Associations between body condition score, locomotion score, and sensor-based time budgets of dairy cattle during the dry period and early lactation.

Lameness, one of the most important disorders in the dairy industry, is related to postpartum diseases and has an effect on dairy cow welfare, leading to changes in cows' daily behavioral variables. This study quantified the effect of lameness on the daily time budget of dairy cows in the transition period. In total, 784 multiparous dairy cows from 8 commercial Dutch dairy farms were visually scored on their locomotion (score of 1-5) and body condition (score of 1-5). Each cow was scored in the early and late dry period as well as in wk 4 and 8 postpartum. Cows with locomotion scores 1 and 2 were grouped together as nonlame, cows with score 3 were considered moderately lame, and cows with scores 4 and 5 were grouped together as severely lame. Cows were equipped with 2 types of sensors that measured behavioral parameters. The leg sensor provided number of steps, number of stand-ups (moving from lying to standing), lying time, number of lying bouts, and lying bout length. The neck sensor provided eating time, number of eating bouts, eating bout length, rumination time, number of rumination bouts, and rumination bout length. Sensor data for each behavioral parameter were averaged between 2 d before and 2 d after locomotion scoring. The percentage of nonlame cows decreased from 63% in the early dry period to 46% at 8 wk in lactation; this decrease was more severe for cows with higher parity. Cows that calved in autumn had the highest odds for lameness. Body condition score loss of >0.75 point in early lactation was associated with lameness in wk 4 postpartum. Moderately lame cows had a reduction of daily eating time of around 20 min, whereas severely lame cows had a reduction of almost 40 min. Similarly, moderately and severely lame dry cows showed a reduction of 200 steps/d, and severely lame cows in lactation showed a reduction of 600 steps/d. Daily lying time increased by 26 min and lying bout length increased by 8 min in severely lame cows compared with nonlame cows. These results indicate a high prevalence of lameness on Dutch dairy farms, with an increase in higher locomotion scores from the dry period into early lactation. Time budgets for multiparous dairy cows differed between the dry period and the lactating period, with a higher locomotion score (increased lameness) having an effect on cows' complete behavioral profile. Body condition score loss in early lactation was associated with poor locomotion postpartum, whereas lameness resulted in less eating time in the dry period and early lactation, creating a harmful cycle.

Sensor based eating time variables of dairy cows in the transition period related to the time to first service.

In dairy cattle, reproductive diseases and infertility are some of the most important reasons for culling, where postpartum negative energy balance (NEB) reduces reproductive performance. This single cohort observational study reports the association between eating time and the interval between calving and first service in 2036 dairy cows on 17 commercial farms in The Netherlands. Cows were equipped with a commercially available neck sensor (Nedap, Groenlo, The Netherlands), that measured the time cows spent eating, from 28 days (d) before until 28 d after parturition. Primiparous cows spent a mean of +45 minutes (min) eating time per day ante partum and +15 min eating time post partum more than multiparous cows. A Cox proportional hazard model was used to analyze eating time variables in relation to the interval between calving and first service. From 4 weeks before until 4 weeks after calving eating time variables per week were used. Weeks -4, -3 + 3 and +4 were used as weeks with stable eating time patterns and therefore the mean eating time per week and the standard deviation of the mean eating time per week were used. Weeks -2, -1, +1 and +2 were addressed as periods with unstable eating patterns and therefore the slope in eating time per week and the residual variance of the slope per week were modeled. Significant results were the mean eating time in week -4 and +3 where in both weeks higher eating time lead to a higher hazard for first service. Difference between primiparous and multiparous cows were also significant with a higher hazard for first service for primiparous cows. Week 4 post partum presented a significant difference between eating time of primiparous cows and multiparous cows. These results display how eating time variables in the transition period could be related to the interval between calving and first service, and that there is a relation between mean eating time in week -4, +3, +4 and the interval between calving and first insemination.

The validity of a monitoring system based on routinely collected dairy cattle health data relative to a standardized herd check.

Dairy cattle health is often assessed during farm visits. However, farm visits are time consuming and cattle health is assessed at only one point in time. Moreover, farm visits are poorly comparable and/or repeatable when inspection is carried out by many different professionals. Many countries register cattle health parameters such as bulk milk somatic cell count (BMSCC) and mortality in central databases. A great advantage of such routinely available data is that they are uniformly gathered and registered throughout time. This makes comparison between dairy cattle herds possible and could result in opportunities to develop reliable tools for assessing cattle health based on routinely available data. In 2005, a monitoring system for the assessment of cattle health in Dutch dairy herds based on routinely available data was developed. This system had to serve as an alternative for the compulsory quarterly farm visits, which were implemented in 2002. However, before implementation of the alternative system for dairy cows, the validity of the data-based monitoring system and the compulsory quarterly visits relative to the real health status of the herd should be known. The aim of this study was to assess the validity of the data-based monitoring system and the compulsory quarterly visits relative to a standardized herd check for detecting dairy herds with health problems. The results showed that routinely available data can be used to develop an effective screening instrument for detecting herds with poor cattle health. Routinely available data such as cattle mortality and BMSCC that were used in this study had a significant association with animal-based measurements such as the general health impression of the dairy cows (including e.g. rumen fill and body condition). Our study supports the view that cattle health parameters based on routinely available data can serve as a tool for detecting herds with a poor cattle health status which can reduce the number of expensive farm visits. Veterinarians and other herd health advisors could use this tool to target visits to those farms that are identified as at risk for poor cattle health. The development of similar tools in other countries seems possible because many countries have similar data in central databases.

Financial aspects of veterinary herd health management programmes.

Veterinary herd health management (VHHM) programmes have been shown to be economically effective in the past. However, no current information is available on costs and benefits of these programmes. This study compared economics and farm performance between participants and non-participants in VHHM programmes in 1013 dairy farms with over 40 cows. Milk Production Registration (MPR) data and a questionnaire concerning VHHM were used. Based on the level of participation in VHHM (as indicated in the questionnaire), costs of the programmes were calculated using a normative model. The economic value of the production effects was similarly calculated using normative modelling based on MPR data. Participants in VHHM had a better performance with regard to production, but not with regard to reproduction. Over 90 per cent of the VHHM participants were visited at least once every six weeks and most participants discussed at least three topics. In most farms, the veterinarian did the pregnancy checks as part of the VHHM programmes. There was a benefit to cost ratio of about five per cow per year for VHHM participants, and a mean difference in net returns of €30 per cow per year after adjusting for the cost of the programme. This portrays that participation in a VHHM programme is cost-efficient. There is, however, much unexplained variation in the net returns, possibly due to diverse approaches by veterinarians towards VHHM or by other factors not included in this analysis, like nutritional quality or management abilities of the farmer.

Short communication: prevalence, risk factors, and a field scoring system for udder cleft dermatitis in Dutch dairy herds.

Udder cleft dermatitis (UCD) is a well-known disorder in dairy cows. Veterinary literature about this subject, however, is scarce. The objectives of this study were to define a clinical scoring system for UCD, estimate the within-herd prevalence of UCD, and identify potential risk factors of UCD at cow and herd level. On 20 randomly selected dairy farms in the Netherlands, each lactating cow was photographed from a ventral, lateral, and caudal position. A scoring system with 6 categories of severity of UCD was proposed based on the ventral photographs. Cow measures such as udder width and depth, and front quarter attachment were determined from the lateral and caudal photographs. A questionnaire was conducted on each farm during farm visits. Udder cleft dermatitis, defined as a score 3 or higher, was detected in 5.2% of the 948 cows involved in this study. Within-herd prevalences of UCD ranged between 0 and 15% and UCD was found in 16 (80%) of the participating farms. Cows with a deep udder (relative to the hock), large front quarters, and a small angle between udder and abdominal wall were more likely to develop UCD. Production level and use of a footbath were identified as being positively associated with herd-level UCD prevalence. Herd size and average bulk milk somatic cell count did not seem to be associated with UCD prevalence. Because of the small herd sample size, no firm conclusions were drawn on herd-level risk factors. However, results from this study can be used in designing a future longitudinal UCD study. The prevalences of UCD found in the present study illustrate the current UCD situation in the Netherlands. Our results demonstrate that multiple potential risk factors of UCD could be identified at both the cow and herd level.

Subacute ruminal acidosis in Dutch dairy herds.

The prevalence of subacute ruminal acidosis (SARA) was determined in 197 dairy cows in 18 herds in the Dutch province of Friesland. Samples of rumen fluid were taken by rumenocentesis from between five and 19 animals on each farm and the pH of each sample was determined. The body condition of 139 of the cows was scored approximately three weeks before they calved and three weeks after they calved. The overall prevalence of SARA was 13.8 per cent, and the prevalence on individual farms ranged between 0 per cent (on seven of the farms) and 38 per cent (on one farm). The stage of lactation did not influence the prevalence of SARA but the cows with the condition lost more body condition over the calving period.

Influence of negative energy balance on the reproductive performance after treatment of cystic ovarian disease with gonadotrophin-releasing hormone in dairy cows.

The aim of this study was to investigate whether a significant relation exists between the presence of a negative energy balance (NEB) in cows early in lactation and the reproductive performance after treatment with gonadotrophin-releasing hormone of cows with clinical cystic ovarian disease. Reproductive performance after treatment was assessed from the interval between treatment and first insemination (ITFI) and the interval between treatment and conception (ITC). Based on the outcome of the daily change of milk fat yield (Deltafatg) between the first and second milk recordings post-partum, cows were considered to have passed the NEB nadir (positive Deltafatg) or not (negative Deltafatg). Lactations (n = 430) were divided into four groups according to the interval between calving and first milk recording (ICMR): (i) 0-9 days; (ii) 10-19 days; (iii) 20-29 days; (iv) 30-49 days. The relation between a NEB-proxy parameter (Deltafatg) and reproductive performance was determined. A significant interaction existed for groups 1 and 3 (ICMR on 0-9 and 20-29 days post-partum respectively) with an increased and a decreased probability of being inseminated the first day after treatment (ITFI) respectively. However, no significant interaction was found between Deltafatg and the groups with regard to ITC.

Rumenocentesis (rumen puncture): a viable instrument in herd health diagnosis.

The use of rumenocentesis as a tool in veterinary practice is to be evaluated; this publication describes the technique and reports results of a field study. From 164 dairy cows samples of ruminal fluid have been collected by means of rumenocentesis. In order to compare reaction of the individuals towards rumenocentesis, reaction has been scored on a five-point scale. In the period after rumenocentesis, the animals were observed and examined clinically in case of any pathologic alteration. To test a possible pain-reducing treatment, two study groups received local anaesthesia, while a third group had been sampled without. About 50% of all animals examined did not show resistance during rumenocentesis, while the rest of the population reacted at different levels. In four animals ruminal fluid sampling was not carried out due too heavy resistance, while six samples showed visible contamination with blood. Local anaesthesia with 2 ml of 2 % lidocaine s. c. and i. m. had influence on reaction of the individual samples, but did not have effect on sample size collected and pathologic alterations post punctionem. In total, 5.5 % of the study population showed alterations at the puncture site as haematomas and abscess forming; in three individuals the general health status was impaired after collection. The authors consider rumenocentesis a viable diagnostic procedure in bovine health diagnostics.

Subacute ruminal acidosis (SARA): a review.

Subacute ruminal acidosis (SARA) is likely to arise when an easily palatable, high-energy diet meets a ruminal environment not adapted to this type of substrate. Increase of short-chained fatty acids (SCFA) will occur. Eventually, this may result in a transient nadir of ruminal pH below 5.5. Two situations are likely to represent the risk of SARA. First, fresh lactating cows are confronted with a diet considerably differing from that in the dry-period. A diet change carried out too rapidly or without proper transition management will put the animals at risk. Secondly, further in lactation, inaccurate calculation of dry-matter-intake (DMI) leading to wrong roughage/concentrate ratio, an inadequate content of structure within the diet or mistakes in preparing of total mixed rations may produce SARA. The consequences of SARA are diverse and complex. Laminitis is regularly connected to SARA and the negative impact of organic acids on the ruminal wall may lead to parakeratosis enabling translocation of pathogens into the bloodstream provoking inflammation and abscessation throughout the ruminant body. Moreover, milk-fat depression (MFD) can be related to SARA. In order to achieve a proper diagnosis, SARA has to be understood as a herd-management problem. A screening of the herd for SARA by means of a rumenocentesis, performed on a sample-group, preferably 12 individuals, may reveal the presence of SARA. The herd screening should include the risk group suspected, preferably. The prevention of SARA applies to the principles of ruminant feeding. Careful transition management from the dry to the lactation period and control of fibre-content and ration quality should be more yielding than the use of buffers or antibiotic drugs.

Fertility parameters of dairy cows with cystic ovarian disease after treatment with gonadotrophin-releasing hormone.

Fertility data were collected every four weeks for 10 years from 40 herds of Holstein-Friesian dairy cattle. The data collected during 925 lactations from cows with cystic ovarian disease which were treated with 500 microg gonadorelin were compared with data from a control group of 13,869 normal lactations. The intervals between parturition and first insemination and between parturition and conception were significantly shorter (P<0.001) in the normal cows, but the interval between first insemination and conception was not. The overall conception rate tended to be higher (P<0.10) in the normal cows, but the conception rate after the first insemination was significantly higher (P<0.001) and the number of services per conception was significantly lower (P=0.008) in the normal cows.

Genetic parameters for cystic ovarian disease in dutch black and white dairy cattle.

Cystic ovarian disease (COD) is one of the most frequently diagnosed gynecological findings in dairy cattle. It causes temporary infertility and is likely to affect reproduction as well as production parameters in cows. The objectives of this study were to investigate the heritability of COD in a Dutch Black and White population and to estimate the genetic and phenotypic relationships with milk production traits. In the data set used, the overall incidence of COD was 7.7% (1204 COD diagnoses in 15,562 lactations). The farm incidence varied between 1.9 and 11.3%. The estimated heritabilities on the underlying and observable scales were 0.102 and 0.087, respectively. The genetic correlations between COD and 305-d milk, fat, and protein yields were 0.345, 0.379, and 0.441, respectively. We concluded that a genetic predisposition for COD exists in Dutch Black and White dairy cattle. The genetic correlations between COD and yield traits indicate that ongoing selection for production will increase the incidence of COD.

Treatment of cystic ovarian disease in dairy cows with gonadotrophin-releasing hormone: a field study.

In a field trial in the Netherlands 765 dairy cows were treated during 869 lactations with 500 micrograms gonadotrophin-releasing hormone (gonadorelin i.m.) for cystic ovarian disease (COD) between June 1987 and April 1996. COD was defined as the presence of a large follicle (> 2.5 cm) on one or both of the ovaries in the absence of a corpus luteum. Two treatment groups were formed, based on the interval from parturition to first treatment, with day 60 being the cut-off between groups 1 and 2. The aim of this study is to examine whether there is a relationship between the moment of diagnosis and treatment (before or after day 60 post partum) and its result. In group 1 90.0% of first treatments were effective and in group 2 93.3% (p = 0.08). This was reflected by the slightly higher number of treatments needed for animals in group 1 (1.11 versus 1.07, p = 0.08). The efficacy rate after one treatment did not significantly differ between the groups (1.63 versus 1.69, p = 0.40) and nor did the interval between 1st insemination after treatment and conception (p < 0.63). In conclusion, it can be stated that gonadorelin is effective as therapy irrespective of the timing of diagnosis and treatment.