Effects of lysine levels of diets formulated based on total or digestible amino acids on broiler carcass composition

Abstract

The study was conducted to evaluate carcass yield and chemical composition of thigh and breast muscles of broilers fed three different lysine requirement levels: high lysine (+10% NRC), standard (NRC) and low lysine (-10% NRC) and two ways of expressing amino acids in feedstuffs (total or digestible amino acids). The results of this study showed that diet formulation based on digestible amino acids significantly influenced breast yield and abdominal fat deposition. The study showed that increasing lysine level (+10% NRC) of diet significantly increased both carcass and breast percentage and also carcass, breast and thigh weight. The interaction between digestible amino acids and lysine requirement levels affected carcass and breast percentage. Feeding broilers high lysine diets (+10% NRC) significantly increased lysine content in breast and thigh. The response to formulation based on digestible amino acids was maximized when broilers received the high lysine level diet.

Performance of Broiler Chickens Fed Low Protein, Limiting Amino Acid Supplemented Diets Formulated Either on Total or Standardized Ileal Digestible Amino Acid Basis

“…al., 2015). This type of difference between TAA and DAA formulation was also reported by earlier studies (Szczurek, 2010; Nasr and Kheiri, 2012). …”

“…During rest of the phases, the feed intake remained similar among the treatments irrespective of differences in the amino acid profile of diets, which follows the “Theory of food intake and growth” proposed by Emmans (1981; 1989) which emphasizes that, birds attempt to grow at their genetic potential, for which they attempt to eat sufficient quantity feed (hence nutrient) required to grow at that rate unless and until the bulkiness of feed or the inability of birds to lose sufficient heat to environment constrains the feed intake. The non-significant pattern of feed intake observed between SIDAA and TAA formulations was also observed by Mairoka et al (2005) and subsequently many studies also reported similar feed intake between TAA and digestible amino acid formulations (Szczurek, 2010; Nasr and Kheiri, 2012). Similar to findings of this study, non-significant effect of low protein limiting amino acid supplemented diets on the feed intake was also observed in previous studies (Narmond et al, 2008; Darsi et al, 2012).…”

Methionine fortified blood meal can replace fish meal in broiler diets

“…This indicated that their capacity to extract and maximize nutrients from the diets (Sibley, 1981) was high compared to others. Absence of significant differences in the weight of liver agreed with the findings of the following authors: Memon et al (2002) when effect of blood meal on the growth and carcass yield of broilers were studied; Khawaja et al (2007) and Nasr and Kheiri (2012) who investigated the effects of lysine levels of diets formulated based on total or digestible amino acids on broiler carcass composition; Ebrahimzadeh et al (2013), El-shinnawy (2015) and Ndelekwute et al (2016) who combined fish meal and blood meal at different proportions and checked for broilers' response in terms of carcass yield and internal organs. Absence of significant differences in the weight of heart and gizzard agreed with the findings of Memon et al (2002) and Khawaja et al (2007).…”

Growth and haematological response of indigenous Venda chickens aged 8 to 13 weeks to varying dietary lysine to energy ratios

“…The difference might be attributed to different breeds used. Broiler chickens require higher lysine levels as they are bred for fast growth (Nasr and Kheiri, ), thus requiring higher lysine to energy ratio in their diets.…”