Barbato Olimpia, Barile Vittoria Lucia, Menchetti Laura, Ricci Giovanni, Achihaei Emilia Larisa, Porcu Cristian, Sotgiu Francesca Daniela, Pasciu Valeria, Berlinguer Fiammetta
Department of Veterinary Medicine, University of Perugia, Via San Costanzo 4, 06126 Perugia, Italy.
Research Centre for Animal Production and Aquaculture, Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria (CREA), Via Salaria 31, 00015 Monterotondo, Italy.
Animals (Basel). 2024 Nov 27;14(23):3427. doi: 10.3390/ani14233427.
To the best of our knowledge, no studies in the literature have reported on the relationship between the pregnancy-associated glycoprotein (PAG) concentration and undernutrition during pregnancy in sheep. Therefore, the aim of this study was to investigate the effects of undernutrition on the blood concentration of PAGs in pregnant ewes carrying single and multiple fetuses, undergoing either dietary energy restriction or receiving 100% of their energy requirements during the period of maximal placenta growth. From d 24 to 100 of pregnancy, the ewes were fed ryegrass hay and two different iso-proteic concentrates, fulfilling either 100% of the ewes' energy requirements (control group; n = 30, 14 singleton pregnancies, 16 multiple pregnancies) or only 50% (feed-restricted group; n = 29; 11 singleton pregnancies, 18 multiple pregnancies). Blood samples were collected from all the ewes the day before intravaginal sponge insertion (T0) and, thereafter, every 30 days starting from d 24 of gestation (T1) until d 30 after parturition (T6), to determine the PAG, progesterone, NEFA, total protein, and glucose concentrations. Our results showed that PAG concentrations are not only influenced by the number of fetuses, but also by the ewe's diet. In particular, the PAG marginal means were higher in the feed-restricted group than in the control group (7.8 ± 0.6 and 10.8 ± 0.9 ng/mL for the control and feed-restricted groups, respectively; = 0.040). This finding confirms that a dietary restriction between d 24 and d 100 of gestation leads to a growth in placental functions as inferred from the increase in the concentration of the PAG levels. Therefore, the measurement of PAG concentrations, in addition to serving as a marker of pregnancy, can also serve as a marker of placental functionality.
据我们所知，文献中尚无关于绵羊妊娠相关糖蛋白（PAG）浓度与孕期营养不良之间关系的研究报道。因此，本研究的目的是调查营养不良对怀有单胎和多胎的妊娠母羊血液中PAG浓度的影响，这些母羊在胎盘生长最快的时期要么接受饮食能量限制，要么获得其能量需求的100%。从妊娠第24天到第100天，给母羊饲喂黑麦草干草和两种不同的等蛋白浓缩饲料，一种满足母羊100%的能量需求（对照组；n = 30，14例单胎妊娠，16例多胎妊娠），另一种仅满足50%（限饲组；n = 29；11例单胎妊娠，18例多胎妊娠）。在阴道海绵栓插入前一天（T0）从所有母羊采集血样，此后，从妊娠第24天（T1）开始，每30天采集一次血样，直至分娩后30天（T6），以测定PAG、孕酮、非酯化脂肪酸、总蛋白和葡萄糖浓度。我们的结果表明，PAG浓度不仅受胎儿数量的影响，还受母羊饮食的影响。特别是，限饲组的PAG边际均值高于对照组（对照组和限饲组分别为7.8±0.6和10.8±0.9 ng/mL；P = 0.040）。这一发现证实，妊娠第24天至第100天的饮食限制会导致胎盘功能增强，这可从PAG水平浓度的增加推断出来。因此，PAG浓度的测定除了可作为妊娠的标志物外，还可作为胎盘功能的标志物。
