Dietary linseed oil in the maternal diet affects immunoglobulins,tissue fatty acid composition and expression of lipid metabolism‐related genes in piglets

This experiment investigated the effects of supplementing the maternal diet with linseed oil (LSO) and soya bean oil (SBO) on immunoglobulins, the fatty acid composition and hepatic expression of lipid metabolism‐related genes in piglets. Multiparous sows (twenty‐four per diet) were fed on diets containing a supplement of either SBO or LSO during last week of gestation and lactation. The results indicated that supplementation of maternal diet with LSO could improve the weaning weight of piglets and average daily gain (ADG) (p < 0.05). The concentration of immunoglobulin G (IgG) and immunoglobulin A (IgA) was enhanced in sow plasma, colostrum and milk by the addition of LSO (p < 0.05). In addition, the concentration of 18: 3n‐3 fatty acids was higher in the milk of LSO sows. Meanwhile, maternal supplementation with LSO increased the levels of plasma IgG, IgA and the tissues n‐3 polyunsaturated fatty acid (PUFA) in piglets (p < 0.05). Correspondingly, the mRNA expression levels of hepatic ?5‐desaturase (D5D) and ?6‐desaturase (D6D) were higher, and fatty acid synthase (FAS) was lower in piglets from LSO‐fed sows when compared with that in the SBO group. In conclusion, LSO supplementation of the maternal diet increases immunoglobulins, modifies the fatty acid composition and affects the gene of D5D and D6D expression of piglets.     

Effects of Inulin Supplementation in Low‐ or High‐Fat Diets on Reproductive Performance of Sows and Antioxidant Defence Capacity in Sows and Offspring

This experiment was conducted to investigate the effects of inulin supplementation in low‐ or high‐fat diets on both the reproductive performance of sow and the antioxidant defence capacity in sows and offspring. Sixty Landrace × Yorkshire sows were randomly allocated to four treatments with low‐fat diet (L), low‐fat diet containing 1.5% inulin (LI), high‐fat diet (H) and high‐fat diet containing 1.5% inulin (HI). Inulin‐rich diets lowered the within‐litter birth weight coefficient of variation (CV, p = 0.05) of piglets, increased the proportion of piglets weighing 1.0–1.5 kg at farrowing (p < 0.01), reduced the loss of body weight (BW) and backfat thickness (BF) during lactation (p < 0.05) and decreased the duration of farrowing as well as improved sow constipation (p < 0.05). Sows fed fat‐rich diets gained more BW during gestation (p < 0.01), farrowed a greater number of total (+1.65 pigs, p < 0.05) and alive (+1.52 pigs p < 0.05) piglets and had a heavier (+2.06 kg, p < 0.05) litter weight at birth as well as a decreased weaning‐to‐oestrous interval (WEI, p < 0.01) compared with sows fed low‐fat diets. However, it is worth noting that the H diet significantly decreased the serum activities of superoxide dismutase (T‐SOD) and glutathione peroxidase (GSH‐Px) and increased the serum malondialdehyde (MDA) levels in sows and piglets (p < 0.05). In contrast, HI diet enhanced the activities of T‐SOD and GSH‐Px and decreased the serum MDA concentrations (p < 0.05) in sows and piglets. In summary, the fat‐rich diets fed to sows during gestation had beneficial effects on reproductive performance, but aggravated the oxidative stress in sow and piglets. Inulin‐rich diets fed to sow during gestation had beneficial effects on within‐litter uniformity of piglet birthweight and enhanced the antioxidant defence capacity of sows and piglets.     

Effects of additional starch or fat in late-gestating high nonstarch polysaccharide diets on litter performance and glucose tolerance in sows

The effects of feeding additional starch or fat from d 85 of gestation until parturition on litter performance and on glucose tolerance in sows that were fed a diet with a high level of fermentable nonstarch polysaccharides (NSP) were studied. The day after breeding, 141 multiparous sows were assigned to the experiment. At d 85 of gestation, sows were assigned to the treatments. Sows were fed 3.4 kg/d (as-fed basis) of a high-NSP diet or the same quantity of the high-NSP diet and an additional 360 g of starch (from wheat starch) daily, or the same quantity of the high-NSP diet and an additional 164 g of fat (from soybean oil) daily. During lactation, all sows were given free access to the same lactation diet. Approximately 1 wk before the expected time of parturition, an oral glucose tolerance test was performed in 38 randomly chosen sows by feeding pelleted glucose (3 g/kg BW0.75). Blood samples for glucose analyses were taken at -10, 10, 20, 30, 40, 50, 60, 70, 80, 90, 105, and 120 min after glucose was fed. The supply of additional dietary starch or fat did not increase piglet birth weight or total litter weight at birth. Sows that were fed the high-NSP diet had more (P = 0.097) live-born piglets and fewer (P = 0.084) stillborn piglets than did sows that were fed additional fat, whereas sows that were fed additional starch were intermediate for these variables. Piglet mortality after birth was not affected by dietary treatment. Body weight and backfat gains in the last month of gestation were higher for sows fed additional starch or fat than for sows fed the high-NSP diet (P < 0.001 and P = 0.017, respectively). Feed intake in lactation was greatest by sows fed the high-NSP diet, least by sows fed additional starch at the end of gestation, and intermediate by sows fed additional fat (P = 0.099). The differences in lactation feed intake did not result in differences in BW and backfat losses during lactation. Sows that were fed additional fat had the greatest glucose area under the curve (P = 0.044), indicating that these sows were less tolerant to glucose. In conclusion, feeding additional energy (starch or fat) in late-gestating sows that are fed a high-NSP diet did not increase litter weight at birth or piglet survival, but did increase maternal gain. Feeding sows additional energy from fat might induce glucose intolerance, whereas feeding sows additional energy from starch did not induce glucose intolerance.     

l‐carnitine and fat type in the maternal diet during gestation and lactation modify the fatty acid composition and expression of lipid metabolism‐related genes in piglets

This study examined the influence of adding different amounts of maternal dietary l ‐carnitine and two fat types on fatty acid (FA) composition and the expression of lipid metabolism‐related genes in piglets. The experiment was designed as a 2 × 2 factorial with two fat types (3.5% soyabean oil, SO, and 3.5% fish oil, FO) and two levels of l ‐carnitine (0 and 100 mg/kg) added to the sows' diets. A higher proportion of n‐3 polyunsaturated fatty acids (PUFA) and a lower ratio of n‐6/n‐3 PUFA in sow milk and piglet tissues were observed in the FO groups than in the SO groups. Adding l ‐carnitine increased the proportion of C16:1 in sow milk and decreased n‐3 PUFA in piglet subcutaneous fat. Hepatic peroxisome proliferator‐activated receptor α (PPAR‐α) was more abundantly expressed in piglets from the FO groups than from the SO groups (p < 0.05), whereas stearoyl‐CoA‐desaturase (SCD), sterol regulatory element binding protein‐1 (SREBP1) and ?6‐desaturase (D6D) genes were less expressed in the FO groups compared with piglets from the SO groups. The expression of fatty acid synthase (FAS) genes was decreased in the SO groups with l ‐carnitine compared to that of the other dietary treatments. No differences among dietary treatments were observed with regard to the expression of acetyl‐CoA carboxylase (ACC). In conclusion, FO and l ‐carnitine supplementation in sows affect FA composition and hepatic gene expression in piglets.     

Dietary manipulation of the sow milk does not influence the lipid absorption capacity of the progeny

A control diet without supplemental fat and four diets containing 8% of coconut oil, rapeseed oil, fish oil or sunflower oil were fed to lactating sows in order to investigate the lipid absorption capacity of their progeny in terms of pancreatic enzyme activity, hormonal regulation, and bile salt concentration. In addition, the effect of age was studied during the four week suckling period, and during a three week postweaning period, in which a standard weaner diet was fed to all piglets. It is concluded that fat source and level in the maternal diet plays a minor role in comparison to piglet age with regard to lipid absorption capacity of the progeny postweaning.     

Perinatal maternal feeding with an energy dense diet and/or micronutrient mixture drives offspring fat distribution depending on the sex and growth stage

Maternal nutrition during pregnancy and lactation influences offspring development and health. Novel studies have described the effects on next generation obesity‐related features depending on maternal macro‐ and micro‐nutrient perinatal feeding. We hypothesized that the maternal obesogenic diet during pregnancy and lactation programs an obese phenotype, while maternal micronutrient supplementation at these stages could partially prevent these features. Thus, the aim was to assess the influence of a perinatal maternal feeding with an obesogenic diet enriched in fat and sucrose and a micronutrient supplementation during pregnancy and lactation on offspring growth and obese phenotypical features during life course. Female Wistar rats were assigned to four dietary groups during pregnancy and lactation: control, control supplemented with micronutrients (choline, betaine, folic acid and vitamin B₁₂), high‐fat sucrose (HFS) and HFS supplemented. At weaning, the offspring were transferred to a chow diet, and weight and fat mass were measured at weeks 3, 12 and 20. At birth, both male and female offspring from mothers fed the obesogenic diet showed lower body weight (?5 and ?6%, respectively), while only female offspring weight decreased by maternal micronutrient supplementation (?5%). During lactation, maternal HFS diet was associated with increased body weight, while micronutrient supplementation protected against body weight gain. Whole body fat mass content increased at weeks 3, 12 and 20 (from 16 to 65%) due to maternal HFS diet. Maternal micronutrient supplementation decreased offspring fat mass content at week 3 (?8%). Male offspring showed higher adiposity than females at weeks 12 and 20. In conclusion, maternal HFS feeding during pregnancy and lactation was associated with a low offspring weight at birth and obese phenotypical features during adult life in a sex‐ and time‐dependent manner. Furthermore, maternal methyl donor supplementation protected against body weight gain in male offspring during lactation and in female offspring also during juvenile period.     

Effect of dietary fish oil on the expression of genes involved in lipid metabolism in liver and skeletal muscle of lactating sows

This study investigated the hypothesis that dietary supplementation of fish oil as a source of n‐3 polyunsaturated fatty acids (PUFA) influences the expression of target genes of sterol regulatory element‐binding proteins (SREBP)‐1 and (SREBP)‐2 involved in triacylglycerol (TAG) synthesis and fatty acid and cholesterol metabolism in the liver, and moreover activates the expression of target genes of peroxisome proliferation‐activated receptor (PPAR)‐α involved in TAG and fatty acid catabolism in liver and skeletal muscle. Twenty lactating sows were fed a control diet or a fish oil diet with either 50 g of a mixture of palm oil and soya bean oil (4:1, w/w) or fish oil per kg. The diet of the fish oil group contained 19.1 g of n‐3 PUFA (mainly 20:5 n‐3 and 22:6 n‐3) per 100 g of total fatty acids, while the diet of the control group contained 2.4 g of n‐3 PUFA (mainly 18:3 n‐3) per 100 g of total fatty acids. The fish oil group had reduced relative mRNA concentrations of various target genes of SREBP‐1 involved in fatty acid and TAG synthesis in comparison with the control group (p < 0.05). Relative mRNA concentrations of target genes of PPARα involved in fatty acid catabolism in both liver and muscle, and mRNA concentrations of target genes of SREBP‐2 involved in cholesterol synthesis and uptake were not influenced by fish oil supplementation. Concentrations of cholesterol and TAG in plasma, fat content of milk and weight gains of litters during the suckling period were not different between the two groups of sows. In conclusion, this study suggests that fish oil has only minor effects on hepatic lipid metabolism, which are non‐critical with respect to milk production in sows.     

Folic acid supplementation prevents the changes in hepatic promoter methylation status and gene expression in intrauterine growth‐retarded piglets during early weaning period

During intrauterine life, genome interacts with maternal signals to influence the mRNA expression levels of specific genes persistently by regulating DNA methylation status. The objective of this study was to examine the responses of glucocorticoid receptor (GR), peroxisome proliferator‐activated receptor alpha and gamma (PPARα and PPARγ) promoter methylation, mRNA expression of genes involved in energy metabolism and metabolite concentrations of intrauterine growth‐retarded (IUGR) piglets to dietary folic acid supplementation. According to a 2 × 2 factorial arrangement, 16 IUGR and 16 normal birth weight (NBW) piglets were fed a basal diet or a basal diet supplemented with 5 mg/kg of folic acid from weaning (day 14) to day 35 of age. Triglycerides in hepatic tissue and plasma were significantly elevated in control diets‐fed IUGR piglets compared with NBW piglets but were decreased by dietary folic acid supplementation. Hepatic mRNA expression levels of GR, PPARα, PPARγ, fatty acid synthase and phosphoenolpyruvate carboxykinase (PEPCK) in IUGR piglets fed a control diet were significantly higher than that in NBW piglets, and promoter methylation status of GR, PPARα and PPARγ in IUGR piglets was reduced significantly compared with NBW piglets. However, the changes in gene expression and DNA methylation status of IUGR piglets were reversed by dietary folic acid supplementation. Hepatic DNA methyltransferase activity was greater with dietary folic acid supplementation regardless of birth weight. Taken together, these results demonstrated that folic acid supplementation during early period of life could prevent the changes of promoter methylation status and gene expressions in the liver of IUGR piglets.     

Effects of gestation and transition diets, piglet birth weight, and fasting time on depletion of glycogen pools in liver and 3 muscles of newborn piglets

The experiment was conducted to assess the effects of maternal nutrition in late gestation on glycogen pools of newborn piglets of different birth weights and to assess how rapidly the glycogen pools in the liver and 3 muscles are mobilized during fasting. Until d 108 of gestation, 48 sows were fed a gestation standard diet (GSD) with low dietary fiber (DF, 17.1%), or 1 of 3 diets with high DF (32.3 to 40.4%) consisting of pectin residue (GPR), potato pulp (GPP), or sugar-beet pulp (GSP). From d 108 until farrowing, sows were fed 1 of 6 transition diets with low or high dietary fat: one group received a standard diet (TSD; control) containing 3% animal fat, another group received the TSD diet + 2.5 g/d of hydroxy-methyl butyrate as topdressing (THB), and 4 other groups received diets with 8% added fat from coconut oil (TCO), sunflower oil (TSO), fish oil (TFO), or 4% octanoic acid + 4% fish oil (TOA). Two piglets per litter (the second and fifth born) were blood sampled, and 1 was killed immediately after birth, whereas the other, depending on the litter, was killed after 12, 24, or 28.5 to 36 h (mean 32.5 h) of fasting. Samples of liver, LM, M. semimembranousus (SM), and M. diaphragm (DP) were collected and analyzed for glycogen concentration. No dietary effects (P > 0.20) on glycogen concentrations in liver, LM, SM, or DP were observed. The weight of the liver was affected by gestation diet (P < 0.05) and was greater in GSD and GSP piglets (36.7 and 36.3 g) than in GPR piglets (32.6 g), and intermediate (33.6 g) in GPP piglets. Liver weight, estimated muscle mass, and glycogen pools (P < 0.001) were affected by birth weight, whereas glycogen concentrations in liver and LM, SM, and DP muscles were not (P > 0.05). Liver weight; glycogen concentrations in liver, LM, SM, and DP; and glycogen pools in liver and muscles decreased (P < 0.001) with increasing duration of fasting, and at 32.5 h of fasting, glycogen concentration was reduced by 80% in liver, 64% in DP, 46% in SM, and 36% in LM. Based on a broken-line model, labile glycogen in SM, a locomotory muscle, was estimated to be depleted after 16.4 h of fasting. In conclusion, piglet size had a major impact on estimated glycogen pools, whereas sow nutrition in late gestation had a minor impact, if any. Furthermore, varying proportions of pools of glycogen present in liver and selected muscles were mobilized, and data indicate that newborn piglets are fatally depleted of energy after 16 h of fasting.     

Effects of Dietary Supplementation of β‐hydroxy‐β‐methylbutyrate on Sow Performance and mRNA Expression of Myogenic Markers in Skeletal Muscle of Neonatal Piglets

The effects of dietary β‐hydroxy‐β‐methylbutyrate (HMB) supplementation during gestation on reproductive performance of sows and the mRNA expression of myogenic markers in skeletal muscle of neonatal pigs were determined. At day 35 of gestation, a total of 20 sows (Landrace × Yorkshire, at third parity) were randomly assigned to two groups, with each group receiving either a basal diet or the same diet supplemented with 4 g/day β‐hydroxy‐β‐methylbutyrate calcium (HMB‐Ca) until parturition. At parturition, the total and live litter size were not markedly different between treatments, however, the sows fed HMB diet had a decreased rate of stillborn piglets compared with the sows fed the control (CON) diets (p < 0.05). In addition, piglets from the sows fed HMB diet tended to have an increased birth weight (p = 0.08), and a reduced rate of low birth weight piglets (p = 0.05) compared with piglets from the CON sows. Nevertheless, lower feed intake during lactation was observed in the sows fed the HMB diet compared with those on the CON diet (p < 0.01). The relative weights of the longissimus dorsi (LD) and semitendinosus (ST) muscle were higher (p < 0.05) in neonatal pigs from the HMB than the CON sows. Furthermore, maternal HMB treatment increased the mRNA levels of the myogenic genes, including muscle regulatory factor‐4 (MRF4, p < 0.05), myogenic differentiation factor (MyoD) and insulin‐like growth factor‐1 (IGF‐1, p < 0.01). In conclusion, dietary HMB supplementation to sows at 4 g/day from day 35 of gestation to term significantly improves pregnancy outcomes and increases the expression of myogenic genes in skeletal muscle of neonatal piglets, but reduces feed intake of sows during lactation.     

Influence of dietary fat source on sow and litter performance,colostrum and milk fatty acid profile in late gestation and lactation

The objective of this study was to investigate the effects of dietary supplementation with various fat sources (3.8–3.9% of diet) during late pregnancy and lactation on the reproductive performance, fatty acids profile in colostrum, milk and serum of sow progeny. A total of 80 multiparous sows were randomly fed a control (adding no oil), palm oil (PO), fish oil (FO) or soybean oil (SO) supplemented diet from 90 days of pregnancy to weaning. Supplementation of FO increased litter size of weak piglets, compared with the control‐fed sows (P < 0.05). Dietary FO and SO supplementation, enhanced the weaning survival rate, litter weaning weight, litter weight gain and fat content in milk (P < 0.05). The highest immunoglobulin (Ig)G and IgM levels in colostrum and milk were observed in the FO group (P < 0.05). Meanwhile, the highest concentration of C22:5 (n‐3) and C22:6 (n‐3) in colostrum, milk and piglet serum was observed in the FO group (P < 0.05). Taken together, dietary inclusion of FO or SO improved growth performance of nursing piglets by increasing milk fat output, and FO consumption by sows might benefit the piglets via increasing n‐3 polyunsaturated fatty acid availability and immunoglobulins (IgG and IgM) secretion.     

Effects of 25‐hydroxycholecalciferol supplementation in maternal diets on milk quality and serum bone status markers of sows and bone quality of piglets

Twenty primiparous sows were allocated to two treatments to evaluate the effects of maternal 25‐hydroxycholecalciferol (25OHD₃) supplementation during gestation and lactation on milk quality and serum bone status markers of sows and bone quality of piglets. Immediately after mating, sows were randomly allotted to one of two diets supplemented with 50 µg/kg 25OHD₃ or basal diets without 25OHD₃. Blood and milk samples were obtained. At birth and weaning, 10 piglets from each treatment were killed for bone quality analysis. 25OHD₃‐fed sows provided one more piglet at farrowing and 1.17 more piglets at weaning than sows fed basal diets. The contents of solids not‐fat, protein, fat or lactose were increased in milk from days 7 and 14 of lactation in 25OHD₃‐supplemented sows and 25OHD₃ concentrations in milk were increased by dietary 25OHD₃ supplementation. Dietary 25OHD₃ supplementation increased serum alkaline phosphatase activity but had no effect on serum tartrate‐resistant acid phosphatase activity of sows. Maternal 25OHD₃ supplementation improved bone strength, density and ash content of newborn piglets rather than those of weaning piglets. In conclusion, 25OHD₃ supplementation in maternal diets improved reproductive performance, milk quality and bone status of sows as well as bone quality of newborn piglets.     

Effects of dietary fiber on performance of multiparous lactating sows in a tropical climate

Sixty-two multiparous Large White sows were used to determine the effect of dietary fiber level on lactation performance according to season under conditions of a humid tropical climate. This experiment was conducted in Guadeloupe (West French Indies, lat 16 degrees N, long 61 degrees W) between October 1999 and January 2001. Two seasons were distinguished a posteriori from climatic measurements parameters continuously recorded in the farrowing room. During the warm season, ambient temperature and relative humidity averaged 25 degrees C and 86.8%, respectively. The corresponding values for the hot season were 27.5 degrees C and 83.5%. Experimental diets fed during lactation were a control diet (C; 14% neutral detergent fiber) and a high-fiber diet (HF; 20% neutral detergent fiber) obtained by substitution of wheat middlings by wheat bran. The two diets were formulated to provide the same ratios between essential amino acids and lysine and between lysine and net energy. No interaction between season and diet composition was found for all criteria studied. Over the 28-d lactation, average daily feed intake (ADFI) was lower and body weight loss was higher (P < 0.001) during the hot season compared to the warm season (3,447 vs 4,907 g/d and 33 vs 17 kg, respectively). The number of stillborn piglets was higher (P < 0.05) during the hot season than during the warm season (2.0 vs 1.1 piglets, respectively). Litter growth rate and mean BW of piglets at weaning were reduced (P < 0.01) during the hot season vs the warm season (2.1 vs 2.3 kg/d and 7.7 vs 8.3 kg, respectively). The ADFI was similar for both diets and digestible energy (DE) intake tended to be lower (P = 0.06) with the HF diet (54.9 vs 59.3 MJ of DE/d for C sows) in relation with its lower DE concentration. The body weight loss was greater (P < 0.01) for HF sows than for C sows (30 vs 21 kg). Compared with the C diet, the HF diet increased (P < 0.05) litter growth rate and piglet body weight at weaning (2.3 vs 2.1 kg/d and 8.3 vs 7.7 kg/d for HF vs C, respectively). Season and diet composition did not affect the weaning-to-estrus interval. In conclusion, the hot season in humid tropical climates, which combines high levels of temperature and humidity, has a major negative effect on the performance of lactating sows.     

Methyl donors dietary supplementation to gestating sows diet improves the growth rate of offspring and is associating with changes in expression and DNA methylation of insulin‐like growth factor‐1 gene

The study aimed to investigate the effects of maternal dietary methyl donors on the performance of sows and their offspring, and the associated hepatic insulin‐like growth factor‐1 (IGF‐1) expression of the offspring. A total of 24 multiparous sows were randomly fed the control (CON) or the CON diet supplemented with methyl donors (MD) at 3 g/kg betaine, 15 mg/kg folic acid, 400 mg/kg choline and 150 μg/kg VB₁₂, from mating until delivery. After farrowing, sows were fed a common lactation diet through a 28‐days lactation period and six litters per treatment were selected to be fed until at approximately 110 kg BW. Maternal MD supplementation resulted in greater birthweight (p < 0.05) and increased the piglet weights (p < 0.01) and litter weights (p < 0.05) at the age of day 28, compared with that in CON group. The offspring pigs in the MD group had greater ADG (p < 0.05) and tended to lower F:G ratio (p = 0.07) compared with that of CON group from day 28 to 180 of age. The offspring pigs from MD group had greater serum IGF‐1 concentrations and expressions of hepatic IGF‐1 gene and muscular IGF‐1 receptor (IGF‐1r) protein at birth (p < 0.05), and greater hepatic IGF‐1 protein (p = 0.03) and muscular IGF‐1r gene expressions (p < 0.05) at slaughter, than that from the CON group. Moreover, the methylation at the promoter of IGF‐1 gene in the liver of newborn piglets and finishing pigs was greater in the MD group than that of the CON group (p < 0.05). In conclusion, maternal MD supplementation throughout gestation could enhance the birthweight and postnatal growth rate of offspring, associated with an increased expression of the IGF‐1 gene and IGF‐1r, as well as the altered DNA methylation of IGF‐1 gene promotor.     

Changes in the spleen and liver of pregnant sows and full-term piglets after feeding diets naturally contaminated with deoxynivalenol and zearalenone

Wheat contaminated naturally with the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) was fed to pregnant Landrace sows for 35days. On day 110, caesarean section was carried out, the offspring were killed immediately after birth, and their livers and spleens examined. At necropsy there were no macroscopic lesions observed in any organ of either sows or piglets. Histopathological evaluation of tissues from sows of the treated group revealed changes in liver and spleen tissues, whereas no significant changes were observed in these tissues in their piglets. Liver damage, as measured by prominent elevated transaminase activities, was not detected in the serum of the sows. In pregnant sows there were individual variations in sensitivity to the Fusarium toxins. In conclusion, it can be assumed that there are no adverse effects on the liver and spleen of full-term piglets when their mothers consumed diets containing up to 9570 and 358mug DON/ZON per kg diet.     

The effect of different concentrations of linseed oil or fish oil in the maternal diet on the fatty acid composition and oxidative status of sows and piglets

N‐3 polyunsaturated fatty acids (PUFA) are essential for foetal development. Hence, including n‐3 PUFA in the sow diet can be beneficial for reproduction. Both the amount and form (precursor fatty acids vs. long chain PUFA) of supplementation are important in this respect. Furthermore, including n‐3 PUFA in the diet can have negative effects, such as decreased arachidonic acid (ARA) concentration and increased oxidative stress. This study aimed to compare the efficacy to increase eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in the piglet, when different concentrations of linseed oil (LO, source of precursor α‐linolenic acid) or fish oil (FO, source of EPA and DHA) were included in the maternal diet. Sows were fed a palm oil diet or a diet including 0.5% or 2% LO or FO from day 45 of gestation until weaning. Linoleic acid (LA) was kept constant in the diets to prevent a decrease in ARA, and all diets were supplemented with α‐tocopherol acetate (150 mg/kg) and organic selenium (0.4 mg/kg) to prevent oxidative stress. Feeding 0.5% LO or 0.5% FO to the sows resulted in comparable EPA concentrations in the 5‐day old piglet liver, but both diets resulted in lower EPA concentrations than when 2% LO was fed. The highest EPA concentration was obtained when 2% FO was fed. The DHA level in the piglet liver could only be increased when FO, but not LO, was fed to the sows. The 2% FO diet had no advantage over the 0.5% FO diet to increase DHA in the piglet. Despite the constant LA concentration in the sow diet, a decrease in ARA could not be avoided when LO or FO were included in the diet. Feeding 2% FO to the sows increased the malondialdehyde concentration (marker for lipid peroxidation) in sow plasma, but not in piglets.     

The influence of additional fat in the diet of sows before and after parturition on piglet viability and performance

Two hundred and six mature sows were used to evaluate the effect of adding a total of 3 kg of fat to sow diets for an average of eight days before and seven days after parturition on piglet viability and performance.The addition of fat to the diet of sows had no effect on the percentage of piglets born alive, individual piglet birth weight, weight of the piglet at three weeks of age or the weaning to service interval in the sows. However, there was a significant increase in piglet survival (3.4%) between treated and control sows. Birth weight had a marked effect on piglet survival but there was no indication of a greater effect of added fat in the sows' diet on the survival of smaller piglets. A number of piglets were cross-fostered but fostering had no effect on piglet mortality. A comparison of the mortality of piglets born from sows receiving added fat and reared on controls and vice versa indicated that the major benefits of additional fat in the sow diet were effected in utero rather than via an increase in the quality of the sows' milk.     

Effects of dietary resistant starch content on metabolic status,milk composition,and microbial profiling in lactating sows and on offspring performance

In the present study, the effects of dietary resistant starch (RS) content on serum metabolite and hormone concentrations, milk composition, and faecal microbial profiling in lactating sows, as well as on offspring performance was investigated. Sixteen sows were randomly allotted at breeding to two treatments containing low‐ and high‐RS contents from normal and high‐amylose corn varieties, respectively, and each treatment had eight replicates (sows). Individual piglet body weight (BW) and litter size were recorded at birth and weaning. Milk samples were obtained on day 10 after farrowing for composition analysis. On day 2 before weaning, blood and faecal samples were collected to determine serum metabolite and hormone concentrations and faecal microbial populations, respectively. Litter size at birth and weaning were not influenced (p > 0.05) by the sow dietary treatments. Although feeding the RS‐rich diet to sows reduced (p = 0.004) offspring birth BW, there was no difference in piglet BW at weaning (p > 0.05). High‐RS diet increased (p < 0.05) serum triacylglycerol and nonesterified fatty acid concentrations and milk total solid content, and tended (p = 0.09) to increase milk fat content in lactating sows. Feeding the RS‐rich diet to sows increased (p < 0.01) faecal bacterial population diversity. These results indicate that high‐RS diets induce fatty acid mobilization and a greater intestinal bacterial richness in lactating sows, as well as a greater nutrient density in maternal milk, without affecting offspring performance at weaning.     

Immunization of Sows in an Integrated Pig‐breeding Herd using a Homologous Inactivated Salmonella Vaccine Decreases the Prevalence of Salmonella typhimurium Infection in the Offspring

The efficacy of a homologous vaccination in preventing infection of suckling piglets with Salmonella (S.) Typhimurium was evaluated after an immunization of pregnant sows using an inactivated herd‐specific S. Typhimurium vaccine. Twenty‐five pregnant sows were vaccinated three times antepartum. The efficiency of this vaccine regime was assessed by comparison with a control group of 37 sows and their suckling piglets, which were daily treated with enrofloxacin from day 14 antepartum until the day of weaning. From the first day of life until day 142 post‐partum, faecal samples of the piglets were collected and analysed for Salmonella shedding. In parallel, systemic antibody responses were monitored using a whole cell‐based isotype‐specific enzyme‐linked immunosorbent assay (ELISA). The bacteriological investigation showed marked effects of vaccination. Salmonella Typhimurium could not be detected in any of the faecal samples of the piglets from the vaccinated sows. In contrast, the piglets of the group with long‐time antibiotic treatment shed salmonellae rating to 47.4% of the animals. Furthermore, the offspring from vaccinated sows showed significantly decreased antibody activities of immunoglobulin (Ig)A and IgG. These bacteriological and serological results indicate a significantly lower Salmonella prevalence in piglets of the vaccinated group. As this study shows, the presented strategy of vaccination of pregnant sows with an inactivated Salmonella vaccine seems to be a suitable measure in decreasing Salmonella prevalence in offspring of infected sows.     

Long‐Term Studies on Maternal Immunity for Aujeszky's Disease and Classical Swine Fever in Wild Boar Piglets

The aim of the studies was to fathom the duration and the role of maternal immunity for Aujeszky's disease (AD) and classical swine fever (CSF) in wild boar offspring. In one experiment, two wild boar sows were infected with a low pathogenic pseudorabies virus (PRV) in 1999. A total of 51 offspring was born between 1999 and 2002 and was monitored for PRV maternal antibodies. In a second experiment, the maternal immunity for CSF was analysed. Therefore, a sow was orally vaccinated against CSF using vaccine baits containing the live‐attenuated C‐strain vaccine. The vaccination took place in January 1999. The sow gave birth to four piglets in 2001 and to two piglets in 2002. With respect to maternal immunity for AD, some piglets reacted positive in the ELISA up to 27‐week post‐partum while in the neutralization test antibodies were detected up to 15‐week post‐partum. The calculated half‐life of neutralizing antibodies was 21 days. Regarding CSF, the neutralization titres of maternal antibodies dropped continuously reaching values of ≤10 ND₅₀ 20‐week post‐partum. After the 12th week post‐partum, most of the sera reacted negative in the ELISA. However, after the third month, low levels of neutralization titres were still detectable. The results are discussed with respect to the epidemiology and control of both diseases in wild boar populations.