Relação metionina + cistina / lisina digestível para frangos de corte cobb

Abstract

Em vista da constante evolução do melhoramento genético de frangos de corte, torna-se necessária a determinação das exigências nutricionais dessas aves, para assegurar seu desempenho. Assim sendo, dois experimentos foram realizados, com o objetivo de avaliar diferentes relações de metionina + cistina / lisina digestível sobre o desempenho de frangos de corte, nas fases de 11 a 21 e 22 a 35 dias de idade. O delineamento experimental nas duas fases avaliadas foi o de blocos casualizados, em arranjo fatorial 2x5+2, (2 sexos e 5 diferentes relações met+cis/lis digestível e um tratamento controle para cada sexo), com oito repetições de 23 e 20 aves (COBB 500) por unidade experimental, nas fases descritas. As dietas atenderam às exigências, exceto para metionina + cistina e lisina. Para evitar o excesso de lisina digestível, seu nível foi calculado para 97% do recomendado para todas as fases. O tratamento controle foi adequado em lisina e metionina + cistina. As relações metionina + cistina/lisina digestível, para máximo desempenho de frangos de corte, machos e fêmeas, respectivamente, são de 75,53 e 78,23%, na fase de 11 a 21 dias, e 78,83 e 79,82%, na fase de 22 a 35 dias.

Effects of Nutritional Levels on Performance, Carcass Characteristics and Nutrient Digestibility of Sexed Broilers

“…In this period, an interaction (p<0.05) between factors (sex and diet) was observed in the feed intake (Table 4), with males consuming diets in greater proportion (around 9.3% more) than females. Similar results were reported by Costa et al (2001); Mendes et al (2004); Sabino et al (2004); Kolling et al (2005); Lima et al (2008); Bernal et al (2014) and Tavernari et al (2014), who, when evaluating diets with different levels of crude protein, energy and amino acids in the finisher phase, observed differences regarding sex, in which male broilers showed best performance. FI (g)-Feed intake; BW (g)-Body weight; WG (g)-Weight gain; FC-Feed conversion; VF-Flock viability; PEI-Index of production efficiency.…”

“…However, in order for feed improvement and to change the nutritional levels of the diets, it is necessary to take the interference of the bird's sex into account, since each sex exhibits differentiated metabolic behavior. In other words, the male chicken may require higher amounts of nutrients, in comparison to the female, due to its greater growth capacity (more significant body weight gain), which will be represented in greater absolute weights for eviscerated carcass, thigh, drumstick and, in some cases, larger absolute weights of breast with bone and breast fillet (Sá et al, 2012;Bernal et al, 2014;Tavernari et al, 2014).…”

“…Such progress is a product of the scientific and technological contributions of different areas of study. Nutrition is directly related to this development and may be the area with the greatest impact on production profitability, deserving constant concern to precisely meet the nutritional requirements of birds (Tavernari et al, 2014).…”

Sensitivity of breeding values for carcass traits of meat‐type quail to changes in dietary (methionine + cystine):lysine ratio using reaction norm models

“…Reports involving the search for the ideal amino acid balance in quails and other species are available in the literature (Tavernari et al . ; Rabie & El‐Maaty ; Reda et al . ; Vidal et al .…”

“…Among the amino acids for poultry, methionine is the first limiting and physiologically essential; in addition, this amino acid can be catabolized to cystine, but the inverse does not occur (Ferreira et al 2012). Reports involving the search for the ideal amino acid balance in quails and other species are available in the literature (Tavernari et al 2014;Rabie & El-Maaty 2015;Reda et al 2015;Vidal et al 2015). All of these reports aimed at stablishing the proper feeding approach to maximize quail performance.…”