The kinetic disposition of pyrantel citrate and pamoate and their efficacy against pyrantel-resistant Oesophagostomum dentatum in pigs

The pharmacokinetic disposition of pyrantel after intravenous (i.v.) and oral (p.o.) administration as the citrate and p.o. administration as the pamoate salt was determined in pigs. Following i.v. administration pyrantel was quickly cleared from the bloodstream, exhibiting a terminal halflife of 1.75 ± 0.19h and a residence time (MRT) of 2.54 ± 0.27h. After p.o. administration as the citrate salt, the absorption time (MAT) of pyrantel was 2.38 ± 0.25h and although significant quantities of pyrantel were absorbed (mean bioavailability of 41%) the rapid clearance resulted in a MRT of only 4.92 ± 0.36h. By comparison, the significantly extended MAT of the less soluble pamoate salt resulted in reduced circulating concentrations and a significantly lower mean bioavailability of 16%. The poor efficacy of pyrantel citrate against nematodes inhabiting the large intestine of pigs is therefore suggested to result from insufficient quantities of drug passaging to the site of infection. When tested against pyrantel-resistant adult Oesophagostomum dentatum the efficacy of pyrantel citrate was only 23%, whereas the efficacy of the lesser absorbed pyrantel pamoate was 75%. These results indicate that for maximum activity pyrantel should be administered to pigs as the pamoate salt.     

Environmental impacts of precision feeding programs applied in pig production

This study was undertaken to evaluate the effect that switching from conventional to precision feeding systems during the growing-finishing phase would have on the potential environmental impact of Brazilian pig production. Standard life-cycle assessment procedures were used, with a cradle-to-farm gate boundary. The inputs and outputs of each interface of the life cycle (production of feed ingredients, processing in the feed industry, transportation and animal rearing) were organized in a model. Grain production was independently characterized in the Central-West and South regions of Brazil, whereas the pigs were raised in the South region. Three feeding programs were applied for growing-finishing pigs: conventional phase feeding by group (CON); precision daily feeding by group (PFG) (whole herd fed the same daily adjusted diet); and precision daily feeding by individual (PFI) (diets adjusted daily to match individual nutrient requirements). Raising pigs (1 t pig BW at farm gate) in South Brazil under the CON feeding program using grain cultivated in the same region led to emissions of 1840 kg of CO₂-eq, 13.1 kg of PO₄-eq and 32.2 kg of SO₂-eq. Simulations using grain from the Central-West region showed a greater climate change impact. Compared with the previous scenario, a 17% increase in climate change impact was found when simulating with soybeans produced in Central-West Brazil, whereas a 28% increase was observed when simulating with corn and soybeans from Central-West Brazil. Compared with the CON feeding program, the PFG and PFI programs reduced the potential environmental impact. Applying the PFG program mitigated the potential climate change impact and eutrophication by up to 4%, and acidification impact by up to 3% compared with the CON program. Making a further adjustment by feeding pigs according to their individual nutrient requirements mitigated the potential climate change impact by up to 6% and the potential eutrophication and acidification impact by up to 5% compared with the CON program. The greatest environmental gains associated with the adoption of precision feeding were observed when the diet combined soybeans from Central-West Brazil with corn produced in Southern Brazil. The results clearly show that precision feeding is an effective approach for improving the environmental sustainability of Brazilian pig production.     

Focusing modelling on the tracheid development period – An alternative method for treatment of xylogenesis intra-annual data

Intra-annual repeated micro-sampling of the developing tree ring is getting more and more applied in xylogenesis studies. Variability in growth magnitude, notably due to different sampling positions on the stem, encouraged application of standardization and modelling techniques. Among these, methods using Gompertz equation had become widely spread, but tests made with black spruce revealed a frequent occurrence of crossovers between the cumulative number of cells in enlargement and the cumulative number of cells in wall thickening. This was due to a localized problem in the fitting for values close to the asymptote and was a major problem for estimating the timing of each individual cell development phases, which is an interesting application of these data. In this paper, a new method, based on a different approach, has been developed in order to avoid that problem and applied to intra-annual growth curves from four sites in Quebec (Canada). Since tracheid development analysis allows discriminating between active and inactive period of a phase, modelling can be restricted on the active period alone. The new method did not cause crossovers between the fitted curves. Therefore, it has been considered appropriate for estimating the timing for each individual cell in the whole range of data. Since resulting functions are polynomials from degree 1 to 3, possible studies concerning general tendency should be easy to lead. Also, the method has been tested with different sampling frequencies. To do this, number of observations from weekly samplings has been halved to simulate a semi-monthly sampling frequency and a comparison of the results from the new method applied on each version of the datasets has been tested. Generally, the simulated semi-monthly sampled dataset did not give significantly different results from the original weekly sampled dataset, in terms of general tendency and predicted intercept time in the extremities of the data range. This is very encouraging for situations when only semi-monthly sampling is available.     

Genome‐wide methylation profile following prenatal and postnatal dietary omega‐3 fatty acid supplementation in pigs

The objective of this study was to determine how prenatal and postnatal dietary omega‐3 fatty acids alter white blood cell (leukocyte) DNA methylation of offspring. Fifteen gilts (n = 5 per treatment) were selected from one of three treatments: (i) control diet throughout gestation, lactation and nursery phase (CON); (ii) algal omega‐3 fatty acid supplementation enriched in EPA and DHA (Gromega^?) fed throughout gestation, lactation and nursery phase (Cn3); or (iii) Gromega^? supplementation maternally, during gestation and lactation only, and control diet during the nursery phase (Mn3). At 11 weeks of age and after 8 weeks of post‐weaning nursery feeding, buffy coat genomic DNA was subjected to methyl CpG binding protein sequencing. The methylation enriched profile mapped to 26% of the porcine genome. On chromosome 4, a 27.7‐kb differentially methylated region downstream of RUNX1T1 was hypomethylated in the Mn3 and Cn3 groups by 91.6% and 85.0% respectively compared to CON pigs. Conversely, hypermethylation was detected in intergenic regions of chromosomes 4 and 12. Regulatory impact factor and differential hubbing methods were used to identify pathways that were coordinately regulated by methylation due to feeding EPA and DHA during pregnancy. Despite limited ability to detect differential methylation, we describe methods that allow the identification of coordinated epigenetic regulation that could not otherwise be detected from subtle single locus changes in methylation. These data provide evidence of novel epigenetic regulation by maternal and early life supplementation of omega‐3 fatty acids that may have implications to growth and inflammatory processes.     

Phenology and seed setting success of snowbed plant species in contrasting snowmelt regimes in the Central Pyrenees

Plant growth and performance in snowbed communities are strongly influenced by the length of the growing period remaining after the snowmelt date. Under the scenario of climate change, studying the phenological responses of snowbed species to variations in snowmelt date might be crucial to understand their ability to adapt and survive under changing conditions. We studied 13 plant species from contrasting biological and ecological groups (i.e. ‘snowbed specialists’, ‘preferential species’ and ‘generalist species’) growing in four snowbed plots with siliceous substrates in the Central Pyrenees. These species were monitored for two consecutive years and in two different microsites, namely the central part and the peripheral part of each snowbed plot. We characterised their phenological cycle and length and their success in seed setting, measured as the number of individuals succeeding in dispersing their seeds.     

First International Workshop on Porcine Chromosome 6

Recent advances in the use of microsatellite markers and the development of comparative gene mapping techniques have made the construction of high resolution genetic maps of livestock species possible. Framework and comprehensive genetic linkage maps of porcine chromosome 6 have resulted from the first international effort to integrate genetic maps from multiple laboratories. Eleven highly polymorphic genetic markers were exchanged and mapped by four independent laboratories on a total of 583 animals derived from four reference populations. The chromosome 6 framework map consists of 10 markers ordered with high local support. The average marker interval of the framework map is 15.1 cM (sex averaged). The framework map is 135, 175 and 109 cM in length (for sex averaged, female and male maps, respectively). The comprehensive map includes a total of 48 type I and type II markers with a sex averaged interval of 3.5 cM and is 166, 196 and 126 cM (for sex averaged, female and male maps, respectively). Additional markers within framework map marker intervals can thus be selected from the comprehensive map for further analysis of quantitive trait loci (QTL) located on chromosome 6. The resulting maps of swine chromosome 6 provide a valuable tool for analysing and locating QTL.     

Whole genome sequencing identifies allelic ratio distortion in sperm involving genes related to spermatogenesis in a swine model

Transmission Ratio Distortion (TRD), the uneven transmission of an allele from a parent to its offspring, can be caused by allelic differences affecting gametogenesis, fertilization or embryogenesis. However, TRD remains vaguely studied at a genomic scale. We sequenced the diploid and haploid genomes of three boars from leukocytes and spermatozoa at 50x to shed light into the genetic basis of spermatogenesis-caused Allelic Ratio Distortion (ARD). We first developed a Binomial model to identify ARD by simultaneously analysing all three males. This led to the identification of 55 ARD SNPs, most of which were animal-specific. We then evaluated ARD individually within each pig by a Fisher’s exact test and identified two shared genes (TOP3A and UNC5B) and four shared genomic regions harbouring distinct ARD SNPs in the three boars. The shared genomic regions contained candidate genes with functions related to spermatogenesis including AK7, ARID4B, BDKRB2, GSK3B, NID1, NSMCE1, PALB2, VRK1 and ZC3H13. Using the Fisher’s test, we also identified 378 genes containing variants with protein damaging potential in at least one boar, a high proportion of which, including FAM120B, TDRD15, JAM2 or AOX4 among others, are associated to spermatogenesis. Overall, our results show that sperm is subjected to ARD with variants associated to a wide variety of genes involved in different stages of spermatogenesis.     

Effect of swine lymphocyte antigen haplotypes on birth and weaning weights in pigs

Birth weights of 708 live piglets and weaning weights of 566 piglets were used to investigate the effect of the swine lymphocyte antigen (SLA) complex on these traits in Large White pigs. Piglets were from litters of a long-term selection experiment to measure response for selection to increase litter size. SLA haplotypes were determined using conventional class I antisera. A total of 14 haplotypes were detected. The effect of SLA haplotype on birth and weaning weights was investigated using a statistical model that included the effects of experimental group, sire, dam, sex and SLA haplotype. Results indicated that SLA class I haplotype 13.1.3 increased birth weights (P less than 0.10) and significantly increased weaning weights (P less than 0.01). This effect of haplotype 13.1.3 on weaning weight was 605 +/- 215 g (0.3 standard deviations). SLA class I homozygosity did not appear to affect birth and weaning weights. These results suggest that the SLA complex plays an important role in early growth in the pig and that further study of SLA effects on growth and reproduction are warranted.