Palma Mariana, Hernández-Castellano Lorenzo E, Castro Noemí, Arguëllo Anastasio, Capote Juan, Matzapetakis Manolis, de Almeida André Martinho
Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
Mol Biosyst. 2016 Jun 21;12(7):2094-107. doi: 10.1039/c5mb00851d.
Goats are of special importance in the Mediterranean and tropical regions for producing a variety of dairy products. The scarcity of pastures during the dry season leads to seasonal weight loss (SWL), which affects milk production. In this work, we studied the effect of feed-restriction on two dairy goat breeds, with different tolerance levels to SWL: the Majorera breed (tolerant) and the Palmera breed (susceptible). Nuclear magnetic resonance (NMR) was used to compare the metabolome of an aqueous fraction of the mammary gland and milk serum from both breeds. Goats in mid-lactation were divided by breed, and each in two feed-regime groups: the control group and the restricted-fed group (to achieve 15-20% reduction of body weight at the end of the experiment). Milk and mammary gland samples were collected at the end of the experimental period (23rd day). (1)H NMR spectra were collected from the aqueous extract of the mammary gland biopsies and the milk serum. Profiling analysis has led to the identification of 46 metabolites in the aqueous extract of the mammary gland. Lactose, glutamate, glycine and lactate were found to be the most abundant. Analysis of milk serum allowed the identification of 50 metabolites, the most abundant being lactose, citrate and creatine. Significant differences were observed, in mammary gland biopsies and milk serum, between control and restricted-fed groups in both breeds, albeit with no differences between the breeds. Variations seem to be related to metabolism adaptation to the low-energy diet and are indicative of breed-specific microflora. Milk serum showed more metabolites varying between control and restricted groups, than the mammary gland. The Majorera breed also showed more variations than the Palmera breed in milk samples, which could be an indication of a prompt adaptation to SWL by the Majorera breed.
山羊在地中海和热带地区对于生产各种乳制品具有特殊重要性。旱季牧场资源稀缺会导致季节性体重减轻（SWL），进而影响产奶量。在这项研究中，我们研究了限饲对两种对SWL耐受水平不同的奶山羊品种的影响：马约雷拉品种（耐受型）和帕尔梅拉品种（敏感型）。利用核磁共振（NMR）比较了这两个品种乳腺水相部分和乳清的代谢组。处于泌乳中期的山羊按品种分组，每组再分为两个饲料供应组：对照组和限饲组（在实验结束时体重减轻15 - 20%）。在实验期结束时（第23天）采集牛奶和乳腺样本。从乳腺活检组织的水提取物和乳清中收集氢核磁共振（¹H NMR）谱。谱图分析已鉴定出乳腺水提取物中的46种代谢物。发现乳糖、谷氨酸、甘氨酸和乳酸含量最为丰富。对乳清的分析鉴定出50种代谢物，含量最丰富的是乳糖、柠檬酸盐和肌酸。在两个品种的乳腺活检组织和乳清中，对照组和限饲组之间均观察到显著差异，尽管品种之间无差异。这些变化似乎与对低能量饮食的代谢适应有关，表明存在品种特异性微生物群。与乳腺相比，乳清中对照组和限饲组之间变化的代谢物更多。在牛奶样本中，马约雷拉品种的变化也比帕尔梅拉品种更多，这可能表明马约雷拉品种能迅速适应SWL。
