Prestage Department of Poultry Science, NC State University, Raleigh NC 27695-7608, USA.
Poult Sci. 2019 Mar 1;98(3):1517-1527. doi: 10.3382/ps/pey463.
The occurrence of wooden breast (WB) and white striping (WS) of broiler breast myopathies may be associated with least-cost feed formulations and the inclusion of greater amounts of synthetic amino acids. Two experiments were conducted to evaluate the effects of supplemental glutamine (Gln-/+, 0 and 1%) and arginine (Arg-/+, 0 and 0.25%) in a 2 × 2 factorial arrangement. Experiment 1 consisted of 8 replicates using 32 pens and focused on live performance to 44 d of age, carcass yield, and meat quality evaluations at 45 d of age. Live performance parameters including feed intake, BW gain, mortality, and feed conversion were evaluated. Post-harvest carcass yield, breast muscle quality (including WB and WS), proximate analysis, and mineral analysis of breast muscle and tibia bone were also evaluated. Experiment 2 comprised 4 replicates using 8 pens with weekly measurements of blood physiology and muscle myopathy development from 21 to 45 d of age. Broilers fed supplemental Gln and Arg (Gln+/Arg+) produced broilers with greater BW and improved FCR. The WB and WS severity increased with Gln+ diets, while only WB increased using Arg+ diets. Weekly observations revealed the greatest increase in WB myopathies occurred between 28 to 35 d, while WS significantly increased one week later (35 to 42 d). When comparing broilers of similar BW at 45 d, Gln+ diets resulted in greater WS scores and percentage breast muscle fat. Further analysis of WB and WS scores (independent of treatment affect) revealed that increased myopathy scores were associated with increased blood CO2, H2CO3, and reduced O2 with increased meat pH, moisture content, and Ca concentration. These results indicated that increased muscle Ca is associated with increased WB, while increased dietary glutamine and lack of oxygen may have resulted in a reverse flux of the citric acid cycle and reduced electron transport chain activity resulting in increased WS.
鸡胸肉木质化（WB）和白条（WS）的发生可能与最低成本的饲料配方和添加更多合成氨基酸有关。进行了两项实验来评估补充谷氨酰胺（Gln-/+，0 和 1%）和精氨酸（Arg-/+，0 和 0.25%）的影响，采用 2×2 析因设计。实验 1 由 32 个栏位的 8 个重复组成，重点关注 44 日龄的活体性能、屠宰率和 45 日龄的肉质评估。评估了活体性能参数，包括采食量、BW 增重、死亡率和饲料转化率。还评估了收获后胴体产率、胸肌质量（包括 WB 和 WS）、肉的近侧分析和胸肌及胫骨的矿物质分析。实验 2由 8 个栏位的 4 个重复组成，每周测量 21 至 45 日龄的血液生理学和肌肉肌病的发展。添加 Gln 和 Arg（Gln+/Arg+）的饲粮可使肉鸡 BW 增加，FCR 提高。用添加 Gln 的饲粮会使 WB 和 WS 的严重程度增加，而用添加 Arg 的饲粮只会使 WB 增加。每周观察结果表明，WB 肌病的最大增加发生在 28 至 35 日龄之间，而 WS 则在一周后（35 至 42 日龄）显著增加。在比较 45 日龄时 BW 相似的肉鸡时，添加 Gln 的饲粮导致 WS 评分和胸肌脂肪百分比更高。对 WB 和 WS 评分（独立于处理效果）的进一步分析表明，增加的肌病评分与增加的血液 CO2、H2CO3 和减少的 O2 以及增加的肉 pH、水分含量和 Ca 浓度有关。这些结果表明，肌肉中 Ca 的增加与 WB 有关，而增加的饲粮谷氨酰胺和缺乏氧气可能导致柠檬酸循环的反向通量和电子传递链活性的降低，从而导致 WS 的增加。
