Effects of β-mannanase-based enzyme in corn-soy and corn-soy-canola diets on broiler performance

Abstract

A 2 × 2 factorial experiment was conducted to evaluate the effects of dietary partial replacement of soybean meal (SBM) by canola meal (CM) with and without a β-mannanase-based enzyme on growth performance of broilers. A total number of 360 one-day-old broiler chicks were weighed and allocated to four iso-caloric and iso-nitrogenous diets, each of which had 9 pens of 10 chicks with the same number of both sexes. Starter, grower and finisher diets were offered to birds from 0 to 21 day, 22 to 42 day and 43 to 49 day of age, respectively. All experimental data were subjected to the general linear model procedure of SAS as a complete randomised design. Dietary partial replacement of SBM by CM decreased body weight (BW) of broilers on days 21, 42 and 49 of age. Dietary CM inclusion decreased and increased feed intake (FI) of broilers during starting and finishing periods, respectively. Broilers fed corn-SBM diet shown improved feed conversion ratio (FCR) in comparing to those fed corn-CM diet during all rearing periods. Dietary enzyme supplementation improved BW of birds on 21, 42 and 49 days of age. Dietary β-mannanase supplementation improved feed conversion ratio feed conversion ratio (FCR) during growing as well as whole periods; but FI of birds was not affected by enzyme. Dietary inclusion of CM increased the relative weights of gizzard, liver, pancreas, fat pad, duodenum, jejunum and ileum; however, the relative length of digestive tracts was increased in CM-included dietary group. The relative weights of gizzard, fat pad, liver, pancreas and digestive tracts were not affected by dietary enzyme supplementation. Litter pH on week 7 was higher in corn-SBM in comparing to corn-SBM-CM dietary group. In conclusion, broilers fed CM-included diets did not achieve similar performance compared to corn-SBM control group. Dietary β-mannanase supplementation improved performance of broilers fed corn-SBM- and/or corn-SBM-CM-based diets.

Keywords:

• soybean meal
• canola meal
• β-mannanase
• performance
• broilers

Acknowledgements

Appreciation is expressed to Research Sector of Razi University, Kermanshah, Iran, for financial and material support of this research. The authors are also grateful to Dr. B.A. Slominski, Department of Animal Science, University of Manitoba and Dr. W.E. Huff, United States Department of Agriculture; Poultry Research Laboratory, University of Delaware, for their kind and scientific guidance for the present study.