Metzler-Zebeli Barbara U, Siegerstetter Sina-Catherine, Magowan Elizabeth, Lawlor Peadar G, O'Connell Niamh E, Zebeli Qendrim
Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria.
Agri-Food and Biosciences Institute, Agriculture Branch, Hillsborough, Northern Ireland BT26 6DR, UK.
Metabolites. 2019 Feb 25;9(2):38. doi: 10.3390/metabo9020038.
Restrictive feeding influences systemic metabolism of nutrients; however, this impact has not been evaluated in chickens of diverging feed efficiency. This study investigated the effect of ad libitum versus restrictive feeding (85% of ad libitum) on the serum metabolome and white blood cell composition in chickens of diverging residual feed intake (RFI; metric for feed efficiency). Blood samples were collected between days 33 and 37 post-hatch. While serum glucose was similar, serum uric acid and cholesterol were indicative of the nutritional status and chicken's RFI, respectively. Feed restriction and RFI rank caused distinct serum metabolome profiles, whereby restrictive feeding also increased the blood lymphocyte proportion. Most importantly, 10 amino acids were associated with RFI rank in birds, whereas restrictive feeding affected almost all detected lysophosphatidylcholines, with 3 being higher and 6 being lower in restrictively compared to ad libitum fed chickens. As indicated by relevance networking, isoleucine, lysine, valine, histidine, and ornithine were the most discriminant for high RFI, whereas 3 biogenic amines (carnosine, putrescine, and spermidine) and 3 diacyl-glycerophospholipids (38:4, 38:5, and 40:5) positively correlated with feed intake and body weight gain, respectively. Only for taurine, feed intake mostly explained the RFI-associated variation, whereas for most metabolites, other host physiological factors played a greater role for the RFI-associated differences, and was potentially related to insulin-signaling, phospholipase A2, and arachidonic acid metabolism. Alterations in the hepatic synthesis of long-chain fatty acids and the need for precursors for gluconeogenesis due to varying energy demand may explain the marked differences in serum metabolite profiles in ad libitum and restrictively fed birds.
限饲会影响营养物质的全身代谢；然而，这种影响尚未在饲料效率不同的鸡中进行评估。本研究调查了自由采食与限饲（自由采食量的85%）对剩余采食量（RFI，饲料效率指标）不同的鸡的血清代谢组和白细胞组成的影响。在孵化后第33天至37天之间采集血样。虽然血清葡萄糖相似，但血清尿酸和胆固醇分别反映了营养状况和鸡的RFI。限饲和RFI等级导致了不同的血清代谢组谱，限饲还增加了血液淋巴细胞比例。最重要的是，10种氨基酸与鸡的RFI等级相关，而限饲几乎影响了所有检测到的溶血磷脂酰胆碱，与自由采食的鸡相比，限饲组中有3种含量较高，6种含量较低。相关性网络分析表明，异亮氨酸、赖氨酸、缬氨酸、组氨酸和鸟氨酸对高RFI最具鉴别性，而3种生物胺（肌肽、腐胺和亚精胺）和3种二酰基甘油磷脂（38:4、38:5和40:5）分别与采食量和体重增加呈正相关。仅对于牛磺酸，采食量主要解释了与RFI相关的变化，而对于大多数代谢物，其他宿主生理因素对与RFI相关的差异起更大作用，并且可能与胰岛素信号传导、磷脂酶A2和花生四烯酸代谢有关。由于能量需求不同导致的肝脏长链脂肪酸合成改变和糖异生对前体的需求，可能解释了自由采食和限饲鸡血清代谢物谱的显著差异。
