Methionine+cystine requirement of broiler chickens fed low-density diets under tropical conditions

Abstract

Two experiments were conducted to determine the M+C requirement of straight-run broiler chickens (Hubbard x Hubbard) during the period 4-21 (Exp. 1) and 21-40 (Exp. 2) days of age. Experiments were conducted during summer months (July-August) in open-sided houses, thus exposing chicks to chronic heat stress. Daily min-max temperature averaged 26-37C (Exp. 1) and 23-36C (Exp. 2). M+C deficient basal diets were formulated to contain low-nutrient-density, i.e., 2750 kcal per kg ME, 20.1% CP (Exp. 1), and 2780 kcal per kg ME, 17.0% CP (Exp. 2). Diets were supplemented with DL-methionine to provide total M+C level ranging from 0.64 to 0.89 % (six increments) and 0.54 to 0.79% (six increments), respectively in experiment 1 and 2. Requirements (0.95 of the maximum quadratic response) were found to be 0.77 and 0.75% total M+C, respectively for gain and feed efficiency, during 4-21 days; and 0.67% total M+C for both gain and feed efficiency during 21-40 days of age. Calculated on the digestible M+C basis, the estimates were 0.67 and 0.65% respectively for gain and feed efficiency during 4-21 days of age; and 0.60% for gain and feed efficiency during 21-40 days of age.

Standardized ileal digestible methionine requirements for 22 to 29-d-old male broilers based on the growth performance and feather development

“…By optimizing Met levels, productivity can be enhanced, and nutrient excretion into the environment reduced, benefiting both the industry and environment. Numerous studies have concentrated on establishing TSAA requirements [3][4][5][6][7], as well as the Met-to-Cys ratio [2]; however, only a few have specifically addressed Met requirements [8][9][10][11]. Furthermore, decades of intensive selective breeding have increased voluntary daily feed intake and enhanced digestive capacity, leading to rapid growth rates in modern broilers [12].…”

“…The Met requirements recommended by the National Research Council [ 13 ] and Rostagno et al [ 14 ] differ from those estimated using empirical methods to determine Met or TSAA requirements. Estimating Met requirements for broilers is complex due to several interacting factors, including estimation methodology [ 15 ], dietary Met sources [ 16 ], and animal-related factors, such as age [ 6 , 7 ], intestinal growth [ 17 ], and onset of feathering [ 3 ]. Moreover, the individual AA needs for broilers may vary depending on dietary nutrient concentrations, body size, and growth stage [ 18 ].…”

Effects of Methionine-Cysteine Amino Acid Supplementations in the Aflatoxin B1 Contaminated Diet on Broiler Production Performance

“…Increased M + C from 75 to 125% generally resulted in significant decrease of feed consumption on each age group of chickens. This was due to sulphuric amino acids (M + C) requirement in feed could increase as the livestock lack of sulphuric amino acids supply, therefore the feed consumption increased to fulfill the content of sulfuric amino acids (Aftab and Ashraf, 2009), thereby 75% M + C level had higher feed consumption than 125% M + C consumption, according to feed consumption data at 7, 14, and 21 days old on Table 5. Ukachukwu et al (2007) explained that the methionine deficiency in feed will lead to increased feed consumption, reduced feed efficiency, stunted growth, fewer feathers, and lipid carcass proportion.…”