Iron status in piglets at three days of age and at weaning and possible seasonal effects on the blood haemoglobin levels in a Swedish outdoor pig-producing farm.

BACKGROUND: Piglets are born with limited stores of iron, and with an increasing number of live-born piglets, there may be a risk that the sows cannot provide enough iron to their offspring. The iron content in soil may not meet the demands of today's piglet, born and reared in an outdoor setting. The study aimed to describe the blood haemoglobin (Hb) levels in pigs reared outdoors and to determine whether piglets have higher Hb levels at weaning when an iron supplement is administered intramuscularly at three days of age, as compared to pigs not given an iron supplement. The seasonal variation in Hb-levels was also to be investigated. The Hb concentration was analysed with a HemoCue 201 + Hb photometer. RESULTS: In total 56 litters (399 piglets) were included in the study and sampled at three days of age, while 378 piglets were sampled at weaning. The mean Hb level at three days of age was 91 g/L (48-154 g/L). In total 47% of the piglets had Hb levels < 90 g/L at three days of age. The mean Hb level at weaning was 127 g/L (76-176 g/L), with a lower level (122 g/L) in the group given the iron supplement than in the group not given an iron supplement (132 g/L). Only 1% of the piglets had Hb levels lower than 90 g/L at weaning. Results indicative of a seasonal effect on Hb levels at three days of age was demonstrated. Piglets born in spring had significantly lower Hb levels, and piglets born in autumn had significantly higher Hb levels. No seasonal effect could be demonstrated for Hb levels at day 33. CONCLUSIONS: The results indicate that the natural uptake from the environment was sufficient, but that there was a seasonal effect on the Hb levels at three days of age. This indicates that there might be a need for different routines regarding iron supplementation in outdoor reared piglets depending on the climate and season.

Evaluation of the potential benefits of iron supplementation in organic pig farming.

Background: Iron from the stock acquired during foetal life and the ingestion of milk is not sufficient to cover the needs of the piglets during their first weeks of life. In organic farming, systematic supplementation with iron is problematic due to a strong limitation in pharmaceutic treatments. Methods: Erythroid parameters around weaning were measured in piglets from organic outdoor and indoor farms, and related to indicators of the inflammatory status. Blood samples were collected from 28.9±2.6 piglets/herd at 42.0±3.2 days of age and 11.9±3.0 kg live weight (mean ± SD) in 21 farms from the west part of France. Among the 11 outdoor farms, only one had supplemented piglets with 200 mg iron while among the 10 indoor farms, only one had not supplemented piglets, one had supplemented them with 100 mg, 8 with 200 mg and one with 400 mg. Results: Compared to outdoor piglets without supplementation, piglets kept indoors and receiving 200 mg iron had lower haemoglobin concentration (105 vs 118±2 g/l, mean ± SE) and red blood cell volume (56 vs 60±1 fl) (P<0.005). The reduction in haemoglobin concentration and red blood cell volume was more pronounced in indoor piglets supplemented with 100 mg of iron and even more when they had not received iron. The plasma concentration of haptoglobin was lower in outdoor than in indoor piglets (0.51±0.06 vs 0.78±0.09 g/l) whereas no effect of housing was observed for markers of oxidative stress (dROM, BAP). In the 14 farms where sow parity was known, the haemoglobin concentration was lower in piglets from primiparous than from multiparous sows (109 versus 114±2 g/l, P < 0.001). Conclusion: With the exception of soils where the content of bioavailable iron is very low, piglets from outdoor farms do not require iron supplementation, unlike those raised indoors.

Effect of dietary arginine-to-lysine ratio in lactation on biochemical indices and performance of lactating sows.

The present study investigated the effect of optimizing the total dietary arginine (Arg)-to-lysine (Lys) ratios on the metabolism of lactating sows and piglet performance by supplementation with l- Arg during lactation. A total of 200 multiparous sows (three to six parities, Yorkshire × Landrace) were selected and randomly and equally assigned to five groups in lactation, and finally, 36, 34, 35, 36, and 33 dams completed the study in the dietary treatments, respectively, where the diets consisted of five step-up Arg-to-Lys ratios (0.9, 1.0, 1.1, 1.2, and 1.3) by the addition of 0%, 0.10%, 0.20%, 0.30%, and 0.40% Arg. The diets contained 3.37 to 3.38 Mcal of digestible energy/kg energy, 17.73% to 17.75% crude protein, and 0.98% to 1.01% Lys and were fed ad libitum during lactation. The performance of sows and suckling piglets was measured, and plasma and milk samples were collected for analysis. The feed intake of sows as well as litter weight gain during lactation increased linearly (P ≤ 0.05), while maternal backfat and milk composition were not affected (P > 0.05) as the dietary Arg-to-Lys ratios increased. Analyzed plasma biochemical indices, including concentrations of free Arg, Orn, and Glu, and prolactin, insulin, and follicle-stimulating hormone, responded linearly (P ≤ 0.05) to increases in dietary Arg-to-Lys ratios. The dietary Arg-to-Lys ratios of 1.01 and 1.02 were optimal for maternal feed intake and litter weight gain, based on broken-line models. Collectively, the results of this study indicate that increasing total dietary Arg-to-Lys ratios in lactation was beneficial for the performance of lactating sows and suckling piglets, and dietary Arg-to-Lys ratios of 1.01 and 1.02 were optimal, from regression analyses, for the practical feeding of lactating sows.

Comparative effects of dietary supplementations with sodium butyrate, medium-chain fatty acids, and n-3 polyunsaturated fatty acids in late pregnancy and lactation on the reproductive performance of sows and growth performance of suckling piglets.

This study was conducted to compare the effects of adding sodium butyrate (SB), medium-chain fatty acids (MCFAs), or n-3 polyunsaturated fatty acids (n-3 PUFAs) to the diet of sows during late gestation and lactation on the reproductive performance of sows and the growth performance and intestinal health of suckling piglets. Twenty-four sows (Landrace × Large-White hybrid; third parity; 200 ± 15 kg) were randomly assigned to receive 1 of 4 diets: basal diet (control group), basal diet + 1 g SB/kg (SB group), basal diet + 7.75 g MCFA/kg (MCFA group), or basal diet + 68.2 g n-3 PUFA/kg (n-3 PUFA group). The experiment began on day 85 of gestation and ended day 22 of lactation. Colostrum samples were collected from each sow. After the experiment, blood and tissue samples were collected from 1 randomly selected piglet. The results showed that the weaning-to-estrus interval of sows in the SB, MCFA, and n-3 PUFA groups was shorter than that of sows in the control group (P < 0.05). The incidence of diarrhea in suckling piglets in the SB, MCFA, and n-3 PUFA groups was lower than that of piglets in the control group (P < 0.05). The fat, protein, IgA, IgG, and IgM concentration in colostrum from sows increased following dietary supplementation with SB, MCFA, or n-3 PUFA (P < 0.05). Comparison with the control group, the mRNA expression of claudin-1, zona occludens 1, and interleukin-10 increased in the jejunum mucosa of suckling piglets in the SB, MCFA, and n-3 PUFA groups, while that of TLR4 decreased (P < 0.05). Compared with the control group, the Chao1 and ACE indexes of microbial flora in the colon contents of piglets in the SB, MCFA, and MCFA groups increased (P < 0.05), while the relative abundance of Firmicutes, Actinobacteria, and Synergistetes decreased at the phylum level (P < 0.05). In conclusion, during late pregnancy and lactation, dietary SB supplementation had a greater effect on intestinal health and caused a greater decrease in preweaning mortality of suckling piglets than did dietary MCFA or n-3 PUFA supplementation; dietary MCFA supplementation shortened the weaning-to-estrus interval of sows to a greater extent than did dietary SB or n-3 PUFA supplementation; and dietary n-3 PUFA supplementation increased the fat and protein content in the colostrum to the greatest extent.

Fosfomycin residues in colostrum: Impact on morpho-physiology and microbiology of suckling piglets.

Fosfomycin is a broad-spectrum bactericidal antibiotic widely used in pig farms for the treatment of a wide variety of bacterial infections. In this study, the elimination of disodium fosfomycin in colostrum/milk of the sow and the impact of this antibiotic on the microbiota and intestinal morpho-physiology of suckling piglets were analyzed. The average amount of fosfomycin eliminated in colostrum (after administration of 15 mg/kg IM) during the first 10 hr postpartum was 0.85 µg/ml, and the mean residual amount ingested by the piglets was 0.26 mg/kg. The elimination profile of fosfomycin concentrations in colostrum occurs at a time of profound changes in the morpho-physiology of the gastrointestinal tract of the piglet. However, the studied concentrations did not produce imbalances on the microbiota or on the morpho-physiology of the gastrointestinal tract of the piglet. Concentrations of fosfomycin were maintained in the mammary gland above the MIC for more than 8 hr for pathogenic bacteria of productive importance. This would indicate that fosfomycin may be considered safe for the specific treatment of bacterial infectious processes in sows during the peri- and postpartum period. This first study with disodium fosfomycin stimulates awareness in the proper use of antimicrobials at farrowing.

Roles of spermine in modulating the antioxidant status and Nrf2 signalling molecules expression in the thymus and spleen of suckling piglets-new insight.

This study aimed to investigate the effects of spermine and extended spermine administration on the antioxidant status and expression of NF-E2-related factor 2 (Nrf2) signalling molecules in the thymus and spleen in suckling piglets. One half of eighty 12-day-old suckling piglets obtained sufficient nutrient intake supplemented with spermine (0.4 mmol/kg body weight), and another half received restricted nutrient intake supplemented with physiological saline in equal doses once a day for 7 hr or 3, 6 or 9 days in pairs. Spermine supplementation and its extended duration significantly decreased malondialdehyde (MDA) and protein carbonyl (PC) contents (p < .05), but markedly improved antisuperoxide anion (ASA), antihydroxyl radical (AHR), catalase (CAT), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities (p < .05) and glutathione (GSH) content (p < .05) in the thymus and spleen. Additionally, real-time PCR analysis showed that spermine administration and extended spermine intake reduced Kelch-like ECH-associated protein 1 (Keap1) gene transcription and enhanced SOD1, GPx1, CAT, glutathione reductase (GR) and Nrf2 mRNA levels of the thymus and spleen (p < .05), and also improved GST gene expression in the thymus (p < .05). Notably, the spermine-supplemented time for the optimal effects of suckling piglet was determined to be 6 days. Collectively, the current study suggested that spermine supplementation and extended spermine administration could protect the health of the thymus and spleen from early weaning by enhancing the antioxidant status and regulating the expression of antioxidant-related signalling molecules.

Maternal dietary linoleic acid supplementation promotes muscle fibre type transformation in suckling piglets.

As meat quality is basically dependent on muscle fibre characteristics, it is important to know how muscle fibres are regulated and transformed. This study aimed to investigate the effect of maternal dietary supplementation on muscle fibre types using 3% saturated fatty acid (palmitic acid, PA) or 3% unsaturated fatty acid (linoleic acid, LA) from 80 days of gestation to the weaning of offspring (25 days post-natal). The results indicated that higher mRNA levels of MyHCI type genes were found in the soleus muscles of piglets that suckled from LA-supplemented sows than from PA-supplemented sows. In addition, LA treatment increased the gene expression of the type I muscle fibre marker troponin I (p < 0.01), suggesting that LA promoted muscle fibre type transformation to type I fibres. Moreover, PGC-1α (p < 0.01) and MEF2c (p < 0.05) mRNA levels were higher in the piglets from the LA treatment group than in those from the PA treatment group. Furthermore, LA supplementation also significantly increased AMP-activated protein kinase (AMPK) mRNA levels (p < 0.05), which is an upstream regulator of PGC-1α. Collectively, these findings demonstrated that maternal dietary LA supplementation promoted muscle fibre transformation to type I fibre and that this process may be mediated through an AMPK-dependent pathway.