本研究调查了与热带环境中自由分娩系统中年轻高产母猪死产发生率相关的因素。共有57头长白猪×约克郡母猪的714头活产仔猪和54头死产仔猪,平均奇偶校验为2.7±1.0(范围:1-4),进行了全面调查。母猪的繁殖变量,包括妊娠长度,分娩时间,每窝出生的仔猪总数,每只仔猪的出生顺序和状况,被记录下来。活产和死胎仔猪生理特性的差异,例如出生间隔,累计出生间隔,出生时的体重,皇冠臀部长度,体重指数(BMI),黄指数(PI),胎粪染色评分,以及脐带断裂的仔猪的百分比,进行了分析。根据出生顺序的四分位数(Q1-Q4)将仔猪分为四组。平均而言,分娩时间为173.3±85.9分钟,每产仔仔猪总数和活产仔猪数分别为14.1±3.8和12.5±3.5。死胎发生率为6.7%(54/801仔猪)。在产仔数较大的母猪中检测到较高的死胎百分比(≥17只仔猪,10.9%)与小(≤13只仔猪相比,6.1%)和中度(14-16只仔猪,2.8%)产仔数(p<.001)。凋落物Q3和Q4的死胎发生率高于Q1和Q2(p<.001)。与活产仔猪相比,死胎仔猪的累积出生间隔较高(103.0±3.71vs.142.4±9.35min,p<.001),BMI(17.1±0.15vs.18.4±0.39kg/m2,p=.002),PI(63.7±0.59vs.70.8±1.59kg/m3,p<.001),胎粪染色评分(1.78±0.04vs.2.04±0.10,p=.021),和出生时脐带破裂的仔猪百分比(45.2%vs.66.0%,p=.004)。在第一头仔猪出生后60、120、150、180和≥210分钟检测到死胎发生率增加,与分娩前30分钟内出生的人相比(p<0.05)。总之,研究发现,年轻时的死胎,多产母猪与几个因素有关:产仔数大(每窝仔猪≥17只),延长的累积出生间隔(142.4分钟),BMI升高18.4kg/m2,PI高70.8kg/m3,胎粪染色得分增加,脐带破裂的发生率较高。为了降低死产的风险,特别是在分娩过程后期出生的身体指数高的仔猪中,建议加强对年轻母猪的产仔监督,从60分钟的累积出生间隔开始。
The present study investigated factors associated with the incidence of stillbirth in young hyper-prolific sows within free farrowing systems in tropical environments. A total of 714 live-born and 54 stillborn piglets from 57 Landrace × Yorkshire sows, with an average
parity of 2.7 ± 1.0 (range: 1 - 4), were comprehensively investigated. Reproductive variables of the sows, including gestation length, farrowing duration, the total number of piglets born per litter, and the birth order and status of each piglet, were recorded. Differences in the physiological characteristics of live-born and stillborn piglets, such as birth interval, cumulative birth interval, body weight at birth, crown-rump length, body mass index (BMI), ponderal index (PI), meconium staining score, and the percentage of piglets with a broken umbilical cord, were analysed. Piglets were divided into four groups based on the quartiles of birth order (Q1-Q4). On average, the duration of farrowing was 173.3 ± 85.9 min, and the total number of piglets born and number of piglets born alive-per litter were 14.1 ± 3.8 and 12.5 ± 3.5, respectively. The incidence of stillbirth was 6.7% (54/801 piglets). The higher percentages of stillbirths were detected in sows with large litter sizes (≥17 piglets, 10.9%) compared to those with small (≤13 piglets, 6.1%) and moderate (14 - 16 piglets, 2.8%) litter sizes (p < .001). The incidences of stillbirth in Q3 and Q4 of the litters were higher than in Q1 and Q2 (p < .001). Compared to live-born piglets, stillborn piglets had higher cumulative birth interval (103.0 ± 3.71 vs. 142.4 ± 9.35 min, p < .001), BMI (17.1 ± 0.15 vs. 18.4 ± 0.39 kg/m2, p = .002), PI (63.7 ± 0.59 vs. 70.8 ± 1.59 kg/m3, p < .001), meconium staining scores (1.78 ± 0.04 vs. 2.04 ± 0.10, p = .021), and the percentage of piglets born with a ruptured umbilical cord (45.2% vs. 66.0%, p = .004). An increase in the incidence of stillbirth was detected at 60, 120, 150, 180, and ≥ 210 min after the first piglet was born, compared to those born within the first 30 min of farrowing (p < .05). In conclusion, the study found that stillbirths in young, hyper-prolific sows were linked to several factors: large litter sizes (≥17 piglets per litter), prolonged cumulative birth intervals (142.4 min), elevated BMI of 18.4 kg/m2, high PI values of 70.8 kg/m3, increased meconium staining scores, and a higher occurrence of ruptured umbilical cords. To reduce the risk of stillbirth, particularly among piglets with high body indices born later in the birthing process, it is recommended to enhance farrowing supervision for young sows, starting at a cumulative birth interval of 60 min.