Algometer Precision for Quantifying Mechanical Nociceptive Threshold When Applied to the Udder of Lactating Dairy Cows.

Objectives of this study were to: (1) quantify the reliability of an algometer for measuring mechanical nociceptive thresholds when applied to the udder of dairy cows; and (2) evaluate whether covariates, such as cow characteristics or time of the day, would influence algometer measurements. This prospective study was performed in a university herd of 37 lactating cows during five consecutive days, involving two raters. Two types of measurement were obtained: one qualitative binary measure (i.e., reaction vs. no reaction) and one quantitative measure presented in kilograms (i.e., mechanical nociceptive threshold, MNT) for the cows that reacted. Kappa statistics were used to investigate test-retest and inter-rater reliability for the qualitative measure, while concordance correlation coefficient (CCC) and limits of agreement plot were used for the quantitative measure. Whether algometer measurements were influenced by several covariates (i.e., time of the day, level of milk production, days in milk, and parity) was then evaluated using logistic or linear regression models, depending on the outcome. The algometer was moderately reliable; there was moderate test-retest reliability (Kappa = 0.53; CCC = 0.58) and inter-rater reliability (Kappa = 0.42; CCC = 0.54). The MNT varied substantially as a function of time of the day and parity. This is the first study reporting reliability of a pressure algometer for quantifying MNT and investigating covariates possibly affecting this measurement when applied to the udder of dairy cows. It is concluded that the use of an algometer for quantifying MNT on the udder is only moderately repeatable and is influenced by extraneous covariates. Its usage in research setting to quantify changes in sensitivity at the udder level should, therefore, be considered very cautiously or it should be further developed

A Conceptual Analysis

Johne’s disease (JD) is a chronic, production-limiting disease of ruminants. Control programs aiming to minimize the effects of the disease on the dairy industry have been launched in many countries, including Canada. Those programs commonly focus on strict hygiene and management improvement, often combined with various testing methods. Concurrently, organic dairy farming has been increasing in popularity. Because organic farming promotes traditional management practices, it has been proposed that organic dairy production regulations might interfere with implementation of JD control strategies. However, it is currently unclear how organic farming would change the risk for JD control. This review presents a brief introduction to organic dairy farming in Canada, JD, and the Canadian JD control programs. Subsequently, organic practices are described and hypotheses of their effects on JD transmission are developed. Empirical research is needed, not only to provide scientific evidence for organic producers, but also for smaller conventional farms employing organic-like management practices

Algometer Precision for Quantifying Mechanical Nociceptive Threshold When Applied to the Udder of Lactating Dairy Cows

Objectives of this study were to: (1) quantify the reliability of an algometer for measuring mechanical nociceptive thresholds when applied to the udder of dairy cows; and (2) evaluate whether covariates, such as cow characteristics or time of the day, would influence algometer measurements. This prospective study was performed in a university herd of 37 lactating cows during five consecutive days, involving two raters. Two types of measurement were obtained: one qualitative binary measure (i.e., reaction vs. no reaction) and one quantitative measure presented in kilograms (i.e., mechanical nociceptive threshold, MNT) for the cows that reacted. Kappa statistics were used to investigate test-retest and inter-rater reliability for the qualitative measure, while concordance correlation coefficient (CCC) and limits of agreement plot were used for the quantitative measure. Whether algometer measurements were influenced by several covariates (i.e., time of the day, level of milk production, days in milk, and parity) was then evaluated using logistic or linear regression models, depending on the outcome. The algometer was moderately reliable; there was moderate test-retest reliability (Kappa = 0.53; CCC = 0.58) and inter-rater reliability (Kappa = 0.42; CCC = 0.54). The MNT varied substantially as a function of time of the day and parity. This is the first study reporting reliability of a pressure algometer for quantifying MNT and investigating covariates possibly affecting this measurement when applied to the udder of dairy cows. It is concluded that the use of an algometer for quantifying MNT on the udder is only moderately repeatable and is influenced by extraneous covariates. Its usage in research setting to quantify changes in sensitivity at the udder level should, therefore, be considered very cautiously or it should be further developed

Incomplete Milking in Early Lactation Does Not Affect Dairy Cows Resting Behaviors: Results from a Randomized Controlled Trial.

The objective of this study was to investigate the effect of incomplete milking during the first 5 days of lactation on the resting behavior of commercial dairy cows. The hypothesis was that the elevated intramammary pressure resulting from milk retained in the udder in incompletely milked cows could lead to a change in lying behavior. This study was a randomized controlled trial in which cows from two farms were randomly allocated into a treatment (n = 18) or a control group (n = 14). Cows in the treatment group were milked incompletely (10-14 L/days) during the first 5 days of lactation, while cows in the control group were milked as usually done on farm. Resting behaviors were recorded with a data logger. Linear mixed models were used to quantify the effects of treatment group on three dependent variables measured between 2 and 14 days in milk: daily duration of lying time (h/d), lying bout frequency (bouts/day), and mean duration of lying bouts (min/bout). There was no significant effect of treatment on lying time. However, the effect of treatment on frequency of lying bouts and on mean lying bout duration varied by parity level. Incompletely milked cows in second parity had a higher number of lying bouts (11.9 vs. 9.2 bouts/day) and shorter mean lying bout duration (57.8 min/bout vs. 66.7 min) than control cows. In third parity or more, the opposite happened. Therefore, our results suggest that an incomplete milking may be slightly problematic for second parity cows and, possibly, slightly beneficial for older cows. Whether the differences observed resulted from a biologic process (discomfort due to the incomplete milking) or from random error will have to be determined by future research

Improved Care and Management through Increased Knowledge of Dairy Cattle Behavior

This information was presented at the 2011 Operations Managers Conference, organized by the PRO-DAIRY program in the College of Agriculture and Life Sciences at Cornell University. This conference provides an opportunity for people responsible for day to day activities to increase their management and operations skills while interacting with other managers. Softcover copies of the entire conference proceedings may be purchased at http://www.ansci.cornell.edu/dm/proceedings_orders.html or by calling (607) 255-4285

A New Perspective on Feeding Dairy Heifers: Promoting Good Health, Efficiency and Behavior

This information was presented at the 2012 Herd Health and Nutrition Conferences, organized by the PRO-DAIRY program in the College of Agriculture and Life Sciences at Cornell University. This conference provides an opportunity for dairy producers, veterinarians, feed industry representatives and agriservice personnel to increase their knowledge of current herd health and nutrition management techniques while interacting with other professionals. Full conference proceedings may be purchased online at http://www.ansci.cornell.edu/dm/proceedings_orders.html

The effects of feeding management and feed area design on dairy cattle behavior

There has been little in-depth research on measures of feeding behavior [i.e feeding behaviour] in dairy cattle and how management and housing influence these measures. Thus, the first study of this dissertation determined which objective measures of feeding behavior are most repeatable and sensitive to treatment differences. The remaining studies focussed [i.e. focused] on assessing how management and design of the feeding area affect the behavior of group-housed dairy cows. To determine which management practice has the greatest effect on stimulating cows to feed, two management practices, feed delivery and milking, were separated and changes in feeding behavior were monitored. The results indicated that the daily feeding pattern of group-housed dairy cows is primarily influenced by the timing of feed delivery. A follow-up study investigated the effects of changing the frequency of feed delivery on the behavior of lactating dairy cows. More frequent delivery of feed improved access to feed for all cows, particularly during peak feeding periods, and reduced the degree of feed sorting, which in turn could reduce the between-cow variation in the composition of feed consumed. The last two experiments determined the effects of feed area design on dairy cattle behavior. Changes in behavior were monitored when cows were provided with more feed bunk space than typically provided. Increased bunk space resulted in more space between cows and fewer aggressive interactions while feeding, allowing cows, especially subordinate ones, to increase their feeding activity. The final study of this dissertation determined if the addition of partitions (feed stalls) between adjacent cows would further limit competition at the feed bunk. The addition of feed stalls resulted in a further reduction in aggressive interactions and a further increase in feeding time compared to providing extra bunk space. This research clearly demonstrates that the provision of increased bunk space, particularly when combined with feed stalls, improves access to feed and reduces competition at the feed bunk, particularly for subordinate cows. These findings provide insight into how one can manage and design the feeding environment to increase access to feed, reduce competition at the feed bunk, and reduce the between-cow variation in the composition of feed consumed.Land and Food Systems, Faculty ofGraduat

Translactational associations of dry off management, milking activity, and somatic cell count in herds with automated milking systems

The objective of this study was to evaluate associations of dry off management factors, milking activity, and production data and somatic cell count prior to dry off and early in the subsequent lactation of cows milked by automated systems. Data were collected for 342 cows from 5 farms, for 2 milk tests prior to dry off and for the 2 milk tests post-calving. The results suggest that the post-calving milking performance of cows milked by automated systems may be more associated with individual cow traits than with their dry off management.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Does the Location of Concentrate Provision Affect Voluntary Visits, and Milk and Milk Component Yield for Cows in an Automated Milking System?

Eight Holstein cows were used in a cross-over design test whether concentrate allocation in an automated milking system (AMS) affects DMI and milk production. Cows were fed a high-energy partial mixed ration (HE-PMR) with 0.5 kg of AMS concentrate or a low-energy PMR (LE-PMR) with 5.0 kg of AMS concentrate. AMS concentrate intake was greater and PMR intake was reduced for LE-PMR than HE-PMR. Milk, fat, and protein yields were not affected by treatment. In a guided traffic flow barn, providing a PMR with greater energy density increases DMI, but has no effect on milk and milk component yield.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Synchronization of dairy cows does not limit the behavioral response to treatment in mixed treatment experimental designs

In many research studies, animals assigned to different treatments are housed adjacently or together in a group. One critique of these designs has been the potential role of behavioral facilitation and synchronization between animals on different treatments in mixed treatment groups (heterogeneous groups). To evaluate this, we compared the synchrony of feeding behavior between dairy cows housed in heterogeneous groups to cows exposed to the same treatment simultaneously (homogenous groups). Twenty-four cows were exposed to each of 2 treatments over 21 d in a replicated cross-over design. Treatments were two different schedules of timing of feed delivery: (A) feeding at milking time and (B) feeding halfway between milking times. For the last 7 d of each treatment period, feeding behavior was recorded electronically. Kappa coefficients were calculated for each animal within each group, as an estimate of agreement that any 2 cows within a group (i.e. each individual and each other cow in her group) would both be engaged in feeding activity for any hour of the day. The level of synchrony was similar for cows within homogenous groups (Kappa = 0.31 ± 0.030) compared to cows on the same treatment within heterogeneous groups (Kappa = 0.32 ± 0.037). Within heterogeneous groups, cows on the same treatment were nearly 50% more synchronized with each other than with those on the other treatment (Kappa = 0.22 ± 0.029). These results suggest that synchronization of feeding behavior does not restrict our ability to impose different treatments on individual cows within a group