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.

Response of Broiler Chicks to Dietary L-Leucine Supplementation in the Starter Period

“…Thus stimulation of protein synthesis by Leu depends on the availability of all essential and non-essential amino acids (Wilson et al 2011); so in diets with sufficient levels of all amino acids, the antagonism between BCAAs and a moderate level of Leu supplementation does not occur. This conclusion is in agreement with Sedghi et al (2015) that dietary excess of Leu is well tolerated when diets contain sufficient levels of Ile and Val.…”

“…The SID Leu requirements were estimated to be 18.67, 18.88, and 19.85 g/kg for BWG, FCR, and breast meat yield, respectively. The SID Leu requirement determined in this study (mean=19.13 g/kg and Leu: Lys ratio=1.594, Table 4) was higher than that of NRC (1994), Farran & Thomas (1990), Baker (2012), Rostagno et al (2011) and Sedghi et al (2015). The difference may be due to levels of other BCAAs in the basal diet, type of the basal diet (purified, semipurified or practical), the genetic potential of modern broilers, and the statistical methods.…”

“…The difference may be due to levels of other BCAAs in the basal diet, type of the basal diet (purified, semipurified or practical), the genetic potential of modern broilers, and the statistical methods. Sedghi et al (2015) estimated dietary SID Leu requirements ranging from 13.45 to 16 g/kg by using different statistical methods. Moreover, the highest BWG and lowest FCR were obtained by dietary SID Leu level of 17.48 g/kg in their field experiment, while researchers did not comment on that.…”

Effect of chitosan oligosaccharide and valine on growth, serum hormone levels and meat quality of broilers

“…The use of COS could promote growth by increasing digestibility and enhancing microbial activity in the gut, whereas Val could enhance muscle protein synthesis (Miranda et al, 2015). Dietary formulations that contained various levels of crude protein supplemented with COS and Val would increase growth performance (Ospina-Rojas et al, 2014;Zhao et al, 2015) and carcass yield in broilers, and lead to an improvement in FCR and efficiency of meat production because broilers are a quick, accessible and cheap source of meat (Sedghi et al, 2015;Ospina-Rojas et al, 2020).…”