Use of In vitro Technique in Predicting In vivo Response of Poultry to Enzyme Supplementation

The need for rapid test in evaluation of feedstuffs in poultry nutrition cannot be overemphasized. Such test must however be able to replace exactly the response in the animal concern. This study was conducted to determine the suitability of In vitro technique in predicting the In vivo response of poultry to enzyme supplemented feedstuffs. Rice husk was used in a Completely Randomized Design with individual and cocktail of enzymes for both In vitro and In vivo trials. Three exogenous enzymes namely a xylanase, a multipurpose and a phytase were used individually, pairwise and altogether with the feedstuff to constitute the treatments namely T1, T2, T3, T4, T5, T6, T7, and T8. Each treatment was replicated thrice for both In vitro and In vivo trials. The In vitro trial was done to simulate the chicken digestive system while the In vivo trial was done using the intubation method. Parameters measured for both trials were digestibility values for dry matter, crude protein, ether extract, crude fiber and fiber fractions. All data collected were statistically analyzed using Analysis of Variance procedure and treatment means were separated using Duncan Multiple Range Test. Correlation analysis was carried out to compare the results of both trials. Results show that enzymes individually and as cocktails significantly improved the digestibility of parameters for both In vitro and In vivo trials. Cocktails of enzymes were significantly better than the individual enzymes for dry matter and crude fiber digestibility for both In vitro and In vivo trials. Correlation analysis shows positive correlation (r=0.99, r=0.96, r=0.94, r= 0.86, r=0.78) between In vitro and In vivo trials in most of digestibility values for the rice husk. It was concluded that In vitro trial can be used as both criterion and replacement for In vivo trial when determining the efficacy of exogenous enzymes in poultry nutrition.