Introductions:
Non-starch polysaccharides (NSPs) encapsulated in feed grains' cell walls contain valuable nutrients that may be wasted since some animals' endogenous enzymes cannot digest them. Xylanase feed additives degrade grain cell walls, releasing entrapped nutrients to the animal.
The soluble portion of NSPs increase digesta viscosity, slowing the passage of feed through the digestive system and preventing an animal's natural enzymes from acting upon nutrients in the diet. Certain xylanase feed additives may act to reduce digesta viscosity, improving overall digestion and gut health.
The purpose of this experiment was to evaluate the effect of supplementing Xylamax (1,4-beta-xylanase) on performance of commercial broilers fed decreasing levels of metabolizable energy, under Indian conditions, when broilers were fed corn-soybean meal based diets from 0 to 42 days of age.
Materials and Methods:
2700 Cobb 400 broiler chickens were randomly assigned to 1 of 9 dietary treatments, with 12 replicate pens of 25 birds each. The nine dietary treatments were arranged in a 3 x 3 factorial of metabolizable energy (ME) and Enerxyme inclusion. Birds were reared for 42 days and fed corn-SBM mash diets ad libitum. Feed energy content was adjusted using vegetable oil. ME values of the control treatments were 2,950, 3,000 and 3,100 kcal/kg in the pre-starter (0-14 days), starter (15-28 days) and finisher (29-42 days), respectively. While two other ME levels were 65 kcal/kg and 130 kcal/kg less than the control.
Key Parameters evaluated:
- Body weight gain (BWG)
- Feed Intake (FI)
- Feed conversion ratio (FCR)
Results and Discussion:
The birds fed the 133 g/MT Xylamax diet and diets supplemented at the inclusion rate of 65 g/MT Xylamax diet had similar results in the trial. The following data is for birds fed the 65 g/MT Xylamax diet.
Overall Performance affected by Xylamax
Overall, birds fed Xylamax showed significantly higher BWG (p<0.026) and FCR (p<0.002). On average, BWG improved by 90 g and FCR improved by 5 points.
Overall Performance affected by Energy Level and Xylamax
Body Weight Gain (BWG)
As expected, without supplementation of Xylamax the BWG decreases as the level of energy in the feed drops. There was almost a linear response to the diet energy levels with no Xylamax inclusion. With the supplementation of Xylamax in diets with decreased energy, the improved BWG to be similar to standard energy diets.
Feed Conversion Rate (FCR)
Adding Xylamax to diets regardless of the energy level provided an improvement in FCR. Maximizing feed cost savings by removing 130 kcal/kg of energy and then supplementing Xylamax to that diet yielded an FCR that was similar to the high energy diet with no Xylamax. By removing 65 kcal/kg at of energy and supplementing Xylamax provides a moderate level of feed cost savings but also showed an improvement in the FCR of those birds when compared to the un-supplemented, high-energy diet.
Conclusion:
Based on this trial, Xylamax works well in poultry production conditions and can be used in two ways:
Reformulation: Reduce dietary energy by 130 kcal/kg and supplement Xylamax at 65 g/MT of diet to maintain performance similar to standard dietary energy level.
On-top: Supplementing Xylamax at 65 g/MT of diet in the existing formulation improves FCR by at least 4 points.
Key Findings:
Birds fed diets supplemented with 65 g/MT Xylamax
- Demonstrated 4 to 6 points of FCR improvement
- Improved BWG by 5% to 7%
- Utilized 130 kcal/kg more energy than birds fed diets not containing Xylamax