Pregnant Sows Research Articles

373 Efficiency of standardized ileal digestible lysine utilization for whole body protein retention in pregnant gilts and sows during early and mid gestation

Abstract NRC (2012) gestating sow model assumes the efficiency of AA use is constant across gestation, which may not reflect changes in metabolic demand during gestation. Efficiency of utilization is determined as the slope of the response to graded levels of test AA. Previous work reported a lack of response to graded Lys [60–90% of NRC (2012) predicted requirement] in early and mid gestation. Therefore, a study was conducted to determine efficiency of SID Lys utilization for whole body protein retention in gilts and sows during early (d 48–52) and mid (d 75–79) gestation. Four isocaloric (3,373 kcal ME/kg) and isoproteic (12.75 % CP) diets containing 40, 50, 60, and 70% of NRC (2012) model-predicted daily SID Lys requirement (10.1 and 9.3 g/d in early and mid gestation, respectively) were randomly assigned to 50 females (PIC 1050; 12 gilts, 21 Parity 1, 17 Parity 2). Dietary indispensable AA contents were set to meet 100–200% of AA:Lys ratios. Whole body nitrogen (N) retention was based on N-balance studies in early and mid gestation (7-d diet adaptation and 5 d total urine collection and grab fecal sampling). Lysine efficiency was determined by simple linear regression using PROC GLM procedure of SAS. Reproductive performance data were analyzed using PROC MIXED procedure of SAS. Reproductive performance of sows (birth weight, born alive, stillborn, and mummies) was not different by parity or diet. Whole body N and SID Lys retention increased linearly (P < 0.0001) with increasing SID Lys intake in early and mid gestation. Efficiency of Lys utilization in early gestation was 0.60, 0.46, and 0.50, and in mid gestation 0.58, 0.44, and 0.48 for gilts, parity 1, and parity 2 sows, respectively. Parity may play a greater role in efficiency of AA use than stage of gestation.

PSIV-25 Development of an indirect calorimetry system to determine heat production in individual lactating sows

Abstract Determining total heat production (THP) in individual sows and litters can be difficult and often requires the use of multiple animals to generate data on a per room basis. These systems may be costly to construct precluding their use by many researchers. The study objective was to develop a low cost indirect calorimetry system to determine THP in individual lactating sows and litters. Six indirect calorimeters were constructed to house 1 sow and litter in a crate throughout farrowing and a 21-d lactation period. Chamber accuracies for O2 and CO2 were evaluated by ethanol combustion. One-week pre-farrowing, 6 pregnant multiparous sows (parity 2.9 ± 0.9; 218.3 ± 38.6 kg BW) were housed individually in each farrowing crate and maintained in thermoneutral conditions (20.9 ± 2.6°C and 43.7 ± 18.6% relative humidity) throughout lactation. On lactation d 4, 8, 14, and 18, indirect calorimetry was performed on all sows and their litters, as well as 2 piglets from a sentinel litter to determine THP. Sentinel piglet data were used to estimate THP for the sows independent of the litter. Sow + litter THP (kcal/h) increased (P = 0.01; 16.6%) on d 8 compared to d 4 and was greater (27.3%) on d 14 and d 18 compared to d 4 and d 8. Sow THP was greater (P = 0.01) on d 8 (401.19 ± 17.15 kcal/h) and d 14 (430.79 ± 12.42 kcal/h) compared to d 4 (346.16 ± 16.62 kcal/h), and was greater on d 14 compared to d 8 and on d 18 (386.16 ± 20.02 kcal/h) compared to d 14. In summary, this cost-effective system can allow researchers to accurately evaluate THP in individual lactating sows and their litters

185 Impact of hydroxy-selenomethionine supplementation during late gestation and lactation in sows on piglet immunocompetence

Abstract The benefits of selenium (Se) supplementation during pregnancy and lactation in sows on piglet immunocompetence are not yet fully understood. This study aimed to assess piglet immune status when sows were fed Se-deficient or supplemented diets with sodium selenite (SS) or hydroxy-selenomethionine (OH-SeMet). Twelve pregnant sows were randomly assigned to 3 dietary treatments (4 sows each): no supplemental Se (NC), SS at 0.3 mg Se/kg (SS-0.3), OH-SeMet at 0.3 mg Se/kg (SO-0.3). The trial was carried out from gestation day (gd) 84 to weaning on postpartum day (ppd) 21, at which time all the piglets received the same diet having as Se source SS. On gd 98 and 105, sows were vaccinated with hen egg white lysozyme (HEWL). On ppd 0 and 21, 8 piglets/treatment were euthanized to obtain blood and muscle samples for total Se analyses. Serum samples were collected from 8 female piglets/treatment on ppd 0 and 2 to assess antigen-specific antibody titer for HEWL. On ppd 23, 6 weaned female piglets/treatment were intramuscular challenged with E. coli lipopolysaccharide (LPS) and serum IL-10 levels were measured at 24 h pre-challenge and at 2 and 48 h post challenge. At day 21, piglets from sows fed SO-0.3 showed the highest muscle Se deposition (P < 0.001). At ppd 0, no difference for HEWL-specific IgG was found while at ppd 2, SO-0.3 showed the highest HEWL-specific IgG concentration (P < 0.05). At 24 h pre-challenge and 2 h post LPS challenge, SO-0.3 showed a greater IL-10 level as compare to NC and SS-0.3, respectively (P < 0.05); no difference was found for the same parameter at 48 h post challenge. Piglets from SO supplemented sows exhibited stronger early immune response to LPS challenge. This study indicates the importance of sow Se supplementation with a pure organic form of Se such as OH-SeMet to enhance piglets Se and immune status.

Adding α-tocopherol-selenium and ascorbic acid to periparturient sow diets influences hemogram, lipid profile, leptin, oxidant/antioxidant imbalance, performance and neonatal piglet mortality

Alpha-tocopherol-selenium (ATS) and ascorbic acid (AA) are the potent antioxidants. The present study investigated whether supplementation of ATS and AA in periparturient sows has positive effects on amelioration of oxidative stress, serum immunoglobulin G (IgG), lipid profile and sows performance. For this, twenty-four pregnant multiparous sows (landrace×indigenous) were randomly distributed into four groups (6 sows per group) 20 days before expected date of farrowing as Control (basal diet); ATS (basal diet + ATS); AA (basal diet + AA) and ATS-AA (basal diet + ATS plus AA). The results of the study revealed that the concentrations of triglyceride and cholesterol significantly reduced from day -7 to day 7 of farrowing irrespective of supplementations to sows, but the leptin concentration significantly reduced on day 7 of farrowing in ATS-AA supplemented sows (p<0.05). Moreover, sows of supplemented groups experienced decreased oxidative stress and cortisol level than control sows. The serum IgG concentration was significantly increased on day 7 post-farrowing in ATS group but it was much earlier on day 2 of farrowing in ATS-AA group (p<0.001). Supplementing sows with ATS and/or AA did not influence significantly the birth weight, weaning weight and litter size at weaning (p>0.05). Although piglet survival rate was not affected significantly by supplementation, however, piglet mortality rate was lowest in ATS-AA than any other groups. It was concluded that supplementation of ATS and/or AA to sows during late gestating and early lactating period ameliorated oxidative stress, improved lipid profile and serum IgG level without influencing reproductive performance.

Caffeine administered to pregnant sows improves piglet vitality, gas exchange and body weight gain

Intra-partum asphyxia is the most common non-infectious etiology limiting the performance of neonate piglets. Previous studies indicate caffeine (orally and subcutaneously) reverses the effects of intra-partum asphyxia in neonate piglets. In this study, there was investigation of whether use of a novel therapeutic protocol for administering caffeine subcutaneously to pregnant sows would improve the newborn piglets’ vitality, physio-metabolic profiles and body weight gain. Sows were randomly divided into two groups (n = 10 each). Caffeine or NaCl 0.9% was administered 2 days pre-farrowing. Physio-metabolic profiles were measured using blood from the anterior vena cava. The vitality of piglets was evaluated immediately after birth. Piglets (n = 180) were weighed at birth and on days 7, 14 and 21 of lactation. Caffeine positively affected the vitality of the piglets, as indicated by greater vitality scores than that for the control group (8.72 ± 0.12 compared with 7.28 ± 0.16, P < 0.001). Metabolic values were similar between groups, but pO2 values were greater in the piglets with greater vitality scores treated with caffeine (19.10 ± 0.82 compared with 14.49 ± 1.42, P < 0.01), indicating increased respiratory rates. Body weight gain at day 21 was greater in the piglets treated with caffeine that had greater vitality scores than the control piglets having greater vitality scores (6.87 ± 0.18 compared with 6.52 ± 0.25 kg, P < 0.05). Caffeine administration before birth improves the vitality and respiratory capacity of piglets, increasing their adaptation to extra-uterine environment.

Stages of pregnancy and weaning influence the gut microbiota diversity and function in sows.

AimsThe gut microbiota is believed to play important roles in the health of pregnant mammals, including their nutrient metabolism, immune programming and metabolic regulation. However, until recently, the shifts in gut microbiota composition and faecal and blood metabolic activity during different stages of pregnancy had not been investigated.Methods and ResultsWe investigated the shifts in backfat thickness, plasma and faecal metabolites and gut microbiota on days 30, 60, 90 and 110 of pregnancy and on day 21 after parturition (weaning) in sows. The backfat thickness of sows did not significantly differ among the different stages of pregnancy. The plasma concentrations of lipid metabolites, including triacylglycerol (TG), total cholesterol, high‐density lipoprotein‐cholesterol, low‐density lipoprotein‐cholesterol and calcium were reduced (P < 0·05) during pregnancy. In addition, the concentration of these metabolites, except TG, reached their maximum at the time of weaning. We also found that Tenericutes, Fibrobacteres and Cyanobacteria varied significantly according to the stages of pregnancy in sows (P < 0·05). Most of the genera, such as Clostridiales, Desulfovibrio, Mogibacteriaceae and Prevotella, increased (P < 0·05) with the progression of pregnancy and decreased (P < 0·05) at weaning. The alpha diversity values (i.e., Shannon diversity and observed species) of sow gut microbiota increased (P < 0·05) from pregnancy to weaning. Pregnancy stages also significantly influenced (P < 0·05) the community structure (beta diversity) of gut microbiota. The progression of pregnancy was associated with changes in lipid metabolism and several carbohydrate‐degradation bacteria (i.e., Prevotella, Succinivibrio, Bacteroides and Parabacteroides).ConclusionsAlthough causal links between the measured parameters remain hypothetical, these findings suggest that the increased diversity and concentration of beneficial gut microbes are associated with the metabolism of pregnant sows.Significance and Impact of the StudyManipulation of the sow gut microbiota composition may potentially influence metabolism and health during pregnancy.

Correction of metabolism and microbiocenosis in pregnant sows

Correction of metabolism and microbiocenosis in pregnant sows

Antiatherogenic effect of lithium ascorbate in pregnant sows

Antiatherogenic effect of lithium ascorbate in pregnant sows

Construction and characterization of the infectious clone of porcine parvovirus carrying genetic marker

Porcine parvovirus (PPV) is one of the major pathogens that bring about reproductive failure of pregnant sows. However, the study of the pathogenesis mechanism is circumscribed due to the lack of efficient genetic manipulation method. Infectious clone is a powerful tool for further studying the genetic mechanisms of PPV. In the present study, the gene fragment (157–4812) of PPV was amplified by PPV China isolate strain as a template, and PPV DNA fragments (1–182) forming Y-structure within in 5′ end and (4788–5074) forming U-structure in 3′ end were synthesized. And then, the above three fragments were inserted into plasmid pKQLL to congregate a PPV full-length recombinant plasmid by means of In-Fusion cloning technology. After the successful sequencing identification of the recombinant plasmid, the EcoR I restriction site was brought out as a genetic marker by nonsense mutation (A3058 T) to produce plasmid Y-PPV, which was transfected into PK-15 cells for rescue of virus. The rescued viral particles were observed under transmission electron microscopy, and the sequencing analysis showed that Y-PPV could stably carry the genetic marker. It could be seen that Y-PPV has similar replicate capability and pathogenicity as the wild-type parental PPV strain by cellular and animal experiments. These results confirmed that Y-PPV maintain similar biological characteristics with wild-type parental PPV strain. Infectious clone could be a valuable tool for studying the individual genes of PPV and applications in gene deletion or live vector vaccines.

Tylvalosin administration in pregnant sows attenuates the enlargement and bluish coloration of inguinal lymph nodes in newborn piglets

In the porcine industry, some piglets show slightly enlarged and bluish inguinal lymph nodes. However, the causative factors for these signs and prevention of these signs remain unclear. Tylvalosin is a broad-spectrum antibiotic with an immunomodulatory function. This study was aimed at evaluating the effect of tylvalosin on the abovementioned signs. Thus, fifteen 90-day pregnant sows were divided into an untreated control group and 0.1 and 0.2 g/kg feed tylvalosin-treated groups until delivery. Forty-five piglets on day 2 after birth (15 each group) were blooded, then oxidative stress, serum cytokine levels, routine blood analysis, and effect of sera on macrophage phagocytic activity were examined. Fifteen piglets on day 2 after birth (5 in each group) were euthanized and pathological changes in the inguinal lymph nodes were observed. The untreated piglets showed hemorrhage, hemosiderin accumulation, and increased macrophages in the inguinal lymph nodes. However, tylvalosin administration in sows alleviated these signs in their piglets; increased total antioxidant capacity and serum glutathione levels; decreased serum IL-1β, TNF-α, and IL-10 levels; improved the percentages of neutrophils and lymphocytes in the blood; and increased the body weight of the weaning piglets. In addition, the serum of newborn piglets also showed enhanced RAW264.7 macrophage phagocytic activity. These results demonstrated that tylvalosin administration in pregnant sows attenuates the enlargement and bluish coloration of inguinal lymph nodes in newborn piglets.

The time of Calcium Feeding Affects the Productive Performance of Sows

Simple SummaryCalcium (Ca) is an important factor that affects the reproductive and lactation performance of sows. Circadian clocks and nutrient metabolism interact. We found that maternal feeding of Ca, varying with feeding time, improved the profile of some mineral elements in umbilical serum and milk, which contribute toward improving the productive performance of sows. This study confirmed that the absorption and metabolism of Ca in mammals also have circadian rhythms.This study aims to investigate the effect of Calcium (Ca) feeding time on a sow’s productive performance and the profiles of serum mineral elements during late pregnancy and lactation. A total of 75 pregnant sows were assigned to three groups: The control (C), earlier-later (E-L), and later-earlier (L-E) groups. During late pregnancy, the C group was fed an extra 4.5 g Ca (in the form of CaCO3) at both 06:00 and 15:00, the E-L group was fed an extra 9 g Ca at 06:00, and the L-E group was fed an extra 9 g Ca at 15:00. Similar treatments with double the amount of Ca were applied during lactation. The results show that, compared with the C group, L-E feeding decreased the number of stillbirths and the duration of farrowing and placenta expulsion (FARPLA) and increased the average daily weight gain (ADG) of piglets. Similarly, E-L feeding increased the ADG of piglets (p < 0.05). Furthermore, both E-L and L-E feeding increased the Ca levels in sow serum and umbilical serum, and the Fe levels in umbilical serum, but decreased the Ca levels in the placenta and colostrum (p < 0.05). Experiments on the genes involved in mineral element transport showed that E-L feeding activated the mRNA expression of TRPV5, S100G, SLC30A7, SLC39A4, and Ferroportin1, while it inhibited the mRNA expression of ATP7A in the placenta (p < 0.05). Moreover, L-E feeding up-regulated the mRNA expression of ATP2B and IREB2, while it down-regulated the mRNA expression of ATP7B in the placenta (p < 0.05). In conclusion, the present study demonstrated that maternal Ca feeding at 15:00 h during late pregnancy and lactation decreased FARPLA and stillbirths and improved the growth performance of suckling piglets by altering the mineral element of the metabolism in the umbilical serum and milk, compared to conventional feeding regimes.

Global miRNA, lncRNA, and mRNA Transcriptome Profiling of Endometrial Epithelial Cells Reveals Genes Related to Porcine Reproductive Failure Caused by Porcine Reproductive and Respiratory Syndrome Virus.

Porcine reproductive and respiratory syndrome virus (PRRSV) can cause respiratory disease and reproductive failure in pregnant pigs. Previous transcriptome analyses in susceptive cells have mainly concentrated on pulmonary alveolar macrophages (PAM) and Marc-145 cells, and on the respiratory system. Some studies reported that apoptosis of placental cells and pig endometrial epithelial cells (PECs) is an obvious sign linked to reproductive failure in pregnant sows, but the mechanism is still unknown. In this study, Sn-positive PECs were isolated and apoptosis rates were assessed by flow cytometry. PRRSV-infected PECs exhibited apoptosis, indicative of their susceptibility to PRRSV. Subsequently, the whole transcriptome was compared between mock- and PRRSV-infected PECs and 54 differentially expressed microRNAs (DEmiRNAs), 104 differentially expressed genes (DEGs), 22 differentially expressed lncRNAs (DElncRNAs), and 109 isoforms were obtained, which were mainly enriched in apoptosis, necroptosis, and p53 signal pathways. Integration analysis of DEmiRNA and DEG profiles revealed two microRNAs (ssc-miR-339-5p and ssc-miR-181d-5p) and five genes (SLA-DQB1, THBS1, SLC3A1, ZFP37, and LOC100517161) participating in the apoptosis signal, of which THBS1 and SLC3A1 were mainly linked to the p53 pathway. Integration analysis of DEGs with DElncRNA profiles identified genes involved in apoptosis signal pathway are regulated by LTCONS_00010766 and LTCONS_00045988. Pathway enrichment revealed that the phagosome and p53 pathways are the two main signals causing apoptosis of PECs, and functional analysis revealed a role of miR-339-5p in regulating apoptosis of PECs after PRRSV inoculation.

Impact of Maternal Selenium Supplementation from Late Gestation and Lactation on Piglet Immune Function.

The present work aimed at assessing passive, innate, and acquired immunity in piglets from sows supplemented with either organic or inorganic selenium (Se). A total of 12 multiparous pregnant sows were randomly allocated to three groups: selenium-deficient, corn and soy-based diet base diet (BD),0.3mgSe/kg ashydroxy-selenomethionine (OH-SeMet), and 0.3mgSe/kg assodium selenite (SS). The feeding trial was carried out from gd 84 to weaning on postpartum day 21 (ppd 21). On gd 98 and 105, sows were vaccinated with hen egg white lysozyme (HEWL) to assess passive immunity. On ppd 23, weaned piglets were intramuscularly challenged with lipopolysaccharide (LPS) to trigger an acute-phase response. On ppd 14, 28, and 35, piglets were vaccinated with ovalbumin (OVA) to assess OVA-specific immunoglobulin G (IgG) and dermal hypersensitivity responses. Se levels in piglet plasma, muscle, and liver on ppd 21 were higher in OH-SeMet group. On ppd 2, piglet HEWL-specific IgG levels in OH-SeMet group were significantly increased. IL-10 and haptoglobin (HP) levels in OH-SeMet group were significantly increased 2h and 48h post-LPS simulation, respectively. The OVA-specific IgG levels in BD group were significantly higher than the other two groups, and the IL-4 concentration following whole blood ex vivo challenge with either OVA or mitogen was significantly increased in OH-SeMet group. OVA-specific skin swelling was lower in OH-SeMet and SS groups at 3h and 6h. This suggests that sow supplementation with OH-SeMet enhances mainly passive immunity through IgG maternal transfer and can influence piglet innate and acquired immunity.

Net energy content of five fiber‐rich ingredients fed to pregnant sows

The present study was conducted to determine the net energy (NE) values and energy efficiency of wheat bran (WB), sugar beet pulp (SBP), corn gluten feed (CGF), soybean hulls (SBH), and defatted rice bran (DFRB) fed to pregnant sows. Thirty-six multiparous pregnant sows were randomly assigned to six dietary treatments with six replicates per treatment. Each period lasted for 21days including 14days for adaptation. On day 15, sows were moved into respiration chambers for heat production (HP) measurement and provided feed at 544kJ/kg BW0.75 /day. On day 20, sows were fasted to measure the fasting heat production (FHP). Experimental diets included corn-soybean meal basal diet and five diets containing 29.20% WB, SBP, CGF, SBH, and DFRB, respectively. Results showed that inclusion of WB, SBP, CGF, SBH, and DFRB to basal diet decreased (p<0.05) the apparent total tract digestibility of energy and nutrients. The average adjusted total HP and FHP were 418kJ/kg BW0.75 /day and 326kJ/kg BW0.75 /day, respectively. The average NE:ME ratio of experiment diets was 82.5%. In conclusion, the NE values of WB, SBP, CGF, SBH, and DFRB were 9.05, 8.59, 8.37, 7.64, and 7.93MJ/kg DM, respectively.

Assessment of the efficacy of an attenuated live marker classical swine fever vaccine (Flc-LOM-BErns) in pregnant sows

Here, we constructed an attenuated live marker classical swine fever (CSF) vaccine (Flc-LOM-BErns) to eradicate CSF. This was done by taking infectious clone Flc-LOM, which is based on an attenuated live CSF vaccine virus (LOM strain), and removing the full-length classical swine fever virus (CSFV) Erns sequences and the 3′ end (52 base pairs) of the CSFV capsid. These regions were substituted with the full-length bovine viral diarrhoea virus (BVDV) Erns gene sequence and the 3′ end (52 base pairs) of the BVDV capsid gene. Sows were vaccinated with the Flc-LOM-BErns vaccine 3 weeks before insemination and then challenged with virulent CSFV at the early, mid- or late stages of pregnancy. We then examined transplacental transmission to the foetuses. Piglets born to sows vaccinated with Flc-LOM-BErns did not show vertical infection, regardless of challenge time. In addition, CSFV challenge did not affect the delivery date, weight or length of the foetus. Pregnant sows inoculated with the Flc-LOM-BErns vaccine were anti-CSF Erns antibody-negative and anti-BVDV Erns antibody-positive. Challenge of pregnant sows with virulent CSFV resulted in anti-CSF Erns antibody positivity. These results strongly indicate that differential diagnosis can be conducted between the Flc-LOM-BErns vaccinated animal and virulent CSFV affected animal by detecting antibody against BVDV Erns or CSF Erns gene. Therefore, the Flc-LOM-BErns vaccine may fulfil the function of differential diagnosis which required for DIVA vaccine.

SWATH-MS quantitative proteomic investigation of intrauterine growth restriction in a porcine model reveals sex differences in hippocampus development

Intrauterine growth restriction (IUGR) is characterized by reduced growth and weight of the foetus, mainly due to the lack of nutrients and oxygen. Animals affected by IUGR show changes in specific brain areas and several neuronal processes. Female offspring affected by IUGR show increased survival and development compared to males. The objective of this study was to analyse changes in the hippocampus proteome in male and female piglets affected by IUGR. Seven pregnant Iberian sows were fed from Day 35 of pregnancy onwards at 50% of their requirements. At Day 100 of pregnancy, foetuses were obtained and classified by sex and weight, as mild IUGR (Normal Body Weight) versus severe IUGR (Low Body Weight). Hippocampi were dissected and the proteomes analysed by SWATH-MS DIA. In this study, 1497 proteins were identified of which 260 were quantitatively analysed. All differential proteins were more abundant in females versus males and were involved in protein synthesis, neuronal development, metabolism, antiapoptotic signalling and vesicular transport. Our findings support that female foetuses tolerate nutrient limitation better than males, especially under mild IUGR. Under severe IUGR, females still seems to maintain normal lipid metabolism and antiapoptotic signalling, which may be related to the increased female survival. SignificanceIn the last years, proteomics have been used to evidence differences related to sex in non-reproductive organs. Intrauterine Growth Restriction (IUGR) can affect female and male offspring differently. Female offspring has stronger protective strategies compared to males, enhancing growth and postnatal survival. Most studies regarding this issue have focused on metabolic organs (i.e. liver). However, the predominance of neurodevelopmental disorders in males suggests that the central nervous system in female offspring adapt better to nutritional stress conditions than that of males. Based on the differential protein expression in hippocampal samples, our work demonstrates that female foetuses indeed adapt better to IUGR than males, especially under mild IUGR conditions. In severe IUGR conditions, differences between males and females were not so evident, but even in this case, the remaining differences suggest increased survival in females than in males.

Effect of gestation dietary methionine/lysine ratio on placental angiogenesis and reproductive performance of sows1.

The current study aims to evaluate the effects of different gestation dietary Met/Lys (methionine, Met/lysine) ratios on the production performance of sows. Specifically, it measured the effect of Met on plasma urea and AA concentrations and placental vascular density of pregnant sows. A total of 325 multiparous sows (third parity, Large × White) were randomly allocated to five dietary treatments (n = 65) with five dietary Met/Lys ratios 0.27 (nutrient requirements of swine [NRC] 2012 level), 0.32, 0.37, 0.42, and 0.47). The litter size and weight at birth were measured and recorded. Blood samples were obtained on days 0, 40, 90, and 114 of gestation, and placenta samples were collected at parturition. The effects of different dietary Met/Lys ratios on the reproductive performance were evaluated based on the prolificacy of sows as either high (≥13 total piglets born) or low (<13 total piglets born). The results showed that dietary Met/Lys ratio had no significant effect on the reproductive performance of lower prolificacy sows (P > 0.05). However, for high-prolificacy sows, litter weight of born alive significantly increased in 0.37 Met/Lys ratios group compared with control group (P < 0.05). The gestation dietary Met/Lys ratio showed significant quadratic effects on the litter birth weight and percentage of piglets born with weight <0.9 kg (P < 0.05), and the Met/Lys ratios to achieve the best reproductive performance determined to be 0.37. Furthermore, plasma urea concentrations of sows also changed with Met/Lys ratios quadratically (P < 0.05). Increasing dietary Met/Lys ratios elevated the concentration of most plasma AA. Although the dietary Met/Lys ratio had no significant effect on the placental vascular density (P > 0.05), the gestation dietary Met/Lys ratio showed significant quadratic effects on the placental vascular density (P < 0.05). In addition, the birth weight of piglets of high-prolificacy sows was positively correlated with the placental vascular density (P < 0.01). Taken as a whole, the dietary Met/Lys ratio showed a quadratic curve relation with birth weight performance and placental angiogenesis performance, to which 0.37 ratio contributed to the best performance of high-prolificacy sows.

Effect of Dietary Hemp Seed on Oxidative Status in Sows during Late Gestation and Lactation and Their Offspring.

Simple SummaryHemp seeds are rich in polyunsaturated fatty acids as well as other bioactive compounds. Using dietary hemp seeds as late gestation and lactation supplementation for sows and early life supplementation for piglets, we found that the indicators of oxidative status were improved in both sows and offspring. Besides the significant improvement in the antioxidant defense system of the sows, our assessment of dietary intervention resulted in an array of increased antioxidative status markers for their progeny. In addition, this could be translated into increased adaptability to the upcoming weaning stage. This study shows the antioxidant effect of a dietary hemp seed diet rich in ω-6 polyunsaturated fatty acid (PUFA) on oxidative status in sows during late gestation and lactation and their offspring. Ten pregnant sows were divided into two groups and fed either a control diet (CD) or a hemp diet (HD) containing 2% hemp seed meal for a period of 10 days before farrowing and 5% throughout the lactation period (21 d). After farrowing, 16 of their resulting piglets were divided into two groups: control group CD (eight piglets derived from control sows) and HD group (eight piglets derived from HD sows), respectively. Blood collected from sows and piglets at day 1, 7 and 21 was used for the measurement of antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), glutathione (GPx)), nitric oxide production (NO), lipid peroxidation (thiobarbituric acid reactive substances—TBARS), reactive oxygen species (ROS) generation and total antioxidant capacity (TAC) in plasma. The results showed a significant improvement in the oxidative status of sows fed HD throughout lactation compared with CD. Similarly, in piglets, HD positively influenced the activities of antioxidant enzymes, TAC and NO levels and significantly decreased lipid peroxidation in plasma until weaning, in comparison with the CD group. This study suggests the potential of hemp seed diet to improve the overall antioxidant status of the lactating sows and their progeny.

Novel nucleotide variants in SLA-DOB and CD4 are associated with immune traits in pregnant sows

Reinforcing the immunity of pregnant sows can not only improve their own health condition but also increase the survival rate and healthy status of their piglets. This study aims to find single-nucleotide polymorphism (SNP) and molecular markers that are associated with the immune traits of pregnant sows. SLA-DOB and CD4 were selected as candidate genes, and blood samples were randomly collected from pregnant Landrace sows and used to detect T-lymphocyte subsets, interferon alpha, interleukin 6, Toll-like receptor 3, serum antibody immunoglobulin G, and porcine reproductive and respiratory syndrome virus-specific antibody. Then, association analyses were conducted for the polymorphic sites of candidate genes with immune traits. We found 12 mutations in the two genes and conducted an association study with eight of them. Our results indicated that among the eight mutations, SNP1, SNP2, and SNP3 of the SLA-DOB gene and Ins9, SNP10, and SNP11 in the CD4 gene are newly discovered mutations. Except for SNP1, SNP3, and SNP11, the other five SNPs are associated with at least one immune trait tested. Especially, SNP2 and Ins9 are significantly associated with at least one of the T-lymphocyte subgroups and at least one antibody. These novel mutations have potential important effects on the polymorphic loci of the above immune traits in pregnant sows. The results suggest that the SLA-DOB and CD4 genes and their genetic mutations can be considered as important candidate genes and mutations for the immunity of pregnant sows.

Feasibility Study: Improving Floor Cleanliness by Using a Robot Scraper in Group-Housed Pregnant Sows and Their Reactions on the New Device.

Simple SummaryA clean slatted floor in the animal housing is important for both hygienic and environmental reasons. In dairy farming, robot scrapers are used to support the floor cleaning process in the housing. As a result, the housing cleanliness is significantly improved. A robot scraper is equipped with various sensors and its own drive. A computer controls it. Taking into account barriers on the route (e.g., animals, walls, etc.), it moves at low speed over the housing floor and cleans it with or without the use of water. In this feasibility study, it has now been investigated whether such a robot scraper can also be used in pig farming. The faeces of pigs are drier than cattle excrement and thus more difficult to clean. Nevertheless, the robot scraper showed good cleaning results in this study. The sows accepted the presence of the robot scraper and were not disturbed by it. In summary, it can be stated that the cleanliness of the slatted floor in pig housings can also be increased by using a robot scraper. Since pigs are curious animals and investigate the robot scraper with their snouts, the technical configuration of the standard robot scraper should be slightly modified.Successful pig farming needs the best conditions of cleanliness in the housings. The present study examined for the first time whether a robot scraper usually applied in dairy farming is usable in sow housings for cleaning the slatted floors and improving hygiene and thus animal welfare. For evaluating the suitability of the robot scraper with regard to the cleaning performance (polluted surface area and occluded slots), the whole housing area was divided into score-squares, which were individually scored at defined intervals. Selected excrement quantities removed by the robot were weighed. In order to assess the animals’ interactions with the robot scraper, their behaviour towards the device was observed. Although the faeces of pigs had a firmer consistency than bovine excrement, excrement quantities of up to 1.4 kg m−2 were almost completely removed. Even 6 h after the cleaning its effect was still visible. Dry-cleaning led faster to nonslip surfaces for the sows than wet-cleaning. Within half an hour of observation, up to 8.2 of 120 sows were occupied with the robot scraper, but without harming it. The use of robot scrapers in pig housings is recommended, although slight technical modifications should be made to the robot scraper.