A randomized controlled trial assessing the effect of intermittent and abrupt cessation of milking to end lactation on the well-being and intramammary infection risk of dairy cows

The objectives were to compare the effects of an intermittent milking schedule with a thrice daily milking schedule during the final week of lactation on the well-being, udder health, milk production, and risk of culling of dairy cows. We hypothesized that cows subjected to an intermittent milking schedule would experience less udder engorgement and pain, lower concentrations of fecal glucocorticoid metabolites (11,17-dioxoandrostanes; 11,17-DOA concentration) after dry-off, lower risk of an intramammary infection during the dry period, higher milk production and lower somatic cell count in the subsequent lactation, and lower culling risk compared with herd mates milked 3 times daily and dried off by abrupt cessation. In a randomized controlled field study, Holstein cows (n = 398) with a thrice daily milking schedule were assigned to treatment and control groups. The treatment consisted of an intermittent milking schedule for 7 d before dry-off (gradual cessation of milking, GRAD). Gradual-cessation cows were milked once daily until the day of dry-off, whereas cows in the control group (abrupt cessation of milking, APT) were milked 3 times daily until the day of dry-off. Udder firmness and pain responses of the udder 3 d after dry-off, as well as the percentage change in fecal 11,17-DOA concentration (3 d after dry-off compared with the dry-off day), were used to assess the well-being of the animals. Compared with cows in the GRAD group, the odds [95% confidence interval (CI)] of udder firmness were 1.55 (0.99–2.42) for cows in the APT group, and the odds of a pain response were 1.48 (0.89–2.44) for cows in the APT group. The least squares means (95% CI) of the percentage change in 11,17-DOA concentration were 129.3% (111.1–150.4) for the APT group and 113.6% (97.5–132.4) for the GRAD group. Quarter-level culture results from the periods before dry-off and after calving were compared, to assess the likelihoods of microbiological cure and new infection. Cows in the APT group had lower odds of a new intramammary infection in the dry period [odds ratio, 95% CI: 0.63 (0.37–1.05)], whereas we observed no meaningful differences in the microbiological cure likelihood among groups. The least squares means (95% CI) for somatic cell counts (log10-transformed) were 4.9 (4.8–5.0) in the APT group and 4.9 (4.8–5.0) in the GRAD group. The odds (95% CI) of clinical mastitis in the first 30 d postcalving were 1.32 (0.53–3.30) in the APT group compared with the GRAD group. We observed no meaningful differences in milk production at the first test date postcalving or the culling risk among groups. We conclude that the gradual-cessation protocol tested herein failed to significantly improve animal well-being, udder health, milk production, and survival in the tested study cohort. However, the observed differences in udder firmness, as well as the numerical differences in udder pain and the percentage change in fecal 11,17-DOA concentrations suggest that this line of research may be useful. Future research is needed to develop drying-off strategies that are appropriate for lowering milk production at the end of the lactation and improve animal well-being without compromising udder health

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

Evaluation of Casein Hydrolysate as an Alternative Dry-Off Treatment and Milk Quality Management Tool in Dairy Cows

Mastitis, an infection of the mammary gland, is the most common and expensive animal health problem for the dairy industry and affects every dairy farm to some degree. This disease complex is painful for dairy cows, increases the on-farm use of antibiotics, presents a threat to milk quality and is a waste of time, money and milk production. Each year, the dairy industry loses as much as a billion dollars to mastitis. Many cows will experience mastitis at least once during a lactation cycle and some animals will develop recurring mastitis episodes in a single mammary quarter. These mastitic quarters can be difficult to manage during the lactation cycle. Cessation of production in the quarter while continuing to milk the other three can be a beneficial management decision in this scenario. However, the current methods available for cessation of lactation in a single quarter are limited. This study investigated the use of casein hydrolysate as a non-antibiotic option for causing cessation of lactation in a quarter. From this preliminary study we were able to apply our results to another aspect of mastitis prevention, which is the routine use of intramammary antibiotics at the end of the lactation cycle. This management practice is known as dry treatment and is a standard practice in the dairy industry with many years of proven efficacy against clearing infections present at the end of the lactation cycle. Increasing pressure from consumers to decrease antibiotic use in food production animals has caused this practice to come under scrutiny. This secondary study investigated the use of casein hydrolysates as a nonantibiotic alternative to standard antibiotic dry cow treatment. Overall, these studies demonstrated that casein hydrolysate has some efficacy in inducing mammary involution of a single quarter mid-lactation and also potentially as an alternative dry cow treatment. None of the animals treated in these studies displayed any symptoms of pain or discomfort, and all treated quarters resumed milk production after the next calving. Additionally, all antimicrobial milk tests on treated animals were negative. Casein hydrolysates may be a useful management tool for milk quality and animal health within the dairy industry

Efficacy of cabergoline in a double-blind randomized clinical trial on milk leakage reduction at drying-off and new intramammary infections across the dry period and postcalving

The abrupt cessation of milking at dry-off may induce milk leakage, which may increase the risk of new intramammary infections (IMI). This study assessed the efficacy of 1 i.m. injection of 5.6 mg of cabergoline (Velactis, Ceva Santé Animale, Libourne, France) at drying-off on milk leakage after dry-off and new IMI across the dry period and postcalving compared with a placebo (negative control) and an intramammary antibiotic treatment (positive control) under field conditions. The study was a double-blind, randomized, 3-arm, multicenter, clinical trial performed under Good Clinical Practice conditions. Data from 900 dairy cows of various breeds from 63 farms in France, Germany, and Hungary were analyzed. Only quarters with no bacterial growth at drying-off and a cow somatic cell count ≤200,000 cells/mL were included. Quarters infected with major or minor pathogens or cows with high somatic cell count at time of inclusion were excluded. Cows that qualified for the study were visited 7 times in total before and after drying-off and after calving. Presence (yes/no) of milk leakage was recorded on the day after dry-off. A new infected quarter (new IMI) was defined as one with a major pathogen present in any one of the 2 postcalving samples. Two mixed logistic regression models were fitted to the data to evaluate the efficacy of cabergoline in the reduction of milk leakage and new IMI. One i.m. injection of cabergoline at drying-off significantly reduced the incidence of milk leakage the day after dry-off compared with both placebo and antibiotic treatment. Cabergoline-treated cows significantly reduced the risk of new IMI by major pathogens across the dry period and postcalving by 21% when compared with placebo cows (20.5 vs. 26.0%, respectively). However, when milk leakage was added to the model, the significance of cabergoline was reduced. We interpreted this to show that milk leakage is an intervening variable between treatment with cabergoline and lower risk of new IMI. The antibiotic treatment significantly decreased the odds of new IMI compared with both cabergoline and placebo. However, because several countries are currently disallowing the preventive use of antibiotics at dry-off in noninfected quarters, the dry-off facilitator cabergoline may therefore be of particular value to reduce the risk of new IMI across the dry period

Identification of on-farm recorded data for the prediction of disease in dairy cattle

Identification of cows at increased disease risk during the transition period is necessary to reduce the negative economic impact of disease and to improve animal welfare. Although timely identification of at-risk cows is a vital component of health management, it is challenging in modern dairy herds, where staff manage an increasing number of cattle. The consequent reduction in time available for individual animal observation has created a need for the development of decision support tools which facilitate individual cow monitoring. However, uncertainty exists as to which measurable traits best reflect cow health status, especially in the dry and transition periods where little monitoring of individual cows is performed. Therefore, the objectives of this project were 1) to quantify the effect of early lactation disease on productivity 2) to identify variables of routinely recorded herd data which could be used for disease prediction or as risk factors for disease and 3) to assess the feasibility of using such indicators in predictive disease modelling. Retrospective analyses were performed on 482 cow-lactations from the Langhill herd of Holstein cattle. Cow-lactations were assigned to 1 of 4 health groups based on disease incidence in the first 30 days of lactation. These groups were no clinical disease (NCD; n = 335, reproductive (REP; n = 77) (which included cases of retained placenta and metritis), subclinical mastitis (SCM; n = 53) (determined by somatic cell counts) and metabolic (MET; n = 17) (which included cases of displaced abomasum, ketosis, hypomagnesaemia and hypocalcaemia). The data were analysed using descriptive statistics, mixed models, and generalised linear mixed models, with a logit link, in SAS 9.3 and GenStat 16. There were significant differences in average milk yield between health groups throughout lactation. In the first 30 days of lactation, NCD cows had significantly higher (p<0.01) daily milk yield than either REP, SCM or MET cows. Days to first observed heat and first service were significantly higher in MET cows than all other groups (p<0.01) and was extended by 27 days compared to NCD cows. No difference existed between services per conception or calving interval across all groups however the 100 day in-calf rate was reduced amongst cows with disease compared to cows without disease. Preceding disease, milk yield at dry-off and the ratio of energy corrected milk to body energy content were found to be significantly different between health groups; both measures were significantly higher in SCM cows compared to REP and MET cows. Additionally, in the first 15 days of the dry period preceding disease diagnoses, REP cows had a significantly (p=0.02) greater rate of change in body energy content than NCD cows; -18.3±7.44 MJ per day vs. 0.6±5.11 MJ per day, respectively. Overall change in body energy content between dry off and calving was significantly greater (p<0.001) in REP cows than both NCD and SCM cows. The predictive ability of candidate indicators identified as being significantly different between health groups was assessed using further statistical analysis. The distribution of each candidate indicator was investigated before Pearson and Spearman correlation tests were used to quantify the relationships between indicators. Single candidate models, employing generalised linear mixed modelling with random effect for cow, were used to test the effect of each candidate indicator on each response measure (health group). Dry period length, change in live weight and body energy content across the dry period, condition score and body energy content at dry off and the rate of change in body energy content in the first 15 days of lactation were significant predictors (p<0.05) of reproductive disorders while the year of calving and live weight at calving were significant predictors (p<0.05) of subclinical mastitis when included in single candidate models. Multivariate models for each of the disease response measures (REP, SCM and MET) were developed using combinations of the candidate indicators as explanatory variables. Despite some highly significant relationships between the candidate indicator variables and response measures, the multivariate models developed do not currently have potential to predict risk of disease at an acceptable level of accuracy, as very few significant effects were found. This can be explained by the large individual cow variance components and a low incidence of disease in the current data set. Future research should focus on tracking candidate indicator data in individual cows with a view to establishing a baseline for each cow. This would allow each cow to be used as its own control, with deviations from the normal indicating potential disease challenge. This study has demonstrated that early lactation disease has both short- and long-term effects on productivity. Further, routine measures of herd data including body weight and body condition score, recorded in the dry period have been shown to be significantly different between cows of different disease status in the subsequent lactation. This study has shown that disease in early lactation has serious consequences for the productivity of dairy cattle and has shown the potential for predicting the risk of disease in the transition period in dairy cows. However, further work is needed with larger datasets and in different herds to develop greater accuracy in prediction

Efficacy of cabergoline in a double-blind randomized clinical trial on milk leakage reduction at drying-off and new intramammary infections across the dry period and postcalving

The abrupt cessation of milking at dry-off may induce milk leakage, which may increase the risk of new intramammary infections (IMI). This study assessed the efficacy of 1 i.m. injection of 5.6 mg of cabergoline (Velactis, Ceva Santé Animale, Libourne, France) at drying-off on milk leakage after dry-off and new IMI across the dry period and postcalving compared with a placebo (negative control) and an intramammary antibiotic treatment (positive control) under field conditions. The study was a double-blind, randomized, 3-arm, multicenter, clinical trial performed under Good Clinical Practice conditions. Data from 900 dairy cows of various breeds from 63 farms in France, Germany, and Hungary were analyzed. Only quarters with no bacterial growth at drying-off and a cow somatic cell count ≤200,000 cells/mL were included. Quarters infected with major or minor pathogens or cows with high somatic cell count at time of inclusion were excluded. Cows that qualified for the study were visited 7 times in total before and after drying-off and after calving. Presence (yes/no) of milk leakage was recorded on the day after dry-off. A new infected quarter (new IMI) was defined as one with a major pathogen present in any one of the 2 postcalving samples. Two mixed logistic regression models were fitted to the data to evaluate the efficacy of cabergoline in the reduction of milk leakage and new IMI. One i.m. injection of cabergoline at drying-off significantly reduced the incidence of milk leakage the day after dry-off compared with both placebo and antibiotic treatment. Cabergoline-treated cows significantly reduced the risk of new IMI by major pathogens across the dry period and postcalving by 21% when compared with placebo cows (20.5 vs. 26.0%, respectively). However, when milk leakage was added to the model, the significance of cabergoline was reduced. We interpreted this to show that milk leakage is an intervening variable between treatment with cabergoline and lower risk of new IMI. The antibiotic treatment significantly decreased the odds of new IMI compared with both cabergoline and placebo. However, because several countries are currently disallowing the preventive use of antibiotics at dry-off in noninfected quarters, the dry-off facilitator cabergoline may therefore be of particular value to reduce the risk of new IMI across the dry period