Does intrauterine crowding affect the force generating capacity and muscle composition of the piglet front limb?

In the pig, intrauterine competition (IUC) greatly affects postnatal traits, such as birth weight, but also locomotor capacities. In a previous study, our group discovered a lower motor performance in piglets with a low birth weight and low vitality (L piglets), compared to piglets with a normal birth weight and normal vitality (N piglets). In order to explain the force deficit causing this reduced motor performance, in a subsequent study, we investigated whether this deficit in L piglets was caused by a lower force generating capacity (FGC) of the extensors of the hind limb and/or a lower number of type II (fast-twitch) fibers in m. vastus lateralis. L piglets had a lower absolute FGC, but surprisingly, a higher relative FGC (to birth weight) in the hind limb, compared to N piglets. In addition, we found no differences in fiber composition of m. vastus lateralis. In the present study, we assessed whether this higher relative FGC is a common feature for front and hind limb locomotor muscles of L piglets. To that end, the physiological cross-sectional area of the main extensor muscles of the front limb was calculated from their volume and fiber length, in order to calculate both the absolute and the relative FGC. By immunohistochemical staining of m. triceps brachii caput longum, the percentage of type II (fast-contracting) fibers could be determined. Similar to the results of the hind limb, we found a smaller absolute FGC, but a larger relative FGC in the front limb of L piglets, compared to N piglets. In addition, m. triceps brachii caput longum did not have a different muscle fiber composition in L and N piglets. As such, we can conclude that IUC affects the locomotor muscles in the front and hind limb in a similar way and that the observed force deficit in L piglets cannot be explained by a different force generating capacity or a lower percentage of type II muscle fibers

Knowledge synthesis: Animal health and welfare in organic pig production - Final Report COREPIG

This report reviews the available information on the welfare of pigs when maintained according to organic standards in Europe. It begins by overviewing the populations of organic pigs in different countries at the time of writing (2007), the organic standards which govern their management and the systems in which they are typically kept. It then reviews for each stage in the production cycle (sows, suckling piglets, weaned pigs and fattening pigs) the available literature on health and welfare problems which might be experienced by the animals and the hazards which might give rise to these problems. Finally the report reviews the methods current available for the measurement of pig health and welfare and the extent to which monitoring systems currently exist in different countries, or might be developed. The information gathered in this review formed the basis for the subsequent development of tools for use in a HACCP based management and surveillance system for organic pig herds. These tools will assist the organic pig farmer to prevent selected pig diseases and welfare problems by monitoring and controlling the risk factors. Further details can be found on the COREPIG project website www.icrofs.org/coreorganic/corepig.htm

Porcine Colostrum Protects the IPEC-J2 Cells and Piglet Colon Epithelium against Clostridioides (syn. Clostridium) difficile Toxin-Induced Effects

Clostridioides difficile toxins are one of the main causative agents for the clinical symptoms observed during C. difficile infection in piglets. Porcine milk has been shown to strengthen the epithelial barrier function in the piglet’s intestine and may have the potential to neutralise clostridial toxins. We hypothesised that porcine colostrum exerts protective effects against those toxins in the IPEC-J2 cells and in the colon epithelium of healthy piglets. The IPEC-J2 cells were treated with either the toxins or porcine colostrum or their combination. Analyses included measurement of trans-epithelial electrical resistance (TEER), cell viability using propidium iodide by flow cytometry, gene expression of tight junction (TJ) proteins and immune markers, immunofluorescence (IF) histology of the cytoskeleton and a TJ protein assessment. Colon tissue explants from one- and two-week-old suckling piglets and from five-week-old weaned piglets were treated with C. difficile toxins in Ussing chamber assays to assess the permeability to macromolecules (FITC-dextran, HRP), followed by analysis of gene expression of TJ proteins and immune markers. Toxins decreased viability and integrity of IPEC-J2 cells in a time-dependent manner. Porcine colostrum exerted a protective effect against toxins as indicated by TEER and IF in IPEC-J2 cells. Toxins tended to increase paracellular permeability to macromolecules in colon tissues of two-week-old piglets and downregulated gene expression of occludin in colon tissues of five-week-old piglets (p = 0.05). Porcine milk including colostrum, besides other maternal factors, may be one of the important determinants of early immune programming towards protection from C. difficile infections in the offspring

Resilience effects of SGK1 and TAP1 DNA markers during PRRSV outbreaks in reproductive sows

The porcine reproductive and respiratory syndrome virus (PRRSV) is a major infectious stressor that causes serious health problems and productivity drops. Based on previous genome-wide analyses, we selected SGK1 and TAP1 as candidate genes for resilience, and genotyped three mutations, including a 3′UTR variant SGK1_rs338508371 and two synonymous variants TAP1_rs1109026889 and TAP1_rs80928141 in 305 Landrace × Large White sows. All polymorphisms affected the reproductive performance in the outbreak, but not during the endemic phase, thereby indicating a potential use of these markers for resilience. Moreover, some genotypes were associated with a stable performance across PRRSV phases. Thus, in the outbreak, the SGK1_rs338508371 AA sows had less piglets born alive (p < 0.0001) and more stillborns (p < 0.05) while other sows were able to keep their productivity. During the outbreak, TAP1_rs80928141 GG sows had less piglets born alive (p < 0.05) and both TAP1 polymorphisms influenced the number of mummies in an additive manner (p < 0.05). Remarkably, TAP1_rs80928141 AA sows had around one mummy more than GG sows (p < 0.01). Resilience to PRRSV could be improved by including the SGK1 and TAP1 markers in crossbreeding and/or selection schemes, as they contribute to maintaining a stable number of piglets born alive and lost, particularly mummies, despite the outbreak.This research and the APC were partially funded by FEDER projects COMRDI16-1-0035-03 and RTI2018-097700-B-I00 from the Spanish Ministry of Science, Innovation, and Universities. M.L. received a postdoctoral grant from UdL-Impuls programme

Mycoplasma suis infection in suckling pigs on a Belgian farm

Mycoplasma suis (formerly known as Eperythrozoon suis) is an epicellular bacterium that affects porcine red blood cells. M. suis infections occur worldwide and are associated with weakness and anemia in suckling and weaned pigs, and reproductive disorders in sows. The present field report describes the detection of M. suis in anemic piglets originating from a Belgian farrow-to-finish herd. The herd was experiencing increased piglet mortality (16%) in the farrowing unit and had a high percentage of repeat breeders (22%). A control program using antimicrobials and hygienic and sanitary measures significantly decreased the number of clinically anemic piglets and the mortality rate in the farrowing unit. However, it did not have any significant influence on the reproductive failure of the farm. The lack of a significant effect on reproductive failure was probably due to the circulation of porcine reproductive and respiratory syndrome virus (PRRSV) on the farm

Effects of environmental enrichment on behavioral responses to novelty, learning, and memory, and the circadian rhythm in cortisol in growing pigs

Previously we showed that pigs reared in an enriched environment had higher baseline salivary cortisol concentrations during the light period than pigs reared under barren conditions. In the present experiment, it was investigated whether these higher baseline salivary cortisol concentrations were a real difference in cortisol concentration or merely represented a phase difference in circadian rhythm. The effects of different cortisol concentrations on the behavioral responses to novelty and learning and long-term memory in a maze test were also studied in enriched and barren housed pigs. At 9 weeks of age enriched and barren housed pigs did not differ in baseline salivary cortisol concentrations nor in circadian rhythm, but at 22 weeks of age barren housed pigs had a blunted circadian rhythm in salivary cortisol as compared to enriched housed pigs. The differences in baseline salivary cortisol concentrations between enriched- and barren-housed pigs are age-dependent, and become visible after 15 weeks of age. Enriched- and barren-housed piglets did not differ in time spent on exploration in the novel environment test. Barren-housed pigs had an impaired long-term memory in the maze test compared to enriched-housed pigs; however, no differences in learning abilities between enriched- and barren-housed pigs were found. Because blunted circadian cortisol rhythms are often recorded during states of chronic stress in pigs and rats or during depression in humans, it is suggested that the blunted circadian rhythm in cortisol in barren-housed pigs similarily may reflect decreased welfare.

Antagonistic Effect of Intestinal Bacteria from the Microflora of Holoxenic (Conventional) Piglets, Against Clostridium Perfringens in the Digestive Tract of Gnotoxenic Mice and Gnotoxenic Piglets

Antagonistic effect of piglet microflora against Clostridium perfringens was studied in germfree mice, to isolate bacterial strains responsible for this colonization resistance. The 1:100 dilution of the feces of a 2 day-old conventional piglet, given per os to germfree mice already harboring C. perfringens, led to the elimination of C. perfringens. From this piglet flora, 8 bacterial strains were selected, belonging to the genera Bacteroides, Clostridium, Eubacterium, Bifidobacterium, Lactobacillus and a strain belonging to the class of Mollicutes. When the 8 strains were given to germfree mice 3 days after C. perfringens inoculation, they led to rapid elimination of C. perfringens from feces. Sixteen other mixtures of 2 to 7 strains were similarly tested, but none was able to fully antagonize C. perfringens. When the 8 strains were given per os to germfree piglets after C. perfringens inoculation, they led to the rapid elimination of C. perfringens from pig feces, and to a quick recovery from diarrhea. This study led to the identification of a simplified fraction of gut microflora, able to exert a barrier effect against C. perfringens comparable to the entire flora of the piglet. This study suggests that gnotoxenic mice can be a suitable model for simplifying the flora responsible for a given effect in another host, animal or human

The effect of an 18-hour delay in solid feed provisioning on the feed intake and performance of piglets in the first weeks after weaning

It is generally accepted that early post-weaning feed intake affects post-weaning health and performance. Especially piglets that have not consumed creep feed before weaning have to learn to recognize solid feed. Weaning is a stressful event with an important impact on the animals. The associated stress level may affect their learning capabilities. Consequently, the question arises whether the first day after weaning is the best day to discover their new type of feed. An experiment was therefore designed to study the effect of delayed provisioning of solid feed on feed intake and performance of piglets. In total, 144 piglets (8.1 +/- 1.1 kg, mean +/- SD), weaned at 4 weeks of age, were tested. They were assigned to 24 pens, blocked per sex (i.e. castrated male or female) and weight group. Prior to weaning, piglets received a commercial creep feed. Per body weight class and per sex, each pen was randomly assigned to one of the 2 treatments: control (C) and delay in feed provisioning (DF). For the control treatment, the pelleted feed (6 mm) was already present in the feeders when the piglets arrived in their pens (13:00-14:00 h). In the DF pens, the feed was provided the next morning (08:00). Feed and water were provided ad libitum. In the first week after weaning, it was not possible to observe differences. However, the DF pigs showed a higher feed intake during the first three weeks of the experiment (455 +/- 25 vs 430 +/- 37 g/day, P = 0.003), which was apparent throughout the entire experiment (4-9 weeks: 594 +/- 30 vs 569 +/- 48 g/day, P = 0.046). This resulted in higher body weights 3 weeks after weaning (7 weeks of age) in the DF vs C pigs (16.1 +/- 1.5 vs 15.6 +/- 1.6 kg, P = 0.005). However, at the end of the experiment at 9 weeks, differences were no longer significant (23.9 +/- 2.1 vs 23.4 +/- 2.0 kg, P = 0.285). Feed efficiency did not differ between the groups (P = 0.456 for the entire experiment). Further research into the underlying mechanisms of the observed differences are mandatory for developing improved management practices of weaned piglets