Cassandra Tucker

Dr. Cassandra Tucker

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Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2008 in Applied Animal Behaviour Science
Verified
Journal Article
Closed access
CTCassandra Tucker
Cassandra Tucker
ARAndrea R. Rogers
Andrea R. Rogers
KSKarin E. Schütz
Karin E. Schütz

1 November 2010 in Journal of Dairy Science
Verified
Journal Article
Open access
PDF file
DLD.N. Ledgerwood
D.N. Ledgerwood
CWC. Winckler
C. Winckler
CTCassandra Tucker
Cassandra Tucker
Lying behavior in dairy cattle can provide insight into how cows interact with their environment. Although lying behavior is a useful indicator of cow comfort, it can be time consuming to measure. In response to these time constraints, using data loggers to automate behavioral recording has become increasingly common. We tested the accuracy of the Onset Pendant G data logger (Onset Computer Corporation, Bourne, MA) for measuring lying behavior in dairy cattle (n=24 cows; 12 in each of 2 experiments). Cows wore the logger on the lateral (experiment 1) or medial (experiment 2) side of the hind leg above the metatarsophalangeal joint. Loggers recorded behavior at 4 sampling intervals (6, 30, 60, and 300 s) for at least 1.5 d. Data were smoothed using 3 editing methods to examine the effects of short, potentially erroneous readings. For this purpose, Microsoft Excel macros (Microsoft Corp., Redmond, WA) converted readings (i.e., lying events bordered by standing or vice versa) occurring singly or in consecutive runs of ≤2 or ≤6. Behavior was simultaneously recorded with digital video equipment. The logger accurately measured lying and standing. For example, predictability, sensitivity, and specificity were >99% using 30-s sampling and the single-event filter compared with continuously scored video recordings. The 6- and 30-s sampling intervals were comparable for all aspects of lying behavior when short events were filtered from the data set. Estimates of lying time generated from the 300-s interval unfiltered regimen were positively related (R(2) ≥ 0.99) to estimates of lying time from video, but this sampling regimen overestimated the number of lying bouts. This is likely because short standing and lying bouts were missed (12 and 34% of lying and standing bouts were <300 s in experiment 1 and 2, respectively). In summary, the data logger accurately measured all aspects of lying behavior when the sampling interval was ≤30 s and when short readings of lying and standing were filtered from the data set.

1 January 2021 in Journal of Dairy Science
Verified
Journal Article
Open access
CTCassandra Tucker
Cassandra Tucker
MJMargit Bak Jensen
Margit Bak Jensen
APAnne Marie de Passillé
Anne Marie de Passillé
LHLaura Hänninen
Laura Hänninen
JRJeffrey Rushen
Jeffrey Rushen
Adequate time lying down is often considered an important aspect of dairy cow welfare. We examine what is known about cows' motivation to lie down and the consequences for health and other indicators of biological function when this behavior is thwarted. We review the environmental and animal-based factors that affect lying time in the context of animal welfare. Our objective is to review the research into the time that dairy cows spend lying down and to critically examine the evidence for the link with animal welfare. Cows can be highly motivated to lie down. They show rebound lying behavior after periods of forced standing and will sacrifice other activities, such as feeding, to lie down for an adequate amount of time. They will work, by pushing levers or weighted gates, to lie down and show possible indicators of frustration when lying behavior is thwarted. Some evidence suggests that risk of lameness is increased in environments that provide unfavorable conditions for cows to lie down and where cows are forced to stand. Lameness itself can result in longer lying times, whereas mastitis reduces it. Cow-based factors such as reproductive status, age, and milk production influence lying time, but the welfare implications of these differences are unknown. Lower lying times are reported in pasture-based systems, dry lots, and bedded packs (9 h/d) compared with tiestalls and freestalls (10 to 12 h/d) in cross-farm research. Unfavorable conditions, including too few lying stalls for the number of cows, hard or wet lying surfaces, inadequate bedding, stalls that are too small or poorly designed, heat, and rain all reduce lying time. Time constraints, such as feeding or milking, can influence lying time. However, more information is needed about the implications of mediating factors such as the effect of the standing surface (concrete, pasture, or other surfaces) and cow behavior while standing (e.g., being restrained, walking, grazing) to understand the effect of low lying times on animal welfare. Many factors contribute to the difficulty of finding a valid threshold for daily lying time to use in the assessment of animal welfare. Although higher lying times often correspond with cow comfort, and lower lying times are seen in unfavorable conditions, exceptions occur, namely when cows lie down for longer because of disease or when they spend more time standing because of estrus or parturition, or to engage in other behaviors. In conclusion, lying behavior is important to dairy cattle, but caution and a full understanding of the context and the character of the animals in question is needed before drawing firm conclusions about animal welfare from measures of lying time.

1 July 2007 in Journal of Dairy Science
Verified
Journal Article
Closed access
JFJ.A. Fregonesi
J.A. Fregonesi
CTCassandra Tucker
Cassandra Tucker
DWDaniel Weary
Daniel Weary
Our objective was to understand the effect of overstocking on the lying and standing behavior of dairy cattle. We manipulated freestall availability by providing 12, 11, 10, 9, or 8 freestalls to 12 cows (n = 4 groups, 12 cows/group), thus creating stocking levels of 100, 109, 120, 133, and 150%, respectively. Treatments were applied for a week at a time in a switchback design. Each group returned to the 100% stocking level after exposure to the other treatments. In addition to lying and standing behavior, we measured each cow's ability to displace others from the freestall to understand the interaction between social status and response to overstocking. When groups of cows had fewer stalls available, they spent less time lying down. There was no effect of overstocking on time spent standing with only the front legs in the stall. Instead, cows compensated for the reduced lying times by spending more time outside of the stall. When fewer stalls were available, animals were more likely to be displaced from stalls. The cow's ability to displace others from the stalls, however, did not explain the magnitude of their reduction in lying time when provided with fewer freestalls. Due to increased competition for stalls, cows lay down sooner at 150% than at the 100% level. Stall use was more uniform across time and across stalls within the pen when fewer freestalls were available. In conclusion, when cows had access to fewer freestalls, there was increased competition for stalls, increased time standing outside the stalls, and reduced lying time.

1 January 2010 in Journal of Dairy Science
Verified
Journal Article
Closed access
KSK.E. Schütz
K.E. Schütz
ARA.R. Rogers
A.R. Rogers
YPY.A. Poulouin
Y.A. Poulouin
NCN.R. Cox
N.R. Cox
CTCassandra Tucker
Cassandra Tucker
The objective was to understand how the amount of shade (shade cloth blocking 99% of solar radiation) influenced the behavior and physiology of Holstein-Friesian dairy cattle managed on pasture. We compared behavior, body temperature, and respiration rate of cattle provided with 1 of 3 treatments for 5 d: access to 2.4m(2) or 9.6m(2) shade/cow, or no shade (n=4 groups/treatment, 10 animals/group). Behavioral observations were carried out between 1000 and 1550h. Cows spent more than twice as much time in the larger shade (24 vs. 50% of observations for 2.4m(2) and 9.6m(2) shade/cow, respectively, SED: 1.7%) and engaged in fewer aggressive interactions when more shade was provided (10.7 vs. 3.2 aggressive interactions/m(2) during 5.8h of observation for 2.4m(2) and 9.6m(2) shade/cow, respectively, SED: 3.16 interactions/m(2)). Time around the water trough increased when little or no shade was provided (11, 5, and 2% of observations within 4.5m of water trough for no shade, 2.4m(2), and 9.6m(2) shade/cow, SED: 2.4%). Respiration rate was higher when cows had less shade available (62, 57, and 51 breaths/min for no shade, 2.4m(2), and 9.6m(2) shade/cow, respectively, SED: 2.1 breaths/min). All cows used the shade more when 9.6m(2) shade/cow was provided; simultaneous use was observed in 15 versus 0% of observations in the 9.6m(2) and 2.4m(2) treatments on the warmest day, respectively. Weather conditions influenced both the behavioral and physiological responses, and these changes were more pronounced when less or no shade was available. Cows spent more time in shade and less time lying with increasing heat load. In addition, aggressive interactions in the shade, time around the water trough, mean body temperature, and respiration rate increased with environmental heat load. Our findings highlight the importance of determining and providing an effective amount of shade to cattle.

1 February 2003 in Journal of Dairy Science
Verified
Journal Article
Closed access
CTCassandra Tucker
Cassandra Tucker
DWDaniel Weary
Daniel Weary
DFD. Fraser
D. Fraser
One important criterion in choosing appropriate housing systems for dairy cattle is that the freestall provides a comfortable surface for the cow. This paper describes two experiments testing the effects of commonly used lying surfaces on stall preference and stall usage by Holstein cows. In both experiments, 12 cows were housed individually in separate pens. Each pen contained three free stalls with a different surface: deep-bedded sawdust, deep-bedded sand, and a geotextile mattress covered with 2 to 3 cm of sawdust. The animals were restricted to each surface in turn, in a random order for either 2 (Experiment 1) or 3 d (Experiment 2). Both before and after this restriction phase, the animals were allowed access to all three surfaces, and preference was determined, based on lying times. Of the 12 cows used in Experiment 1, 10 preferred sawdust before and nine after the restriction phase. During the restriction phase, average lying times and number of lying events during the restriction phase were significantly lower for the sand-bedded stalls (P < or = 0.05), and standing times were higher on mattresses (P < or = 0.05), compared with sawdust. Although these cows had some experience with all three surfaces during the experiment, they had been housed in sawdust-bedded stalls during their previous lactation. Cows used in Experiment 2 had spent their previous lactation in sand bedded stalls. In this experiment, about half the cows preferred sand and half sawdust, after the restriction phase. During the restriction phase of experiment, lying times and number of lying events were lower, and standing times were higher when the animals were restricted to the mattresses compared to either sand or sawdust (P < or = 0.05). These results indicate that (1) free stall surface can affect both stall preferences and stall usage, and (2) mattresses are less preferred.