Risk factors associated with dystocia in swine

Influence of prepartum feed levels on colostrum production and farrowing performance in highly prolific sows in a tropical environment

Currently, there is a lack of data on the effects of altering feed levels on sow performance and piglet characteristics during the transition period in tropical environments. The present study determined the effect of sow feed levels during the transition period on colostrum yield, colostrum immunoglobulin (Ig) G, colostrum intake of piglets, farrowing duration, proportion of stillborn piglets per litter (SB) and the incidence of farrowing assistance in highly prolific sows. A total of 114 Landrace × Yorkshire crossbred sows and their offspring (n = 2 072) were included in the experiment. Sows were assigned to different feed supply levels from entry to farrowing at 110 days of gestation until farrowing based on their parity number. Three feed-level groups were the control group who received 3.0 kg/day of lactation feed (n = 40), treatment 1 group who received 3.6 kg/day of gestation feed (n = 39) and treatment 2 group who received 4.0 kg/day of lactation feed (n = 35). Colostrum samples (5 ml) were obtained from the sows within 3 h after the onset of farrowing for IgG assay. Piglets were weighed immediately after birth and then again 17-24 h later to estimate their colostrum intake. Colostrum yield was determined by aggregating the colostrum intake of piglets within the litter. The total number of piglets born, SB and farrowing duration were 18.2 ± 3.8, 7.5% and 259.1 ± 138.1 min, respectively. Among these sows, 28.9% experienced a farrowing duration exceeding 300 min and 50.9% required assistance during farrowing. Interestingly, piglets in the treatment 2 group demonstrated a greater colostrum intake (403.1 ± 14.9 g) compared to the control group (360.6 ± 15.1 g, P = 0.046) and the treatment 1 group (361.0 ± 12.9 g, P = 0.033). On average, colostrum yield of sows in the treatment 2 group tended to be higher than in the control group (+0.5 kg, P = 0.081), but did not differ from the treatment 1 group (+0.3 kg, P = 0.191). No significant differences in farrowing duration, SB, farrowing assistance, or colostrum IgG concentration were found across various feed-level groups (P > 0.05). In conclusion, the study showed that raising lactation feed by 1.0 kg/day prefarrowing increased piglet colostrum intake and tended to boost sow colostrum production, without significantly affecting farrowing duration, stillbirth rates, or need for assistance.

Factors associated with farrowing assistance in hyperprolific sows

OBJECTIVE

The present study was performed to determine risk factors associated with the frequency of farrowing assistance in hyperprolific sows in a tropical environment and to investigate the impacts of farrowing assistance on piglet colostrum consumption and sow colostrum yield.

METHODS

Farrowing data from 352 Landrace×Yorkshire crossbred sows and 5,554 piglets in five commercial swine herds in Thailand were investigated. The sows were classified according to parity numbers: 1 (n = 72), 2 to 4 (n = 128), 5 to 6 (n = 84), and ≥7 (n = 68) and the total number of piglets born per litter (TB): 10 to 13 (n = 90), 14 to 16 (n = 117), and ≥17 (n = 145). The incidence of farrowing assistance and associated parameters were investigated.

RESULTS

The TB and farrowing duration averaged 15.8±0.2 and 279.9±11.2 min, respectively. The percentage of sows that required farrowing assistance was 29.8% and varied among herds from 5.7% to 53.3% (p<0.001). The percentage of piglets born after birth assistance using manual intervention was 8.4%. Sows with parity numbers 1 and 2 to 4 had a lower frequency of farrowing assistance than sows with parity numbers ≥7 (p<0.01). The colostrum yield of sows that required farrowing assistance did not differ from sows that farrowed without assistance (5.3±0.2 and 5.1±0.1 kg; p = 0.288); however, the colostrum consumption of piglets born from sows that required farrowing assistance was lower than those born from sows that farrowed without assistance (302.2±15.7 and 354.2±5.6 g; p<0.001). Blood oxygen saturation of the piglets born after birth assistance tended to be lower than the piglets that farrowed without birth assistance (87.8%±1.3% vs 90.4%±0.4%; p = 0.054).

CONCLUSION

The frequency of farrowing assistance in sows varied among herds and was influenced by parity number. The piglets born after receiving birth assistance should receive special care to improve their blood oxygen saturation and enhance colostrum intake.

Defining "Normal" in Pig Parturition

Simple Summary

The dual considerations of efficient food production and good animal welfare have never been so important nor under such strong public scrutiny as they are in current times. Intensive animal production industries play an important role in feeding an ever-growing, increasingly affluent population that is hungry for animal proteins. The efforts to improve efficiency in these production systems must not come at the cost of animal welfare. One pain point in pig production is that of parturition, where factors such as litter size and sow-housing type have been shown to influence the process and outcome. However, there are still many gaps in knowledge surrounding the normal physiology and endocrinology in a farrowing and this review seeks to summarise what is known and highlight areas where further work is required.

Abstract

Animal production industries rely on efficient and successful reproductive outcomes, with pigs being no exception. The process of parturition in pigs (farrowing) can be especially prolonged, due to the large numbers of piglets being born (on average, approximately 13 piglets per litter in Australian conditions). Difficulties in farrowing (dystocia) lead to poor piglet outcomes and health problems in sows, in turn, causing economic loss for producers and welfare concerns for the animals. Despite the importance of this topic and publications in the area stretching back nearly 50 years, there is still no consensus on the prevalence of dystocia in pigs nor on how to identify a pig experiencing the condition. Understanding the process of parturition and the factors that influence its success is a crucial step towards the early identification of sows undergoing dystocia and development of best practices to assist them. This article describes the key factors that contribute to successful farrowing and identifies areas in which more research is required before the parturition process in the pig can be fully understood.

Defining the Effect of Oxytocin Use in Farrowing Sows on Stillbirth Rate: A Systematic Review with a Meta-Analysis

Simple Summary

Oxytocin is a hormone that causes smooth muscle contraction and is particularly important during parturition. The administration of exogenous oxytocin to sows at farrowing has been used for decades as a means of assisting sows during parturition. Over the past decade, swine-litter size has dramatically increased, as well as the stillbirth rate. The objective of this systematic review and meta-analysis was to identify the benefits and possible negative side effects of oxytocin use during farrowing. By accumulating data from 25 randomized controlled trials, a meta-analysis examined whether the average number of stillborn piglets, the farrowing duration, and the time interval between the births of piglets were different in the sows that received oxytocin compared to the controls. The results from this study demonstrated that the sows that received oxytocin had an increased average number of stillborn piglets, but experienced reduced farrowing duration and shorter birth intervals between piglets compared to the controls. Future research is required to refine oxytocin usage guidelines, including dosages and the timing of administration. The results of this study demonstrate that it is important to recognize that oxytocin can have adverse side effects, including an increase in stillborn pigs.

Abstract

The objective of this systematic review and meta-analysis was to identify the benefits and possible adverse side effects of oxytocin use during farrowing. Randomized controlled trials that were published in English within the last 50 years were eligible for inclusion. Eligible research needed to contain the PICO elements: population (P)—sows at farrowing; intervention (I):—oxytocin given to sows—comparator (C): sows at farrowing not given oxytocin, as well as sows given different dosages and/or different timing of administration; and outcomes (O):—stillbirths, sow mortality, and piglet viability. Four bibliographic databases were used: PubMed, CAB Direct, Web of Science Core Collection, and ProQuest Dissertations, and Theses Global. In addition, we performed a manual search of the table of contents in the American Association of Swine Veterinarians database for relevant conference proceedings and reports. To assess the risk of bias at the study level, a modified version of the Cochrane 2.0 ROB was used. Meta-analyses were performed to examine the average stillbirth rate, farrowing duration, and birth interval between piglets using random-effect standardized mean difference (SMD) models. To explore heterogeneity, a sub-group analysis was performed on the objectives of the study, dose, time, and route of administration. Of the 46 studies eligible for meta-analyses, only 25 had sufficient information. The pooled analyses of the random effect model demonstrated that the average number of stillborn pigs was lower in the comparator group (SMD = 0.23; CI95% = 0.1, 0.36), and both the farrowing duration (SMD = −8.4; CI95% = −1.1, −0.60) and the birth interval between piglets (SMD = −1.41; CI95% = −1.86, −0.97) were shorter in the oxytocin group. The majority of the studies had an overall risk of bias of ‘some concerns’. It was concluded that the use of oxytocin increases the overall number of stillborn piglets, but decreases the farrowing duration and time interval between piglets. However, future studies should focus on the effect of oxytocin on the experience of dystocia among sows.

Effects of farrowing induction using cloprostenol on sow farrowing characteristics

Background and Aim: Previous findings regarding the effects of farrowing induction on the farrowing characteristics of sows are controversial. This study aimed to investigate the effects of farrowing induction on the following characteristics: (1) Proportion of sows that farrowed during working hours, (2) stillbirth rate, (3) number of stillbirths per farrow, (4) dystocia rate per farrow, (5) dystocia rate (the proportion of farrowings that had at least one dystocia event), (6) number of dystocia events per farrow, (6) farrowing duration, (7) birth interval, and (8) birth weight. Materials and Methods: Thirty-eight Landrace x Yorkshire sows were randomly allocated into two groups; the control group and the treatment group. In the control group (n = 18), sows farrowed spontaneously. In the treatment group (n = 20), farrowing was induced approximately 2 days earlier than the herd's average length of gestation (7:00 am on day 114) by injecting cloprostenol into the perivulval region. All sows were supervised throughout their farrowing. We recorded the interval between induction and farrowing; total number of births; number of live, stillborn, and mummified piglet births; number of dystocia events; birth interval; farrowing duration; and birth weight. A generalized linear mixed model, a linear mixed-effects model, the Chi-squared test, and Student's t-test were used to compare outcomes between the two groups. Results: Farrowing induction did not influence the percentage of sows that farrowed during working hours (7 am–5 pm), stillbirth rate, birth weight, and number of dystocia events per farrow. Farrowing induction led to an increase in birth interval, dystocia rate, dystocia per farrow (p < 0.05) and in addition to the percentage of sows that farrowed on the day following induction (60% vs. 27.8%; p < 0.05). Conclusion: Farrowing induction using a single dose of cloprostenol 2 days before the expected farrowing date can be performed with care to concentrate farrowing into a short interval. This can enhance the optimization of cross-fostering and the practice of an all-in-all-out strategy in the swine breeding industry.

Bacillus subtilis QST 713 Supplementation during Late Gestation in Gilts Reduces Stillbirth and Increases Piglet Birth Weight

Recent studies have shown that probiotic supplementation during late gestation exerts some beneficial effects on reproductive performance of the sows. This study aimed to investigate effects of Bacillus subtilis QST 713 supplementation in gilts on different reproductive criteria. A total of 94 Camborough-48 gilts at day 85 of gestation were randomly allocated into 2 groups: (1) control diet; (2) control diet + 4 × 10⁸ CFU Bacillus subtilis QST 713 per day. Gilts were supplemented until farrowing. At farrowing, litter size, number of piglets born alive, stillbirths, mummies, birth weight, farrowing duration, and birth interval were recorded. Within litter variation of piglet birth weight, depicted as SDBW and CVBW, was also calculated. Results showed that Bacillus subtilis QST 713 supplementation decreased stillbirth rate (1.26 vs. 4.37%, p=0.035) and increased birth weight of the piglets (1303.94 vs. 1234.09 g, p=0.007). Also, the litter size (11.85 vs. 10.67, p=0.03), number of piglets born alive (11.71 vs. 10.23, p=0.008), and litter weight (15473.06 vs. 13174.86 g, p=0.002) in the treatment group were higher than those in the control. Farrowing duration (174.39 vs. 160.81 minutes, p=0.162), birth interval (16.32 vs. 16.59 minutes, p=0.674), SDBW (85.07 vs. 94.65 g, p=0.343), and CVBW (6.42 vs. 7.85, p=0.12) were independent of the Bacillus subtilis QST 713 supplementation. Results of the present study indicate that supplementation of Bacillus subtilis QST 713 during late gestation in gilts reduces stillbirth and increases birth weight thereby improving their reproductive performance.

Incidence of dystocia at piglet level in cloprostenol-induced farrowings and associated risk factors

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 min 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 g and stillborn piglets had higher odds of dystocia in comparison with piglets with a birth weight of 900–1700 g (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.