Arginine requirements for maintenance and egg production for broiler breeder hens

• Autor(a) principal: Lima, M. B. [UNESP]
• Data de Publicação: 2020
• Outros Autores: Sakomura, N. K. [UNESP], Silva, E. P. [UNESP], Leme, B. B. [UNESP], Malheiros, E. B. [UNESP], Peruzzi, N. J., Fernandes, J. B.K.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.anifeedsci.2020.114466; http://hdl.handle.net/11449/201119
• topic: Amino acid; Breeder roosters; Broiler breeder hen; Efficiency of utilization; Egg production; Nitrogen retention

Two studies were conducted with objective of determine the specific requirements of arginine (Arg) for maintenance using different unit systems; evaluate the response of broiler breeder hens of Ross 308AP genotype to different intakes of arginine, determine amino acid utilization efficiency (k), and develop a factorial model. One nitrogen balance trial (Experiment 1) was performed using 42 roosters and another dose response trial was performed using 64 broiler breeder hens (Experiment 2). The nitrogen balance trial lasted five days with 48 h of fasting (with roosters receiving only water + sucrose) and the last 72 h for feeding and excreta collection. Forty grams of each diet first-limiting in arginine was fed by tube each day (three days) to give a range of intakes from 0 to 18.5 g/kg BW d of arginine. Excreta were collected during the last 3 days of the balance period and the nitrogen content of the excreta was analyzed. A linear regression between nitrogen retention (NR) and arginine intake was performed. The studies were conducted in a complete random design. Were used with 6 treatments, 6 replicates for Experiment 1 and, 8 treatments with 6 replicates for Experiment 2, and one bird per cage. To confirm that the amino acid studied was indeed limiting and that the responses were due to the limitation of the test amino acid and not protein, we added one more treatment consisting of a control diet (totaling 7 treatments for Experiment 1 and 8 treatments for Experiment 2). The diets were formulated by dilution technique using one summit diet and one nitrogen (N)-free diet, resulting in AA levels that ranged from 2.37 to 10.27 g of arginine/kg. The data obtained were AA intake (AAI), body weight (BW), and egg output (EO). Broken line model was used to evaluate the responses. The equation from linear regression was: NR = -39.9 (± 4.5) + 1.8 (± 0.1) × Arg. The arginine required to maintain the body at zero NR were calculated to be 23 mg/kg body weight per day, respectively. For the system unit mg per kg of metabolic weight, the intake of arginine was 36. Considering the degree of maturity of the animal and body protein content the amounts of arginine required for maintenance was calculated to be 151 mg per unit of maintenance protein (BP m 0.73 × u) per day. The values estimated by the model for utilization efficiency was 62 %. The arginine requirement estimated by the model at 30 weeks was 753 mg/day. The prediction of the model was improved using the coefficients estimated here with physiologically relevant units.