Abstract:
The current study investigated the effects of intermittent feeding (IF) and fasting strategies at different times post-hatch on muscle growth and white striping (WS) breast development. In the first trial, 32 one-day-old Abor Acre broilers were fed ad libitum (AL) for 3 d post-hatch and then randomly allotted into 4 feeding strategies including AL, 1h-IF group (1 h IF, 4 times feeding/d, 1 h each time), 1.5h-IF (1.5 h IF, 4 times feeding/d, 1.5 h each time), and fasting (1d acute fasting, 6 d free access to feed) groups and fed for 7 d. Although angiogenic genes including VEGFA, VEGFR1, and VEGFR2, and myogenic genes including MYOG and MYOD were upregulated (P < 0.05), the breast muscle satellite cell (SC) number and PAX7, MYF5 expression were decreased by the IF strategies (P < 0.05). One-day fasting at 6 d of age also upregulated angiogenic genes and MYOD expression (P < 0.05), downregulated MYF5 expression (P < 0.05), but did not change SC number (P > 0.05). In the second trial, 384 one-day-old birds were fed AL for 1 wk and then randomly allotted to the above 4 feeding strategies starting at 8 d of age until 42 d of age. Similarly, IF and fasting strategies upregulated the expression of angiogenic and myogenic genes (P < 0.05). Both 1h-IF and 1.5h-IF increased breast muscle SC number (P < 0.05). At slaughter, breast muscle fiber diameter of 1.5h-IF was smaller but the SC number was larger than that of the birds fed AL (P < 0.05). The IF and fasting strategies prevented WS development, and reduced breast WS scores and triglyceride content (P < 0.05) without changing the body weight (P > 0.05). Fasting and 1h-IF reduced the expression of adipogenic genes ZNF423 and PDGFRα (P < 0.05). Moreover, IF and fasting strategies reduced fibrosis in breast muscle and reduced skeletal muscle-specific E3 ubiquitin ligases (TRIM63 and MAFBX) (P < 0.05). Fasting significantly reduced CASPASE-3 in breast muscle (P < 0.05). In conclusion, IF starting in the first week decreases SC number. Compared to AL, IF or fasting promotes muscular angiogenesis, increases SC number, prevents muscle degeneration, and prevents the development of WS without impairing the growth performance of broiler chickens.
摘要:
目前的研究调查了间歇喂养(IF)和禁食策略在孵化后不同时间对肌肉生长和白条纹(WS)乳房发育的影响。在第一次审判中,32只1日龄AborAcre肉鸡在孵化后随意饲喂(AL)3d,然后随机分配到4种饲喂策略中,包括AL,1h-IF组(1hIF,4次饲喂/d,每次1小时),1.5h-IF(1.5hIF,4次饲喂/d,每次1.5h),和禁食(1d急性禁食,6d自由进入饲料)组,喂养7d。尽管血管生成基因包括VEGFA,VEGFR1、VEGFR2和MYOG、MYOD等生肌基因表达上调(P<0.05),IF策略降低了乳腺肌肉卫星细胞(SC)数量和PAX7,MYF5的表达(P<0.05)。6d时禁食1天也上调血管生成基因和MYOD表达(P<0.05),MYF5表达下调(P<0.05),但SC数没有改变(P>0.05)。在第二次审判中,向384只一天大的禽类喂食AL1周,然后从8日龄开始随机分配上述4种喂养策略,直到42日龄。同样,IF和禁食策略上调血管生成和生肌基因的表达(P<0.05)。1h-IF和1.5h-IF均增加胸肌SC数(P<0.05)。在屠杀时,1.5h-IF的胸肌纤维直径较小,但SC数量大于饲喂AL的禽类(P<0.05)。IF和禁食策略阻止了WS的发展,乳腺WS评分和甘油三酯含量降低(P<0.05),但不改变体重(P>0.05)。空腹和1h-IF降低了成脂基因ZNF423和PDGFRα的表达(P<0.05)。此外,IF和禁食策略可减少胸肌纤维化并减少骨骼肌特异性E3泛素连接酶(TRIM63和MAFBX)(P<0.05)。禁食显著降低胸肌CASPASE-3(P<0.05)。总之,如果在第一周开始减少SC数量。与AL相比,如果或禁食促进肌肉血管生成,增加SC号,防止肌肉退化,并在不损害肉鸡生长性能的情况下阻止WS的发展。