Sow and litter performance after cross-fostering one surplus piglet and co-mingling the litters at early lactation.

The number of piglets born alive is frequently greater than the functional teats, and some farms are equalizing litters with surplus piglets, limiting piglet udder access. Removing the barrier among farrowing crates may allow piglets to socialize and seek other sows. Thus, we evaluated the effects litter size at cross-fostering and socialization on the sow and piglet performance during lactation. Two factors were included in a 2 × 2 factorial design: socialization and litter size relative to sow functional teat number at cross-fostering. Litters (n = 189) were then assigned to one of four groups: CONT+0 (litters not co-mingled with no additional piglet), CONT+1 (not co-mingled with one additional piglet), Co-M+0 (co-mingled with no additional piglet), Co-M+1 (co-mingled with one additional piglet). Piglets were cross-fostered from 12-16 h after birth, and 24 h later, Co-M groups were socialized by removing the barrier between two adjacent pens. During lactation, sows lost more caliper units in the + 1 group than in the + 0 group (P = 0.04). The number of functional teats did not differ among groups, but Co-M sows had a higher udder lesion score at weaning than CONT (6.55 vs 4.83; P < 0.01). Furthermore, +1 sows had fewer vacant teats throughout lactation (P < 0.01). Milk yield did not differ among the groups (P ≥ 0.13). Regarding the number of weaned piglets, no difference was observed for socialization (P = 0.84), but + 1 sows weaned 0.67 more piglets than + 0 (P < 0.01). Although CONT+0 had the heaviest piglets at weaning (P < 0.01), litter weight did not differ among the groups (P ≥ 0.08). Facial and joint lesions were frequently observed in Co-M (P < 0.01) than CONT. Piglet loss rate did not differ among treatments (overall rate = 12.6%; P ≥ 0.26). The removal rate, however, was more frequent in + 1 litters than in  + 0 (P < 0.01). Death due to starvation was higher in CONT+1 than CONT+0 (P < 0.01) but did not differ between the Co-M groups (P = 0.99). Litters formed with one additional piglet relative to functional teat number weaned more piglets, albeit with lower individual weight. Litter socialization may alleviate the impact of high litter size but shows greater percentages of udder injuries and facial and joint lesions in weaned piglets.

Effects of whole-day versus half-day cow-calf contact on cows' and calves' performance.

Cow-calf contact systems (CCCs), where dairy cows nurse their own calves for several weeks while being milked, have some advantages in terms of animal welfare. However, one major challenge is the loss of collected milk due to suckling and milk ejection problems during milking. Reducing daily CCC can decrease milk losses. Our study investigated the effect of half-day CCC during daytime (HC, n = 11 cows) compared to whole-day contact (WC, n = 13) and no contact (NC, n = 14) on harvested milk yield, milk content, udder health, calving interval, and calf weight gain in a dual purpose breed-herd with concentrate-free feeding. 'Nursing' (9 weeks postpartum) was followed by separation of cow and calf, but still with visual CCC and twice daily milk feeding by nipple buckets (6 l per day, 'in sight/milk feeding'). During the 11th-12th week, calves were housed out of sight and gradually weaned. Calves of NC were separated from their mothers 1 day postpartum, obtained 6 l whole-milk per day and were gradually weaned. During 'nursing', NC and HC cows gave more milk than WC in the morning. In the evening, HC and WC gave less milk than NC, but HC cows had also a slightly lower milk yield than WC. During 'nursing', a reduced fat content (-1% point) pointed at milk ejection problems in both CCC treatments independent from daytime. After separation from the calf (periods: 'in sight/milk feeding' and 'out of sight/weaning') and over the whole lactation, milk yield between HC and the other treatments did not significantly differ while WC cows gave less milk than NC cows. Protein contents were higher in dams than in NC. There were no indications of differences in the incidence of mastitis, somatic cell score or calving interval between treatments. During 'nursing', NC calves gained about 0.3 kg less per day than CCC-calves (nNC = 12, nHC = 7, nWC = 10). After separation from the mother, there was a growth check in both CCC groups. During 'in sight/milk feeding', HC gained less weight than NC and WC (nNC = 11, nHC = 9, nWC = 10). Hereafter, weight development did not differ. Two weeks after weaning, nursed calves were still significantly heavier than NC (n  =  5-8). Nine weeks of HC during the day compared to WC helped to reduce losses of sellable milk during the nursing period and over the whole lactation while calf development was similar.

Central δ/κ opioid receptor signaling pathways mediate chronic and/or acute suckling-induced LH suppression in rats during late lactation.

In mammals, secretion of tonic (pulsatile) gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) is often suppressed during lactation. Suppression of GnRH/LH pulses in lactating dams is assumed to be caused by suckling stimuli and a chronic negative energy balance due to milk production. The present study aimed to investigate whether the central enkephalin-δ opioid receptor (DOR) signaling mediated the suppression of LH secretion by acute suckling stimuli and/or chronic negative energy balance due to milk production in rats during late lactation when dams were under a heavy energy demand. On postpartum day 16, the number of Penk (enkephalin mRNA)-expressing cells in the arcuate nucleus was significantly higher in lactating rats than in non-lactating control rats. Pulsatile LH secretion was suppressed in rats with chronic suckling or acute 1-h suckling stimuli 6 h after pup removal on day 16 of lactation. Central DOR antagonism significantly increased the mean LH concentrations and the baseline of LH pulses in rats with chronic suckling but not with acute suckling stimuli on day 16 of lactation. Besides, central κ opioid receptor (KOR) antagonism increased the amplitude of LH pulses in rats with the acute suckling stimuli on day 16 of lactation. These results suggest that central DOR signaling mediates the suppression of LH secretion caused by a negative energy balance in rats receiving chronic suckling during late lactation. On the other hand, central KOR signaling likely mediates acute suckling stimuli-induced suppression of LH secretion in rats during late lactation.

A meta-analysis approach for annotation and identification of lncRNAs controlling perirenal fat deposition in suckling lambs.

Long non-coding RNAs (lncRNAs) are being studied in farm animals due to their association with traits of economic interest, such as fat deposition. Based on the analysis of perirenal fat transcriptomes, this research explored the relevance of these regulatory elements to fat deposition in suckling lambs. To that end, meta-analysis techniques have been implemented to efficiently characterize and detect differentially expressed transcripts from two different RNA-seq datasets, one including samples of two sheep breeds that differ in fat deposition features, Churra and Assaf (n = 14), and one generated from Assaf suckling lambs with different fat deposition levels (n = 8). The joint analysis of the 22 perirenal fat RNA-seq samples with the FEELnc software allowed the detection of 3953 novel lncRNAs. After the meta-analysis, 251 differentially expressed genes were identified, 21 of which were novel lncRNAs. Additionally, a co-expression analysis revealed that, in suckling lambs, lncRNAs may play a role in controlling angiogenesis and thermogenesis, processes highlighted in relation to high and low fat deposition levels, respectively. Overall, while providing information that could be applied for the improvement of suckling lamb carcass traits, this study offers insights into the biology of perirenal fat deposition regulation in mammals.

Inflammatory damage caused by Echovirus 30 in the suckling mouse brain and HMC3 cells.

Echovirus 30 (E30), a member of the species B Enterovirus family, is a primary pathogen responsible for aseptic meningitis and encephalitis. E30 is associated with severe nervous system diseases and is a primary cause of child illness, disability, and even mortality. However, the mechanisms underlying E30-induced brain injury remain poorly understood. In this study, we used a neonatal mouse model of E30 to investigate the possible mechanisms of brain injury. E30 infection triggered the activation of microglia in the mouse brain and efficiently replicated within HMC3 cells. Subsequent transcriptomic analysis revealed inflammatory activation of microglia in response to E30 infection. We also detected a significant upregulation of polo-like kinase 1 (PLK1) and found that its inhibition could limit E30 infection in a sucking mouse model. Collectively, E30 infection led to brain injury in a neonatal mouse model, which may be related to excessive inflammatory responses. Our findings highlight the intricate interplay between E30 infection and neurological damage, providing crucial insights that could guide the development of interventions and strategies to address the severe clinical manifestations associated with this pathogen.

Breast Milk-Derived Antibodies Impair Vaccine Immunity in Suckling Mice.

Breast milk confers multiple benefits to the neonate, including passive immunity against multiple microorganisms via Abs. However, it remains unclear whether breast milk-derived Abs affect vaccine-induced immunity in the neonate. We evaluated in C57BL/6 and BALB/c mice whether breastfeeding from an mRNA-SARS-CoV-2-vaccinated dam affects vaccine-induced immunity in neonate mice. Using an experimental model that allows the distinction of maternal Abs and neonate Abs based on their allotype, we show that breastfeeding from an immune dam is associated with reduced vaccine immunity in the neonate. Importantly, mice that breastfed from an immune dam showed reduced numbers of plasma cells after vaccination, relative to mice that breastfed from a naive dam. Our subsequent studies using an mRNA-luciferase reporter system show that passive transfer of Abs through breastfeeding accelerates the clearance of vaccine Ag in suckling mice, resulting in reduced Ag availability. Altogether, maternal Abs transferred through breast milk can protect against infectious microorganisms, but they may also interfere with the neonate's response to vaccination by accelerating the clearance of vaccine Ag. These findings are important for understanding the effects of maternal Abs on the neonate's response to vaccines and may provide insights for improving neonatal vaccines.

Maternal Synbiotic Supplementation with B. breve M-16V and scGOS/lcFOS Shape Offspring Immune Development and Gut Microbiota at the End of Suckling.

Immune system development during gestation and suckling is significantly modulated by maternal environmental and dietary factors. Breastfeeding is widely recognized as the optimal source of nutrition for infant growth and immune maturation, and its composition can be modulated by the maternal diet. In the present work, we investigated whether oral supplementation with Bifidobacterium breve M-16V and short-chain galacto-oligosaccharide (scGOS) and long-chain fructo-oligosaccharide (lcFOS) to rat dams during gestation and lactation has an impact on the immune system and microbiota composition of the offspring at day 21 of life. On that day, blood, adipose tissue, small intestine (SI), mesenteric lymph nodes (MLN), salivary gland (SG), cecum, and spleen were collected. Synbiotic supplementation did not affect the overall body or organ growth of the pups. The gene expression of Tlr9, Muc2, IgA, and Blimp1 were upregulated in the SI, and the increase in IgA gene expression was further confirmed at the protein level in the gut wash. Synbiotic supplementation also positively impacted the microbiota composition in both the small and large intestines, resulting in higher proportions of Bifidobacterium genus, among others. In addition, there was an increase in butanoic, isobutanoic, and acetic acid concentrations in the cecum but a reduction in the small intestine. At the systemic level, synbiotic supplementation resulted in higher levels of immunoglobulin IgG2c in plasma, SG, and MLN, but it did not modify the main lymphocyte subsets in the spleen and MLN. Overall, synbiotic maternal supplementation is able to positively influence the immune system development and microbiota of the suckling offspring, particularly at the gastrointestinal level.

Foot-and-mouth disease-associated myocarditis is age dependent in suckling calves.

Myocarditis is considered a fatal form of foot-and-mouth disease (FMD) in suckling calves. In the present study, a total of 17 calves under 4 months of age and suspected clinically for FMD were examined for clinical lesions, respiratory rate, heart rate, and heart rhythm. Lesion samples, saliva, nasal swabs, and whole blood were collected from suspected calves and subjected to Sandwich ELISA and reverse transcription multiplex polymerase chain reaction (RT-mPCR) for detection and serotyping of FMD virus (FMDV). The samples were found to be positive for FMDV serotype "O". Myocarditis was suspected in 6 calves based on tachypnoea, tachycardia, and gallop rhythm. Serum aspartate aminotransferase (AST), creatinine kinase myocardial band (CK-MB) and lactate dehydrogenase (LDH), and cardiac troponins (cTnI) were measured. Mean serum AST, cTn-I and LDH were significantly higher (P < 0.001) in < 2 months old FMD-infected calves showing clinical signs suggestive of myocarditis (264.833 ± 4.16; 11.650 ± 0.34 and 1213.33 ± 29.06) than those without myocarditis (< 2 months old: 110.00 ± 0.00, 0.06 ± 0.00, 1050.00 ± 0.00; > 2 months < 4 months: 83.00 ± 3.00, 0.05 ± 0.02, 1159.00 ± 27.63) and healthy control groups (< 2 months old: 67.50 ± 3.10, 0.047 ± 0.01, 1120.00 ± 31.62; > 2 months < 4 months: 72.83 ± 2.09, 0.47 ± 0.00, 1160.00 ± 18.44). However, mean serum CK-MB did not differ significantly amongst the groups. Four calves under 2 months old died and a necropsy revealed the presence of a pathognomic gross lesion of the myocardial form of FMD known as "tigroid heart". Histopathology confirmed myocarditis. This study also reports the relevance of clinical and histopathological findings and biochemical markers in diagnosing FMD-related myocarditis in suckling calves.

Concentrations of selected immunological parameters in the serum and processing fluid of suckling piglets and the serum and colostrum of their mothers.

BACKGROUND: Blood sampling from neonatal piglets is related to multiple disadvantages. Therefore, a new, alternative matrix is required to assess piglets' early immune status efficiently. The present study aimed to assess the usefulness of processing fluid for determining selected piglets' immune parameters. 264 pigs - 31 sows, 146 male piglets, and 87 female piglets from commercial indoor farrow-to-finish pig herd were included in this study. 264 serum, 31 colostrum, and 146 processing fluid samples were collected. Serum was collected from all animals, colostrum was collected from sows, and processing fluid was collected from male piglets only. Using commercial ELISA tests, the concentration of various immunoglobulins, cytokines, and acute phase proteins was assessed in each matrix. Statistical analyses were employed to determine differences in the concentration of measured indices between piglets' serum and processing fluid and correlations in the concentration of tested indices between particular sets of matrices. RESULTS: Statistical analyses did not reveal significant differences in the IgG, IgA, IL-1ß, IL-4, IL-6, and IFN-γ concentration between piglets' serum and processing fluid (p > 0.05). A positive correlation (p < 0.05) regarding the concentration of some indices between processing fluid and samples collected from sows was also observed. CONCLUSIONS: Processing fluid can be considered a promising alternative to blood for assessing some immunological indices in piglets, such as IgG, IgA, IL-1ß, IL-4, IL-6, and IFN-γ, and, possibly, in the indirect assessment of some indices in lactating sows, including IgA, IL-1ß, IL-4, IL-6, IL-8, IFN-γ, or Pig-MAP.

Performance and incidence of diarrhea in suckling Jersey calves supplemented with mineral-vitamin complex and Virginiamycin.

The rearing of calves is an essential activity of a dairy system, as it impacts the future production of these animals. This study aims to evaluate the incidence of diarrhea, performance, and blood parameters of suckling calves that received mineral-vitamin supplementation in milk plus virginiamycin that was offered in milk (via the abomasum) or by esophageal tube (via the rumen). Twenty-seven calves were used, from the first week to 60 days of age, submitted to the following treatments: CONTROL, without supplementation; MILK, supplementation of 20 g of a mineral-vitamin complex with 100 mg of virginiamycin, diluted in milk; RUMEN, supplementation of 20 g of a mineral-vitamin complex diluted in milk and 100 mg of virginiamycin in gelatin capsules via an esophageal applicator. MILK and RUMEN calves had lower fecal consistency scoring, fewer days with scores 2 and 3 throughout the experimental period, and lower spending on medication compared to the CONTROL animals. Supplemented calves had higher fat and protein intake and reached feed intake of 600 g earlier than CONTROL animals, but did not differ in performance and hematological parameters. Supplementation with virginiamycin and vitamin-mineral complex for suckling calves reduced the incidence and days of diarrhea, and reduced medication costs, with no difference in performance, but the supplemented animals had higher initial protein and fat intake and reached targeted feed intake earlier to begin the weaning process.

Detection and Characterization of Influenza A Virus Endemic Circulation in Suckling and Nursery Pigs Originating from Vaccinated Farms in the Same Production System.

Inactivated influenza A virus (IAV) vaccines help reduce clinical disease in suckling piglets, although endemic infections still exist. The objective of this study was to evaluate the detection of IAV in suckling and nursery piglets from IAV-vaccinated sows from farms with endemic IAV infections. Eight nasal swab collections were obtained from 135 two-week-old suckling piglets from four farms every other week from March to September 2013. Oral fluid samples were collected from the same group of nursery piglets. IAV RNA was detected in 1.64% and 31.01% of individual nasal swabs and oral fluids, respectively. H1N2 was detected most often, with sporadic detection of H1N1 and H3N2. Whole-genome sequences of IAV isolated from suckling piglets revealed an H1 hemagglutinin (HA) from the 1B.2.2.2 clade and N2 neuraminidase (NA) from the 2002A clade. The internal gene constellation of the endemic H1N2 was TTTTPT with a pandemic lineage matrix. The HA gene had 97.59% and 97.52% nucleotide and amino acid identities, respectively, to the H1 1B.2.2.2 used in the farm-specific vaccine. A similar H1 1B.2.2.2 was detected in the downstream nursery. These data demonstrate the low frequency of IAV detection in suckling piglets and downstream nurseries from farms with endemic infections in spite of using farm-specific IAV vaccines in sows.

Maternal behavior of dairy cows and suckling behavior of dairy calves in different cow-calf contact conditions.

Cow-calf contact has been suggested as an alternative to the common practice of early separation of dairy cow and calf. Increasing cow-calf contact poses challenges by reducing the machine milk yield and increasing separation stress. Part-time cow-calf contact may prove more feasible than full-time contact for farmers but may affect the maternal behavior of the cows. Gradually reducing the daily contact could gradually wean the calf off milk, preparing it for separation. This study aims to investigate (1) how cows' maternal behaviors toward their own calf are affected by part-time contact, and (2) whether calves' suckling behavior is reduced by reducing daily cow contact. Fifty-six dairy cows and their calves were assigned to either full-time (23 h/d) or part-time (10 h/d) cow-calf contact for 7 wk (main rearing period). This was followed by 2 wk of either reduced contact (50% in wk 8, then 25% of original contact time in wk 9) or unchanged contact. First, the maternal behavior of full- and part-time cows was observed for 24 h in the third week of the main rearing period. Part-time cows spent less time nursing and grooming their own calf than full-time cows did. However, the amount of nursing in the inverse parallel position and the probability of a cow nursing a calf other than her own did not differ between the 2 treatments. Second, calf suckling behavior was observed for 24 h in both weeks of the reduced contact period. Averaged across both observations, total suckling time (i.e., time spent suckling any cow) was lower in part-time calves that experienced reduced contact compared with part-time calves with unchanged contact. In wk 9, time spent suckling only the dam was lower for full-time calves with reduced contact compared with part-time calves with unchanged contact. In conclusion, although we found a lower nursing and grooming time in part-time cows compared with full-time, we found no difference between treatments with regard to nursing in the inverse parallel position and nursing a calf other than the cow's own. The effect of gradually reducing cow-calf contact on calves' suckling time requires more research.

Long-lasting adverse effects of short-term stress during the suckling-mastication transition period on masticatory function and intraoral sensation in rats.

Early-life stress affects brain development, eventually resulting in adverse behavioral and physical health consequences in adulthood. The present study assessed the hypothesis that short-term early-life stress during infancy before weaning, a period for the maturation of mastication and sleep, poses long-lasting adverse effects on masticatory function and intraoral sensations later in life.Rat pups were exposed to either maternal separation (MS) or intermittent hypoxia (IH-Infancy) for 6 h/day in the light/sleep phase from postnatal day (P)17 to P20 to generate "neglect" and "pediatric obstructive sleep apnea" models, respectively. The remaining rats were exposed to IH during P45-P48 (IH-Adult). Masticatory ability was evaluated based on the rats' ability to chew pellets and bite pasta throughout the growth period (P21-P70). Intraoral chemical and mechanical sensitivities were assessed using two-bottle preference drinking tests, and hind paw pain thresholds were measured in adulthood (after P60).No differences were found in body weight, grip force, and hind paw sensitivity in MS, IH-Infancy, and IH-Adult rats compared with naïve rats. Masticatory ability was lower in MS and IH-Infancy rats from P28 to P70 than in naïve rats. MS and IH-Infancy rats exhibited intraoral hypersensitivity to capsaicin and mechanical stimulations in adulthood. The IH-Adult rats did not display inferior masticatory ability or intraoral hypersensitivity.In conclusion, short-term early-life stress during the suckling-mastication transition period potentially causes a persistent decrease in masticatory ability and intraoral hypersensitivity in adulthood. The period is a "critical window" for the maturation of oral motor and sensory functions.

Effects of simplified group housing on behavior, welfare, growth performance, and health of preweaned dairy calves on a California dairy.

Most US dairy calves are raised in individual hutches for biocontainment purposes and to facilitate monitoring and handling of calves. However, individual hutches typically restrict calves' activity and social interactions. Previous studies showed that group housing (GH) is beneficial to calf welfare and is associated with social benefits. The adoption of GH on dairies is hindered by several concerns, with the primary concern being the potential for increased transmission of diseases due to heightened calf-to-calf contact. In light of this, our study aimed to compare the behavior, health, and growth outcomes of calves housed in groups of 3 to individually housed (IH) calves during the preweaning period. A total of 42 Holstein heifer calves on a commercial dairy in Northern California were enrolled in groups of 3 to different housing treatments; IH (n = 21) or GH (n = 21) between July and October 2020. Each treatment was composed of 7 groups of 3 calves each. Calves in the GH treatment were housed in groups of 3 from 6 to 10 d until 70 d of age. Individual pens consisted of one polyethylene hutch with a 1.5 m × 1.2 m outside exercise area. Group pens were constructed by assembling 3 polyethylene hutches with a 1.5 m × 3.6 m outside exercise area of wire panel fencing. Calves were weighed and measured for height at birth and weaning. Diarrhea and bovine respiratory disease (BRD) scores were recorded daily throughout the preweaning period. Cumulative incidence and hazard ratios were estimated for BRD and diarrhea for GH and IH. A mixed model with pen as a random effect was specified to evaluate the effect of treatment. Group-housed calves gained 0.64 ± 0.02 kg/d while IH calves gained 0.65 ± 0.02 kg/d. Similarly, there was no evidence for treatment differences in withers height gain in GH calves (0.22 ± 0.01 cm/d) compared with IH calves (0.21 ± 0.01 cm/d). The cumulative incidence of BRD based on the California scoring system in GH calves was 75 ± 9.68% compared with 66.66 ± 10.28% in IH calves. Group-housed calves had a BRD hazard of 1.14 times that of IH calves (95% CI: 1.21-2.40). The cumulative incidence of diarrhea (fecal score 3) in GH calves was 100% in comparison to 95.20% ± 4.66% in IH calves. The mean proportion of scan observations of calves feeding on concentrates was significantly higher in GH (0.145 ± 0.004/h) compared with IH calves (0.076 ± 0.003/h) during the preweaning period. The study results provide evidence that this simplified GH system provides benefits of GH without detrimental short-term effects on calf growth and health during the preweaning period.

Stimulation of GHRH Neuron Axon Growth by Leptin and Impact of Nutrition during Suckling in Mice.

Nutrition during the early postnatal period can program the growth trajectory and adult size. Nutritionally regulated hormones are strongly suspected to be involved in this physiological regulation. Linear growth during the postnatal period is regulated by the neuroendocrine somatotropic axis, whose development is first controlled by GHRH neurons of the hypothalamus. Leptin that is secreted by adipocytes in proportion to fat mass is one of the most widely studied nutritional factors, with a programming effect in the hypothalamus. However, it remains unclear whether leptin stimulates the development of GHRH neurons directly. Using a Ghrh-eGFP mouse model, we show here that leptin can directly stimulate the axonal growth of GHRH neurons in vitro in arcuate explant cultures. Moreover, GHRH neurons in arcuate explants harvested from underfed pups were insensitive to the induction of axonal growth by leptin, whereas AgRP neurons in these explants were responsive to leptin treatment. This insensitivity was associated with altered activating capacities of the three JAK2, AKT and ERK signaling pathways. These results suggest that leptin may be a direct effector of linear growth programming by nutrition, and that the GHRH neuronal subpopulation may display a specific response to leptin in cases of underfeeding.

Cystoisospora suis infection in suckling piglets in Brazil: Prevalence and associated factors.

Piglet coccidiosis is a parasitic disease caused by the protozoan Cystoisospora suis, which is regarded as the most prevalent gastrointestinal parasite in intensive pig farms. Despite the availability of highly effective chemo-metaphylaxis (toltrazuril), coccidiosis is still prevalent in European and other countries. We conducted a cross-sectional study on swine farms in Brazil, to assess the prevalence of Cystoisospora suis in fecal samples and determined the associated factors. In total, 666 litters from 50 farms were sampled twice within one week between samplings (mean age at sampling: 10.75 and 17.7 days). Of 666 litters, 225 (33.8%) were positive at least once, and the expected within farm prevalence of C. suis oocysts was 32.9% (25.4-41.3%; 95% confidence interval). Oocysts were more prevalent in fecal samples collected from farms with diarrhea (odds ratio = 6.75). The room temperature was also positively associated with oocyst detection; a one-degree increase in room temperature increased the chance of a litter being positive by 23.2%. Up-to-date, this is the most comprehensive technical evidence of factors associated with C. suis infection in Brazilian industrial piglet farms.

The Role of the VP4 Attachment Protein in Rotavirus Host Range Restriction in an In Vivo Suckling Mouse Model.

The basis for rotavirus (RV) host range restriction (HRR) is not fully understood but is likely multigenic. RV genes encoding VP3, VP4, NSP1, NSP2, NSP3, and NSP4 have been associated with HRR in various studies. With the exception of NSP1, little is known about the relative contribution of the other RV genes to HRR. VP4 has been linked to HRR because it functions as the RV cell attachment protein, but its actual role in HRR has not been fully assessed. We generated a collection of recombinant RVs (rRVs) in an isogenic murine-like RV genetic background, harboring either heterologous or homologous VP4 genes from simian, bovine, porcine, human, and murine RV strains, and characterized these rRVs in vitro and in vivo. We found that a murine-like rRV encoding a simian VP4 was shed, spread to uninoculated littermates, and induced diarrhea comparably to rRV harboring a murine VP4. However, rRVs carrying VP4s from both bovine and porcine RVs had reduced diarrhea, but no change in fecal shedding was observed. Both diarrhea and shedding were reduced when VP4 originated from a human RV strain. rRVs harboring VP4s from human or bovine RVs did not transmit to uninoculated littermates. We also generated two rRVs harboring reciprocal chimeric murine or bovine VP4. Both chimeras replicated and caused disease as efficiently as the parental strain with a fully murine VP4. These data suggest that the genetic origin of VP4 partially modulates HRR in the suckling mouse and that both the VP8* and VP5* domains independently contribute to pathogenesis and transmission. IMPORTANCE Human group A rotaviruses (RVs) remain the most important cause of severe acute gastroenteritis among infants and young children worldwide despite the introduction of several safe and effective live attenuated vaccines. The lack of knowledge regarding fundamental aspects of RV biology, such as the genetic basis of host range restriction (HRR), has made it difficult to predictively and efficiently design improved, next-generation live attenuated rotavirus vaccines. Here, we engineered a collection of VP4 monoreassortant RVs to systematically explore the role of VP4 in replication, pathogenicity, and spread, as measures of HRR, in a suckling mouse model. The genetic and mechanistic bases of HRR have substantial clinical relevance given that this restriction forms the basis of attenuation for several replication-competent human RV vaccines. In addition, a better understanding of RV pathogenesis and the determinants of RV spread is likely to enhance our ability to improve antiviral drug and therapy development.

A field trial on the effect of cross-fostering on performance, clinical health and antibiotic usage during the suckling period of pigs.

Cross-fostering is a common nursing strategy in pig production, but there is sparse evidence on its effect on antibiotic usage and disease occurrence in piglets. The objective of this study was to compare the effect of two nursing strategies on antibiotic usage, disease occurrence, weight gain and mortality in piglets. A 2×2 randomized factorial experiment was conducted in three Danish commercial pig production herds. The factors were nursing strategy (cross-fostering allowed (CF) vs. cross-fostering not allowed after initial litter equalisation (non-CF)) and weaning age (four vs. five weeks). In CF litters, the herd's usual cross-fostering strategy was applied. Piglets were followed individually from birth until weaning. Data was collected on antibiotic usage, mortality, weight gain and clinical disease. Only individual antibiotic treatments were allowed. At litter level, the effect of nursing strategy (CF vs. non-CF) on average daily gain, mortality, antibiotic treatment, clinical disease, face wounds and carpal wounds was analysed. In total, 241 litters were used for the data analysis. Approximately 30% of the CF litters were cross-fostered (either given a nurse sow, mingled with non-siblings or both) during the nursing period. The odds for antibiotic treatment during the suckling period were 1.58 times higher for CF litters compared to non-CF litters (P < 0.001). Across experimental groups, 60.8% of antibiotic treatments were administered for leg diseases. In CF litters, 15.7-21.3% of the antibiotic treatments were directed against diarrhoea, whereas in non-CF litters this was the case for less than 1%. In CF litters, the odds for carpal wounds were 1.40 times higher than in non-CF litters (P = 0.005). There was a tendency towards a higher occurrence of face wounds (OR = 1.30, P = 0.095) and clinical disease (OR = 1.25, P = 0.059) at weaning in CF litters compared to non-CF litters. There was no difference in average daily gain and mortality from birth to weaning between CF and non-CF litters. The results show that cross-fostering increases antibiotic usage in piglets during the nursing period and tends to affect the clinical health at weaning negatively.

Body weight of newborn and suckling piglets affects their intestinal gene expression.

Modern hyperprolific sows must deal with large litters (16-20 piglets) which reduce piglet birthweight with a concomitant increase in the proportion of small and intrauterine growth retarded piglets. However, larger litters do not only have a greater variation of piglet weights, but also a greater variation in colostrum and milk consumption within the litter. To further understand the impact that body weight has on piglets, the present study aimed to evaluate the degree of physiological weakness of the smallest piglets at birth and during the suckling period (20 d) compared to their middle-weight littermates through their jejunal gene expression. At birth, light piglets showed a downregulation of genes related to immune response (FAXDC2, HSPB1, PPARGC1α), antioxidant enzymes (SOD2m), digestive enzymes (ANPEP, IDO1, SI), and nutrient transporter (SLC39A4) (P < 0.05) but also a tendency for a higher mRNA expression of GBP1 (inflammatory regulator) and HSD11ß1 (stress hormone) genes compared to their heavier littermates (P < 0.10). Excluding HSD11ß1 gene, all these intestinal gene expression differences initially observed at birth between light and middle-weight piglets were stabilized at the end of the suckling period, when others appeared. Genes involved in barrier function (CLDN1), pro-inflammatory response (CXCL2, IL6, IDO1), and stress hormone signaling (HSD11ß1) over-expressed compared to their middle-weight littermates (P < 0.05). In conclusion, at birth and at the end of suckling period, light body weight piglets seem to have a compromised gene expression and therefore impaired nutrient absorption, immune and stress responses compared to their heavier littermates.

Under hyperprolific situations, piglets must deal with a reduced birthweight and a severe sibling competition for nutrients. Therefore, light body weight newborn and suckling piglets may also have physiological disadvantages compared to their middle-weight littermates. To further understand the impact that body weight has on piglets, the present study aimed to evaluate the degree of physiological weakness of the smallest piglets at birth and during the suckling period (20 d) compared to their middle-weight littermates through their jejunal gene expression. Newborn light piglets downregulated genes related to immunity, antioxidant, and digestive activities, but also a tendency to upregulate other genes related to inflammation and stress responses. At the end of the suckling period, those genes expression differences vanished while others appear. Light weight piglets showed lower expression of genes involved in barrier function, inflammation, and stress responses compared to their middle-weight littermates. At birth and at the end of lactation, light piglets seem to have a compromised intestinal gene expression for nutrient absorption, immune and stress responses compared to their heavier littermates.

Maternal probiotics supplementation improves immune and antioxidant function in suckling piglets via modifying gut microbiota.

AIM: Probiotics could improve the health, growth, and development of host or their foetuses/offspring via regulating gut microbiota. The present study was conducted to determine the effects of maternal probiotics supplementation on gut microbiota and metabolites of sows and their suckling piglets, as well as plasma biochemical parameters, oxidative/anti-oxidative indexes, and inflammatory cytokine levels of suckling piglets. METHODS AND RESULTS: A total of 32 pregnant Bama mini-pigs were selected and randomly divided into two groups. The sows were fed a basal diet (control group) or a basal diet supplemented with probiotics (probiotics group) from mating to day 21 of lactation. Samples from sows were collected on day 105 of pregnancy and day 21 of lactation and from piglets on day 21 of lactation. The results showed that probiotics supplementation increased the faecal abundances of Ruminococcus, Bacteroides, and Anaeroplasma and decreased Tenericutes on day 105 of pregnancy while increased the abundances of Actinobacteria and Anaerostipes and decreased Proteobacteria and Desulfovibrio on day 21 of lactation. In addition, probiotics supplementation decreased the faecal levels of tryptamine, putrescine, and cadaverine on day 105 of pregnancy and isovalerate and skatole on day 21 of lactation while increased butyrate level on day 21 of lactation. Further studies showed that maternal probiotics supplementation decreased the plasma levels of AMM, TC, LDL-C, Ala, Tau, MDA, H2 O2 , IL-1ß, IL-2, IL-6, and IFN-α of suckling piglets. Moreover, maternal probiotics supplementation increased the abundances of Deferribacteres, Fusobacteria, and Fusobacterium while decreased Anaerostipes in piglet's colon. Spearman's correlation analysis revealed a potential link between gut microbiota alterations and their metabolites. CONCLUSIONS: Dietary probiotics supplementation during pregnancy and lactation periods could improve sow status, alleviate oxidative stress and inflammation response, and improve nutrient metabolism of piglets by altering the gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: The probiotics alter maternal and offspring's gut microbiota involving in offspring's physiological and metabolic changes, and present a new perspective that the effects of gut microbiota changes induced by probiotics supplementation will help in addressing the growth and development and health problem of their foetuses/offspring.