title: Optimisation of broiler chicken responses from 0 to 7 d of age to dietary leucine, isoleucine and valine using Taguchi and mathematical methods.
abstract: Three experiments were conducted to evaluate the applicability of the Taguchi method (TM) and optimisation algorithms to optimise the branch chain amino acids (BCAA) requirements in 0 to 7 d broiler chicks. In the first experiment, the standardised digestible (SID) amino acids and apparent metabolisable energy (AME) values of maize, wheat and soya bean meal were evaluated. In the second experiment, three factors including leucine (Leu), isoleucine (Ile) and valine (Val), each at 4 levels, were selected, and an orthogonal array layout of L16 (4(3)) using TM was performed. After data collection, optimisation of average daily gain (ADG) and feed conversion ratio (FCR) were obtained using TM. The multiobjective genetic algorithm (MOGA) and random search algorithm (RSA) were also applied to predict the optimal combination of BCAA for broiler performance. In the third experiment, a growth study was conducted to evaluate the applicability of obtained optimum BCAA requirements data by TM, MOGA and RSA, and results were compared with those of birds fed with a diet formulated according to Ross 308 recommendations. In the second experiment, the TM resulted in 13.45 g/kg SID Leu, 8.5 g/kg SID Ile and 10.45 g/kg SID Val as optimum level for maximum ADG (21.57 g/bird/d) and minimum FCR (1.11 g feed/g gain) in 0- to 7-d-old broiler chickens. MOGA predicted the following combinations: SID Leu = 14.8, SID Ile = 9.1 and SID Val = 10.3 for maximum ADG (22.05) and minimum FCR (1.11). The optimisation using RSA predicted Leu = 16.0, Ile = 9.5 and Val = 10.2 for maximum ADG (22.67), and Leu = 15.5, Ile = 9.0 and Val = 10.4 to achieve minimum FCR (1.08). The validation experiment confirmed that TM, MOGA and RSA yielded optimum determination of dietary amino acid requirements and improved ADG and FCR as compared to Aviagen recommendations. However, based on the live animal validation trial, MOGA and RSA overpredicted the optimum requirement as compared to TM. In general, the results of these studies showed that the TM may be used to optimise nutrient requirements for poultry.
authors.affiliation: a Animal Science Department, Faculty of Agriculture , Ferdowsi University of Mashhad , Mashhad , Iran.
authors.forename: M
authors.initials: M
authors.lastname: Sedghi
authors.affiliation: a Animal Science Department, Faculty of Agriculture , Ferdowsi University of Mashhad , Mashhad , Iran.
authors.forename: A
authors.initials: A
authors.lastname: Golian
authors.affiliation: b Department of Mechanical Engineering , Ferdowsi University of Mashhad , Mashhad , Iran.
authors.forename: F
authors.initials: F
authors.lastname: Kolahan
authors.affiliation: c Evonik Degussa Iran AG , Tehran , Iran.
authors.forename: A
authors.initials: A
authors.lastname: Afsar
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000822:Animal Husbandry / Q000379:methods*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D002645:Chickens / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D004063:Digestion / Q000187:drug effects; D007532:Isoleucine / Q000378:metabolism*; D007930:Leucine / Q000378:metabolism*; D008297:Male; D008954:Models, Biological; D009751:Nutritional Requirements; D013025:Glycine max / Q000737:chemistry; D014908:Triticum / Q000737:chemistry; D014633:Valine / Q000378:metabolism*; D003313:Zea mays / Q000737:chemistry
chemical_list: D007532:Isoleucine; D007930:Leucine; D014633:Valine