Epidemiologic approach to antibiotic dry cow therapy in dairy herds

The nonlactating period is a critically important time for dairy cow health and optimal subsequent milk yield. Regarding udder health, at the beginning and end of this period, cows are most susceptible to new intramammary infections. In addition, dry-off is also the optimal time to cure any existing mammary-gland infections. Hence, intramammary-infused antibiotic dry cow therapy (DCT) after final milking is an important and widely used mastitis control measure. DCT can be administered either to all quarters of all cows or only to infected cows or quarters. The global antibiotic resistance problem causes an increasing need to reduce antibiotic use in livestock, but a shift in management should not harm animal welfare or impair farm profitability. Although selective treatment of only infected cows is a more sustainable approach, accurate and cost-effective identification of cows or quarters in need of medication is a challenge. The objective of this epidemiologic study was to determine ideal drying-off practices to maintain good udder health and productivity while implementing prudent use of antibiotics. The specific focus of interest was on DCT, and an additional aim was to examine risk factors for post-calving udder health problems and reduced milk yield. The three cohort studies comprised retrospective herd- and cow-level dairy-herd-recording data registered from conventional, commercial Finnish dairy farms. The first study evaluated herd-level associations between milk somatic cell count (SCC), milk yield, and various farm characteristics, with an emphasis on antibiotic usage at dry-off. The second study investigated whether the herd-level DCT practice was associated with cow-level udder health in early lactation. The third study determined cow-level milk yield and SCC differences within the first half of lactation between selectively DCT-treated and -untreated cows. Results show that herd-level selective-DCT strategy, even with a very moderate proportion of medicated cows, is no hindrance to maintenance of low herd-average SCC and good milk yield. Regardless of the farm’s DCT practice, average milk yield increased over time, while average SCC remained rather constant. However, the large variation between farms in average yield and SCC over DCT practices suggests the need for farm-specific protocols. The practice of treating all cows in a herd was associated with lower test-day SCC within early lactation compared with the selective-DCT practice. Moreover, a DCT-treated cow on a selective-DCT farm had lower SCC after calving than did an untreated cow. This indicates that DCT continues to be an effective mastitis control practice. Most selective-DCT farms administered DCT to only one-third of their cows, or less. The DCT effect on milk yield differed depending on late-lactation SCC, so that a higher SCC near dry-off led to an increased difference in yield between treated and untreated cows within the first half of lactation. A missed DCT for a high-SCC cow thus had an adverse effect on subsequent lactation milk yield and on SCC, highlighting the need for accurate selection of cows to be treated. Risk factors associated with higher post-calving SCC included high late-lactation SCC, lactational mastitis treatment, high parity, high preceding-lactation average SCC, and high milk yield near dry-off. Rising awareness of the selective-DCT approach currently is emerging in those countries where it is common to treat all cows at the end of lactation. The successful implementation of selective DCT on Finnish farms will hopefully encourage these countries to gradually reduce antibiotic use in dairy livestock. Such a development would perhaps have a positive effect on consumer confidence in the dairy industry. On Finnish dairy farms, rapid structural change in agriculture continues, and therefore maintaining the current low consumption of antibiotics requires optimal farm management, professional advice, and active monitoring.Umpikausi on lypsylehmän tulevan terveyden ja optimaalisen maidontuotannon kannalta kriittisen tärkeä tuotantokierron vaihe. Lehmät ovat kaikkein alttiimpia uusille utaretulehduksille heti umpeutuksen jälkeen ja juuri ennen poikimista. Lisäksi umpeutusvaihe on paras aika lääkitä jo olemassa olevia utaretulehduksia. Tämän vuoksi umpihoito antibioottia sisältävillä, utareen sisäisesti annosteltavilla lääkkeillä lypsykauden lopuksi on tehokas ja yleinen keino vähentää utaretulehduksen esiintyvyyttä. Umpihoito voidaan antaa karjan kaikille lehmille tai valikoidusti vain piilevää utaretulehdusta sairastaville lehmille. Maailmanlaajuisen antibioottiresistenssiongelman myötä on tarve vähentää antibioottien käyttöä kotieläinten hoidossa. Valikoidusti toteutettu umpihoito on vastuullisempi toimintatapa, mutta sen haasteena on umpihoitoa tarvitsevien lehmien tunnistaminen tarkasti ja kustannustehokkaasti. Tämän epidemiologisen tutkimuksen tavoitteena oli kartoittaa umpeutuskäytäntöjä, joilla saavutetaan hyvä utareterveys ja maidontuotanto vastuullisesti antibiootteja käyttäen. Tutkimuksen erityisen kiinnostuksen kohteena olivat lääkkeelliset umpihoidot. Lisäksi tutkimus kartoitti umpeutukseen liittyviä riskitekijöitä, jotka altistavat utareterveysongelmille sekä alentuneelle maidontuotannolle umpikauden jälkeen. Tutkimuksen aineisto koostui suomalaisten lypsykarjatilojen karja- ja lehmäkohtaisista tuotosseurantatiedoista. Ensimmäinen osatutkimus kartoitti umpihoitokäytäntöjen ja erilaisten tilaominaisuuksien yhteyksiä lypsykarjojen maidon keskisolulukuun ja keskituotokseen. Toinen osatutkimus selvitti tilojen umpihoitokäytäntöjen yhteyksiä lehmien alkulypsykauden utareterveyteen. Kolmas osatutkimus kartoitti valikoidusti umpilääkittyjen ja lääkitsemättömien lehmien välisiä eroja maitotuotoksessa ja soluluvussa seuraavan lypsykauden alkupuoliskolla. Tulokset osoittavat, että jopa hyvin maltillisella umpihoidettujen lehmien osuudella voidaan saavuttaa karjan hyvä utareterveys ja keskituotos. Riippumatta tilan umpihoitokäytännöstä, tarkasteltujen vuosien aikana maidon keskituotos nousi, ja maidon keskisoluluku pysyi melko muuttumattomana. Tilojen väliset erot keskituotoksessa ja -soluluvussa olivat suuria, mikä viittaa tilakohtaisten umpeutusohjeiden tarpeeseen. Verrattuna valikoivaan umpihoitokäytäntöön, karjan kaikkien lehmien lääkitseminen oli yhteydessä lehmien alhaisempaan solulukuun alkulypsykaudella. Tiloilla, jotka toteuttivat valikoivaa umpihoitokäytäntöä, poikimisen jälkeinen soluluku oli alhaisempi lääkityillä kuin lääkitsemättömillä lehmillä. Tämän perusteella umpihoito on edelleen tehokas utaretulehduksen torjuntakeino. Suurin osa valikoivasti hoitavista maidontuottajista lääkitsi enintään kolmanneksen lehmistään. Umpihoidon vaikutus tuotokseen vaihteli loppulypsykauden soluluvun mukaan. Loppulypsykaudella korkean soluluvun omaavan lehmän lääkitsemättä jättäminen vaikutti haitallisesti myöhempään maitotuotokseen ja utareterveyteen, mikä korostaa hoidettavien lehmien tarkan valinnan merkitystä. Umpeutukseen liittyviä utaretulehdusongelmien riskitekijöitä olivat loppulypsykauden korkea soluluku, aiemmin sairastettu ja lääkehoitoa vaatinut utaretulehdus, korkea ikä, edeltävän lypsykauden korkea keskisoluluku ja korkea päivämaitotuotos lähellä umpeutusta. Maissa, joissa on tavanomaista lääkitä kaikki lehmät lypsykauden lopuksi, tiedostetaan enenevässä määrin, että valikoiva hoito on vastuullisempi hoitokäytäntö. Toivottavasti suomalaisilla lypsykarjatiloilla onnistuneesti toteutettu valikoiva umpihoito toimii kannustavana esimerkkinä kansainvälisille pyrkimyksille vähentää antibioottien käyttöä. Maatalouden nopea rakennemuutos jatkuu suomalaisilla maitotiloilla, ja vallitsevan, vähäisen antibioottikulutuksen ylläpitäminen edellyttää ihanteellista maatilanhoitoa, ammattitaitoista neuvontaa ja aktiivista seurantaa

Selective dry cow therapy effect on milk yield and somatic cell count: A retrospective cohort study

Peer reviewe

Economic perspectives on blanket and selective dry cow therapy

Peer reviewe

Cortical Sequence of Word Perception in Beginning Readers

Efficient analysis of written words in normal reading is likely to reflect use of neural circuits formed by experience during childhood rather than an innate process. We investigated the cortical sequence of word perception in first-graders (7–8 years old), with special emphasis on occipitotemporal cortex in which, in adults, letter-string-sensitive responses are detected at 150 ms after stimulus. To identify neural activation that is sensitive to either the amount of basic visual features or specifically to letter strings, we recorded whole-head magnetoencephalography responses to words embedded in three different levels of noise and to symbol strings. As was shown previously in adults, activation reflecting stimulus nonspecific visual feature analysis was localized to occipital cortex in children. It was followed by letter-string-sensitive activation in the left occipitotemporal cortex and, subsequently, in the temporal cortex. These processing stages were correlated in timing and activation strength. Compared with adults, however, the timing of activation was clearly delayed in children, and the delay was progressively increased from occipital to occipitotemporal and further to temporal areas. This finding is likely to reflect increasing immaturity of the underlying neural generators when advancing from low-level visual analysis to higher-order areas involved in written word perception. When a salient occipitotemporal letter-string-sensitive activation was detected (10 of 18 children), its strength was correlated with phonological skills, in line with the known relevance of phonological awareness in reading acquisition.Peer reviewe

Dry cow therapy and early lactation udder health problems - Associations and risk factors

Mastitis remains the most expensive disease of dairy cows, and antibiotic dry cow therapy (DCT) at dry-off is an important part of mastitis control. Regardless of the infection status, blanket DCT is administered to all quarters of all cows, which is controversial due to the worldwide problem of antimicrobial resistance. Even though selective DCT of only infected cows is a more sustainable approach, choosing animals for treatment is not always straightforward. Our aim was to evaluate whether the herd-level DCT approach is associated with early lactation udder health problems, taking into account the cow characteristics. The information source was 2015?2017 Dairy Herd Improvement data with 7461 multiparous cows from 241 Finnish dairy herds. Information on the herd-level DCT approach was obtained from farmers? questionnaire responses in 2017, and the three different approaches were selective DCT, blanket DCT, and no DCT. The statistical tool for the data analysis was a generalized linear mixed model with a random herd effect for binary outcomes and a linear mixed model with a random herd effect for a continuous outcome. The two binary outcomes were the odds of having high milk somatic cell count (SCC ? 200 000 cells/mL) on the first test-day within 5?45 days in milk (DIM) and the odds of mastitis treatment in early lactation up to 45 DIM. The third outcome was the mean milk lnSCC (? 1000 cells/ mL) within 120 DIM. Selective DCT was the prevailing treatment practice in our data. Blanket DCT was associated with lower SCC after calving. Cows more likely to have high SCC after calving were older cows, cows with high average SCC during the previous lactation, and cows with high milk yield near dry-off. A mastitis treatment in the early lactation was more likely if, during the previous lactation, the cow had high average SCC, high peak milk production, or high milk yield near dry-off. Our findings indicate that DCT is still effective in mastitis control. Cows with high milk yield, especially near dry-off, and cows with persistently high SCC require attention when considering next lactation udder health.Mastitis remains the most expensive disease of dairy cows, and antibiotic dry cow therapy (DCT) at dry-off is an important part of mastitis control. Regardless of the infection status, blanket DCT is administered to all quarters of all cows, which is controversial due to the worldwide problem of antimicrobial resistance. Even though selective DCT of only infected cows is a more sustainable approach, choosing animals for treatment is not always straightforward. Our aim was to evaluate whether the herd-level DCT approach is associated with early lactation udder health problems, taking into account the cow characteristics. The information source was 2015?2017 Dairy Herd Improvement data with 7461 multiparous cows from 241 Finnish dairy herds. Information on the herd-level DCT approach was obtained from farmers? questionnaire responses in 2017, and the three different approaches were selective DCT, blanket DCT, and no DCT. The statistical tool for the data analysis was a generalized linear mixed model with a random herd effect for binary outcomes and a linear mixed model with a random herd effect for a continuous outcome. The two binary outcomes were the odds of having high milk somatic cell count (SCC ? 200 000 cells/mL) on the first test-day within 5?45 days in milk (DIM) and the odds of mastitis treatment in early lactation up to 45 DIM. The third outcome was the mean milk lnSCC (? 1000 cells/ mL) within 120 DIM. Selective DCT was the prevailing treatment practice in our data. Blanket DCT was associated with lower SCC after calving. Cows more likely to have high SCC after calving were older cows, cows with high average SCC during the previous lactation, and cows with high milk yield near dry-off. A mastitis treatment in the early lactation was more likely if, during the previous lactation, the cow had high average SCC, high peak milk production, or high milk yield near dry-off. Our findings indicate that DCT is still effective in mastitis control. Cows with high milk yield, especially near dry-off, and cows with persistently high SCC require attention when considering next lactation udder health.Peer reviewe

Warfarin dose requirement in patients having severe thrombosis or thrombophilia

Aims Warfarin dose requirement varies significantly. We compared the clinically established doses based on international normalized ratio (INR) among patients with severe thrombosis and/or thrombophilia with estimates from genetic dosing algorithms. Methods Fifty patients with severe thrombosis and/or thrombophilia requiring permanent anticoagulation, referred to the Helsinki University Hospital Coagulation Center, were screened for thrombophilias and genotyped for CYP2C9*2 (c.430C>T, rs1799853), CYP2C9*3 (c.1075A>C, rs1057910) and VKORC1 c.-1639G>A (rs9923231) variants. The warfarin maintenance doses (target INR 2.0-3.0 in 94%, 2.5-3.5 in 6%) were estimated by the Gage and the International Warfarin Pharmacogenetics Consortium (IWPC) algorithms. The individual warfarin maintenance dose was tailored, supplementing estimates with comprehensive clinical evaluation and INR data. Results Mean patient age was 47 years (range 20-76), and BMI 27 (SD 6), 68% being women. Forty-six (92%) had previous venous or arterial thrombosis, and 26 (52%) had a thrombophilia, with 22% having concurrent aspirin. A total of 40% carried the CYP2C9*2 or *3 allele and 54% carried the VKORC1-1639A allele. The daily mean maintenance dose of warfarin estimated by the Gage algorithm was 5.4 mg (95% CI 4.9-5.9 mg), and by the IWPC algorithm was 5.2 mg (95% CI 4.7-5.7 mg). The daily warfarin maintenance dose after clinical visits and follow-up was higher than the estimates, mean 6.9 mg (95% CI 5.6-8.2 mg, P <0.006), with highest dose in patients having multiple thrombophilic factors (P <0.03). Conclusions In severe thrombosis and/or thrombophilia, variation in thrombin generation and pharmacodynamics influences warfarin response. Pharmacogenetic dosing algorithms seem to underestimate dose requirement.Peer reviewe

Antibiotic dry cow therapy, somatic cell count, and milk production : Retrospective analysis of the associations in dairy herd recording data using multilevel growth models

Antibiotic dry cow therapy (DCT) is an important part of most mastitis control programs. Updating DCT recommendations is an ongoing topic due to the global problem of antimicrobial resistance. Finland, along with other Nordic countries, has implemented selective DCT for decades. Our study analyzed Dairy Herd Improvement (DHI) information from 241 Finnish farmers who participated in a survey about their drying-off practices. The aim was to evaluate herd-level associations between milk somatic cell count (SCC), milk production, and various antimicrobial DCT approaches both cross-sectionally in 2016 and longitudinally in 2012 - 2016. The three DCT approaches in the study were selective, blanket, and no DCT use. An additional aim was to evaluate whether dynamic changes occurred in herd-average SCC and annual milk production over five years, and whether these potential changes differed between different DCT approaches. The method for the longitudinal analyses was growth modeling with random coefficient models. Differences in SCC and milk production between farms with different DCT approaches were minor. Regardless of the farm's DCT approach, annual milk production increased over the years, while average SCC was reasonably constant. The variability in SCC and milk production across all DCT groups was low between years, and most of the variability was between farms. Compared to other milking systems, farms with automatic milking system (AMS) had higher SCC, and in 2016 higher milk production. The results of this study suggest that it is possible to maintain low herd-average SCC and good milk production when using selective DCT and following the guidelines for prudent antimicrobial use. Average SCC and milk production varied across the herds, suggesting that advice on DCT practices should be herd-specific. The methodology of growth modeling using random coefficient models was applicable in analyzing longitudinal data, in which the time frame was relatively short and the number of herds was limited.Peer reviewe

Assessing the risks and uncertainties of regional crop potential under a changing climate in Finland

Results are presented of a modelling study to estimate the regional suitability and potential productivity of selected crops in Finland under a changing climate. Model simulations were conducted across a regular 10 km grid over Finland for various cultivars of the following crops: spring wheat, barley, oats, potato and maize, and for two nematode pests and a fungal disease of potato. Models were run for both the present-day (1961-1990) climate and scenarios of future climate. Results are presented as maps. The main findings of the study are: (1) A warming of the climate induces shifts in the northern limit of cereal suitability of some 100-150 km per °C. (2) Changes in climate and carbon dioxide concentration by 2050 are estimated to enhance average grain yields of present-day barley cultivars in all regions. (3) Under projected warming, the potential distribution of nematode species expands northwards and additional generations of some species are likely. The risk of late blight occurrence increases in all regions. (4) By 2050 grain maize could be cultivated reliably in favourable regions of southern Finland, and satisfactory yields obtained. (5) Uncertainties surround all estimates, including uncertainties in projections of future climate, model errors and assumptions and observational errors

Assessing the risks and uncertainties of regional crop potential under a changing climate in Finland

Results are presented of a modelling study to estimate the regional suitability and potential productivity of selected crops in Finland under a changing climate. Model simulations were conducted across a regular 10 km grid over Finland for various cultivars of the following crops: spring wheat, barley, oats, potato and maize, and for two nematode pests and a fungal disease of potato. Models were run for both the present-day (1961-1990) climate and scenarios of future climate. Results are presented as maps. The main findings of the study are: (1) A warming of the climate induces shifts in the northern limit of cereal suitability of some 100-150 km per °C. (2) Changes in climate and carbon dioxide concentration by 2050 are estimated to enhance average grain yields of present-day barley cultivars in all regions. (3) Under projected warming, the potential distribution of nematode species expands northwards and additional generations of some species are likely. The risk of late blight occurrence increases in all regions. (4) By 2050 grain maize could be cultivated reliably in favourable regions of southern Finland, and satisfactory yields obtained. (5) Uncertainties surround all estimates, including uncertainties in projections of future climate, model errors and assumptions and observational errors