The effect of piglet vitality, birth order, and blood lactate on the piglet growth performances and preweaning survival

Influence of genotype and environment on piglet vitality and metabolic state during the suckling period of divergent birth weight classes

The high mortality rate of suckling piglets in commercial farms is a cause for concern and requires the adoption of innovative breeding and management approaches for effective mitigation. Piglets are particularly vulnerable during the first days of life, which concerns especially neonates with a low birth weight. In this study, neonatal adaptation was analysed regarding genotype and housing conditions following hormonally induced farrowing. A total of 96 piglets from 27 farrowings of German Landrace (GL; birth induction at day 115 of gestation) and German Saddleback sows (GS; birth induction at day 112 of gestation), kept either in crates (1.0 square metre) or pens (6.5 square metre) were studied. The piglets were assigned to birth weight categories (hypotrophic: 800-1 100 g; eutrophic: > 1 100-1 500 g; hypertrophic: > 1 500 g) and examined via repeated blood analyses on the following time period: 0-6 h, day 1, day 4, day 20 postnatum, and one-day postweaning. Analysed plasma metabolites included albumin, ammonia, chloride, cortisol, creatinine, fructose, glucose, haptoglobin, inositol, insulin, lactate, non-esterified fatty acids, sodium, total protein, triglycerides, triiodothyronine, urea, and uric acid. Eutrophic and hypertrophic piglets were grouped as controls due to metabolic similarities (P = 0.272), whereas hypotrophic piglets could be discriminated from heavier littermates (P = 0.025). The GS piglets appeared to have higher tissue maturity compared to GL piglets, as indicated by improved clearance of plasma ammonia and creatinine levels. This suggests that inducing birth in GS sows at gestation day 112 corresponds to the physiological gestation length of this breed. The housing environment during farrowing influenced plasma glucose and inositol levels during the neonatal adaptation period, which might be attributed to differences in physical activity in farrowing pens compared to crates. Results suggest a higher risk for hypotrophic neonates to exhibit a hypoglycaemia-hypothermia complex at birth, which can have significant implications for neonatal health and development but might be mitigated by the observed increased release of cortisol. These findings highlight that piglet vitality and plasma metabolite dynamics during the suckling period are shaped by genetic background, housing conditions, and birth weight, reflecting differences in tissue maturity, physical activity, and energy reserves.

Thiamine Pyrophosphate Effects on Newborn Piglets as a Measure of Vitality and Survival Indicators

The objective of this study was to evaluate the prophylactic effect of thiamine pyrophosphate (TPP) on the vitality scores of piglets based on their behavior and survival. A total of 149 piglets born from 15 multiparous sows were evaluated. The sows were randomly divided into two groups, control and TPP, with treatments administered 24 and 12 h before the expected farrowing date. The duration of farrowing was recorded. Furthermore, for all newborns, the Apgar vitality scale, teat suckling, newborn weight and weight at weaning, piglet vitality based on behavior (at birth and at 24 h), and skin temperature (at birth and at 24 h) were evaluated. The results indicated that the sows treated with TPP presented a lower farrowing duration (p = 0.0060) and their piglets exhibited a higher percentage in the piglet vitality-based behavior score (>50%). In addition, the newborn piglets of TPP-treated sows, which exhibited higher scores in behavior parameters, also displayed higher scores (>80%) in the Apgar vitality scale (>8), suckled on the teat for longer periods of time, and had higher daily weight gain (p < 0.0001). Our findings suggest that administering TPP at the end of gestation may shorten labor while also increasing the vitality of newborns. Therefore, it could be considered that, in practice, the administration of this treatment could have an impact on the energy that sows need during the farrowing process for the initiation of uterine contractions and abdominal effort. Therefore, this treatment could have an impact on the productivity and well-being of sows with a history of dystocic farrowing, which can increase the incidence of endometritis, vulvar discharge, placental retention, or mastitis-metritis-agalactia syndrome-alterations that can result in the reduced growth of piglets and a higher mortality before weaning. Therefore, the application of this treatment could not only reduce the probability of sows presenting these problems but perhaps also increase the probability of their offspring surviving in the first days after birth.

Commentary on the Adaptive Significance of Sociality Around Parturition Events, and Conspecific Support of Parturient Females in Some Social Mammals

In recent decades, it has become apparent that during parturition events in a number of social mammals, social support behaviours from group mates can be directed to parturient females (and their newborn neonates). Such behaviour has been documented in diverse taxa, across non-human primates, Elephantidae, Cetacea, and Chiroptera, living in a range of social group organisations, from matrilineal groups to cooperatively breeding groups and multi-male, multi-female groups. Since sociality, in association with parturition, has been demonstrated to confer several health benefits to human mothers and neonates, here, we also consider the potential adaptive significance of social support behaviours for other, non-human, social mammals. If appropriate social environments reduce a parturient female's dystocia risk and improve her responsiveness to her neonate following a successful birth, then the impacts of the peri-parturient social environment may ultimately have far-reaching impacts on the mother-neonate dyad's fitness. This seems a logical sequela since the health condition of a neonate at birth and the successful establishment of a strong maternal-neonate bond are often the most critical factors influencing mammalian offspring survival to independence. The principles of kin selection and alliance enhancement may serve to explain the fitness benefits to individuals who support group mates during their parturition and thus the selective advantage conferred to those exhibiting such behaviours. Older, multiparous females appear to hold a particularly important role in the assistance they can provide during the parturition of their group mates, given their greater level of experience of these events. Furthermore, a social birth may have an important influence on horizontal information transfer within a group. In particular, in long-lived, cognitively advanced social mammals (e.g., non-human primates, Elephantidae, Cetacea), witnessing birth events, early neonate responses, and maternal care, and engaging in allomaternal care with young neonates may be essential for nulliparous females' normal development. Such events may serve to prepare them for their own parturition and may improve their own parturition-related survivorship and that of their first-born offspring. Thus, it is vital that a better understanding is gained of the importance and salient features of social births in improving the health and survivorship outcomes for both the mother and her offspring in highly social species. The aim of this commentary is to assemble our current understanding of these highly interconnected themes. We suggest in the future, insights gained through observation of non-human social parturition in domestic and non-domestic species, by a wide and highly interdisciplinary range of stakeholders (including zookeepers, wildlife tourism guides, breeders of domestic animals, indigenous people, and ethologists), will be critical for enhancing our understanding of the influence of social environment on this rarely witnessed, yet highly important life event.

Large litters have a detrimental impact on litter performance and postpartum maternal behaviour in primiparous sows

BACKGROUND

Our previous study confirmed that large litter size adversely affects prepartum maternal hormones and behaviour, concurrently with heightened oxidative stress in primiparous sows. The purpose of this study was to examine the effect of large litter size on litter performance, postpartum maternal behaviour, salivary cortisol levels, and colostral immunoglobulin levels in sows, as well as investigate their correlations with the levels of oxidative stress parameters.

RESULTS

A total of 24 primiparous sows (Landrace[Formula: see text]Large white) and their offspring were categorised into two groups based on litter size: NORMAL (n = 8) with litter size ranging from 7 to 14 (mean 11.5[Formula: see text]2.7), and LARGE (n=16) with litter size ranging from 15 to 20 (mean 15.9[Formula: see text]1.4). All sows were housed in a group housing system during gestation and transitioned to an adaptable loose housing system (2.4[Formula: see text]2.3 m) during the farrowing and lactation periods. The nursing and carefulness behaviour of the sows was monitored over a 24-h period between 72 and 96 h after parturition. Saliva samples were collected for cortisol assay on 35, 21, and 7 days before parturition (D-35, D-21, and D-7, respectively), as well as on days 1, 7, and 28 after parturition (D1, D7, and D28, respectively). On D1, higher piglet mortality rates were observed among the LARGE group compared to the NORMAL group (p<0.01). The total and successful nursing behaviours of the sows were less frequent in the LARGE group than in the NORMAL group (p<0.05, for both), and the carefulness score of the LARGE group was also lower than that of the NORMAL group (p< 0.01). On D1, cortisol levels in LARGE sows were higher than those in NORMAL sows (p< 0.05), and for other time points (D-21, D-7, D7, and D28), cortisol levels in LARGE sows tended to be higher than those in NORMAL sows (p < 0.10, for all). Successful nursing behaviour displayed negative correlations with levels of salivary cortisol and certain oxidative stress parameters measured on D1.

CONCLUSIONS

These findings suggest that the strategy for alleviating physiological and oxidative stress during the peripartum periods could benefit potential postpartum maternal behaviour and litter performance in the sows with large litters.

Dietary 25 Hydroxyvitamin D3 Improved Serum Concentration Level and Alkaline Phosphatase Activity during Lactation but Had Meager Impact on Post-Farrowing Reproductive Performance in Sows

Dietary 25 hydroxyvitamin D3 (25(OH)D3) promotes serum 25(OH)D3 concentration and alkaline phosphatase activity (ALP); however, post-farrowing reproductive performance of lactating sows fed with 14-epimer of 25(OH)D3 is uncertain. This study investigated post-farrowing reproductive performance, serum ALP activity, and serum 25(OH)D3 concentration in sows fed VD3, 25(OH)D3, or 14-epi 25(OH)D3. Weaned sows (n = 203) in parities 2 and 3 were blocked weekly and treated with 2000 IU/kg VD3 (T1), 25 μg/kg 25(OH)D3:14-epi 25(OH)D3 (T2), or 50 μg/kg 25(OH)D3 (T3) diets, all equilibrated to 2000 IU/kg as fed. Sow performance, treatment, and sampling period effects were analyzed. Environmental conditions were analyzed as covariates. The number of piglets weaned (p = 0.029), pre-weaning mortality (p = 0.029), sampling period (p < 0.001), and treatment and period interaction (p = 0.028) differed significantly. There was an increase in 25(OH)D3 during lactation due to physiological demands for milk calcium and milk production. Supplementing twice the concentration of 25(OH)D3 compared to its epimer, 25(OH)D3:14-epi 25(OH)D3, had no significant effect on the post-farrowing reproductive performance of lactating sows. The effect of 25(OH)D3 on post-farrowing reproductive performance and ALP activity in sows was influenced by metabolic demand for calcium due to physiological changes during lactation as well as epimer conformation.

Statistical and machine learning approaches to describe factors affecting preweaning mortality of piglets

High preweaning mortality (PWM) rates for piglets are a significant concern for the worldwide pork industries, causing economic loss and well-being issues. This study focused on identifying the factors affecting PWM, overlays, and predicting PWM using historical production data with statistical and machine learning models. Data were collected from 1,982 litters from the U.S. Meat Animal Research Center, Nebraska, over the years 2016 to 2021. Sows were housed in a farrowing building with three rooms, each with 20 farrowing crates, and taken care of by well-trained animal caretakers. A generalized linear model was used to analyze the various sow, litter, environment, and piglet parameters on PWM. Then, different models (beta-regression and machine learning model: a random forest [RF]) were evaluated. Finally, the RF model was used to predict PWM and overlays for all listed contributing factors. On average, the mean birth weight was 1.44 kg, and the mean mortality was 16.1% where 5.55% was for stillbirths and 6.20% was contributed by overlays. No significant effect was found for seasonal and location variations on PWM. Significant differences were observed in the effects of litter lines on PWM (P < 0.05). Landrace-sired litters had a PWM of 16.26% (±0.13), whereas Yorkshire-sired litters had 15.91% (±0.13). PWM increased with higher parity orders (P < 0.05) due to larger litter sizes. The RF model provided the best fit for PWM prediction with a root mean squared errors of 2.28 and a correlation coefficient (r) of 0.89 between observed and predicted values. Features' importance from the RF model indicated that, PWM increased with the increase of litter size (mean decrease accuracy (MDA) = 93.17), decrease in mean birth weight (MDA = 22.72), increase in health diagnosis (MDA = 15.34), longer gestation length (MDA = 11.77), and at older parity (MDA = 10.86). However, in this study, the location of the farrowing crate, seasonal differences, and litter line turned out to be the least important predictors for PWM. For overlays, parity order was the highest importance predictor (MDA = 7.68) followed by litter size and mean birth weight. Considering the challenges to reducing the PWM in the larger litters produced in modern swine industry and the limited studies exploring multiple major contributing factors, this study provides valuable insights for breeding and production management, as well as further investigations on postural transitions and behavior analysis of sows during the lactation period.

Relationship between piglets' survivability and farrowing kinetics in hyper-prolific sows

BACKGROUND

Prolonged farrowing and more piglets born with low birth weight are undesirable consequences of genetic selection for increased litter size. The objective of the present observational study was to evaluate the relationship between piglets' survivability and farrowing kinetics in hyperprolific sows. A total of 58 sows of different parities and 1190 piglets were included. The entire farrowing process was monitored and the following parameters were recorded: inter-piglet birth interval, birth order, total born, live born, dead born, and mummified piglets, obstetric intervention, weight at birth and 24h, colostrum yield and intake.

RESULTS

The sows included in this study had on average 20.6 ± 0.6 total piglets born, of which 16.4 ± 0.6 were live born, 3.3 ± 0.4 were stillborn and 0.9 ± 0.2 were mummified piglets. The average farrowing duration and average birth interval were 411.3 ± 31.6 and 20.6 ± 1.7 min, respectively. Farrowing duration was positively associated (p < 0.05) with parity, number of stillborn and mummified piglets. Piglet mortality 24h after birth was negatively affected (p < 0.01) by birth weight and positively affected (p < 0.01) by cumulative birth interval. The last tercile of piglets born (birth order ≥ 17) had the highest (p < 0.01) inter-piglet birth interval (IPBI) (43.4 ± 4.17 min) compared to piglets born in the first (birth order between 2 and 7) (26.5 ± 3.8 min) and second (birth order between 8 and 16) terciles (21.9 ± 3.8 min). Cumulative birth interval, birth weight, occurrence of stillborn piglets and manual intervention were positively associated (p < 0.05) with IPBI. Piglet birth weight was also positively associated (p < 0.01) to individual colostrum intake. Piglets ingesting more colostrum had lower (p < 0.01) mortality from 24h after birth until weaning. Sow's parity and cumulative birth interval were positively associated with the presence of stillborn piglets (p = 0.02 and p < 0.01, respectively).

CONCLUSION

Reducing farrowing duration may be crucial to decrease stillbirth rate and neonatal mortality in hyperprolific sows. Moreover, special care must be provided to the lighter piglets within a litter to increase their colostrum intake and minimize piglet's mortality throughout lactation.

The impact of birth weight, birth order, birth asphyxia, and colostrum intake per se on growth and immunity of the suckling piglets

Colostrum is the only source of passive immunity and the major source of nutrients and is crucial for thermoregulation of newborn piglets in their early life. However, the amount of colostrum obtained by each piglet [colostrum intake (CI)] differs considerably in large litters as born by contemporary hyperprolific sow lines. This experiment aimed to investigate the impact of the following individual characteristics of piglets; birth weight, birth order and neonatal asphyxia at birth on CI, and further to determine the relationship between the CI and the passive immunity transfer, and the growth performance of piglets prior to weaning. Twenty-four Danbred sows of the second-parity and their progeny (n = 460) were used. As main inputs in the prediction model to assess individual piglet CI were piglet birth weight, their weight gain, and the duration of colostrum suckling of the piglets. The asphyxia (state of oxygen deprivation) was assessed by measuring blood lactate concentration immediately after birth, and piglets sampled at d 3 of age for determination of blood plasma concentrations of immunoglobulins (Ig) G, A, and M. Piglets' CI was negatively associated with asphyxia (P = 0.003), birth order (P = 0.005) and low birth weight have compromised the individual CI (P < 0.001). Average daily gain during the suckling period was greater among piglets with high CI (P = 0.001) and birth weight (P < 0.001). Body weight at weaning (d 24 of age) was positively associated with CI (P = 0.0004) and birth weight (P < 0.001). The probability of weaning was positively associated with CI and birth weight (P < 0.001) of the piglets. Concentrations of IgG (P = 0.02), IgA (P = 0.0007), and IgM (P = 0.04) in piglets' plasma at d 3 of age were positively associated with CI, and were negatively associated with birth order (P < 0.001). The present study demonstrated that piglets' individual characteristics at birth (birth weight, birth order, state of oxygen deprivation) have considerable effects on their CI. The knowledge gained from the results of this study gives a scientific base for development and implementation of more effective techniques in practice aimed to improve the piglets' robustness during the suckling period.

Vitality in Newborn Farm Animals: Adverse Factors, Physiological Responses, Pharmacological Therapies, and Physical Methods to Increase Neonate Vigor

Vitality is the vigor newborn animals exhibit during the first hours of life. It can be assessed by a numerical score, in which variables, such as heart rate, respiratory rate, mucous membranes' coloration, time the offspring took to stand up, and meconium staining, are monitored. Vitality can be affected by several factors, and therapies are used to increase it. This manuscript aims to review and analyze pharmacological and physical therapies used to increase vitality in newborn farm animals, as well as to understand the factors affecting this vitality, such as hypoxia, depletion of glycogen, birth weight, dystocia, neurodevelopment, hypothermia, and finally, the physiological mechanism to achieve thermostability. It has been concluded that assessing vitality immediately after birth is essential to determine the newborn's health and identify those that need medical intervention to minimize the deleterious effect of intrapartum asphyxia. Vitality assessment should be conducted by trained personnel and adequate equipment. Evaluating vitality could reduce long-term neonatal morbidity and mortality in domestic animals, even if it is sometimes difficult with the current organization of some farms. This review highlights the importance of increasing the number of stock people during the expected days of parturitions to reduce long-term neonatal morbidity and mortality, and thus, improve the farm's performance.