An evaluation of the effect of storage of a locally produced natural vitamin premix on the performance of laying hens
AbstractOne hundred and eight (108) Harco pullets (38 weeks old and 14 weeks in lay) were fed diets containing a locallyproduced natural vitamin premix (NVP) variously stored for 19, 20, 21, 22 and 23 weeks (to form diets B, C, D, E and F respectively) for 6 weeks; and their performance were compared to a synthetic vitamin premix (SVP) diet (Diet A). Daily feed intake was significantly higher (P<0.05) for the SVP diet (85.16g) than for those obtained for the natural premix diets (B: 79.05g, C: 81.59g, D: 81.19g, E: 81.11g and F: 80.95g), but there were no significant (P>0.05) differences in weekly egg number (A: 67, B:70, C:73, D:70, E: 72 and F: 70), hen day production (A: 53%, B: 56%, C: 58%, D: 56%, E: 57% and F: 55%) and total egg mass in g/bird/week (A: 222.68, B: 234.31, C: 246.87,
D; 231.25, E: 236.04 and F: 227.46) for the different diets. Also, there was no significant (P>0.05) difference among the various dietary treatments in egg specific gravity, egg shell thickness, yolk colour score, yolk index and Haugh Unit, but birds fed the NVP diets produced better feed utilization (kg of feed per dozen eggs laid) and better gross profit values (N) than birds fed the SVP diet. Hence, it can be concluded that the NVP as compounded by Bolu and Balogun (1998) can be stored for about 6 months without the use of any anti-oxidant and give a satisfactory egg laying performance in laying hens.