Piglet performance and colostrum intake in litters either or not split-suckled during the first day or during the first three days of life

Effects of parity, season of birth, and sex on within-litter variation and pre-weaning performance of F1 Large White × Landrace pigs

Background and Aim

A piglet's pre-weaning performance significantly influences both animal welfare and profitability in pig production. Understanding piglet pre-weaning performance influencing factors is key to enhancing animal welfare, reducing losses, and boosting profitability. The study aimed to evaluate the impact of parity, season of birth, and sex on within-litter variation and pre-weaning performance of F1 Large White × Landrace pigs.

Materials and Methods

Information regarding total litter size, number of born alive, number of stillbirths, piglet weight at birth, mortality, and count of weaned F1 Large White × Landrace piglets was acquired from the farm database (April 2022-February 2023). 2602 females and 2882 males, a total of 5484 piglets were utilized, with records from 360 sows. The coefficient of variation (CV) of birth weights among piglets within a litter was calculated. The general linear model analysis in MiniTab 17 was used to evaluate the data, with Fisher's least significant difference test (p < 0.05) used for mean separation and Pearson's moment correlation coefficient calculated to assess relationships between survival rates, mortality rates, litter size, birth weight, and birth weight CV.

Results

Parity had a statistically significant impact on litter size, birth weight, and survival rate (p < 0.05). The sow's parity did not significantly (p > 0.05) impact the number of piglets born alive or weaned. Multiparous sows had a significantly larger litter size (p < 0.05) than primiparous sows at birth. The litter weights for parities 2, 4, and 5 did not significantly differ (p > 0.05), with averages of 20.95, 20.74, and 20.03 kg, respectively. About 91.29% was the highest survival rate recorded in parity 2 (p < 0.05). The 1st week of life recorded an 8.02% mortality rate. The mortality rate in parity 3-5 group was significantly (p < 0.05) higher (11.90%) in week 1 than in the other groups (parity 1: 6.79%, parity 2: 5.74%, parity 3-5: 8.54 and 9.21%). The litter sizes in autumn (17.34) and spring (17.72) were significantly larger (p < 0.05) than those in summer (16.47) and winter (16.83). In autumn and spring, the survival rate (83.15 and 85.84%, respectively) was significantly lower (p < 0.05) compared to summer (88.40%) and winter (89.07%). In all seasons, the litter weights did not significantly differ (p > 0.05). The birth weight CV was significantly (p < 0.05) lower during summer (20.11%) than during spring (22.43%), autumn (23.71%), and winter (21.69%). The season of birth had no significant effect (p > 0.05) on the number of live piglets. Males (1.34 kg) were heavier (p < 0.05) than females (1.30 kg) at birth. Notably, the birth weight CV was similar between males (22.43%) and females (22.52%). Litter size was positively correlated with average litter weight (rp = 0.576, p < 0.001), birth weight CV (rp = 0.244, p < 0.001), and mortality rate (rp = 0.378, p < 0.001). An insignificant relationship was observed between average litter weight and birth weight CV (rp = -0.028, p > 0.05) and survival rate (rp = -0.032, p > 0.05).

Conclusion

In F1 Large White × Landrace pigs, birth uniformity among piglets declines as litter size grows larger. In parity 3-5, multiparous sows yield litters with reduced uniformity. With an increase in litter size, uniformity among piglets at birth worsens. A larger litter size and greater piglet birth weight variation are linked to a higher pre-weaning mortality rate. Producers need a balanced selection approach to boost litter size and must cull aging sows carefully to introduce younger, more productive females.

Short- and Long-Term Effects of Split-Suckling in Pigs According to Birth Weight

Forty-eight litters were used, with a total number of 645 piglets involved in the study. The split-suckling technique was applied to half of the litters at the end of farrowing by removing the heaviest piglets over three periods of 1 h. The piglets were individually weighed at 0, 1 d, and at weaning. Piglet losses were recorded daily. Traceability was maintained until the carcass splitting and meat analysis took place. Carcasses were eviscerated and weighed individually. Total mortality at weaning was affected by body weight, where the low-body-weight piglets showed a mortality rate almost four times higher than that of the normal-weight piglets. Mortality was highest in the first days of life, especially in the low-body-weight piglets. At weaning, split-suckling treatment caused a slight increase in mortality compared to the control group piglets (25% vs. 17.1%). Split-suckling had a positive effect on weight gain during the first 24 h of life (p = 0.014), and there was an interaction between treatment and parity (p = 0.007), with split-suckling being more effective in the primiparous sows compared to the multiparous sows. The piglets from litters receiving the split-suckling treatment had a lower average daily gain during the lactation period (p < 0.001) than the piglets from the control group. Weight gain during the first 24 h of life of the piglets subjected to split-suckling was higher than those of the control group. A lower IgG and α-tocopherol in plasma in the heavier piglets subjected to split-suckling treatment was observed in comparison to their respective control. The piglets from litters receiving the treatment showed a lower average daily gain during the lactation period (p < 0.001) than the piglets from the control group. No difference in slaughter weight was observed according to treatment. The pigs which received split-suckling treatment showed lower subcutaneous fat thickness (p < 0.0013) and higher lean meat yield (p < 0.0027), this effect being more marked in pigs from primiparous sows. Intramuscular fat concentration was higher in the Longissimus Dorsi muscle of the low-body-weight piglets. In the pigs that received split-suckling treatment, a higher concentration of C18:3n-3 (p = 0.036) and a tendency towards a higher concentration of C18:2n-6 (p = 0.107) and unsaturation index (p = 0.113) was observed in intramuscular fatty acids at slaughter, together with a lower concentration of C16:0 (p = 0.053) and SFA (p = 0.064). In conclusion, long-term response to split-suckling, particularly in low-birth-weight piglets, suggests an alteration in adiposity and metabolic regulation in these piglets that receive high levels of colostrum.

Preweaning performance in intrauterine growth-restricted piglets: Characteristics and interventions

Intrauterine growth restriction (IUGR) is frequently observed in pig production, especially when using highly prolific sows. IUGR piglets are born with low body weight and shape indicative of differences in organ growth. Insufficient uteroplacental nutrient transfer to the fetuses is the leading cause of growth restriction in the pig. Supplementing the sow's gestation diet with arginine and/or glutamine improves placenta growth and functionality and consequently is able to reduce IUGR incidence. IUGR piglets are at higher risk of dying preweaning and face higher morbidity than their normal-weight littermates. A high level of surveillance during farrowing and individual nutrient supplementation can reduce the mortality rates. Still, these do not reverse the long-term consequences of IUGR, which are induced by persistent structural deficits in different organs. Dietary interventions peri-weaning can optimize performance but these are less effective in combating the metabolic changes that occurred in IUGR, which affect reproductive performance later in life. IUGR piglets share many similarities with IUGR infants, such as a poorer outcome of males. Using the IUGR piglet as an animal model to further explore the structural and molecular basis of the long-term consequences of IUGR and the potential sex bias could aid in fully understanding the impact of prenatal undernutrition and finding solutions for both species and sexes.

Selected Nutrition and Management Strategies in Suckling Pigs to Improve Post-Weaning Outcomes

Weaning is a critical period in a pig's life. Piglets are confronted with abrupt changes to their physical and social environment, as well as management and nutritional changes. Weaning has always been associated with a growth check and is frequently accompanied by post-weaning diarrhoea in piglets. However, rapid increases in litter size in the last decade have increased within-litter piglet weight variation, with piglets now generally lighter at weaning, making the challenges associated with weaning even greater. Many interventions can be employed during the suckling period to ease the weaning transition for piglets. Pre-weaning strategies such as supervised farrowing (assistance with suckling and oxytocin provision), the provision of pain relief to sows around farrowing, split-suckling, early oral supplementation with glucose, bovine colostrum, faecal microbiota transplantation, feed additives and solid and liquid creep feeding (milk and liquid feed) have all been investigated. The objective of these strategies is to stimulate earlier maturation of the digestive tract, improve immunity, reduce latency to the first feed post-weaning and increase early post-weaning feed intake and growth. This review focuses in particular on: (1) pain relief provision to sows around farrowing, (2)split-suckling of piglets, (3) pre-weaning provision of supplementary milk and/or liquid feed, (4) other strategies to stimulate earlier enzyme production (e.g., enzyme supplementation), (5) other nutritional strategies to promote improved gut structure and function (e.g., L-glutamine supplementation), and (6) other strategies to modulate gut microbiota (e.g., probiotics and prebiotics). Correctly implementing these strategies can, not only increase post-weaning growth and reduce mortality, but also maximise lifetime growth in pigs.

Effects of early intermittent maternal separation on behavior, physiological, and growth performance in piglets

In pig production, the management of piglets by batch lactation due to the increase in litter sizes of sows may result in intermittent early neonatal maternal separation (NMS). We speculated that NMS may affect the piglets cognitive growth performance and health. To determine the extent of the effect, 12 litters of crossbred piglets (Large White × Duroc × Min-pig) were used in this trial. Piglets in the control (Con) group (n = 6) were given a standard feeding method during lactation. Piglets in the experimental group (n = 6) were subjected to the NMS model, in which sows were led out of the enclosure with food every day (8:00-11:00 and 13:00-16:00) starting from postnatal day (PND) 7. During the separation, the piglets were supplemented with milk. All experimental piglets were weaned on PND 35. The piglets were observed for aggression, play, mutual sniffing, and exploratory behavior on PNDs 7, 8, 21, 22, 34, 35, 38, 39, 51, 52, 64, and 65. Physiological indicators, namely serum adrenaline, cortisol, interleukin (IL)-1β, IL-4, IL-6, and tumor necrosis factor (TNF)-α were measured on PNDs 35, 38, and 65, while piglet growth performance was evaluated during suckling and 1 month after weaning. The results showed that aggressive behavior in the MS group was significantly higher than that in the Con group (P < 0.05). Playful and mutual sniffing behaviors in the MS group were significantly lower than those in the Con group except for PNDs 38 and 39 (P < 0.05). Active exploratory behavior in the MS group was significantly higher than that in the Con group on PNDs 7 and 8, and PNDs 21 and 22 (P < 0.05). The frequency of belly-nosing behavior was significantly higher in the MS group than that in the Con group except for PNDs 64 and 65 (P < 0.05). Compared with the Con group, epinephrine, IL-1β, IL-6, and TNF-α concentrations on PNDs 35, 38, and 65 were significantly increased in the MS group (P < 0.01), while IL-4 concentration was significantly decreased (PND 35: P < 0.05; PNDs 38 and 65: P < 0.01). Compared with the Con group, the piglet diarrhea rate in the MS group during suckling was significantly increased (P < 0.01), the weaning weight was significantly decreased (P < 0.05), and it had no significant effect on the body weight at the end of the trial (P > 0.05). In conclusion, the early intermittent NMS created stress and affected the growth performance of piglets during suckling. However, the growth rate was improved by compensatory measures during late weaning.

Postpartum meloxicam administration to sows but not split-suckling increases piglet growth and reduces clinical incidence of disease in suckling piglets

Each suckling pig should receive ≥200 g of colostrum within the first 24 h of life, but with increased litter size this is now difficult to achieve. The aim of this study was to assess the effect of split-suckling and postpartum meloxicam provision to sows as a means of ensuring adequate colostrum intake, on growth and health in pigs pre- and postweaning. One hundred and four sows (Large White × Landrace) and their litters, averaging 16.3 piglets born alive, were assigned to one of four treatments in a two-by-two factorial arrangement. Factors were provision of meloxicam (yes/no; Mel/N-Mel) and split-suckling (yes/no; Split/N-Split). Meloxicam was administered intramuscularly at 0.4 mg/kg body weight to sows on release of the placenta (~2 h postpartum). Split-suckling commenced 4 h after birth of the first piglet, with the six heaviest piglets removed from the sow for 1 h to allow the lightest piglets to suckle. This was repeated after 1.5 h. Pigs were weighed at birth and at days 1, 6, 14, and 27 after birth and at days 6, 14, 21, 28, 47, and 129 postweaning. Carcass data were collected at slaughter. Medication usage was recorded from birth to slaughter. There was a split-suckling by meloxicam interaction effect at days 1 to 6 (P < 0.001) and days 6 to 14 (P < 0.001) after birth. Meloxicam administration had no effect on average daily gain (ADG) when split-suckling was applied; however, when split-suckling was not applied, postpartum meloxicam administration increased ADG. There was a meloxicam × split-suckling interaction for ADG from weaning to day 6 postweaning (P = 0.03). Meloxicam increased ADG when split-suckling was applied but not in its absence. Carcass weight was increased by meloxicam (P = 0.01) but was not affected by split-suckling (P > 0.05). Meloxicam use in sows reduced the number of clinical cases of disease (P = 0.04) in suckling pigs which tended to reduce the volume of antibiotics (P = 0.08) and anti-inflammatories (P = 0.08) administered. Split-suckling had no effect on medication usage in sows and piglets during lactation but increased their use from weaning to slaughter. In conclusion, postpartum administration of meloxicam to sows is an easily implemented strategy. It reduced clinical cases of disease, increased ADG in pigs during the first two weeks of life and early postweaning and increased carcass weight at slaughter. However, no split-suckling benefit was observed.

Changes in piglet and litter characteristics across parities in two highly prolific sow hybrids in an outdoor organic herd

High piglet mortality constitutes a welfare challenge in organic pig production. Litter characteristics were investigated from parities 1-5 of two hyper-prolific hybrids with different selection traits in an organic commercial herd (DanBred vs. Topigs Norsvin [TN70]). TN70 sows had more functional teats than DanBred sows, and their offspring had higher birth weights. Several interactions between hybrid and parity were found. The total born increased with higher parity and was more pronounced for DanBred sows. Litter weight at weaning was higher in parities 1-4 for TN70 compared with DanBred, and within DanBred parities 4 and 5 had higher litter weight at weaning than parity 1. The survival rate was higher for TN70 in parities 1 and 2 compared with DanBred, and for both hybrids, the survival rate was higher in parities 1 and 2 compared with parities 4 and 5. The number of weaned piglets was stable across parities 1-4 but lower in parity 5 for both hybrids. Thus, despite a lower number of total born piglets in TN70, TN70 sows weaned the same number of piglets as DanBred, with a lower mortality rate and a heavier litter at weaning.

Improving young pig welfare on-farm: The Five Domains Model

Considering welfare through the "neonatal and nursery pig perspective" is an exciting approach, and one that resonates with consumers. Overlaying this with the Five Domains Model, as we suggest in this review, points to practical on-farm improvements that provide each pig the opportunity to experience positive mental states. The Five Domains Model is broken into physical and functional states, that includes Domain 1 Nutrition, Domain 2 Physical Environment, Domain 3 Health and, Domain 4 Behavioral Interaction, and Domain 5 Mental State. The Five Domains Model can build on the breadth and depth of swine welfare science to highlight opportunities to improve welfare on-farm. In Domain 1 management of increasingly large litters is considered, with examples of sow vs. artificial rearing, colostrum quality and quantity, and creep feed management strategies. Efforts can result in positive mental states such as feeling full and content and the ability to experience pleasure of drinking and food tastes/smells. Domain 2 considers space complexity and access to key resources, along with thermal and physical amenities, to promote feelings of physical comfort. Domain 3 considers pig health in three broad, yet inter-linking categories, (a) congenital and hereditary health, (b) environmental pathogen load and, (c) colostrum quality and quantity, and its effect on the microbiome. Improvements can result in a pig that displays vitality and feels healthy. Domain 4 provides the pig opportunities to express its rich behavioral repertoire, specifically positive social interactions, play, and exploration. These efforts can result in pigs feeling calm, safe, comfortable, having companionship, engaged, interested and rewarded. In conclusion, using the Five Domains Model can highlight numerous opportunities to improve current and future housing and management through the "neonatal and nursery pig perspective" with a focus on inducing positive mental states that can result in improved quality of life and welfare state.