Nam Nguyen Hoai, Sukon Peerapol
Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam.
Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand.
Arch Anim Breed. 2022 Mar 7;65(1):97-103. doi: 10.5194/aab-65-97-2022. eCollection 2022.
Few studies have investigated risk factors for dystocia in swine, although this birthing abnormality can compromise welfare of both sows and piglets by increasing stillbirth rate and decreasing sow productivity. This study aimed to determine risk factors associated with dystocia at piglet level in cloprostenol-induced farrowings. A dystocia event was recorded when a birth interval exceeded 45 or when manual extraction was applied. Data were collected from 898 piglets born from 77 Landrace Yorkshire crossbred sows, which were induced for farrowing on day 114 of gestation. Generalized linear mixed models (GLMMs) were used to evaluate the association between dystocia and parity, gestation length, litter size, relative birth order (RBO (%) 100 birth order/litter size), birth weight, crown rump length, body mass index, ponderal index, piglet's sex, use of oxytocin, and stillbirth. Sows nested in farrowing batches were fitted as random factors in GLMMs. Incidence of dystocia at piglet and farrowing levels was 11.0 % and 75.3 %, respectively. The final multivariate model explained 20.1 % variation of dystocia. RBO had a quadratic effect on dystocia in which incidence of dystocia decreased from RBO 40 % to RBO 60 %-70 %, and then increased to the end of parturition. Piglets with birth weight 1700 and stillborn piglets had higher odds of dystocia in comparison with piglets with a birth weight of 900-1700 (OR 2.63; 95 % CI 1.66-4.18) and live-born piglets (OR 2.62; 95 % CI 1.12-6.15), respectively. This study indicates that dystocia is very common in cloprostenol-induced farrowings and suggests that the last one-third of parturitions is the most important stage to be supervised, and selection for homogenous litters and moderate high birth weight may reduce the rate of dystocia.
虽然难产这种分娩异常情况会通过提高死产率和降低母猪繁殖力而损害母猪和仔猪的健康，但很少有研究调查猪难产的风险因素。本研究旨在确定氯前列醇诱导分娩时仔猪水平上与难产相关的风险因素。当出生间隔超过45分钟或采用人工助产时，记录为难产事件。收集了77头长白猪与约克夏猪杂交母猪所产898头仔猪的数据，这些母猪在妊娠第114天被诱导分娩。采用广义线性混合模型(GLMMs)评估难产与胎次、妊娠期长度、窝产仔数、相对出生顺序(RBO(%) = 100×出生顺序/窝产仔数)、出生体重、顶臀长度、体重指数、 ponderal指数、仔猪性别、催产素使用情况和死产之间的关联。在GLMMs中，将分娩批次中的母猪作为随机因素。仔猪和分娩水平的难产发生率分别为11.0%和75.3%。最终的多变量模型解释了难产20.1%的变异。RBO对难产有二次效应，其中难产发生率从RBO≤40%降至RBO为60%-70%，然后在分娩结束时又升高。与出生体重为900-1700克的仔猪(OR = 2.63；95%CI = 1.66-4.18)和活产仔猪(OR = 2.62；95%CI = 1.12-6.15)相比，出生体重≤1700克的仔猪和死产仔猪发生难产的几率更高。本研究表明，氯前列醇诱导分娩时难产非常常见，并表明分娩的最后三分之一阶段是最重要的监测阶段，选择均匀的窝产仔数和适度较高的出生体重可能会降低难产率。
