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ARS Home » Southeast Area » Fayetteville, Arkansas » Poultry Production and Product Safety Research » Research » Publications at this Location » Publication #420723
Research Project: Developing Best Management Practices for Poultry Litter to Improve Agronomic Value and Reduce Air, Soil and Water Pollution

Location: Poultry Production and Product Safety Research

Title: Male Cobb 500 broiler responsiveness to reduced crude protein-amino acid supplemented grower diets

Author
item NELSON, KENNETH - University Of Arkansas
item WELLS-CRAFTON, SAVANNAH - University Of Arkansas
item SLICK, VIRGINIA - University Of Arkansas
item GREENE, ELIZABETH - University Of Arkansas
item Moore, Philip
item KIDD, MICHAEL - University Of Arkansas

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Sustained feed-grade amino acid (AA) production will provide dietary least cost formulation flexibility. However, broiler diets formulated to the sixth or seventh limiting AA can compromise live performance. Therefore, the objective of this experiment was to assess broiler responsiveness to reduced CP diets supplemented with various AA and a probiotic. Cobb 500 broiler chicks were placed in floor pens (0.11 m2/bird) containing new pine shavings, nipple drinkers, and ad libitum pan feeder access. After a 14-d common feed, birds were offered 8 treatment diets from 15 to 35 d of age (6 replicate pens per treatment). Treatments diets represented: 1) a positive control (21.5% CP, 3,000 kcal/kg ME, and 1.18% digestible Lys); 2) as 1 minus 3% CP and formulated to be equal in ME and AA to Trp; 3) as 2 plus L-His and L-Phe; 4) as 2 plus Gly and L-Pro; 5) as 2 plus L-Ala and L-Gln; 6) as 2 plus L-His, L-Phe, Gly, L-Pro, L-Ala, and L-Gln; 7) as 2 plus Bacillus subtilis (probiotic); and 8) as 6 plus probiotic. Supplemental His (0.20%), Phe (0.69%), Gly (0.73%), and Pro (0.35%) were added to equal digestible levels in treatment 1 and treatments 5, 6, and 8 had equal CP to treatment 1 from a 1:1 blend of L-Ala and L-Gln. Treatments were randomly distributed in a complete block design and pen was the experimental unit. Live performance by pen was assessed from 15 to 35 d and processing yields (4 birds per pen) at 36 d of age. Intestinal permeability was assessed (1 bird per pen) by FITC-dextran assay at 35 d. All data were subjected to a one-way ANOVA using JMP Pro 17.0 with significance established as P '' 0.05 and significant means separated using a Tukey’s HSD test. Reducing CP by 3% in treatment 2 compromised BW gain (P < 0.001) by 7.4% and feed conversion (FCR) (P < 0.001) by 18 points compared to treatment 1. Only numerical differences in feed intake were observed (P > 0.05). Similar trends were observed for carcass traits, with treatment 2 having reduced (P '' 0.05) breast filet and tender yields with an increased (P < 0.001) percentage peritoneal fat compared to treatment 1. Separate AA additions in treatments 3, 4, and 5 resulted in statistically similar BW gains as treatment 1, but FCR remained inferior, albeit that treatments 4 and 5 were improved over treatments 2 and 3. However, all AA added in concert in treatments 6 and 8 restored BW gain, FCR, and carcass traits (P > 0.05) to values observed for treatment 1, in addition to having increased (P < 0.001) footpad lesion scores of 0. Treatments did not impact (P > 0.05) intestinal permeability. Results from this study indicate non-essential N was likely first limiting in the reduced CP diet followed by either His, Phe, Gly, Pro, or their combination.