Evaluation of Nutritional Strategies Focused on Exogenous Enzymes and Synthetic Amino Acids Aimed at Maximizing Broiler Performance and Nutrient Utilization
MetadataShow full item record
The objective of this research was to evaluate nutritional strategies focused on exogenous enzymes and synthetic amino acids aimed at maximizing broiler performance and nutrient utilization. Four experiments were conducted in total. Three experiments evaluated the use of exogenous enzymes beta-mannanase and xylanase, and a fourth experiment determined the digestible sulfur containing amino acid requirement. In Experiment 1, the dietary inclusion of beta-mannanase improved the growth performance of broilers fed a low energy diet to that of birds fed a high energy control diet. Growth improvement was related to increases in ileal digestible energy (IDE) during the early rearing period (increased by 55 kcal/kg on d17). This observation is linked to the presence of a higher level of soybean meal in the earlier phases of rearing which contains galactomannan, the substrate for beta-mannanase. Experiment 2 further investigated the impact of beta-mannanase in diets with varying galactomannan concentration. Galactomannan content was increased with the addition of guar gum which is a highly concentrated galactomannan. Increasing levels of galactomannan in diets without beta-mannanase negatively influenced growth performance by increasing intestinal viscosity and decreasing IDE. Improvements in digestibility and performance associated with beta-mannanase inclusion were related to the concentration of galactomannan in the diet. In Experiment 3, the necessity of synthetic amino acids was demonstrated as all performance parameters evaluated showed strong relationships for digestible sulfur amino acid (dSAA) level, except for feed intake. The dSAA requirements that maximize d 49 body weight and body weight gain and minimized mortality adjusted FCR and cumulative FCR were 0.793, 0.800, 0.764, and 0.772%, respectively. During experiment 4, the impact of xylanase on multiple corn sources was evaluated. Xylanase increased starter feed consumption and d 18 body weight. Corn source nutrient variation resulted in growth performance differences, and xylanase impact was greater in corn sources that resulted in poorer performance. In summary, this demonstrates the performance benefits of exogenous enzymes and synthetic amino acids which the poultry industry can use to reduce production costs.
Latham, Rocky Edward (2016). Evaluation of Nutritional Strategies Focused on Exogenous Enzymes and Synthetic Amino Acids Aimed at Maximizing Broiler Performance and Nutrient Utilization. Doctoral dissertation, Texas A & M University. Available electronically from