A review of the effects of different marking and tagging techniques on marine mammals

Wildlife research often requires marking and tagging animals to collect data on survival, reproduction, movement, behaviour and physiology. Identification of individual marine mammals can be carried out using tags, brands, paint, dye, photogrammetry, telemetry and other techniques. An analysis of peer-reviewed articles published from January 1980 to April 2011 addressing the effects of marking revealed a preponderance of studies focussed on short-term effects such as injuries and behavioural changes. Some marking techniques were reported to cause pain and to change swimming and haul-out behaviour, maternal attendance, and duration of foraging trips. However, marking has typically not been found to affect survival. No published research has addressed other possible long-term effects of marking related to injuries or pain responses. Studies of the more immediate effects of marking (mostly related to externally attached devices such as radio-transmitters) have shown a variety of different types and magnitudes of responses. It is important to note that studies failing to find treament differences are less likely to be published, meaning that the present and any other reviews based on published literature may be a biased sample of all research conducted on the topic. Publishing results that found no or low impacts (i.e. best practices) as well as those that found significant impacts on animals should both be encouraged. Future research under more controlled conditions is required to document acute effects of marking, including injury and pain, and to better understand longer-term effects on health, reproduction and survival. We recommend that studies using marked animals standardise their reports, with added detail on methodology, monitoring and sampling design, and address practices used to minimise the impact of marking on marine mammals.

Hay intake improves performance and rumen development of calves fed higher quantities of milk

Research to date has suggested that access to forage before weaning can limit rumen development in calves, but no research has yet addressed the role of forage for calves fed higher quantities of milk. This study compared performance and rumen development of calves provided high volumes (equivalent to approximately 20% of calf birth weight) of milk with and without access to hay. At d 3 of age, individually housed calves were randomly assigned to treatment (either ad libitum access to chopped grass hay or no forage; n=15 calves per treatment, 10 heifers, and 5 bulls). All calves were provided ad libitum access to water and starter throughout the study. All calves were offered 8L of milk/d from a nipple bottle from d 3 to 35, 4 L/d from d 36 to 53, and 2L/d until weaning at d 56. Solid feed intake and growth parameters were monitored from d 3 to 70. At d 70, males from both treatments were slaughtered to measure rumen development parameters. Overall dry matter (DM) intake from solid feed did not differ between treatments before wk 5. However, during wk 6 to 10, calves fed forage consumed more total DM (starter plus hay) than did calves fed no forage. Hip and wither height, heart girth, and body barrel at d 3, 56, and 70 did not differ between treatments. Reticulorumen weight was heavier in calves fed hay versus those fed only starter (12.77±1.29 vs. 7.99±0.69 kg with digesta; 1.89±0.05 vs.1.60±0.09 kg without digesta). Body weight without digesta was similar in calves fed forage or no forage. Mean rumen pH was higher in calves fed hay compared with those fed no forage (5.49±0.08 vs. 5.06±0.04). In conclusion, provision of chopped hay to calves fed high volumes of milk can promote solid feed DM intake and rumen development without affecting BW gain.

Effects of hot-iron branding on heart rate, breathing rate and behaviour of anaesthetised Steller sea lions

This study assessed the heart rate, breathing rate and behavioural responses of 12 juvenile Steller sea lions during hot-iron branding under isoflurane anaesthesia. Physiological and behavioural measures were recorded in four periods: baseline (five minutes), sham branding (one minute), branding (approximately 2.7 minutes) and postbranding (five minutes). No difference in heart rate was noted from baseline to sham branding, but heart rate increased from mean (sem) 78.3 (2.4) bpm in the baseline period to 85.6 (2.5) bpm in the branding period. Heart rate remained elevated in the postbranding period, averaging 84.7 (2.5) bpm. Breathing rate averaged 2.5 (1.0) breaths/minute in the baseline and sham branding periods increased to 8.9 (1.0) breaths/minute during branding, but returned to baseline by the postbranding period. Behaviourally, half of the sea lions exhibited trembling and head and shoulder movements during branding.

Tail docking dairy cattle: responses from an online engagement

Tail docking remains a common practice on dairy farms in the United States. This paper describes the results of an online engagement designed to create discussion on tail docking, to document the reasons participants put forward for and against the practice, and to compare these reasons with the literature available on this topic. A total of 178 people responded; 30% were producers, 23% were veterinarians, 25% had no experience with the dairy industry, and 22% included a mixture of teachers, students, and industry professionals. Approximately 79% of participants were opposed to docking. Responses varied with participant demographics (e.g., females were more likely than males to oppose docking), but in every demographic subgroup (e.g., by sex, age, country of origin, and dairy production experience), the majority of respondents were opposed to tail docking. Common reasons for opposition to docking included the lack of scientific evidence that docking improves cleanliness or udder health, that docking is painful for cows, that docking is unnatural, and that tails are important for controlling flies. Some respondents in favor of docking cited cow cleanliness as an issue, despite the scientific evidence showing no positive effect of docking on cow cleanliness or udder health. Additional reasons included protecting producer safety. These results illustrate the range of reasons that are cited for supporting and opposing tail docking. This approach can be used to better target outreach efforts (e.g., improving farmer education on the lack of positive effects of docking on cleanliness and udder health while addressing concerns about producer safety). More generally, this type of online discussion provides a safe and productive format for discussions about contentious issues in the dairy industry and provides a mechanism for producers, industry professionals, and the public to share perspectives on these topics.

Invited review: effects of milk ration on solid feed intake, weaning, and performance in dairy heifers

A feeding regimen that allows a smooth transition from milk to solid feed is vital for successful heifer-rearing programs. In the past, research efforts have focused on the development of feeding methods that allow early weaning, perhaps because the risk of disease is highest during the milk feeding stage. To encourage early intake of calf starter, conventional feeding programs have limited the supply of milk (often to 10% of BW at birth). However, dairy calves provided free access to milk will typically consume more than twice this amount. We critically review the available literature examining the relationship between milk feeding method, solid feed consumption, and rumen development in young dairy calves and identify areas where new work is required. We conclude that milk-fed dairy calves can safely ingest milk at approximately 20% of body weight (BW)/d, and greater milk consumption supports greater BW gain, improved feed efficiency, reduced incidence of disease, and greater opportunity to express natural behaviors, which in combination suggest improved welfare. Method of weaning greatly influences feed consumption, rumen development, and growth check in calves provided higher amounts of milk. Gradual weaning encourages starter intake during the preweaning period, and both weaning age and duration of weaning influence this consumption. Increased solid feed consumption during the weaning process contributes to rumen development, permitting higher starter intake and BW gain after weaning. Growth factors in milk may also enhance the growth and maturation of the gastrointestinal tract, but more research is required to understand the role of these factors. Greater nutrient supply through increased amount of milk appears to improve immune function and long-term performance of heifer calves; for example, reducing the age at first breeding and increasing first-lactation milk yield, but more research is needed to confirm these effects.

Lying behavior as an indicator of lameness in dairy cows

Lameness is widely recognized as one of the most serious welfare and production concerns in the dairy industry. Our objectives were to evaluate the associations between lying behavior and lameness, and to determine whether lying behavior can be used as a diagnostic tool for lameness. Electronic data loggers recorded lying behavior of 1,319 cows from 28 farms at 1-min intervals for 5 d. These cows were gait scored according to a 5-point Numerical Rating System (NRS), and categorized as NRS <or=2, NRS=3, or NRS=4; no cow was scored as NRS=5. Lameness was dichotomized twice: LAME (NRS >or=3) and SEVLAME (NRS=4). Data were divided into 2 groups: 11 farms using deep-bedded stalls (DB) and 17 farms using mattress stalls (MAT). Differences in the daily lying time (h/d), frequency of lying bouts (n/d), duration of lying bouts (min/bout), and the standard deviation of bout duration (min/bout) between LAME or SEVLAME cows and those that were not were tested using mixed models. Receiver operating characteristic curves were constructed to identify behavioral thresholds to distinguish SEVLAME cows from the rest. Odds ratios for SEVLAME were estimated using logistic regression. Overall, 28.5% of cows were LAME including 7.3% that were SEVLAME. The prevalence of SEVLAME was higher on MAT farms than on DB farms (9.3+/-1.3 vs. 4.4+/-1.2%, respectively). SEVLAME cows on DB farms spent 12.8 [confidence interval (CI): 12.0 to 13.7] h/d lying down compared with 11.2 (CI: 10.7 to 11.8) h/d for cows that were not SEVLAME. These cows had longer duration of lying bouts [95.3 (CI: 84.6 to 107.3) vs. 80.3 (CI: 74.9 to 86.1) min/bout] and greater SD of bout duration [44.4 (CI: 41.1 to 48.0) vs. 50.7 (CI: 44.1 to 58.3) min/bout]. There were no behavioral differences among lameness categories on MAT farms. Within DB farms, cows with lying times >14.5 h/d had 16.2 (5.8 to 45.2) times higher odds of being SEVLAME. Cows with average lying bouts >90 min/bout were at 3.0 (1.2 to 7.4) times higher odds of being SEVLAME, and cows with average SD of bout duration >55 min/bout were at 4.1 (1.7 to 9.9) times higher odds of being SEVLAME. These results show that high lying times, long lying bouts, and variability in the duration of lying bouts were associated with lameness, and that stall surface influenced the behavioral responses of lame cows.

Technical note: Evaluation of a scoring system for rumen fill in dairy cows

Changes in feed intake are useful in early detection of disease in dairy cows. Cost and complexity limit our ability to monitor dry matter intake (DMI) of individual cows kept in loose-housing systems. A 5-point subjective scoring system has been developed to visually describe rumen fill, but no work to date has evaluated these scores as an indicator of feed intake. The objective of this study was to evaluate the performance of within-cow changes in visual rumen fill scores as estimates of changes of DMI and feed intake in dairy cows. Our results illustrate that rumen fill scored on a scale from 1 to 5 has substantial intra- (Cohen's kappa coefficient=0.69) and interobserver (Cohen's kappa coefficient=0.68) repeatability. Within-cow changes in visual rumen fill score are correlated with changes in DMI (Spearman's rank correlation=0.68). The depth of the paralumbar fossa (mean +/- SD; 5.6+/-0.9 cm) changes considerably (up to 4.8 cm) within 70+/-5 min. This more objective measure was also correlated with visual rumen fill scores (Spearman's rank correlation=-0.62). Our results indicate that subjective rumen fill scores are statistically associated with both an objective measure of paralumbar fossa indentation and feed intake. However, much of the variation in visual rumen fill scores is not associated with either measure, suggesting that caution is required in clinical usage of these scores.

Attitudes towards the use of genetically modified animals in research

Here we provide the first experimental evidence that public concerns about the use of animals in research are accentuated when genetically modified (GM) animals are used. Using an online survey, we probed participant views on two uses of pigs as research animals (to reduce agricultural pollution or to improve organ transplant success in humans) with and without GM. We surveyed 327 animal technicians, researchers, advocates, university students and others. In both scenarios and across demographics, support dropped off when the research required the use of GM pigs or GM corn. For example, 66% of participants supported using pigs to reduce phosphorus pollution, but this declined to 49% when the pigs were fed GM corn and to 20% when the research required the creation of a new GM line of pigs. Those involved in animal research were more consistently supportive compared to those who were not or those who were vegetarians.

Review: Feeding behaviour of dairy cattle: Meaures and applications

There is growing scientific interest in feeding behaviour of dairy cattle, in part because dairy nutritionists are now becoming interested in how changes in feed intake are mediated by changes in behaviour and, in part, because changes in feeding behaviour are increasingly recognized as useful indicator of cow health. In this review we describe key methodological approaches to the study of feeding behaviour in dairy cattle. We also review empirical work addressing how changes in management and housing can affect this behaviour. We show how cows divide their daily intake into several discrete feeding events made up of a number of visits or “meals” that are separated by longer periods with little feeding activity. Feeding behaviour can be described using several measures, including the number and duration of meals, as well as intake and feeding rate. Feeding behaviour within a group of intensively managed cows is often highly synchronized, similar to that seen in extensively housed cattle, with delivery of fresh feed appearing to be the primary factor stimulating feeding by housed dairy cows. Competition at the feed bunk can affect feeding behaviour, increasing the feeding rate and reducing intake, especially for subordinate animals. We also review empirical work showing that feed intake, feeding times, and feeding rate are altered when cows are ill. Feeding behaviour changes in the days before calving, and these changes are greatest among cows at greatest risk of succumbing to disease in the early post partum period. These results suggest that monitoring changes in feeding behaviour may be useful in early detection and prevention of disease in transition cows.Key words: Dairy cattle, feeding behaviour, management, health

Effects of sawdust bedding dry matter on lying behavior of dairy cows: a dose-dependent response

The objective was to determine the effect of sawdust bedding dry matter on the lying behavior of Holstein cows. Dry matter (DM) was varied systematically over 5 treatment levels to test how cows respond to damp bedding. This experiment was repeated during summer and winter to test if the effects of damp bedding varied with season. The 5 bedding treatments averaged (+/-SD) 89.8+/-3.7, 74.2+/-6.4, 62.2+/-6.3, 43.9+/-4.0, and 34.7+/-3.8% DM. Over the course of the trial, minimum and maximum temperatures in the barn were 2.6+/-2.0 and 6.8+/-2.2 degrees C in the winter and 13.3+/-2.5 and 22.6+/-4.1 degrees C in the summer. In both seasons, 5 groups of 3 nonlactating cows were housed in free stalls bedded with sawdust. Following a 5-d acclimation period on dry bedding, groups were exposed to the 5 bedding treatments in a 5 x 5 Latin square. Each treatment lasted 4 d, followed by 1 d when the cows were provided with dry bedding. Stall usage was assessed by 24-h video scanned at 5-min intervals. Responses were analyzed within group (n=5) as the observational unit. Bedding DM affected lying time, averaging 10.4+/-0.4 h/d on the wettest treatment and increasing to 11.5+/-0.4 h/d on the driest bedding. Lying time varied with season, averaging 12.1+/-0.4 h/d across treatments during the winter and 9.9+/-0.6 h/d during the summer, but season and bedding DM did not interact. These results indicate that access to dry bedding is important for dairy cows.

Duration of weaning, starter intake, and weight gain of dairy calves fed large amounts of milk

When calves are weaned abruptly off large amounts of milk, weight gain is reduced as a result of low intake of starter. We compared gradual and abrupt weaning of 40 calves allowed to drink up to 12kg of milk/d by automated feeders, housed in groups of 4, and weaned at 41 d abruptly or over 3 gradual weaning periods (4, 10, or 22 d), with one calf within each group randomly allocated to each treatment, balancing for sex and birth weight. During the milk-feeding period, the calves weaned over 22 d drank the least milk and ate the most starter, but these calves had the lowest total digestible energy intake and weight gains. The abruptly weaned calves had the highest digestible energy intakes and weight gains during the period before weaning. During the 9 d following weaning, the calves weaned over 22 and 10 d ate more starter and had better weight gains than abruptly weaned calves and those weaned over 4 d. Abruptly weaned calves lost weight during this period. In summary, gradual weaning improved starter intake, but because of reduced milk availability, this resulted in reduced total digestible energy intake before weaning. Weaning over 10 d resulted in the best overall weight gains over the study.

Lying behavior: assessing within- and between-herd variation in free-stall-housed dairy cows

One of the most important design criteria for dairy cow housing is access to a comfortable lying area. Behaviors such as the time cows spend lying down and how often they lie down can be used to evaluate the quality of stalls; however, assessing lying behavior on farms can be challenging. Indices such as the cow comfort index (CCI) and stall use index (SUI) have been widely used in on-farm assessments. The aims were to establish reliable sampling and recording methods for measuring lying behavior, to evaluate the adequacy of the CCI and SUI as estimates of lying behavior, and to describe variation in the lying behaviors of free-stall-housed dairy cows. The time spent lying down and the number of lying bouts for 2,033 cows on 43 farms were recorded for 5 d using electronic data loggers sampling at 1-min intervals. The CCI and SUI were calculated based on a single observation taken 2 h before the afternoon milking on each farm. Subsets of data were created, including 4, 3, 2, or 1 d per cow and 40, 30, 20, 10, 5, or 1 cow(s) per farm. The estimates derived from each sample size were compared with the overall means (based on 5 d and 44 cows per farm) for lying time and number of lying bouts, and the CCI and SUI were compared with the farm means of lying time, number of lying bouts, and bout duration using linear regression. Recording 30 or more cows for 3 d or more represented the overall means with high accuracy (R(2) > 0.9), but using fewer cows or fewer days per cow resulted in poorer estimates of the farm mean. The CCI and SUI showed no association with the daily lying time (h/d; R(2) < 0.01), and CCI was only weakly associated with the number of lying bouts per day (R(2) = 0.16) and bout duration (min/bout; R(2) = 0.09). Cows lay down 11.0 +/- 2.1 h/d in 9 +/- 3 bouts/d, with a bout duration of 88 +/- 30 min/bout. These values ranged from 9.5 to 12.9 h/d, 7 to 10 bouts/d, and 65 to 112 min/bout across farm means, and 4.2 to 19.5 h/d, 1 to 28 bouts/d, and 22 to 342 min/bout across individuals, showing that variation in lying behavior among individual cows within farm was greater than differences among farms.

Preference and usage of pasture versus free-stall housing by lactating dairy cattle

The aim of the current study was to assess if cows preferred pasture or indoor housing, and how diurnal and environmental factors affected this preference. Lactating dairy cows (n = 5 groups, each containing 5 cows) were sequentially housed either in a free-stall barn on pasture, or given the choice between the 2 environments. Each group was tested 3 times under each condition, for a total of 21 d, to assess the effects of varying climatic conditions (outdoor temperature ranged from 9.9 to 28.2 degrees C and daily rainfall from 0 to 65 mm/d over the course of the experiment). When provided the choice, cows spent on average (+/- SD) 13.0 +/- 0.6 h/d on pasture, mainly at night. The time cows spent on pasture during the day decreased with the temperature-humidity index (R(2) = 0.55); time on pasture at night decreased with rainfall (R(2) = 0.12). When provided a choice, cows spent more of their lying time on pasture (69.4 +/- 0.02% of the total lying time/d) than indoors in the free-stalls. Cows also spent more time in total lying down when provided a choice than when confined to pasture [0.6 h/d more lying time; standard error of the difference (SED) = 0.21 h/d] and spent even more time lying down when confined indoors (1.1 h/d more time; SED = 0.21 h/d). Cows used the indoor housing especially for feeding; feeder use peaked when cows returned from morning and afternoon milkings. However, cows with free access to pasture spent 1.0 h/d (SED = 0.09 h/d) less time eating the TMR available indoors, resulting in a decline in intake of 2.9 kg of dry matter/d (SED = 0.36 kg of dry matter/d). How cows used the indoor housing differed when cows were provided a choice; for example, cows spent a greater percentage of their time indoors at the feed alley both during the day (47% of the total time spent indoors, versus 41% for cows confined indoors, SED = 0.02%) and at night (22 vs. 5%, SED = 0.04%). In conclusion, under the housing and environmental conditions tested, cows showed a strong preference for access to pasture at night and for access to indoor housing during the day when temperature and humidity increased.

Worldwide trends in the use of animals in research: the contribution of genetically-modified animal models

The Three Rs--Reduction, Replacement and Refinement--which were first proposed in 1959 by Russell and Burch, have become widely accepted principles in the governance of humane animal research. However, there is substantial variation in the ways in which different countries document the numbers and types of research animals used, making it difficult to determine how effectively the Three Rs are being implemented. Here, we provide the first data illustrating worldwide trends in animal use for research purposes. To document global trends in animal use, we sampled 2691 articles from 24 countries, published between 1983 and 2007, in four scientific journals. We show that the percentage of articles reporting animal use has risen in the past 15 years. The rising popularity of genetic modification methods has contributed to this trend: reported genetically-modified animal use has more than doubled since 1997. We also show that mice are the most commonly-used species for genetic modification, and that, even in 2007, relatively inefficient random integration methods were still widely used to achieve genetic modification. These results illustrate shortcomings in the effort to implement the Three Rs in animal research.

Neck-rail position in the free stall affects standing behavior and udder and stall cleanliness

This study tested the effect of neck-rail position on stall usage and udder and stall cleanliness. Thirty Holstein lactating cows were tested in groups of 6. Each group was tested with each of 5 neck-rail positions (130, 145, 160, 175, and 190 cm from the rear curb, at a constant height of 125 cm above the bedded surface) for 1 wk, with the order of testing allocated in a 5 x 5 Latin square. When the neck rail was positioned further from the rear curb, cows spent less time standing with their front 2 hooves in the stall (2.2 +/- 0.26 h/d at 130 cm vs. 1.7 +/- 0.27 h/d at 190 cm, mean +/- SE) and more time standing with all 4 hooves in the stall (0.0 +/- 0.02 h/d at 130 cm vs. 0.6 +/- 0.07 h/d at 190 cm). These effects of neck-rail position tended to be more marked for smaller cows, perhaps because the standing behavior of larger cows was restricted even in the 190-cm treatment. Cows were more likely to defecate and urinate in the stalls when the neck rail was positioned further from the rear curb. Cows using these stalls tended to have dirtier udders and these stalls required more cleaning time (0.4 +/- 0.16 min/d at the 130-cm position vs. 1.6 +/- 0.35 min/d at the 190-cm position). In summary, positioning the neck rail further from the curb increased the time that cows spent standing fully in the stall. This change in standing behavior is likely beneficial for hoof health, but reduced udder and stall cleanliness.