ABSTRACT
Low crude protein (CP) diets can reduce nitrogen (N) excretion and costs by increasing N utilization efficiency. Exogenous proteases may further improve protein digestibility in low CP diets. This study first evaluated in vitro the efficacy of a multiprotease on amino acid (AA) release from feedstuffs and broiler feed. Later, a broiler study evaluated the effect of feeding corn-soybean meal diets containing 3 CP levels (17, 19, and 21% CP) with supplementation on top of 0 or 2,400 U/kg multiprotease on chicken growth performance, total tract CP, and ileal AA digestibilities, and energy utilization. Ross 708 male chickens were placed in 42 cages and assigned to 6 treatments resulting from a 3 × 2 factorial arrangement. Three isocaloric basal diets were formulated to reduce CP, but all diets maintained digestible Lys:CP in 5.47% and the same ideal protein profile. Data were analyzed in a completely randomized design. On average, the multiprotease increased (P < 0.05) in vitro free AA release by 27.81% in most feedstuffs evaluated compared to the control. For broiler feed, 1,200 U/g multiprotease addition improved (P < 0.001) in vitro free AA release by 18.90%. This multiprotease showed interaction effects (P < 0.05) on chicken FCR, energy, and CP digestibility. As expected, BW at 24 d, BW gain, and FCR (8-24 d) worsened (P < 0.001) as dietary CP reduced from 21 to 17%, and multiprotease addition did not improve (P > 0.05) these parameters. BW gain decreased by 12.9% when N intake was reduced from 49.32 to 38.49 g/bird. Multiprotease supplementation improved (P < 0.01) AMEn by 71 kcal/kg, CP digestibility from 59.45 to 63.51%, ileal AA digestibility, and DM digestibility from 67.08 to 73.49%, but only in the 21% CP diet. No differences in ileal AA digestibility due to CP level (P > 0.05) were detected, except for Cys digestibility (P < 0.01). In conclusion, low CP diets reduced growth performance and improved N utilization but negatively affected energy utilization efficiency. Exogenous multiprotease supplementation improved AME, AMEn, protein, ileal AA, and DM digestibility in the 21% CP diet without significantly affecting growth performance.
Subject(s)
Amino Acids , Animal Feed , Animal Nutritional Physiological Phenomena , Chickens , Diet , Dietary Proteins , Dietary Supplements , Digestion , Energy Metabolism , Animals , Chickens/physiology , Chickens/growth & development , Animal Feed/analysis , Diet/veterinary , Male , Amino Acids/metabolism , Animal Nutritional Physiological Phenomena/drug effects , Energy Metabolism/drug effects , Digestion/drug effects , Dietary Supplements/analysis , Dietary Proteins/metabolism , Dietary Proteins/administration & dosage , Random Allocation , Nutrients/metabolism , Peptide Hydrolases/metabolism , Peptide Hydrolases/administration & dosage , Dose-Response Relationship, DrugABSTRACT
The experiment was conducted to evaluate the feed intake, body weight gain, total energy (kJ), protein (g) intake, energy and protein efficiency ratio (EER, PER), net energy, and metabolic body weight, on two commercial broiler chickens (Arian and Ross 308 strains). Four treatmentsincluded diets formulated based onAMEn(kJ/g) Total Amino Acid (TAA) (T1), AMEn(kJ/g) Digestible Amino Acid (T2), TMEn (kJ/g) Total Amino Acid (T3), and TMEn (kJ/g) Digestible Amino Acid (DAA) (T4) for commercial broilers chickens. The findings of the study indicated that AMEn or TMEn treatments yielded improved utilization of net energy in 42 days, but did not affect the efficiency of dietary AMEn and TMEn for net energy, diet energy and protein efficiency ratio (EER, PER) in broilers. Findings indicated that NE is a better predictor of poultry feeds than AMEn or TMEn. This is attributed to the fact that AMEn had a significant effect on NE and efficiency of AMEn or TMEn and HI (Heat Increment) for NE value. Finally, NE is the final objective of energy evaluation of feed and feedstuffs for poultry nutrition.(AU)
Subject(s)
Animals , Animal Feed/analysis , Animal Feed , Weight Gain , Diet, Food, and Nutrition , Chickens/metabolismABSTRACT
The experiment was conducted to evaluate the feed intake, body weight gain, total energy (kJ), protein (g) intake, energy and protein efficiency ratio (EER, PER), net energy, and metabolic body weight, on two commercial broiler chickens (Arian and Ross 308 strains). Four treatmentsincluded diets formulated based onAMEn(kJ/g) Total Amino Acid (TAA) (T1), AMEn(kJ/g) Digestible Amino Acid (T2), TMEn (kJ/g) Total Amino Acid (T3), and TMEn (kJ/g) Digestible Amino Acid (DAA) (T4) for commercial broilers chickens. The findings of the study indicated that AMEn or TMEn treatments yielded improved utilization of net energy in 42 days, but did not affect the efficiency of dietary AMEn and TMEn for net energy, diet energy and protein efficiency ratio (EER, PER) in broilers. Findings indicated that NE is a better predictor of poultry feeds than AMEn or TMEn. This is attributed to the fact that AMEn had a significant effect on NE and efficiency of AMEn or TMEn and HI (Heat Increment) for NE value. Finally, NE is the final objective of energy evaluation of feed and feedstuffs for poultry nutrition.