University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, Arkansas 72701.
University of Arkansas Stable Isotope Lab, Dept. of Biological Sciences, Fayetteville, Arkansas 72701.
Poult Sci. 2018 Feb 1;97(2):531-539. doi: 10.3382/ps/pex306.
A study was conducted to evaluate the effect of sexual maturity on pectoralis major and gastrocnemius muscle protein turnover in broiler breeder pure lines. Protein turnover in skeletal muscle tissue was determined in 4 broiler breeder pure lines (Line A, Line B, Line C and Line D) at 22, 27, 33, 37, 44, and 50 wk of age. A completely randomized design with a factorial arrangement 4 × 6 (4 lines and 6 time periods (ages)) was used. There were 5 replicates per line/time and each hen represented a replicate. Five hens/line at each age were given an intravenous flooding-dose of 15N-phenylalanine (150 mM, 40 atom percent excess (APE) at a dose of 10 mL/kg. After 10 min, birds were euthanized using CO2 asphyxiation and the breast and leg muscle excised and snap frozen in liquid nitrogen for protein turnover analysis. Excreta was collected from each breeder for 3-methyl histidine (3-MH) analysis. There was a significant age effect for the breast muscle fractional synthesis rate (FSR), but no main effects (age and line) for leg muscle FSR. The FSR in breast muscle tissue decreased in hens from wk 22 (first egg) to wk 33 (peak egg production). There was a significant age effect on fractional breakdown rate (FBR) in breast and leg muscle. The FBR in breast muscle increased in hens from wk 22 to wk 33 and remained high through wk 37. Breast muscle FBR significantly decreased in hens from wk 37 to wk 50. The FBR in leg muscle tissue increased in hens from wk 33 to wk 37 and then decreased at wk 50. No line effect was seen for FSR or FBR. There is a large increase in skeletal muscle FBR during the transition for the pullet to sexual maturity with increases in skeletal muscle FBR in the breast and leg muscle through peak egg production. Protein turnover in skeletal muscle tissue is believed to be a source of nutrients for egg production.
一项研究旨在评估性成熟对肉鸡种鸡纯系胸肌和腓肠肌蛋白质周转率的影响。在 22、27、33、37、44 和 50 周龄时，对 4 个肉鸡种鸡纯系（A 系、B 系、C 系和 D 系）的骨骼肌组织蛋白质周转率进行了测定。采用完全随机设计，因子安排为 4×6（4 个系和 6 个时期（年龄））。每个系/时间有 5 个重复，每个母鸡代表一个重复。每个年龄的 5 只母鸡/系接受静脉内 15N-苯丙氨酸（150mM，40 原子百分比过量（APE），剂量为 10mL/kg。10 分钟后，用 CO2 窒息处死鸟类，并切除胸肌和腿肌，在液氮中快速冷冻用于蛋白质周转率分析。从每个种鸡收集排泄物进行 3-甲基组氨酸（3-MH）分析。胸肌的合成率（FSR）有显著的年龄效应，但腿肌 FSR 没有主要的年龄和系效应。从第 22 周（第一枚蛋）到第 33 周（产蛋高峰期），母鸡胸肌组织的 FSR 下降。胸肌和腿肌的分解率（FBR）有显著的年龄效应。从第 22 周到第 33 周，母鸡胸肌 FBR 增加，并一直保持到第 37 周。从第 37 周到第 50 周，母鸡胸肌 FBR 显著下降。从第 33 周到第 37 周，母鸡腿肌组织的 FBR 增加，然后在第 50 周下降。FSR 或 FBR 没有系效应。从育成鸡到性成熟的过渡期间，骨骼肌 FBR 会大幅增加，胸肌和腿肌的骨骼肌 FBR 在产蛋高峰期增加。骨骼肌组织的蛋白质周转率被认为是产蛋的营养来源。
