Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/10/2004
Publication Date: 7/25/2004
Citation: Corzo, A., Kidd, M.T., Burnham, D.J., Branton, S.L., Kerr, B.J. 2004. Interrelationship of threonine and glycine in growing broilers. Poultry Science Association Meeting. v. 83(Suppl. 1). Abstract W6. p. 314. Interpretive Summary: abstract only, no summary required
Technical Abstract: Threonine has the capability of partially sparring Gly in chickens. However, there is little information regarding this interconversion and the impact it has on growing broilers. A study was conducted to evaluate possible Thr and Gly interactions in growing broilers. Day-old Ross 508 male chicks were placed into 30 floor pens of a curtain sided house (14 chicks/pen). Chicks were given a common corn-soybean meal starter diet (3100 kcal ME/kg; 23.0% CP) from 0 to 21 d of age. At 21 d of age, floor pens were equalized in bird number (12 broilers/pen). Birds were fed a corn-soybean meal basal diet (3150 kcal ME/kg; 18.2% CP) with two total Gly+Ser levels (1.55 vs 1.65% of diet) and three digestible Thr levels (0.57, 0.61, and 0.65% of diet) from 21 to 42 d of age. Dietary treatments were generated by the addition of crystalline Gly or L-Thr at the expense of a filler. Two-way interactions (P < 0.05) were observed for BW gain where broilers fed the 1.55% Gly+Ser diets increased BW gain with Thr supplementation, while those fed 1.65% Gly+Ser were unaffected by dietary Thr. Similarly, whole carcass weight and yield increased (P < 0.05) with Thr supplementation when broilers were fed 1.55% Gly+Ser, but not observed when Gly+Ser was incremented to 1.65%. In parallel with previous effects, total breast meat weight responded in a similar fashion (P < 0.05), while its yield as well as percentage abdominal fat were unaffected by either Gly+Ser or Thr. Plasma free concentrations of Ser and Gly were increased (P < 0.01) as Gly was supplemented, but Thr was unaffected by Gly. As expected, plasma free Thr only increased (P < 0.01) with Thr supplementation. There appears to be an interrelationship between Gly+Ser and Thr, but practical implications are elusive at this point. Further research is warranted to clarify such effects.