A dynamic programming model for optimising the timing of replacement of sows

Replaced with revised version of poster 07/20/10.Farm Management, Research and Development/Tech Change/Emerging Technologies,

A dynamic programming model for optimising the timing of replacement of sows

vo

Lihasikalassa kiinnitettävä huomiota porsaserän laatuun ja sikalan tyhjennystapaan

Teurastuksen ajoitus on tärkeä lihasikojen kasvatuksen kannattavuuteen vaikuttava tekijä. Liian aikaisinteurastettaessa osa sian kasvupotentiaalista jää käyttämättä ja liian myöhään teurastettaessa sian paras kasvupotentiaalion jo käytetty. Sikojen kasvukyvyssä ja siten teuraspainoissa voi kuitenkin olla suuria eroja,jolloin tuottajan ongelmana on valita koko kasvatuserän kannalta optimaalinen teurastusajankohta. Teurastuksenajoituksen taloudellista merkitystä lisää se, että teurastamot maksavat alempaa hintaa niin sanotunkärkipainovälin ylittävistä tai alittavista ruhoista. Ruhojen hinnoittelusta ja painovaihtelusta aiheutuvientulonmenetysten vähentämiseksi tuottaja voi lähettää siat teuraaksi joko yhdessä tai useammassa erässä.Tämän tutkimuksen tarkoituksena on selvittää, missä vaiheessa tuottajan kannattaa teurastaa sika,miten nopeasti kertatäyttöinen sikala kannattaa tyhjentää silloin, kun sikojen kasvukyky vaihtelee, ja mitenpaljon kertatäyttöisessä sikalassa on hyötyä teurastusten jaksottamisesta useaan erään. Tutkimuksessa verrattiinkahta erilaista sikalan tyhjennystapaa, joissa 1) kaikki siat lähetetään samana päivänä teuraaksi (kertatyhjenteinensikala) tai 2) siat voidaan lähettää teuraaksi enintään kymmenessä yhtä suuressa erässä (jaksotettuteurastus). Molemmissa vaihtoehdoissa uudet porsaat tuodaan vasta viimeisten sikojen lähdettyäteuraaksi. Tutkimuksessa kehitettiin stokastinen dynaaminen optimointimalli, joka maksimoi sikapaikantuoton. Tämä tavoite on tärkeä sikatalouden kilpailukyvyn kannalta, sillä tuotanto on pääomavaltaista. Mallissakasvatuserän porsaat tuodaan sikalaan yhdessä erässä. Kunkin sian kasvu kuvataan mekanistista kasvumalliahyödyntäen. Malli optimoi teurastuksen ajoituksen kullekin ryhmän sialle ottaen huomioon muidenkasvatuserän sikojen painon, kasvukyvyn ja teurastuksen ajoituksen.Tulosten mukaan kasvatuserän nopeimmin kasvavat siat kannattaa teurastaa, kun ne saavuttavatkärkipainovälin ylärajan. Sen sijaan kasvatusryhmän hitaimmin kasvavat siat kannattaa myydä teuraaksi joniiden ollessa kärkipainovälin alarajan tuntumassa. Tulos johtuu siitä, että hidaskasvuiset siat ovat muitasikoja heikompituottoisia ja siitä, että loppuja sikapaikkoja ei kannata makuuttaa tyhjillään muutaman hidaskasvuisensian vuoksi.Tulosten mukaan mahdollisuus jakaa teurastukset useaan erään nostaa sikapaikan tuottoa 4,6 - 8,5eurolla vuodessa, mikä esimerkiksi 500 sian sikalassa vastaa tuhansien eurojen lisätuottoa vuodessa. Matalasianlihan hinta, kapea kärkipainoväli ja sikatalouden tukien irrottaminen tuotannosta lisäävät teurastustenjaksottamisen kannattavuutta ja pidentävät sikalan tyhjennysaikaa. Myös tilalla käytetty eläinaines, kutenrotuyhdistelmä, vaikuttaa optimaaliseen teurastustapaan. Kun sikojen kasvukyvyn hajonta lisääntyy 15 %,sikapaikan tuotto laskee tulosten mukaan 3,2 euroa vuodessa. Tulokset viittaavatkin siihen, että lihasikalavoi parantaa kilpailukykyään, jos se kiinnittää huomiota porsaiden tasalaatuisuuteen ja teurastuksen ajoitukseen

In vivo genotoxicity and inflammatory effects of uncoated and coated CeO2 NPs in mice

P17-045 Ceria nanoparticles (CeO2 NPs) have several industrial applications and pharmacological potential due to their antioxidant properties. However, toxicity data on CeO2 NPs are scarce and show contradictory results. In the present study, uncoated, polyethylene glycol- and citrate-coated CeO2 NPs (4-8 nm) were administrated to C57Bl/6 mice by repeated dose (3×) pharyngeal aspiration using four different doses of each type of NPs (corresponding to 4.4, 8.8, 17.6 and 35.2 µg Ce2+/mouse/aspiration), and sampled 1 and 28 days after the last administration. DNA damage was assessed by the comet assay locally in bronchoalveolar lavage (BAL) and lung cells, and systemically in liver cells. Micronuclei, a biomarker of chromosome damage, were analysed in bone marrow and peripheral blood erythrocytes. Immunotoxicity was evaluated by BAL cell counting. Furthermore, histopathological effects on the lungs and biodistribution of the NPs (analysis of Ce2+ in several organs) were assessed. At 24-h, a significant increase in DNA damage was induced at the highest doses by uncoated and citrate-coated NPs in BAL cells. For these NPs a significant, but non-dose-dependent, effect was observed in lung and liver cells at 28-d. No systemic genotoxic effects were observed with any of the NPs. A dose-dependent accumulation of macrophages and activated lymphocytes was seen in the lungs for all the NPs, although a milder reaction was elicited by the coated NPs. Our findings show that short-term exposure of mice to CeO2 NPs induces pulmonary inflammation, and non-dose-dependent DNA damage, but no systemic genotoxicity. (Funded by the EU FP-7 GUIDEnano, Grant Agreement No.604387)

Occupational exposure and markers of genetic damage, systemic inflammation and lung function: a Danish cross-sectional study among air force personnel

Air force ground crew personnel are potentially exposed to fuels and lubricants, as raw materials, vapours and combustion exhaust emissions, during operation and maintenance of aircrafts. This study investigated exposure levels and biomarkers of effects for employees at a Danish air force military base. We enrolled self-reported healthy and non-smoking employees (n = 79) and grouped them by exposure based on job function, considered to be potentially exposed (aircraft engineers, crew chiefs, fuel operators and munition specialists) or as reference group with minimal occupational exposure (avionics and office workers). We measured exposure levels to polycyclic aromatic hydrocarbons (PAHs) and organophosphate esters (OPEs) by silicone bands and skin wipes (PAHs only) as well as urinary excretion of PAH metabolites (OH-PAHs). Additionally, we assessed exposure levels of ultrafine particles (UFPs) in the breathing zone for specific job functions. As biomarkers of effect, we assessed lung function, plasma levels of acute phase inflammatory markers, and genetic damage levels in peripheral blood cells. Exposure levels of total PAHs, OPEs and OH-PAHs did not differ between exposure groups or job functions, with low correlations between PAHs in different matrices. Among the measured job functions, the UFP levels were higher for the crew chiefs. The exposure level of the PAH fluorene was significantly higher for the exposed group than the reference group (15.9 +/- 23.7 ng/g per 24 h vs 5.28 +/- 7.87 ng/g per 24 h, p = 0.007), as was the OPE triphenyl phosphate (305 +/- 606 vs 19.7 +/- 33.8 ng/g per 24 h, p = 0.011). The OPE tris(1, 3-dichlor-2-propyl)phosphate had a higher mean in the exposed group (60.7 +/- 135 ng/g per 24 h) compared to the reference group (8.89 +/- 15.7 ng/g per 24 h) but did not reach significance. No evidence of effects for biomarkers of systemic inflammation, genetic damage or lung function was found. Overall, our biomonitoring study show limited evidence of occupational exposure of air force ground crew personnel to UFPs, PAHs and OPEs. Furthermore, the OH-PAHs and the assessed biomarkers of early biological effects did not differ between exposed and reference groups

Pulmonary toxicity of synthetic amorphous silica–effects of porosity and copper oxide doping

Materials can be modified for improved functionality. Our aim was to test whether pulmonary toxicity of silica nanomaterials is increased by the introduction of: a) porosity; and b) surface doping with CuO; and whether c) these modifications act synergistically. Mice were exposed by intratracheal instillation and for some doses also oropharyngeal aspiration to: 1) solid silica 100 nm; 2) porous silica 100 nm; 3) porous silica 100 nm with CuO doping; 4) solid silica 300 nm; 5) porous silica 300 nm; 6) solid silica 300 nm with CuO doping; 7) porous silica 300 nm with CuO doping; 8) CuO nanoparticles 9.8 nm; or 9) carbon black Printex 90 as benchmark. Based on a pilot study, dose levels were between 0.5 and 162 µg/mouse (0.2 and 8.1 mg/kg bw). Endpoints included pulmonary inflammation (neutrophil numbers in bronchoalveolar fluid), acute phase response, histopathology, and genotoxicity assessed by the comet assay, micronucleus test, and the gamma-H2AX assay. The porous silica materials induced greater pulmonary inflammation than their solid counterparts. A similar pattern was seen for acute phase response induction and histologic changes. This could be explained by a higher specific surface area per mass unit for the most toxic particles. CuO doping further increased the acute phase response normalized according to the deposited surface area. We identified no consistent evidence of synergism between surface area and CuO doping. In conclusion, porosity and CuO doping each increased the toxicity of silica nanomaterials and there was no indication of synergy when the modifications co-occurred

A Comparison of Approaches to Estimate the Inbreeding Coefficient and Pairwise Relatedness Using Genomic and Pedigree Data in a Sheep Population

Genome-wide SNP data provide a powerful tool to estimate pairwise relatedness among individuals and individual inbreeding coefficient. The aim of this study was to compare methods for estimating the two parameters in a Finnsheep population based on genome-wide SNPs and genealogies, separately. This study included ninety-nine Finnsheep in Finland that differed in coat colours (white, black, brown, grey, and black/white spotted) and were from a large pedigree comprising 319 119 animals. All the individuals were genotyped with the Illumina Ovine SNP50K BeadChip by the International Sheep Genomics Consortium. We identified three genetic subpopulations that corresponded approximately with the coat colours (grey, white, and black and brown) of the sheep. We detected a significant subdivision among the colour types (FST = 5.4%, P<0.05). We applied robust algorithms for the genomic estimation of individual inbreeding (FSNP) and pairwise relatedness (ΦSNP) as implemented in the programs KING and PLINK, respectively. Estimates of the two parameters from pedigrees (FPED and ΦPED) were computed using the RelaX2 program. Values of the two parameters estimated from genomic and genealogical data were mostly consistent, in particular for the highly inbred animals (e.g. inbreeding coefficient F>0.0625) and pairs of closely related animals (e.g. the full- or half-sibs). Nevertheless, we also detected differences in the two parameters between the approaches, particularly with respect to the grey Finnsheep. This could be due to the smaller sample size and relative incompleteness of the pedigree for them

Whole-genome SNP association analysis of reproduction traits in the Finnish Landrace pig breed

<p>Abstract</p> <p>Background</p> <p>Good genetic progress for pig reproduction traits has been achieved using a quantitative genetics-based multi-trait BLUP evaluation system. At present, whole-genome single nucleotide polymorphisms (SNP) panels provide a new tool for pig selection. The purpose of this study was to identify SNP associated with reproduction traits in the Finnish Landrace pig breed using the Illumina PorcineSNP60 BeadChip.</p> <p>Methods</p> <p>Association of each SNP with different traits was tested with a weighted linear model, using SNP genotype as a covariate and animal as a random variable. Deregressed estimated breeding values of the progeny tested boars were used as the dependent variable and weights were based on their reliabilities. Statistical significance of the associations was based on Bonferroni-corrected <it>P</it>-values.</p> <p>Results</p> <p>Deregressed estimated breeding values were available for 328 genotyped boars. Of the 62 163 SNP in the chip, 57 868 SNP had a call rate > 0.9 and 7 632 SNP were monomorphic. Statistically significant results (<it>P</it>-value < 2.0E-06) were obtained for total number of piglets born in first and later parities and piglet mortality between birth and weaning in later parity, and suggestive associations (<it>P</it>-value < 4.0E-06) for piglet mortality between birth and weaning in first parity, number of stillborn piglets in later parity, first farrowing interval and second farrowing interval. Two of the statistically significant regions for total number of piglets born in first and later parities are located on chromosome 9 around 95 and 79 Mb. The estimated SNP effect in these regions was approximately one piglet between the two homozygote classes. By combining the two most significant SNP in these regions, favourable double homozygote animals are expected to have 1.3 piglets (<it>P</it>-value = 1.69E-08) more than unfavourable double homozygote animals. A region on chromosome 9 (66 Mb) was statistically significant for piglet mortality between birth and weaning in later parity (0.44 piglets between homozygotes, <it>P</it>-value = 6.94E-08).</p> <p>Conclusions</p> <p>Three separate regions on chromosome 9 gave significant results for litter size and pig mortality. The frequencies of favourable alleles of the significant SNP are moderate in the Finnish Landrace population and these SNP are thus valuable candidates for possible marker-assisted selection.</p

Economically optimal pig delivery scheduling and the design of meat pricing schemes when pig group is heterogeneous

Sisältö: CD-rom.vo