摘要
Farrowing duration is rather long in sows most likely due to selection for large litters, and we hypothesized that prolonged farrowings would compromise sow energy status during farrowing and in turn the farrowing process. Two studies were performed as follows: 1) to evaluate whether sow energy status during farrowing compromise the farrowing kinetics (FK, i.e., farrowing duration and birth intervals) and 2) to study the underlying mechanisms potentially affecting stillbirth rate and farrowing assistance. In study-1, parameters affecting FK were characterized based on data from a total of 166 farrowings from 7 feeding trials focused on sow colostrum production. The data were screened for associations with FK using the CORR procedure of SAS. Traits that were correlated with the FK at P < 0.05 were included in a multivariate regression model. Time since last meal until the onset of farrowing greatly affected the farrowing duration (r = 0.76; n = 166; P < 0.001) and a broken-line model was fitted to describe that relationship. According to the model, farrowing duration was constant (3.8 ± 1.5 h) if the farrowing started before the breakpoint (3.13 ± 0.34 h after the last meal), whereas farrowing duration increased to 9.3 h if the farrowing started 8 h after the last meal. Subsequently, sows were divided into 3 categories based on that trait (≤3, 3 to 6, and >6 h) to evaluate the impact on birth intervals, farrowing assistance, and stillbirth rate. Birth intervals (P < 0.001), odds for farrowing assistance (P < 0.001), and odds for stillbirth (P = 0.02) were low, intermediate, and high when time since last meal was ≤3, 3 to 6, and >6 h, respectively. In study-2, blood samples were collected once or twice each week in late gestation and each hour during farrowing to measure arterial concentrations and uterine extractions of plasma metabolites. Time since last meal was strongly negatively correlated with arterial glucose 1 h after the onset of farrowing (r= −0.96; n = 9; P < 0.001). Glucose appeared to be the key energy metabolite for oxidative metabolism of gravid uterus. In conclusion, the present study strongly suggests that a substantial proportion of sows suffer from low-energy status at the onset farrowing and that this negatively affects the farrowing process. Transferring this knowledge into practice, the results suggest that sows should be fed at least 3 daily meals in late gestation.
摘要译文
母猪的分娩时间相当长，这很可能是由于大型窝的选择，我们假设延长的分娩会影响分娩期间的母猪能量状况，进而影响分娩过程。两项研究如下进行：1）评估分娩期间的母猪能量状态是否影响分娩动力学（FK，即分娩时间和分娩间隔）和2）研究可能影响死产率和分娩援助的潜在机制。在研究-1中，影响FK的参数基于来自7个以母猪初乳生产为重点的饲养试验的166个分娩的数据来表征。使用SAS的CORR程序筛选数据与FK的关联。在P 0.05时与FK相关的特征包括在多变量回归模型中。自上次进餐到分娩开始的时间对分娩时间的影响很大（r \x3d 0.76; n \x3d 166; P 0.001），并且拟合了折线模型来描述这种关系。根据该模型，如果分娩在断点之前开始（最后一餐后3.13±0.34小时），分娩持续时间是恒定的（3.8±1.5小时），而分娩持续时间增加到9。如果分娩在最后一餐后8小时开始，则为3小时。随后，根据该特征（≤3,3至6和 6 h）将母猪分为3类，以评估对分娩间隔的影响，分娩援助和死产率。出生间隔（P 0.001），分娩援助的几率（P 0.001）和死产的几率（P \x3d 0.02）低，中间，当自上次餐后的时间分别≤3,3至6和 6小时，并且高。在研究-2中，在妊娠晚期每周一次或两次采集血样，在分娩期间每小时采集一次，以测量血浆代谢物的动脉浓度和子宫提取。在分娩开始后1小时，自上次餐后的时间与动脉葡萄糖强烈负相关（r \x3d -0.96; n \x3d 9; P 0.001）。葡萄糖似乎是妊娠子宫氧化代谢的关键能量代谢物。结论是，本研究强烈表明，相当一部分母猪在分娩时遭受低能量状态，这对分娩过程产生负面影响。将这些知识转化为实践，结果表明母猪应该在妊娠晚期至少每天喂3次。
Takele Feyera;Trine Friis Pedersen;Uffe Krogh;Leslie Foldager;Peter Kappel Theil. Impact of sow energy status during farrowing on farrowing kinetics, frequency of stillborn piglets, and farrowing assistance[J]. Journal of Animal Science, 2018,96(6): 2320–2331