Abstract

This study evaluated the effects of betaine and pre-slaughter transport of broilers on meat quality, blood parameters, selected water channels (AQP) and stress-related transcripts. Ross 308 broilers (n = 336) were housed in 56-floor pens with seven replicates per treatment. In a 4 × 2 design, broilers were either supplemented with betaine in the feed (0.2%), in drinking water (1 or 2 mL/L), or un-supplemented, and then were transported for 5-min or 4-h pre-slaughter. The results revealed that broilers transported for long-distance had elevated blood glucose pre-slaughter, and their breast meat was characterised with lower initial pH, higher ultimate pH, higher 0-h post-mortem temperature, and lower water holding capacity than those transported for short-distance. Moreover, there was a two-way interaction effect between betaine and transport on the expression of brain genes (Proopiomelanocortin, AQP1, AQP4), muscle glucocorticoid receptor (GR), hepatic AQP3 and AQP9 and intestinal AQP3. Long-distance transport upregulated the relative expression of the muscle AQP9 and downregulated the hepatic GR. Furthermore, betaine in the water at 2 mL upregulated the muscle AQP9 and hepatic GR. In conclusion, betaine could ameliorate the water-deprivation stress associated with transportation by reducing the expression of stress-related transcripts and modulate water channels without improving broiler meat quality.

• HIGHLIGHTS

• Long-distance transport of broilers is stressful, as evidenced by rising blood glucose, high temperature of fresh meat, and expression of stress-related transcripts.

• Betaine could ameliorate the water-deprivation stress associated with transport by reducing the expression of stress-related transcripts and modulating water channels.

摘要

这项研究评估了甜菜碱和屠宰前肉鸡运输对肉品质，血液参数，选择的水通道（AQP）和应激相关转录本的影响。罗斯308肉鸡（n = 336）放在56层的围栏中，每次处理重复7次。在4×2设计中，肉鸡在饲料中添加甜菜碱（0.2％），在饮用水中添加甜菜碱（1或2 mL / L）或不补充，然后运输5分钟或4小时屠宰前。结果表明，远距离运输的肉鸡屠宰前血糖升高，其胸肉的特征是初始pH值较低，最终pH值较高，死后0小时温度更高，持水量较低。对于短距离。此外，甜菜碱和转运对脑基因（Proopiomelanocortin，AQP1，AQP4），肌肉糖皮质激素受体（GR）的表达有双向相互作用。），肝AQP3和AQP9以及肠道AQP3。长途运输上调了肌肉AQP9的相对表达，下调了肝GR。此外，水中的甜菜碱在2 mL时上调了肌肉AQP9和肝GR。总之，甜菜碱可以通过减少应激相关转录本的表达并调节水通道而改善运输过程中的缺水压力，而不会提高肉品质。

• 强调

• 血糖升高，新鲜肉类温度升高以及应激相关转录本的表达证明了肉鸡的长途运输很紧张。

• 甜菜碱可以通过减少应激相关转录本的表达并调节水通道来减轻与运输相关的缺水胁迫。