M. Lessard

Behavioural responses of piglets to castration: the effect of piglet age

It has long been assumed that neonatal animals are less sensitive than older animals to pain, and this reasoning has been used to recommend that routine surgical procedures be performed at an early age. In this study we tested if vocal and other behavioural responses to castration increase with piglet age. Piglets (n=84) from 14 litters were assigned to one of six treatment groups: castration or sham castration at 3, 10 or 17 days of age. During the procedure castrated piglets produced high-frequency calls (>1000Hz) at more than three times the rate of piglets in the sham-castrate group. The rate of low-frequency (<1000Hz) calls was also higher for piglets in the castrate group. The rate of high-frequency calling was lower for the youngest pigs but there was no relationship between age and the effect of treatment for any of the vocal responses measured (i.e. no age by treatment interaction). During the first 2h after castration, castrated piglets spent more time sitting or standing and less time lying. During the subsequent 22h, castrated piglets spent marginally more time at the udder and less time lying down. Older piglets missed more nursings. However, the effect of castration did not vary with the age of the piglet for any measure. We conclude that while the factors affecting both the shams and the castrates (e.g. distress due to restraint) may vary with age, the pain of castration is not affected by age within the range of ages that we tested.

Administration of probiotics influences F4 (K88)-positive enterotoxigenic Escherichia coli attachment and intestinal cytokine expression in weaned pigs

This study evaluated the effect of the probiotics Pediococcus acidilactici and Saccharomyces cerevisiae boulardii on the intestinal colonization of O149 enterotoxigenic Escherichia coli harbouring the F4 (K88) fimbriae (ETEC F4) and on the expression of ileal cytokines in weaned pigs. At birth, different litters of pigs were randomly assigned to one of the following treatments: 1) control without antibiotics or probiotics (CTRL); 2) reference group in which chlortetracycline and tiamulin were added to weanling feed (ATB); 3) P. acidilactici; 4) S. cerevisiae boulardii; or 5) P. acidilactici + S. cerevisiae boulardii. Probiotics were administered daily (1 × 109 CFU per pig) during the lactation period and after weaning (day 21). At 28 days of age, all pigs were orally challenged with an ETEC F4 strain, and a necropsy was performed 24 h later. Intestinal segments were collected to evaluate bacterial colonization in the small intestine and ileal cytokine expressions. Attachment of ETEC F4 to the intestinal mucosa was significantly reduced in pigs treated with P. acidilactici or S. cerevisiae boulardii in comparison with the ATB group (P = 0.01 and P = 0.03, respectively). In addition, proinflammatory cytokines, such as IL-6, were upregulated in ETEC F4 challenged pigs treated with P. acidilactici alone or in combination with S. cerevisiae boulardii compared with the CTRL group. In conclusion, the administration of P. acidilactici or S. cerevisiae boulardii was effective in reducing ETEC F4 attachment to the ileal mucosa, whereas the presence of P. acidilactici was required to modulate the expression of intestinal inflammatory cytokines in pigs challenged with ETEC F4.

Effect of age on the behavioral and physiological responses of piglets to tail docking and ear notching1

Neonatal piglets are often subject to potentially painful processing procedures such as tail docking and ear notching during the first few days after birth. However, these procedures may influence the development of suckling behavior and passive transfer of immunoglobulins, especially if done within the first day postpartum. The objective of this experiment was to compare the effects of processing piglets during the first 24 h versus at 3 d of age on suckling and pain-related behavior, the passive transfer of immunoglobulins, and growth. Six piglets per litter from 20 litters (n = 120 piglets) were used in a 3 x 2 complete block design. Piglets were weighed at birth and assigned to 1 of 3 treatments (balanced by birth weight): control (unmanipulated), sham processed (manually manipulated), and processed (tail docked and ear notched) at 1 of 2 ages (1 or 3 d of age). Vocalizations were recorded during the procedures, and piglets were observed after the procedures for pain-related behavior. Suckling behavior was observed for 6 h on each of d 1 to 4. Colostrum samples were collected after the birth of all piglets (before first suck), and blood samples were collected on d 5 to examine concentrations of immunoglobulins (IgA and IgG) and IGF-I. Body weights were measured at birth and on d 5 and 14. During the procedures, processed piglets, regardless of age, vocalized at a greater frequency (P < 0.001) and produced more high frequency calls (P = 0.016) than sham-processed piglets. All piglets on d 1 produced more high frequency calls than all piglets on d 3 (P = 0.047). Immediately after the procedures, sham-processed and processed piglets spent less time lying and more time standing than control piglets (P < 0.001), whereas processed piglets jammed their tail between their legs more than sham-processed or control piglets (P < 0.001). Lying, standing and tail posture were not influenced by age, nor were there age by treatment interactions. Piglets on d 1 trembled more than piglets on d 3 (P < 0.001), and this tended to be exacerbated by processing (P = 0.076). There was no effect of treatment or age of treatment on suckling behavior. Processed piglets had decreased IgG serum concentrations compared with sham-processed and control piglets (P = 0.029), although there was no interaction between treatment and age of treatment (P = 0.67). Whereas tail docking and ear notching do appear to result in short-term pain and modulated immune status, processing on d 1 appears neither better nor worse than processing on d 3.

Osteopontin: an early innate immune marker of Escherichia coli mastitis harbors genetic polymorphisms with possible links with resistance to mastitis

BackgroundMastitis is the most important disease in dairy cows and it causes significant lost of profit to producers. Identification of the genes, and their variants, involved in innate immune responses is essential for the understanding of this inflammatory disease and to identify potential genetic markers for resistance to mastitis. The progeny of dairy cows would benefit from receiving favourable alleles that support greater resistance to infection, thus reducing antibiotic use. This study aims to identify a key gene in the innate immune response to mastitis, led us to evaluate its genetic association with somatic cell score (SCS), which is an indicator of clinical mastitis, and to evaluate its impact on other traits related to milk production.ResultsThe osteopontin transcript (SPP1) was identified in the somatic cells from cows experimentally infected with Escherichia coli. By selecting bulls with extreme estimated breeding values (EBVs) for SCS, which is an indicator of mammary gland health, four DNA polymorphisms in the SPP1 genomic sequence were found. Statistical analysis revealed that the SNP SPP1c.-1301G>A has an impact on EBV for SCS (P < 0.001) Using an allele substitution model, SPP1c.-1251C>T, SPP1c.-430G>A, and SPP1c.*40A>C have an impact on SCS whereas SPP1c.-1301G>A has an effect on the EBVs for milk yield (second and third lactations), fat and protein percentages (all three lactations). Analysis revealed statistically significant differences between haplotype groups at a comparison-wise level with sire EBVS for SCS for the first (P = 0.012), second (P < 0.001), and third (P < 0.001) lactations.ConclusionThis study reports the link between DNA polymorphisms of SPP1, the number of milk immune cells and, potentially, the susceptibility to mastitis. These SNPs were identified by in silico search to be located in transcription factor recognition sites which factors are presumably involved in the Th1 immune response and in the Th2 regulation pathway. Indeed, one SNP abolished the SP1 recognition site, whereas another SNP affected the transcription binding factor IKAROS. All together, these findings support the genetic potential of these variants in terms of selection for the improvement of mastitis resistance in dairy cows.

Impact of deoxynivalenol (DON) contaminated feed on intestinal integrity and immune response in swine

This study was performed to characterize the influence of consuming DON naturally contaminated feeds on pigs intestinal immune defenses, antibody response and cellular immunity. Sixteen 4-week-old piglets were randomly allocated to two dietary treatments: control diet or diet contaminated with 3.5 mg DON/kg. At days 7 and 21, animals were immunized with ovalbumin (OVA). On day 42, intestinal samples were collected for measurement of gene expression involved in immune response, oxidative status and barrier function. Primary IgG antibody response to OVA was increased in pigs fed DON diet compared to control animals. In the ileum of pigs fed DON diet, claudin, occludin, and vimentin genes involved in integrity and barrier function were down-regulated compared to controls. Results also revealed that expression of two chemokines (IL-8, CXCL10), interferon-γ, and major antioxidant glutathione peroxidase 2 (GPX-2) were up-regulated whereas expression of genes encoding enzymatic antioxidants including GPX-3, GPX-4 and superoxide dismutase 3 (SOD-3) were down-regulated in pigs fed DON-contaminated diet. These results strongly suggest that ingestion of DON naturally contaminated feed impaired intestinal barrier and immunological functions by modulating expression of genes coding for proteins involved in tight junctions, tissue remodelling, inflammatory reaction, oxidative stress reaction and immune response.

Humoral and cellular immune responses of piglets after castration at different ages

In this study, growth of piglets and their humoral and cellular immune responses were used to evaluate the effect of castration at different ages. Piglets (n = 84) from 14 litters were assigned to one of the six treatments: castration or sham-castration at 3, 10 or 17 d of age. An injection of bovine serum albumin (BSA) was given on the day of castration and a second one 14 d later. Blood samples were taken at different times to evaluate the antibody levels against BSA and lymphocyte blastogenesis responses to concanavalin A (Con A), phytohaemagglutinin (PHA) and pokeweed mitogen (PWM). The age of piglets at the first immunization significantly influenced (P < 0.0001) the ability to raise antibodies to the injected antigen. Three-day-old piglets developed weaker antibody response than those immunized at 10 or 17 d of age. Ten- and 17-d-old castrated piglets tended to develop weaker secondary antibody responses than sham-castrated piglets, while those castrated and sham-castrated at 3 d of age did not diff...

Dietary supplementation with different forms of flax in late gestation and lactation: effects on sow and litter performances, endocrinology, and immune response.

The impact of feeding flax as seed, meal, or oil to late-pregnant and lactating sows on hormone concentrations, immune responses, and sow and litter performances was studied. Sixty sows were fed 1 of 4 diets from 68 d of gestation until 21 d of lactation. Diets were standard (CTL; n = 15); 10% flaxseed supplementation (FS; n = 16); 6.5% flaxseed meal supplementation (FSM; n = 14); and 3.5% flaxseed oil supplementation (FSO, n = 15). On d 88 and 101 of gestation, sows were immunized against ovalbumin (OVA). Jugular blood samples were obtained on d 62, 88, and 110 of gestation and on d 2 and 21 of lactation to measure concentrations of estradiol, prolactin, and progesterone as well as antibody (Ab) against OVA (anti-OVA), lymphocyte proliferation, and lymphocyte production of interferon-gamma (IFN-gamma). Milk samples were obtained on d 3 and 20 of lactation. One piglet per litter was slaughtered on d 1 for compositional analyses, and a jugular blood sample was obtained for anti-OVA analyses. Remaining piglets were weighed on d 2, 7, 14, 21 (weaning), 28, and 56. Circulating hormone concentrations in sows were not affected by treatment overall (P > 0.1). On d 20 of lactation, milk from FS, FSM, and FSO sows had more protein than that from CTL sows (P < 0.01). The FSM piglets weighed more on d 56 (P < 0.05) than FS and FSO piglets. Carcasses of 1-d-old FSM piglets also had greater glycogen (P < 0.001) and DM (P = 0.05) contents than FS and FSO piglets, but organ weights and circulating concentrations of glucose and IGF-I did not differ (P > 0.1). In CTL sows, IFN-gamma production decreased between d 101 of gestation and d 2 of lactation, whereas, in FS sows, IFN-gamma production increased (P < 0.01). Anti-OVA for the whole experimental period was greater in FS than in FSO sows (P < 0.05). Concentrations of anti-OVA in milk on d 3 of lactation and lymphocyte proliferative responses were not affected by treatments (P > 0.1). Serum concentrations of anti-OVA in 2-d-old piglets that gained BW during the first 24 h after birth were greater (P < 0.01) in FS, FSM, and FSO litters than in CTL litters and percent mortality on d 2 and 21 postpartum was less (P < 0.05) for FS, FSM, and FSO litters compared with CTL. Therefore, feeding flax to sows may have beneficial effects on immune resistance of piglets and feeding FSM improved postweaning growth of piglets.

The case for plant-made veterinary immunotherapeutics.

The excessive use of antibiotics in food animal production has contributed to resistance in pathogenic bacteria, thereby triggering regulations and consumer demands to limit their use. Alternatives for disease control are therefore required that are cost-effective and compatible with intensive production. While vaccines are widely used and effective, they are available against a minority of animal diseases, and development of novel vaccines and other immunotherapeutics is therefore needed. Production of such proteins recombinantly in plants can provide products that are effective and safe, can be orally administered with minimal processing, and are easily scalable with a relatively low capital investment. The present report thus advocates the use of plants for producing vaccines and antibodies to protect farm animals from diseases that have thus far been managed with antibiotics; and highlights recent advances in product efficacy, competitiveness, and regulatory approval.

Intestinal Physiology and Peptidase Activity in Male Pigs Are Modulated by Consumption of Corn Culture Extracts Containing Fumonisins

Fumonisin B(1) (FB1) alters intestinal epithelial cell cycle and absorptive, secretory, and barrier properties in vitro, but in vivo data are lacking. Therefore, we tested the hypothesis that repeated intake of a corn culture extract rich in fumonisins, mainly in FB1, alters indices of intestinal absorptive and secretory physiology and barrier function in vivo. Intra-litter pairs of pigs (n = 36) weaned at 28 d, were fed the vehicle (control) or the extract (providing 1.5 mg FB1/kg body weight) daily for 9 d starting 7 d postweaning. After slaughter, the jejunal mucosa of pigs was mounted in Ussing chambers (UC). Extract consumption for 9 d decreased the gain:feed ratio (P = 0.04) and increased liver weight (P = 0.01). Basal net ion secretion (P = 0.02), sodium-dependent glucose absorption (P = 0.02), and theophylline-induced secretion (P < 0.01) of the jejunal mucosa determined in UC were higher in pigs fed the extract than in controls. By contrast, jejunal permeability to the horseradish peroxidase model protein in UC was not influenced by extract consumption. Ileal villi tended to be longer (P = 0.07) and jejunal aminopeptidase N activity was lower (P < 0.01) in pigs fed the extract. In conclusion, consumption of an extract rich in fumonisins for 9 d has the potential to alter intestinal physiology, villous architecture, and enzyme activities. Underlying mechanisms remain to be investigated.

Consumption of fumonisin B1 for 9 days induces stress proteins along the gastrointestinal tract of pigs

Fumonisin B(1) (FB1) is a mycotoxin which alters intestinal epithelial cell physiology and barrier properties, and accumulates in the colon. Data on effects of FB1 on stress proteins in the gastrointestinal tract (GIT) are lacking. Therefore, we hypothesized that repeated consumption of FB1 alters GIT tissue levels of stress proteins. This was tested using 36 weaned pigs fed a FB1 solution (n=18) or the vehicle (control; n=18) for 9 days. The pigs were then slaughtered, the organs were weighed and GIT tissues were collected for assessing GIT integrity, and for analysing stress proteins by Western blotting and densitometry (n=7 in each group). FB1 had little effects on growth rate but the liver was heavier (P<0.01) in FB1-fed pigs. alphaB crystallin and COX-1 concentrations were eight-fold and 12-fold higher in the colon of FB1-fed pigs than in the controls (P<0.0001). Concentrations of COX-1 and nNOS in the stomach, HSP 70 in the jejunum and HO-2 in the colon were also higher in FB1-fed pigs (P<0.05 to P<0.001). In conclusion, the FB1 extract drastically enhanced colonic levels of alphaB crystallin and COX-1, with milder increases in other stress proteins along the GIT of pigs. The data suggest that the colon is an important target for FB1-induced stress responses.