Submitted to: Southern Poultry Science Society Meeting Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 1/20/2004
Publication Date: 1/20/2004
Citation: Hale, L.L., Barber, S.J., Corzo, A., Kidd, M.T., Kerr, B.J. 2004. Isoleucine needs of female broilers: growth and processing measurements. Southern Poultry Science Society Meeting Abstracts. p. 1768. Interpretive Summary:
Technical Abstract: In commercial broiler diets Ile can be limiting after Thr, rendering it the fourth limiting amino acid. Experiments were conducted to evaluate Ile needs in 30 to 42 d old female broilers. Broilers in these Experiments received common diets up to d 30. The Ile test diet was composed of corn, soybean meal, and blood cells, and contained: 3,150 kcal ME/kg, 15.25% CP, 1.05% Lys (0.94% digestible Lys), and 0.42% Ile (0.38% digestible Ile). In Experiment 1, dietary Ile (0.42 and 0.72% of total diet) and broiler strain (A, multipurpose broiler; B, high yield broiler; C, high yield broiler) were evaluated. In Experiment 2, dietary Ile dose responses (0.42 to 0.82% total of diet in 0.08% increments) were evaluated. A corn-soybean meal based control (0.70%) diet was used in Experiment 2. Experiment 1 consisted of a 2 x 3 factorial arrangement of treatments resulting in 5 replications per treatment (30 pens containing 30 broiler each). Experiment 2 contained 12 birds per pen in 48 pens with 7 replications for test diets 1-6 and 6 replications in the control diet. No Ile x strain interactions occurred. Feeding broilers 0.42% Ile suppressed (P < 0.05) BW gain, feed intake, feed conversion, and breast and thigh yields. Differences in BW of strains did not occur. However, strain A had a higher (P < 0.05) feed intake and feed conversion than strains B and C. Differences (P < 0.05) between strains were observed in breast and thigh yields. Birds fed surfeit Ile in the titration diets grew equally (P < 0.05) to birds fed the control diet. Quadratic responses (P < 0.05) were obtained for BW gain, feed intake, feed conversion, and breast meat yield. Optimization of dietary Ile (0.95% of the asymptote) was reached at 0.68, 0.66, 0.68 and 0.63% for BW gain, feed intake, feed conversion, and breast meat yield, respectively. Levels of plasma free Ile displayed a linear response. The 30 to 42 d Ile need for female broilers is between 0.63 and 0.68% total of diet (0.59 to 0.64% digestible Ile).