Genetics of Sow Efficiency in the Finnish Landrace and Large White Populations

The results showed that the sow efficiency traits are generally lowly heritable. The only exceptions are buck kneed on fore legs (conformation trait), age at first farrowing and gestation length, which are moderately heritable. The most substantial unfavorable correlation among sow efficiency traits exists between litter size and piglet mortality. In general, there was a tendency for sow efficiency traits to be favorably correlated with performance traits, and unfavorably with carcass lean and fat percentages, whereas there was no clear association between sow efficiency and meat quality

Effects of sowing time on pink snow mould, leaf rust and winter damage in winter rye varieties in Finland

Disease infection in relation to sowing time of winter rye (Secale cereale) was studied in southern Finland in order to compare overwintering capacity of modern rye varieties and to give recommendations for rye cultivation. This was done by using three sowing times and four rye varieties in field trials conducted at three locations in 1999–2001. The early sown rye (beginning of August) was severely affected by diseases caused by Puccinia recondita and Microdochium nivale, whereas postponing sowing for two weeks after the recommended sowing time resulted in considerably less infection. The infection levels of diseases differed among rye varieties. Finnish rye varieties Anna and Bor 7068 were more resistant to snow mould and more winter hardy than the Polish variety Amilo, or the German hybrid varieties Picasso and Esprit. However, Amilo was the most resistant to leaf rust. In the first year snow mould appeared to be the primary cause of winter damage, but in the second year the winter damage was positively correlated with leaf rust. No significant correlation between frit fly infestation and winter damage or disease incidence of snow mould or leaf rust was established. The late sowing of rye (in the beginning of September) is recommended in Finland, particularly with hybrid varieties, to minimize the need for chemical plant protection in autumn

Muuntuva ohranverkkolaikku haastaa kasvinsuojelun

Monet kasvitautien aiheuttajat vastaavat kasvinsuojeluun muuntumalla torjuntamenetelmiä kestävimmäksi. Taudinaiheuttajien muuntelu aiheuttaa haasteita kasvinsuojelulle. Ohranverkkolaikku voi lisääntyä Suomessa suvullisesti, mutta silti muuntelu on meillä vähäisempää kuin esimerkiksi Krasnodarissa, Mustanmeren rannalla. Mikä vaikuttaa ohranverkkolaikun muunteluun ja voidaanko taudinkestäviä lajikkeita viljelemällä välttyä kemiallisen torjunnan käytöltä?vo

Ohranverkkolaikun aiheuttajan, Pyrenophora teres, populaatiorakenne

Spring barley is the most important crop in Finland based on cultivated land area. Net blotch, a disease caused by Pyrenophora teres Drech., is the most damaging disease of barley in Finland. The pressure to improve the economics and efficiency of agriculture has increased the need for more efficient plant protection methods. Development of durable host-plant resistance to net blotch is a promising possibility. However, deployment of disease resistant crops could initiate selection pressure on the pathogen (P. teres) population. The aim of this study was to understand the population biology of P. teres and to estimate the evolutionary potential of P. teres under selective pressure following deployment of resistance genes and application of fungicides. The study included mainly Finnish P. teres isolates. Population samples from Russia and Australia were also included. Using AFLP markers substantial genotypic variation in P. teres populations was identified. Differences among isolates were least within Finnish fields and significantly higher in Krasnodar, Russia. Genetic differentiation was identified among populations from northern Europe and from Australia, and between the two forms P. teres f. teres (PTT, net form of net blotch) and P. teres f. maculata (PTM, spot form of net blotch) in Australia. Differentiation among populations was also identified based on virulence between Finnish and Russian populations, and based on prochloraz (fungicide) tolerance in the Häme region in Finland. Surprisingly only PTT was recovered from Finland and Russia although both forms were earlier equally common in Finland. The reason for the shift in occurrence of forms in Finland remained uncertain. Both forms were found within several fields in Australia. Sexual reproduction of P. teres was supported by recover of both mating types in equal ratio in those areas although the prevalence of sexual mating seems to be less in Finland than in Australia. Population from Krasnodar was an exception since only one mating type was found in there. Based on the substantial high genotypic variation in Krasnodar it was suggested go represent an old P. teres population, whereas the Australian samples were suggested to represent newer populations. In conclusion, P. teres populations are differentiated at several levels. Human assistance in dispersal of P. teres on infected barley seed is obvious and decreases the differentiation among populations. This can increase the plant protection problems caused by this pathogen. P. teres is capable of sexual reproduction in several areas but the prevalence varies. Based on these findings it is apparent that P. teres has the potential to pose more serious problems in barley cultivation if plant protection is neglected. Therefore, good agricultural practices, including crop rotation and the use of healthy seed, are recommended.Pinta-alansa perusteella ohra on tärkein viljelykasvi Suomessa. Ohran merkittävin tauti ja sadon alentaja on ohranverkkolaikkutauti, jota aiheuttaa Pyrenophora teres Drech. -sieni Taudille aroilla lajikkeilla sairastunut lehtipinta-ala on keskimäärin 40 %. Taudinkestävät lajikkeet tarjoaisivat ympäristöystävällisen torjuntavaihtoehdon, mutta taudinaiheuttajan populaatiorakennetta ei tunneta riittävän hyvin. Kasvinsuojeluaineiden käyttö sekä taudinkestävien lajikkeiden viljely voivat muokata taudinaiheuttajan populaatiota torjuntamenetelmiä paremmin kestäväksi. Tässä tutkimuksessa selvitettiin P. teres -sienen populaation rakennetta tutkimalla geneettistä muuntelua molekyylimerkein, virulenssia ja prokloratsin sietokykyä. Suomalaisia P. teres populaatioita edustavat kannat kerättiin vuosien 1989-2003 välillä. Varsinaiset peltopopulaatiot kerättiin Lounais-Hämeestä sekä Ylistarosta. Lisäksi mukana oli kaksi venäläistä peltopopulaatiota sekä kokoelma australialaisia P. teres -kantoja. Tutkimus osoitti, että P. teres -kannat olivat erittäin muuntelevia molekyylimerkkien perusteella (AFLP). Populaatiot olivat erilaistuneet niin peltojen kuin paikkakuntien ja vuosien välillä. Ohranverkkolaikkutaudin aiheuttajan erilaistuminen oli ilmeistä myös virulenssitestauksen ja prokloratsi-kasvinsuojeluaineen siedon perusteella. Prokloratsin sietotesti antoi viitteitä, että kasvinsuojeluaine voi valikoida tautikantoja. Suomesta ja Venäjältä kerätyt taudinaiheuttajakannat olivat kaikki ohranverkkolaikun verkkotyyppiä, vaikka 70-luvulla taudin molemmat oiretyypit: verkko- ja laikkutyyppi olivat yhtä yleisiä Suomessa. Taudinaiheuttajan molempia pariutumistyyppejä löydettiin yhtä yleisesti, vaikka suvullisen lisääntymisen merkitystä ja esiintymistä Suomessa on epäilty. Suvullista lisääntymistä tapahtuu Suomessa, koska pariutumistyypit eivät olleet erilaistuneita. Krasnodarin P. teres -kannat erosivat muista populaatioista ollen erittäin muunteleva, mutta vain toista pariutumistyyppiä. Australiassa molemmat pariutumistyypit sekä oiretyypit olivat yleisiä. Tulosten perusteella oletetaan Krasnodarin edustavan vanhaa populaatiota ja Australian uudempaa taudinaiheuttaja populaatiota. Tämä tutkimus vahvisti oletusta, että oiretyyppien aiheuttajat olisivat luonnossa erillisiä, eivätkä lisäänny keskenään. Tämän työn havainnot (suvullinen lisääntyminen, toisen oiretyypin yleistyminen Suomessa ja populaatioiden erilaistuminen usealla tasolla) korostavat monipuolisen kasvinsuojelun tarvetta, vaikka viljelymenetelmät muuttuvatkin

Genetic improvement of sow longevity and its economic impact on commercial pork production

Sow longevity (sow productive lifetime) plays an important role in economically efficient piglet production. Direct selection for sow longevity is not commonly practiced in any pig-breeding program. In recent years, an increased number of peer reviewed articles addressing the economic impact, genetic parameter estimates, and genomic information (including markers and single nucleotide polymorphisms for sow longevity) have been published in the scientific literature. The studies in the literature indicate that sow longevity is a complex trait having economic value and is an animal well-being concern for commercial pork producers. Studies have concluded that sufficient genetic variation exists so that selection to improve sow longevity should be effective. Unlike the dairy industry, the primary parent animal used in the swine industry is a crossbred female, typically F1 (Landrace X Large White or Yorkshire). Sow longevity has shown to be genetically related with prolificacy and leg conformation traits. Sow longevity seems to be the ideal trait to utilize genomic selection when attempting to improve the trait. The genetic correlation between purebred and crossbred sow longevity is low. Since the crossbred sow is the breeding objective, phenotypic data from the crossbred females should ideally be used when estimating the breeding values for sow longevity that are used in the indexes to evaluate nucleus animals. Genomic selection is best suited for sex-limited traits, traits expressed later in life, and many animals do not reach some defined end-point parity, sow longevity seems ideally suited to be evaluated using the latest genome enabled selection technology. Keywords: heritability, leg conformation, selection, sow productive lifetim

Emakon kestävyyttä voi parantaa

Emakon kestävyys on periytyvä ominaisuus ja sitä on mahdollista parantaa jalostuksen avulla. Se on perinnöllisesti yhteydessä hedelmällisyyteen ja jakojen rakenneominaisuuksiin. Siksi jalostusarvojen laskennassa tulisi ottaa huomioon monta ominaisuutta. Emakon kestävyyteen vaikuttaa suuresti myös eläinten hoito tilalla sekä muut tilakohtaiset tekijät. Yksi tärkeimmistä tekijöistä on riittävä energiansaanti imetysaikana.vo

A Comparison of Six Maternal Genetic Lines for Sow Longevity

Data from the National Pork Producers Council Maternal Line National Genetic Evaluation Program were used to compare the sow longevity of six different genetic lines, and to estimate the associations of gilt backfat thickness, age at first farrowing, litter size at first farrowing, litter weight at first farrowing, average feed intake during lactation, and average backfat loss during lactation with sow longevity. The lines evaluated were American Diamond Genetics, Danbred North America, Dekalb-Monsanto DK44, Dekalb-Monsanto GPK347, Newsham Hybrids, and National Swine Registry. The results suggest that the sows of Dekalb-Monsanto GPK347 had a clearly lower risk of being culled than the sows of other five lines. Moreover, the shape of the survival distribution function of Delkab- Monsanto GPK347 is clearly different than the other five lines. There were high culling rates due to reproductive failure after first weaning in the sows of the five other lines, however this increased culling rate did not exist in the Dekalb-Monsanto GPK347 line. The results further suggest that sows with lower feed intake and greaterer backfat loss during lactation had the shorter productive lifetime. These between line differences indicate that it is possible to select for sow longevity. More research is needed to show the most efficient methods to select for sow longevity