Descriptive analyses of maternally-derived antibody levels against porcine circovirus 2 (PCV-2) in 3- and 21-day-old piglets from farms of four European countries using different vaccination protocols in sows.

BACKGROUND: Up to now, information on the levels of maternally-derived antibodies (MDA) against PCV-2 in suckling piglets born to sows vaccinated with different strategies is scarce in the literature. In the present observational study, the PCV-2-specific MDA titres from piglets from 109 farms (thirty 3-day-old and thirty 21-day-old piglets per farm) across four different European countries (France n = 30, Germany n = 27, Italy n = 22 and Spain n = 30) using different sow vaccination strategies (during gestation, as a gilt, as a piglet or never) were assessed. RESULTS: In all four countries, mean log PCV-2 MDA titres were higher in 3-day-old piglets than in the 3-week-old ones, being significant in most of all the comparisons performed. Within each country, the highest PCV-2-specific MDA titres were observed in the 3-day-old piglets born to sows vaccinated during gestation. Indeed, in the four countries, more than 60% of this subpopulation (3-day-old piglets from sows vaccinated during pregnancy) had the highest log PCV-2 titres detectable with the ELISA technique used in this study. The lowest MDA titres were more variable. Whereas in France and Germany the lowest titres corresponded to 21-day-old piglets born from sows vaccinated as a piglet, in Italy, they corresponded to 21-day-old piglets derived from sows vaccinated as a gilt and in Spain to 21-day-old piglets born from non-vaccinated sows. In this study, PCV-2-specific MDA titres at 3 and 21 days of age were not affected by sow parity. CONCLUSIONS: Data obtained could be considered as a European global overview of PCV-2-specific MDA titres present in the pre-vaccinated piglet populations in different European countries, with titres tending to be higher in younger piglets, but with values variable among countries and sow vaccination strategies.

Fermentation products as feed additives mitigate some ill-effects of heat stress in pigs.

Heat stress (HS) may result in economic losses to pig producers across the USA and worldwide. Despite significant advancements in management practices, HS continues to be a challenge. In this study, an in-feed antibiotic (carbadox, CBX) and antibiotic alternatives ( [XPC], and [SGX] fermentation products) were evaluated in a standard pig starter diet as mitigations against the negative effects of HS in pigs. A total of 100 gilts were obtained at weaning (6.87 ± 0.82 kg BW, 19.36 ± 0.72 d of age) and randomly assigned to dietary treatments (2 rooms/treatment, 2 pens/room, 6 to 7 pigs/pen). After 4 wk of dietary acclimation, half of the pigs in each dietary group (1 room/dietary treatment) were exposed to repeated heat stress conditions (RHS; daily cycles of 19 h at 25°C and 5 h at 40°C, repeated for 9 d), and the remaining pigs were housed at constant thermal neutral temperature (25°C, [NHS]). Pigs subjected to RHS had elevated skin surface temperature ( < 0.05; average 41.7°C) and respiration rate ( < 0.05; 199 breaths per minute (bpm) during HS, and overall reduced ( < 0.05) BW, ADG, ADFI, and G:F regardless of dietary treatment. Independent of diet, RHS pigs had significantly shorter ( < 0.05) jejunum villi on d 3 and d 9 compared to NHS pigs. Heat stress resulted in decreased villus height to crypt depth ratio (V:C) in pigs fed with control diet with no added feed additive (NON) and CBX diets at d 3, whereas the pigs fed diets containing XPC or SGX showed no decrease. Transcriptional expression of genes involved in cellular stress (, , , ), tight junction integrity (, , ), and immune response (, , and ) were measured in the ileum mucosa. Pigs in all dietary treatments subjected to RHS had significantly higher ( < 0.05) transcript levels of and , and an upward trend ( < 0.07) of mRNA expression. RHS pigs had higher ( < 0.05) transcript levels of and in NON diet, in XPC and CBX diets, and in SGX diet compared to the respective diet-matched pigs in the NHS conditions. Neither RHS nor diet affected peripheral natural killer () cell numbers or NK cell lytic activity. In conclusion, pigs subjected to RHS had decreased performance, and supplementation with fermentation products in the feed (XPC and SGX) protected pigs from injury to the jejunum mucosa.

Effect of cross-fostering on transfer of maternal immunity to Mycoplasma hyopneumoniae to piglets.

The aim of this study was to assess the effect of cross-fostering on transfer of maternal Mycoplasma hyopneumoniae-specific humoral and cell-mediated immunity (CMI) from gilts to piglets. Cross-fostering, carried out within gilt pairs, was based on the gilts' M hyopneumoniae vaccination status in accordance with the following scheme: six pairs of vaccinated gilt × non-vaccinated gilt (V × N); five pairs of non-vaccinated gilt × vaccinated gilt (N × V); and five pairs of vaccinated gilt × vaccinated gilt (V × V). The piglets were cross-fostered at 0, six, 12 or 20 hours after birth. Two piglets per gilt per time point were cross-fostered (that is, eight piglets per gilt were moved) and the remaining piglets served as non-cross-fostered controls. In addition, four litters served as non-cross-fostered controls. A maximum of 10 piglets per gilt were sampled. The piglets' M hyopneumoniae-specific humoral immunity was assessed by ELISA and their CMI was assessed by delayed-type hypersensitivity testing. M hyopneumoniae-specific antibodies were detected in non-cross-fostered piglets from vaccinated dams and from piglets cross-fostered within the V × N gilt pair at six hours or more, and within the V × V gilt pair at all time points. Piglets cross-fostered within the N × V gilt pair had detectable M hyopneumoniae-specific antibodies only if they had been moved within six hours of birth. The transfer of M hyopneumoniae-specific CMI to piglets appeared to be source-dependent, and was detected only in piglets maintained on their vaccinated dams for at least 12 hours after birth.

Effect of dietary supplementation of oregano essential oils to sows on colostrum and milk composition, growth pattern and immune status of suckling pigs.

This study evaluated the effects of supplementing sow diets with oregano essential oils (OEO) during gestation and lactation on sow colostrum and milk composition and on the growth pattern and immune status of suckling pigs. A total of 70 second-parity sows were randomly assigned to 1 of 2 gestation dietary treatments within 24 h after service: control (CON) or CON + 250 mg/kg of OEO (OREG). In lactation, sows were again assigned to either the CON or OREG dietary treatment. Thus, the lactation treatments were CON-CON, CON-OREG, OREG-CON, and OREG-OREG. Colostrum and blood samples were collected from 6 sows per lactation dietary treatment. Thymus lymphocyte (T lymphocyte) subpopulations (γδ, cluster of differentiation 8, and 32 cluster of differentiation 4) were enumerated in blood and mammary secretions along with IGF-1, IgG, and IgA concentrations. Piglet growth rate were determined from 18, 17, 17, and 18 litters from the CON-CON, CON-OREG, OREG-CON, and OREG-OREG lactation dietary treatments, respectively. Growth rates were determined in 630 piglets, and piglets were individually identified and weighed on 1, 5, 9, 12, 16, and 19 d of age. Oregano essential oil supplementation during gestation or lactation had no effect (P > 0.05) on GE, CP, GE:CP, GE:fat, and IGF-1 in sow milk. Reductions of the fat percentage in milk on d 7 (P < 0.05) and d 14 (P = 0.07) were found in sows supplemented with OEO during lactation compared with those in the CON treatment. Milk from sows supplemented with OEO during lactation had the greatest number of T lymphocytes compared with those in the lactation CON treatment on d 14 of lactation (P < 0.01). The number of T lymphocytes in milk was greater for sows in the CON-OREG treatment compared with those other treatments on d 14 of lactation (P < 0.05). Energy intake was greater on d 1 to 5 in piglets from sows fed OEO during gestation than those from sows in the CON treatment (P < 0.05). A trend (P = 0.10) for greater milk intake was observed in piglets from sows supplemented with OEO during gestation compared with those from sows in the CON treatment. Similarly, a tendency for an increase in ADG on d 1 to 5 was found in piglets from sows supplemented with OEO during gestation compared with those from sows in the CON treatment (P = 0.10). Insulin-like growth factor-1 at birth and on d 7 and 14 of lactation did not differ among piglets from sows assigned to the different dietary treatments. Oregano essential oil supplementation of sow diets did not affect (P > 0.05) immunoglobulin concentrations in piglets after suckling. Supplementing sow diets with OEO during gestation or lactation did not affect (P > 0.05) the T lymphocytes, percentage of T-lymphocyte subpopulations, and natural killer cell activity of piglets during lactation. Supplementing sow diets with 250 mg/kg of OEO during gestation and lactation did not affect the growth potential of and immune responses in suckling piglets.