Gut microbiome changed dramatically during pregnancy and played important roles in metabolic status and reproductive endocrinology in mammals. However, investigating the functional microbiota and metabolites to improve the reproductive performance and understanding the host–microbiota interaction are still arduous tasks. This study aims to reveal the dominant strains and metabolites that improve the reproductive performance. We analyzed the fecal microbiota composition and metabolic status of higher yield Chinese pig breed Meishan (MS) sows and lower yield but widespread raised hybrid pig breed Landrace × Yorkshire (L × Y) sows on days 28 and 100 of gestation. Results showed that MS sows had higher litter sizes and steroid hormone level but lower short-chain fatty acid level in feces. Fecal metabolomic analysis revealed that MS sows showed a different metabolic status compared with L × Y sows both at early and late pregnancy, which enriched with phenylpropanoid biosynthesis, bile secretion, steroid hormone biosynthesis, and plant secondary metabolite biosynthesis. In addition, 16S rDNA and internal transcribed spacer sequencing indicated that MS sows showed different structures of microbiota community and exhibited an increased bacterial α-diversity but non-differential fungal α-diversity than L × Y sows. Moreover, we found that the litter sizes and bacteria including Sphaerochaeta, Solibacillus, Oscillospira, Escherichia–Shigella, Prevotellaceae_UCG-001, dgA-11_gut_group, and Bacteroides, as well as fungi including Penicillium, Fusarium, Microascus, Elutherascus, and Heydenia both have positive association to the significant metabolites at the early pregnancy. Our findings revealed significant correlation between reproductive performance and gut microbiome and provided microbial and metabolic perspective to improve litter sizes and steroid hormones of sows.

The objective of this paper was to investigate how the predicted level of body energy mobilized and the stage of lactation affects performance and energy partitioning in lactating sows kept under commercial conditions. Seventy-seven lactating sows from three consecutive batches were weaned at 28 d and all measures were taken over the first 20 d. Total feed consumption was measured and sows’ live weight was registered when entering the lactation facilities and at 21 d of lactation. Blood samples were collected at farrowing and once a week thereafter. Net energy (NE) mobilization or loss was calculated by difference using the general NRC equation for ME partitioning. Compared to low mobilizers (low NE loss values), high mobilizing sows had lower feed intake and higher loss of live weight, body fat and body protein. High mobilizers also weaned more piglets and had heavier litters than low mobilizers. Energy mobilization (NE loss) was higher from day 1 to 10 of lactation compared to day 11 to 20, and the difference in mobilized energy between high and low mobilizing sows was also higher in the first than in the second half of lactation. Body weight and back fat thickness losses were significantly correlated with NE loss. A more accurate prediction of the changes in live weight or back fat thickness over lactation should help better predict total amount of energy mobilized, and more research is needed to assess the relative contribution of lean and fat to mobilized tissue.

Dietary fiber (DF) is receiving increasing attention, and its importance in pig nutrition is now acknowledged. Although DF for pigs was frowned upon for a long time because of reductions in energy intake and digestibility of other nutrients, it has become clear that feeding DF to pigs can affect their well-being and health. This review aims to summarize the state of knowledge of studies on DF in pigs, with an emphasis on the underlying mode of action, by considering research using DF in sows as well as suckling and weaned piglets, and fattening pigs. These studies indicate that DF can benefit the digestive tracts and the health of pigs, if certain conditions or restrictions are considered, such as concentration in the feed and fermentability. Besides the chemical composition and the impact on energy and nutrient digestibility, it is also necessary to evaluate the possible physical and physiologic effects on intestinal function and intestinal microbiota, to better understand the relation of DF to animal health and welfare. Future research should be designed to provide a better mechanistic understanding of the physiologic effects of DF in pigs.

Ninety-six pregnant sows, previously penned in individual stalls, were housed in groups of four in pens containing three zones: a) four individual feeding stalls without rear gates, b) a communal sleeping kennel and c) a dunging area between the stalls and kennel. The feeding stalls were either long (2m) or short (1m) with barriers made of wire mesh. The daily allowance of 2.5kg pelleted feed per sow was presented either all at once (dump) or at the rate of approximately 100g/min by a manual system (trickle). Dung disposal systems were either a pit füled with sawdust-based compost, a slatted floor, or straw on a sloped concrete floor. There were two replicates of the 2×2×3 factorial design. The location of sows was observed from time-lapse video recordings taken at regular intervals throughout the 31 day experimental period.

Use of the three zones of the pens was influenced by feeding method, barrier length and dung disposal system. Overall the feeding stalls were used more with trickle than with dump feeding (P<0.05); more with long than with short barriers (P<0.001), and most with slatted floors and least with the straw system (P<0.001). AU these treatments had the opposite effects on the use of the communal kennel The use of the dunging area was not affected by feeding method or stall length but was greater (P<0.01) on the compost compared with the other two dung disposal systems. Throughout the experimental period the use of feeding stalls decreased (P<0.001). Orcadian use of the pen zones interacted with barrier length and dung disposal system. Kennels were used most at night in pens with straw, exceeding 54minlh with half length (1m) stalls. The lowest night-time use of kennels, around 8min/h, was found in pens with full length (2m) stalls combined with either compost or slats. Ambient temperature did not have a major influence on use of pen zones.

The occupation of stalls, especially full length stalls, indicates that offering a choice between solitary and communal areas may improve the welfare of group-housed sows.

In the social debate about animal welfare we can identify three different views about how animals should be raised and how their welfare should be judged: (1) the view that animals should be raised under conditions that promote good biological functioning in the sense of health, growth and reproduction, (2) the view that animals should be raised in ways that minimise suffering and promote contentment, and (3) the view that animals should be allowed to lead relatively natural lives. When attempting to assess animal welfare, different scientists select different criteria, reflecting one or more of these value-dependent views. Even when ostensibly covering all three views, scientists may differ in what they treat as inherently important versus only instrumentally important, and their selection of variables may be further influenced by a desire to use measures that are scientifically respected and can be scored objectively. Value assumptions may also enter animal welfare assessment at the farm and group level (1) when empirical data provide insufficient guidance on important issues, (2) when we need to weigh conflicting interests of different animals, and (3) when we need to weigh conflicting evidence from different variables. Although value assumptions cannot be eliminated from animal welfare assessment, they can be made more explicit as the first step in creating animal welfare assessment tools. Different value assumptions could lead to different welfare assessment tools, each claiming validity within a given set of assumptions.

Crating sows in farrowing systems greatly restricts their normal behaviour, which is usually justified by the assumption that piglet mortality is higher with loose-housed sows. Based on experiments showing that this is not the case, farrowing crates were banned in Switzerland in 1997. Since then, many farms have introduced loose farrowing systems, enabling a comparison of piglet mortality in farrowing systems with and without crates based on a large sample size. Data of a sow-recording scheme (UFA2000) were analysed using generalised linear mixed-effects models with an underlying Poisson distribution. In 2002 and 2003, the average total piglet mortality on 173 farms (n = 18,824 litters) with loose farrowing systems amounted to 1.40 piglets per litter and did not differ from that of 482 farms (n = 44,837 litters) with crates (1.42 piglets per litter). Nevertheless, the number of crushed piglets was significantly higher in pens with loose-housed sows (0.62 versus 0.52 piglets per litter), whereas the number of piglets that died for other reasons was significantly higher in crates (0.78 versus 0.89 piglets per litter). Total piglet mortality was influenced by litter size at birth, age of the sow and season. Consequently, evaluation of the reproductive data of commercial farms shows that no more piglet losses occur in loose farrowing pens, common nowadays in Switzerland, than in farrowing pens with crates, and that litter size at birth is the main influence on piglet losses.

Forty-eight Large White x Landrace multiparous sows were mixed into twelve groups of four animals after their piglets were weaned. These groups were defined as static, with no animals being added to or removed from the groups after their formation. Aggressive and submissive behaviours were recorded continuously for 9 h after the sows were mixed, and the sows were assigned high or low social status on the basis of their relative aggressiveness and success in aggressive interactions. After five weeks, each static group was mixed into a dynamic group of 40 ±2 sows for an 11-week period. Three static groups (ie 12 animals) at a time were added to the dynamic group at three-week intervals; the same number of animals was removed at these time-points in order to maintain the group number at 40 ± 2. Injury levels increased significantly with the transition from static groups to the dynamic group (P < 0.001). Sows with low social status had lower bodyweights (P < 0.001) and higher injury levels one week after mixing into static and dynamic groups (P < 0.01). Social status did not significantly affect salivary Cortisol levels. Sows with low social status were positioned lower in the feed order, determined using an electronic feeder (P < 0.001), and tended to be displaced from the feeder queue more often (P < 0.1) in the dynamic group. Sows with low social status were also displaced from the drinker more often than highranking sows in the dynamic group (P < 0.01). This may have led to the greater frequency of drinking behaviour shown by low-ranking sows (P < 0.05). Sows with low social status were observed less often in the kennel areas than were the high-ranking sows in the dynamic group (P < 0.05), suggesting that they were denied access to the prime lying areas. The results suggest that the welfare of sows is negatively affected by low social status in both small static and large dynamic groups.

Each of two 20-sow groups consisted of gilts ie virgin sows (one third) and sows (parity 2-5, ie sows which had given birth 2-5 times). One group was housed indoors with a straw-covered lying area and dunging area. Another group was housed outdoors with a covered straw lying area and two rooting fields. Behavioural observations were made on both groups: indoor sows were observed for 4h day−1, for 10 days (40h); outdoor sows were observed for 6h day−1, for 21 days (126h). Social interactions were classified as threat, bite, knock and push. Continuous data on the type of interaction and the winner or loser were recorded. Four measures of social status, based on social behaviour, were calculated: i) displacement index; ii) level of interaction; iii) success in interactions; and iv) matrix dominance. Spearman rank correlation coefficients between different ranked measures of social status within each group (outdoor or indoor) were significant for displacement index, success in interaction and matrix dominance. The level of interaction did not correlate with other measures (except for matrix dominance in the indoor group). Measures of displacement, success in interaction and matrix dominance provide highly consistent and correlated measures of social status.

It has been argued that the welfare of gestating sows is higher in groups than singly in stalls, in part because group housing offers them more space and social contact. This study set out to ascertain how important access to a group pen was to dominant sows housed in stalls, using a measure of motivation. Subjects were trained to perform a panel-pressing task, then housed in a stall and permitted each day to work for a day's access to a fully slatted group pen containing two familiar, subordinate sows at a stocking density of 2.7m2 per pig. Social ranking was determined by observations at mixing and from feed competition tests. The fixed-ratio schedule was increased daily and the highest schedule reached (the reservation price) was used as a measure of motivational strength. To interpret this measure, it was compared with the highest schedule that subjects reached when working for access to the last 1/16th of their estimated ad libitum daily food intake after having consumed the first 15/16ths free. Sixteen subjects were tested, eight working for access to the group pen first and eight for access to the food first. Seven subjects yielded useable data: four reached a higher schedule working for food and three reached a higher schedule working for the group pen. Overall, subjects attached no more importance to a day's access to the group pen than to the last 1/16th of their estimated ad libitum food intake. It is likely that the subjects were close to satiation when working for food because consumption frequently fell substantially short of the ‘ad libitum‘ allowance. These results suggest that dominant, stall-housed sows are only weakly motivated to gain access to a fully slatted group pen, although motivation might be higher when deprived of access to the group pen for longer than one day, if tested at a different time of day or if the quality of the group space was improved; these three possibilities still need to be tested.

Pregnant (dry) sows (Sus scrofa) are fed a rationed amount of feed to maintain healthy weight and production but this does not satisfy their hunger. This study measured the extent of feed restriction compared to sows’ desired intake. Forty-seven Large White × Landrace sows were housed in small groups with straw bedding and individual feeding stalls. Following three days on a standard ration of 2.5 kg, they were offered 10 kg a day of commercial dry sow feed for three days, split into four 2.5-kg meals a day which enabled individual intakes to be measured. This quantity was effectively ad libitum (maximum daily intake 9.4 kg). Mean (± SEM) intake per day over the three ad libitum days was 5.67 (± 0.24) kg, compared to the 2.5-kg standard ration. The ration thus provides less than half (44.1%) of sows’ desired intake. Behaviour on their third rationed day was compared with behaviour on the third day of ad libitum. Eating rate and the display of hunger-related behaviours, particularly following the morning feed, was greater under ration feeding; sows spent more time in the food stall and less in the straw bed, and more time active rather than resting. During ration-feeding sows also chewed and nosed more at straw bedding and pen equipment and used the drinker more after their morning meal than when they were fed ad libitum. Eating rate on the last rationed day was positively correlated with feed intake on each of the ad libitum days. Despite an EU requirement for fibre to be added to diets to ameliorate this problem, and the provision of straw bedding, hunger resulting from food restriction remains a welfare concern for dry sows.

Investigating variability of scores between different observers, between animals and over time aids the design of valid sampling methodologies for measuring animal welfare. Locomotion scores (0 to 5 scale) were collected: i) from 154 sows in one herd, using three to five observers each time, and scoring sows on up to ten occasions over a 19-month period; and ii) for 123 of these sows, locomotion scoring also took place prior to farrowing and at weaning. The distribution of scores was highly skewed towards low scores (0: 84.8%, 1: 9.5%, 2:4.0%, 3+: 1.7%). Sows showed moderate consistency in their scores over time and later parity sows had higher scores, but there was no effect of stage in the reproductive cycle (days pregnant, pre-farrowing, post-weaning). This suggests that infrequent visits to a farm (eg annual) might provide an accurate estimate of the extent of lameness if a representative range of parities was sampled, although a larger study of more farms would be required to investigate this. The three different types of agreement between observers (absolute differences, matching and association) were assessed as follows: i) analysis of absolute differences between observers showed that the farm manager scored lower than researchers/technicians; ii) exact matching approaches suggested fair or good agreement — agreement was poorest for mild gait abnormalities (score 1 ‘stiff’), and agreement improved if scores were combined into ‘sound’ (0-1) and ‘lame’ (2-5) categories; and iii) measures of association suggested moderate agreement. Inter-observer reliability improved over time until the 5th scoring event. To improve inter-observer agreement, observer training/practice and the use of fewer categories are recommended, and inter-observer agreement should be checked regularly.

This study assessed the effect of increasing fibre levels in the concentrate ration on the welfare of sows housed in a large dynamic group. One hundred and twelve Large White * Landrace sows were allocated to one of two treatments over six replicates. Treatments were as follows: (i) High Fibre diet (~15% CF [Crude Fibre]), and (ii) Control diet (~5% CF). Treatments were applied to two separate dynamic groups each containing 33 (±3) sows in a cross-over design, after three replicates the treatments were switched between the groups. Approximately nine sows were replaced in each of these groups at 3-week intervals (each replacement constituting a replicate of the study). Sows on the high fibre diet spent a greater percentage of time lying (High Fibre: 43.8, Control: 28.0, SEM 3.25%), while sows on the control diet spent more time sham chewing (High Fibre: 7.2, Control: 28.8, SEM 1.55%). Sows newly introduced to the group on the high fibre treatment spent proportionally more time in the kennel areas compared to newly introduced sows in the control treatment (High Fibre: 0.893, Control: 0.788, SEM 5.10). In general, aggression occurred at a very low frequency and overall levels did not differ between treatments (High Fibre: 0.005, Control: 0.003, SEM 0.0007 [occurrences per min]). However, sows in the control treatment performed head thrusting (High Fibre: 0.02, Control: 0.00, SEM 0.001 [occurrences per min]), and biting behaviour (High Fibre: 0.02, Control: 0.01, SEM 0.002 [occurrences per min]) more frequently than sows on the high fibre diet. There was no effect of treatment on physiological parameters such as plasma cortisol (High Fibre: 1.34, Control: 1.44, SEM 0.114 ng ml−1) or haptoglobin levels (High Fibre: 0.73, Control: 0.64, SEM 0.080 mg ml−1). In summary, provision of a high fibre diet had a positive effect on the welfare of group-housed dry sows. Sows on the high fibre treatment spent more time resting in the kennel areas, less time performing stereotypic behaviours and showed a reduction in some aggressive behaviours relative to sows fed the control diet.

The aim of this study was to assess the interobserver reliability of the measures forming the Welfare Quality® animal welfare assessment protocol for sows and piglets. The study was carried out at nine farms in Northern Germany. Two trained observers evaluated identical animals simultaneously but independently in 40 joint farm visits. Interobserver reliability was calculated at individual animal level using Cohen's kappa, weighted kappa and the prevalence-adjusted, bias-adjusted kappa (PABAK) and at farm level using Spearman's rank correlation coefficient (RS), the intraclass correlation coefficient (ICC), smallest detectable change (SDC) and limits of agreement (LoA). While a direct comparison of the adjectives of the qualitative behaviour assessment showed poor interobserver reliability, a Principal Component Analysis detected good interobserver reliability. The assessment of social and exploratory behaviours showed acceptable interobserver reliability, while the assessment of stereotypies displayed good interobserver reliability. The human-animal relationship test showed only poor interobserver reliability at individual animal and farm levels. In most cases, measures of health and physical state assessed in sows and piglets exhibited acceptable or good interobserver reliability. In conclusion, after some measures are revised, particularly those examining the human-animal relationship, the Welfare Quality® protocol for sows and piglets will represent a reliable approach in terms of interobserver reliability to assess the welfare of sows and piglets.

This study assessed the effects of increasing dietary fibre levels in concentrate rations and providing access to straw in racks on the welfare of pregnant sows housed in small static groups. In a 2 × 2 factorial design experiment, 128 Large White × Landrace pregnant sows were offered one of two diets: (i) High fibre diet with 9% crude fibre, or (ii) Control diet with 4.5% CF, and one of two levels of access to a foraging substrate: (i) access to straw in racks or (ii) no straw. The study was replicated eight times using groups of four sows, and treatment periods lasted four weeks. Sows were housed in pens with voluntary cubicles and a slatted exercise area and were offered a wet diet twice a day. Back-fat levels were measured before sows were mixed into groups at 28 days post partum, and four weeks later. Aggressive interactions were recorded on the day of mixing, and injury scores were recorded one week post mixing. Scan sampling was used to collect data on general activity, posture and location of the sows, and on sham-chewing and bar-biting behaviours across the treatment period. In addition, detailed focal observations were carried out on all sows across the treatment period. Straw usage was also recorded. There were no treatment effects on changes in back-fat levels over the treatment period. Treatments had no effect on post-mixing aggression or on injury scores. However, focal observations showed that sows with access to straw were involved in fewer bouts of head-thrusting over the treatment period. Control diet sows spent more time inactive than sows on the high fibre diet, however high fibre diet sows spent more time lying with eyes closed than sows on the control diet. Sows on the high fibre diet with access to straw showed less sham-chewing and bar-biting behaviour than sows in other treatments. These results show that although a diet containing 9% crude fibre promoted resting behaviour, it was necessary to combine it with access to straw to reduce stereotypic behaviour of sows in small static groups.

The Welfare Quality® project aims to develop a European on-farm welfare assessment standard for pigs, amongst other species. A prototype monitoring system was developed for sows and piglets using predominantly animal-based measures of behaviour, health and physiology to assess welfare. The prototype monitoring system was evaluated on a total of 82 farms in the UK and The Netherlands, encompassing a wide variety of farming systems. Preliminary analysis of the data indicates that the incidence of clinical welfare problems were low, with 1.2, 0.8, 1.1 and 0.1%, respectively of pregnant and lactating sows recorded as having substantial skin lesions, bursitis and vulval lesions, and extremely poor body condition. Some clinical problems were more prevalent in certain types of feeding system than others, particularly the severity of vulval lesions with electronic sow feeding (ESF) systems. Fear of humans, assessed by the extent of withdrawal behaviour from an unknown human, was low, and median scores were similar for sows housed in groups indoors, outdoors and in stalls. Some form of stereotyped behaviour was observed on almost 75% of farms visited, with sham chewing the most commonly recorded stereotyped behaviour. System design affected the practicality of some measures, particularly on outdoor farms. Full investigation of the complete data set will enable a refined, final, on-farm monitoring system to be developed and benchmark standards established.

In this study we aimed to identify possible causes of within-litter variation in piglet birth weight (birth weight variation) by studying follicular development of sows at weaning in relation to their estimated breeding value (EBV) for birth weight variation. In total, 29 multiparous sows (parity 3 to 5) were selected on their EBV for birth weight variation (SD in grams; High-EBV: 15.8±1.6, N=14 and Low-EBV: −24.7±1.5, N=15). The two groups of sows had similar litter sizes (15.7 v. 16.9). Within 24 h after parturition, piglets were cross-fostered to ensure 13 suckling piglets per sow. Sows weaned 12.8±1.0 and 12.7±1.0 piglets, respectively, at days 26.1±0.2 of lactation. Blood and ovaries were collected within 2 h after weaning. The right ovary was immediately frozen to assess average follicle size and percentage healthy follicles of the 15 largest follicles. The left ovary was used to assess the percentage morphologically healthy cumulus-oocyte complexes (COCs) of the 15 largest follicles. To assess the metabolic state of the sows, body condition and the circulating metabolic markers insulin, IGF1, non-esterified fatty acid, creatinine, leptin, urea and fibroblast growth factor 21 were analysed at weaning. No significant differences were found in any of the measured follicular or metabolic parameters between High-EBV and Low-EBV. A higher weight loss during lactation was related to a lower percentage healthy COCs (β= −0.65, P=0.02). Serum creatinine, a marker for protein breakdown, was negatively related to average follicle size (β= −0.60, P=0.05). Backfat loss during lactation was related to a higher backfat thickness at parturition and to a higher average follicle size (β=0.36, P<0.001) at weaning. In conclusion, we hypothesise that modern hybrid sows with more backfat at the start of lactation are able to mobilise more energy from backfat during lactation and could thereby spare protein reserves to support follicular development.

Iron-deficiency anemia is a public health concern that frequently occurs in pregnant mammals and neonatal offspring. Ferrous N-carbamylglycinate chelate (Fe-CGly) is a newly designed iron fortifier with proven effects in iron-deficient rats and weanling piglets. However, the effects of this new compound on pregnant mammals are unknown. Therefore, this experiment was conducted to evaluate the effects of Fe-CGly on sow reproductive performance and iron status of both sows and neonatal piglets. A total of 40 large-white sows after second parity were randomly assigned to two groups (n=20). They were receiving a diet including 80 mg Fe/kg as FeSO4 or Fe-CGly, respectively, from day 85 of gestation to parturition. The serum (day 110 of pregnancy) and placentas of sows were sampled. Litter size, mean weight of live born piglets, birth (live) litter weight, number of live born piglets, and the number of still-born piglets, mummies, and weak-born piglets were recorded. Once delivered, eight litters were randomly selected from the 20 litters per treatment, and one new-born male piglet (1.503±0.142 kg) from each selected litter was slaughtered within 3 h after birth from the selected litters, without colostrum ingestion. The serum, longissimus muscle, liver and kidneys of the piglets were collected. The iron status of the serum samples and the messenger RNA level of iron-related genes in the placenta, liver and kidney were analyzed. The results showed that litter weight of live born piglets was higher (P=0.030) in the Fe-CGly group (19.86 kg) than in the FeSO4 group (17.34 kg). Fe-CGly significantly increased placental iron concentration (P<0.05) of sows. It also significantly increased iron saturation and reduced the total iron-binding capacity of piglets (P<0.05) at birth. However, the results revealed that supplementation of Fe-CGly in sows reduced liver and kidney iron concentration of neonatal piglets (P<0.05), indicating decreased iron storage. In addition, the concentration of iron in the colostrum was not significantly changed. Therefore, the present results suggested that replacement of maternal FeSO4 supplement with Fe-CGly in the late-gestating period for sows could improve litter birth weight, probably via enhanced iron transportation in the placenta.

To explore the effects of maternal nutrition on offspring muscle characteristics, a total of 56 sows were assigned to one of the four dietary groups during gestation: control (CON), or control diets supplemented with methyl donor (MET), bisphenol A (BPA), and combined BPA and MET (BPA+MET). Compared with CON offspring, MET offspring showed a higher meat redness value, but lower glycogen content in the longissimus thoracis (LT). Moreover, compared with CON offspring, MET offspring showed lower LT glycogen synthase (GS) mRNA levels at birth and the finishing stage, and increased methylation at the GS promoter. Prenatal BPA exposure reduced the pH and redness value of meat, but increased the lightness value, lactate content, glycolytic potential and lactate dehydrogenase (LDH) enzyme activity in the LT muscle. Prenatal BPA exposure increased LDH mRNA levels in the LT muscle at birth and the finishing stage, and reduced methylation at the LDH promoter. Thus, maternal MET affects muscle GS and LDH expression via DNA methylation, thereby resulting in persistent effects on pork quality.

Actigen™ is a second generation, unique bioactive fraction derived from the outer cell wall of a specific strain of yeast, Saccharomyces cerevisiae, where it acts in the gut to bind pathogenic bacteria, preventing disease and competition for nutrients. In the current trial, 260 sows were used and fed either an unsupplemented control diet or one containing Actigen™ at 0.08% of the formulation during gestation, farrowing and lactation, to assess its impact on sow and piglet performance. Results showed significant increases in feed intake for sows fed Actigen™ pre-farrowing, but this was reversed during lactation, leading to a 7 kg saving in feed intake per animal. At birth, piglets weighed 42 g more in litters from Actigen™-fed sows compared to the control group. Weaning weight of the total litter from Actigen™ sows was significantly higher (P< 0.05) by 3.3 kg, although individual piglet weights were the same. Sows showed no significant loss in body weight during the trial, indicating that the improved piglet production was related to improved nutrient availability and perhaps Ig status of piglets due to the addition of Actigen™ in the diet.

Silymarin is an extract from the plant milk thistle that was shown to have antioxidant and hyperprolactinemic properties. Taking into account the essential role of prolactin for lactating sows and the systemic oxidative stress occurring during lactation, it is of interest to investigate the potential beneficial effects of silymarin on lactating sows. A study was therefore carried out to determine the effects of providing either 1 or 8 g/day of the plant extract silymarin to lactating sows. Sows in first, second or third parity were fed conventional diets during gestation and, at farrowing, were assigned as controls (CTL, n=33), or were fed 1 g/day (SYL1, n=33) or 8 g/day (SYL8, n=33) of silymarin. The silymarin was provided in two equal amounts per day, and was fed throughout a 20-day lactation. The performance of sows and their litters was assessed and circulating concentrations of prolactin (days 7 and 18), urea (days 7 and 18) and oxidative status, via protein carbonyls and superoxide dismutase activity (day 18), were measured in sows. Milk samples were obtained on day 18 to measure standard composition. There was no effect of silymarin (P>0.10) on circulating prolactin or urea, or on oxidative damage to proteins or antioxidant potential in sows. Lactation feed intake, backfat and BW of sows were unaffected by treatment (P>0.10) as was the case for milk composition and piglet growth (P>0.10). Results demonstrate that providing up to 8 g/day of the plant extract silymarin to lactating sows had no beneficial effects in terms of circulating prolactin concentrations or oxidative status of sows, or in terms of performances of sows and their litters.