (FI) and body weight (BW) were weighed and recorded daily and weekly respectively. Feed conversion efficiency (FCE) and GR were also calculated. For experiment two, ileal nutrient digestibility (IND) and the populations of dominant ileal bacteria (DIB) were determined. Both experiments were laid out in a completely randomized design (CRD) with data being analysed using statistical analysis system (SAS version 9.4) software. Tukey pairwise comparisons were conducted to compare variations among diets where analysis of variance (ANOVA) showed differences at probability values (α = 0.05). Results from experiment one showed that the birds supplemented with NLM at 1% and CSM at 0.5% showed significant mean FI of 162.03g and 193g respectively. Significantly higher GR was recorded for all the dietary treatments; both for NLM and CSM supplemented groups (p<0.05) with the highest GR being 113.56g for NLM at 1.5% and 119.31g for CSM at 0.5%. Birds supplemented with NLM at 2% showed the highest FCE of 7.98 amongst the NLM group and CSM at 1.5% (8.35) for the CSM supplemented group. From the study, supplementing the diets of starter broiler chickens with NLM at 1.5% and CSM at 0.5% resulted to the highest GR. Results from experiment two showed that FI, GR and FCE were significantly (p<0.05) affected by the dietary treatments. The group of birds supplemented with Blend showed higher FI (133.08g), GR (117.10g) and FCE (5.35) as compared to the other dietary treatments. The IND of dry matter (DM) (85.21%), crude protein (CP) (89.86%) and crude fibre (CF) (67.65%) was significantly higher in the groups of birds fed on Blend. For the birds fed on Cox and control diets, the IND of DM and CF was numerically different but non-significant at p<0.05. The CP digestibility was significant for all the diets offered to the experimental animals at p<0.05. Additionally, all diets had a significant effect on the proliferation of ileal bacteria studied at p<0.05. The growth of Escherichia coli (E. coli) was significantly increased by the Control diet (4.56 cfu/ml), with Cox showing the least effect (3.13 cfu/ml). The populations of Clostridium perfringens (C. perfringens) were significantly increased with feeding Control diet (4.69 cfu/ml) but were decreased by Cox diet (2.09 cfu/ml). The Blend had the most significant effect on the growth of Lactobacillus species (spp.) (7.82 cfu/ml), with the Cox diet having the least effect (2.67 cfu/ml). From the study, dietary inclusion of a blend of NLM at 1.5% and CSM at 0.5% can be used as alterative to infeed oxytetracycline in growing of starter broiler chickens in Kenya.