title: Influence of source of soybean meal and lysine content of the diet on performance and total tract apparent retention of nutrients in broilers from 1 to 36 days of age.
abstract: The influence of soybean meal (SBM) source and total Lys content of the diet on performance and total tract apparent retention of nutrients was evaluated in broilers from 1 to 36 d of age. There were 6 treatments arranged factorially with 2 sources of SBM [regular SBM with 46.3% CP (R-SBM) and high-protein SBM with 48.6% CP (HP-SBM)] and 3 Lys:AME(n) ratios (Lys:ME; 380, 415, and 450 mg of total Lys:1,000 kcal of AME(n) from 1 to 21 d; and 312, 338, and 364 mg of total Lys:1,000 kcal of AME(n) from 22 to 36 d of age). From 1 to 36 d of age, broilers fed the HP-SBM diets had higher ADG and better feed:gain ratio (F:G) than broilers fed the R-SBM diets (P < or = 0.001). Both ADG and F:G improved (P < or = 0.05) with increases in the Lys:ME ratio. From 1 to 21 d of age, ADG and F:G (P < or = 0.001) were improved when the Lys:ME ratio increased and the benefits were more pronounced with the diets based on R-SBM. From 22 to 36 d of age, increasing the Lys:ME ratio from 312 to 338 increased ADG (P < or = 0.05) and F:G (P < or = 0.01), but no further improvements were observed when the ratio was increased to 364. The total tract apparent retention of DM and gross energy of the diets were higher (P < or = 0.05) for the HP-SBM than for the R-SBM diets. An increase in the Lys:ME ratio reduced organic matter and N retention (P < or = 0.05). The improvements in growth performance and nutrient retention observed in broilers fed the HP-SBM diets with respect to those fed the R-SBM are consistent with a better availability of nutrients of the high-protein meal. In addition, the results indicate that Lys requirements of broilers are at least, 30, 20, and 8% higher from 1 to 10, 10 to 21, and 21 to 36 d of age, respectively, than current NRC recommendations.
authors.affiliation: Departamento de Producción Animal, Universidad Politécnica de Madrid, Madrid 28040, Spain.
authors.forename: A
authors.initials: A
authors.lastname: de Coca-Sinova
authors.forename: E
authors.initials: E
authors.lastname: Jiménez-Moreno
authors.forename: J M
authors.initials: JM
authors.lastname: González-Alvarado
authors.forename: M
authors.initials: M
authors.lastname: Frikha
authors.forename: R
authors.initials: R
authors.lastname: Lázaro
authors.forename: G G
authors.initials: GG
authors.lastname: Mateos
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002645:Chickens / Q000254:growth & development / Q000378:metabolism*; D004063:Digestion / Q000502:physiology; D004435:Eating / Q000502:physiology; D041981:Gastrointestinal Tract / Q000378:metabolism*; D008239:Lysine / Q000008:administration & dosage*; D011897:Random Allocation; D013025:Glycine max
chemical_list: D008239:Lysine