Babacanoğlu Çakır Elif
Animal Science Department, Faculty of Agriculture, Van Yuzuncu Yil University, Van, Türkiye.
BMC Vet Res. 2025 Mar 27;21(1):210. doi: 10.1186/s12917-025-04670-7.
L-carnitine, derived from methionine and lysine, is present in plasma and tissues as free active carnitine in poultry. L-carnitine (L-car) plays a role in mitochondrial metabolism by enhancing β-oxidation and as an antioxidant molecule in the mitochondria. L-car synthesis is limited during embryonic development of birds. Therefore, the aim of this study was to investigate the influence of intra-amniotic injection of L-car on total antioxidant status (TAS) in tissues, plasma testosterone level and developmental parameters in male broiler chicks at the posthatching stage. The 360 eggs used as experimental material were divided into 3 groups: a non-injection group (control group) and in ovo (IO) injection groups, which were pure water (PW) group, or pure water + L-carnitine (PW + L-car) group. The 2.5 mg of L-car in 500 µl of PW was injected to fluid of the amnion membrane at day 18 of incubation. The total antioxidant status in the yolk before incubation and yolk membranes at day 19 of incubation and at hatching was analysed. Blood plasma testosterone and liver TAS levels were measured at hatching and at days 3 and 7 of age. Organ development, morphological characteristics and relative asymmetry (RA) of bilateral lengths were quantified at the same measuring days.
The TAS levels of yolk and residual yolk membranes decreased in comparison to the TAS in the initial yolk. The TAS in yolk membrane was higher than in residual yolk membrane in the IOPW + L-car group. Male chicks in the IOL-car group had the lowest TAS level in the liver at day 3 of age. Plasma testosterone level was significantly found higher in the IOPW + L-car group than in the other groups at all the ages. The chick development was not affected by IOPW + L-car injection. At hatching, IOPW + L-car group had shorter beak, face and middle toe lengths and lower RA of face length than control group at day 7 of age.
In conclusion, IOPW + L-car injection reveals age-related effects on tissue TAS levels and increases testosterone level interacted with the formation of the hypothalamic-pituitary-testicular axis of male broiler chicks at posthatching stage.
L-肉碱由蛋氨酸和赖氨酸衍生而来，在家禽的血浆和组织中以游离活性肉碱的形式存在。L-肉碱（L-car）通过增强β-氧化作用在线粒体代谢中发挥作用，并作为线粒体中的抗氧化分子。鸟类胚胎发育期间L-肉碱的合成受限。因此，本研究的目的是探讨孵化后阶段羊膜腔内注射L-肉碱对雄性肉鸡雏鸡组织总抗氧化状态（TAS）、血浆睾酮水平和发育参数的影响。用作实验材料的360枚鸡蛋被分为3组：非注射组（对照组）和卵内（IO）注射组，后者又分为纯水（PW）组和纯水+L-肉碱（PW+L-car）组。在孵化第18天，将500μl纯水中的2.5mg L-肉碱注射到羊膜腔内。分析孵化前蛋黄以及孵化第19天和出雏时卵黄膜中的总抗氧化状态。在出雏时以及3日龄和7日龄时测量血浆睾酮和肝脏TAS水平。在相同测量日对器官发育、形态特征和双侧长度的相对不对称性（RA）进行量化。
与初始蛋黄中的TAS相比，蛋黄和残留卵黄膜中的TAS水平降低。在IOPW+L-car组中，卵黄膜中的TAS高于残留卵黄膜中的TAS。IOL-car组的雄性雏鸡在3日龄时肝脏中的TAS水平最低。在所有年龄段，IOPW+L-car组的血浆睾酮水平均显著高于其他组。IOPW+L-car注射未影响雏鸡发育。出雏时，IOPW+L-car组在7日龄时的喙、面部和中趾长度比对照组短，面部长度的RA较低。
总之，IOPW+L-car注射对组织TAS水平显示出与年龄相关的影响，并增加了睾酮水平，这与孵化后阶段雄性肉鸡雏鸡下丘脑-垂体-睾丸轴的形成相互作用。
