|
|
Croney, C. C., & Millman, S. T. (2007). BOARD-INVITED REVIEW: The ethical and behavioral bases for farm animal welfare legislation. J. Anim Sci., 85(2), 556–565.
Abstract: Concerns about farm animal welfare vary among individuals and societies. As people increasingly consider the values underlying current farm animal production methods, farm animal welfare policy debates have escalated. Recent food animal protection policies enacted in the European Union have fueled highly contentious discussions about the need for similar legislative activity in the United States. Policymakers and scientists in the United States are apprehensive about the scientific assessment, validation, and monitoring of animal welfare, as well as the unforeseen consequences of moving too hastily toward legislating farm animal welfare. The potential impact of such legislation on producers, food prices, animals, and concerned citizens must also be considered. Balancing the interests of all stakeholders has therefore presented a considerable challenge that has stymied US policymaking. In this review, we examine the roles of ethics and science in policy decisions, discuss how scientific knowledge relative to animal behavior has been incorporated into animal welfare policy, and identify opportunities for additional refinement of animal welfare science that may facilitate ethical and policy decisions about animal care.
|
|
|
|
Apple, J. K., Kegley, E. B., Galloway, D. L., Wistuba, T. J., Rakes, L. K., & Yancey, J. W. S. (2006). Treadmill exercise is not an effective methodology for producing the dark-cutting condition in young cattle. J. Anim Sci., 84(11), 3079–3088.
Abstract: Holstein steer calves (n = 25) were used to evaluate the effects of treadmill exercise (TME) on blood metabolite status and formation of dark-cutting beef. Calves were blocked by BW (156 {+/-} 33.2 kg) and assigned randomly within blocks to 1 of 5 TME treatments arranged in a 2 x 2 factorial design (4 or 8 km/h for a duration of 10 or 15 min) with a nonexercised control. Venous blood was collected via indwelling jugular catheters at 10, 2, and 0 min before TME and at 2-min intervals during exercise. Nonexercised steers were placed on the treadmill but stood still for 15 min. Serum cortisol levels, as well as plasma concentrations of glucose, lactate, and NEFA, were similar (P > 0.05) before TME. Serum cortisol concentrations were unaffected (P > 0.05) during the first 6 min of TME, but between 8 and 15 min of TME, cortisol concentrations were greater (P < 0.05) in steers exercised at 8 km/h than those exercised at 4 km/h or controls (speed x time, P < 0.001). Although TME did not affect (P > 0.05) plasma glucose levels, plasma lactate concentrations in steers exercised at 8 km/h increased (P < 0.05) sharply with the onset of the TME treatment and remained elevated compared with steers exercised at 4 km/h or unexercised controls (speed x time, P < 0.001). Exercised steers had the lowest (P < 0.05) plasma NEFA concentrations during the first 6 min of TME compared with unexercised steers; however, NEFA concentrations were similar after 10 and 12 min of TME, and by the end of TME, steers exercised at 8 km/h had greater (P < 0.05) NEFA levels than nonexercised controls or steers exercised at 4 km/h (speed x time, P < 0.001). Even though muscle glycogen levels and pH decreased (P < 0.001) and muscle lactate concentrations increased (P < 0.001) with increasing time postmortem, neither treadmill speed nor TME duration altered postmortem LM metabolism. Consequently, there were no (P > 0.05) differences in the color, water-holding capacity, shear force, or incidences of dark-cutting carcasses associated with preslaughter TME. It is apparent that preslaughter TME, at the speeds and durations employed in this study, failed to alter antemortem or postmortem muscle metabolism and would not be a suitable animal model for studying the formation of the dark-cutting condition in ruminants.
|
|
|
|
Steelman, S. M., Michael-Eller, E. M., Gibbs, P. G., & Potter, G. D. (2006). Meal size and feeding frequency influence serum leptin concentration in yearling horses. J. Anim Sci., 84(9), 2391–2398.
Abstract: Energy is an essential nutrient for all horses, and it is especially important in performance horses, pregnant and lactating mares, and young growing horses. A negative energy balance in horses such as these may result in unsatisfactory performance, decreased fertility, or slow growth. Therefore, ensuring adequate energy intake is an important aspect of the nutritional management of the equine. This study was undertaken to investigate the effects of feeding large, carbohydrate-rich, concentrate meals on the satiety-inducing hormone, leptin. Three groups of yearling horses were rotated through 3 feeding schedules in a replicated 3x3 Latin square design. Horses were fed 2, 3, or 4 times per day (2x, 3x, and 4xfeeding schedules, respectively), each for a period of 11 d, with the total amount of daily feed held constant. Horses were weighed and BCS was determined on the first day of each period. Blood samples were collected before the morning meal on d 1, 4, and 7 of each period. Additionally, blood was sampled for the last 24 h of the 2xand 4xdietary periods. Neither weight nor BCS changed during the study (P = 0.99 and P = 0.28, respectively). Both mean and peak plasma glucose were greatest in 2xhorses (P < 0.05), as were mean areas under the curve. Serum leptin concentration increased in 2xhorses (P < 0.05), but not in horses fed 3 or 4 times daily. Leptin was elevated in horses with greater BCS (P < 0.05) and increased steadily throughout the study (P < 0.05). Data from the 24-h collection indicated that 2xhorses had fluctuations in leptin production throughout the day (P < 0.05), whereas horses fed 4 times daily did not. Overall, this study indicates that feeding horses 2 large concentrate meals daily can increase mean serum leptin concentrations and may cause fluctuations in leptin production over a 24-h period. This departure from baseline leptin concentration has the potential to affect appetite, along with numerous other physiological processes.
|
|
|
|
Ordakowski-Burk, A. L., Quinn, R. W., Shellem, T. A., & Vough, L. R. (2006). Voluntary intake and digestibility of reed canarygrass and timothy hay fed to horses. J. Anim Sci., 84(11), 3104–3109.
Abstract: Thousands of hectares of timothy (Phleum pretense L.) grown in the Mid-Atlantic region are infected by cereal rust mite (Abacarus hysterix) that causes discoloration and curling of leaves, decreased nutritional quality, and substantial decreases in yield. A decline in production of timothy hay can lower income for hay producers and cause horse owners to search for alternative hays. Low alkaloid reed canarygrass (Phalaris arundinacea L.) hay has potential as an alternative to timothy hay because it grows well in the Mid-Atlantic region, is believed to have a similar nutrient quality to timothy, and is not as susceptible to cereal rust mite. Eleven mature, stalled Thoroughbred geldings (549 +/- 12.1 kg) that were exercised daily were used to compare voluntary DMI and apparent nutrient DM digestibility of timothy and low-alkaloid Chiefton variety reed canarygrass hay. Horses were paired by age and BW and randomly assigned to timothy or reed canarygrass hay during a 14-d period to measure voluntary DMI followed by a 4-d period to measure apparent DM digestibility. Both hays met the minimum requirements for DE, CP, Ca, P, K, Fe, and Mn, but they did not meet the minimum requirements for Cu, Zn, and Na for horses at maintenance and averaging 550 kg of BW. Timothy hay seemed to have a lower CP concentration (14.4%) compared with reed canarygrass hay (17.1%) and a more desirable Ca:P ratio at 1.6:1 compared with 0.8:1 for reed canarygrass hay. Horses fed timothy consumed more hay (P <0.001) during the voluntary DMI period compared with horses fed reed canarygrass. Greater voluntary DMI of timothy occurred on d 1, 3, and 5 (P <0.05), but DMI was similar for other days. Apparent DM digestibility was greater in horses fed timothy hay by 9.6% compared with horses fed reed canarygrass hay (P <0.05). Horses fed timothy had greater DM digestibility of ADF (P = 0.001), NDF (P = 0.001), sugar (P = 0.05), and Ca (P = 0.001) but lower apparent DM digestibility of CP (P = 0.012) and crude fat (P = 0.004). Timothy hay was superior in voluntary DMI and apparent DM digestibility compared with low-alkaloid reed canarygrass hay fed to horses.
|
|
|
|
Apple, J. K., Kegley, E. B., Galloway, D. L., Wistuba, T. J., & Rakes, L. K. (2005). Duration of restraint and isolation stress as a model to study the dark-cutting condition in cattle. J. Anim Sci., 83(5), 1202–1214.
Abstract: Holstein steer calves (n = 32; 156 {+/-} 33.2 kg average BW) were used to evaluate the duration of restraint and isolation stress (RIS) on endocrine and blood metabolite status and the incidence of dark-cutting LM. Calves were blocked by BW and assigned randomly within blocks to one of four stressor treatments: unstressed controls (NS) or a single bout of RIS for 2, 4, or 6 h. Venous blood was collected via indwelling jugular catheters at 40, 20, and 0 min before stressor application and at 20-min intervals during RIS. Unstressed calves remained in their home stanchions and, except for blood sampling, were subjected to minimal handling and stress. Serum cortisol and plasma lactate concentrations were increased (P <0.01) during the first 20 min after RIS application, and remained elevated throughout the 6 h of RIS. Plasma concentrations of glucose and insulin were greater (P <0.05) in RIS calves than in NS calves after 80 and 100 min of stressor application, respectively; however, RIS did not (P >0.80) affect plasma NEFA concentrations. Calves were slaughtered within 20 min of completion of RIS, and muscle samples were excised from right-side LM at 0, 0.75, 1.5, 3, 6, 12, 24, and 48 h after exsanguination for quantifying LM pH, and glycogen and lactate concentrations. The pH of the LM from calves subjected to 6 h of RIS exceeded 6.0, and was greater (P <0.05) at 24 and 48 h postmortem than the pH of NS calves or calves subjected to 2 or 4 h RIS. Muscle glycogen concentrations did not differ (P = 0.16; 25.58, 10.41, 13.80, and 14.41 {micro}mol/g of wet tissue weight for NS and 2-, 4-, and 6-h RIS, respectively), and LM lactate concentrations tended to be lower (P = 0.08) in calves subjected to 6 h of RIS. At 48 h after exsanguination, the LM from calves subjected to 6 h of RIS had more (P <0.05) bound and less (P <0.05) free moisture than did the LM from NS calves or calves subjected to 2 or 4 h of RIS. Additionally, the LM from RIS calves was darker (lower L* values; P <0.05) than the LM of NS calves. Visual color scores for the LM were greatest (P < 0.05) for calves subjected to 6 h of RIS and least (P <0.05) for NS calves. Subjecting lightweight Holstein calves to 6, 4, and 2 h of RIS resulted in six (75%), two (25%), and two (25%) carcasses characteristic of the dark-cutting condition, respectively. There were no dark-cutting carcasses produced from NS calves. Thus, RIS may be a reliable animal model with which to study the formation of the dark-cutting condition. N1 -
|
|
|
|
Hall, C. A., Cassaday, H. J., & Derrington, A. M. (2003). The effect of stimulus height on visual discrimination in horses. J. Anim Sci., 81(7), 1715–1720.
Abstract: This study investigated the effect of stimulus height on the ability of horses to learn a simple visual discrimination task. Eight horses were trained to perform a two-choice, black/white discrimination with stimuli presented at one of two heights: ground level or at a height of 70 cm from the ground. The height at which the stimuli were presented was alternated from one session to the next. All trials within a single session were presented at the same height. The criterion for learning was four consecutive sessions of 70% correct responses. Performance was found to be better when stimuli were presented at ground level with respect to the number of trials taken to reach the criterion (P < 0.05), percentage of correct first choices (P < 0.01), and repeated errors made (P < 0.01). Thus, training horses to carry out tasks of visual discrimination could be enhanced by placing the stimuli on the ground. In addition, the results of the present study suggest that the visual appearance of ground surfaces is an important factor in both horse management and training.
|
|
|
|
Bracke, M. B. M., Spruijt, B. M., Metz, J. H. M., & Schouten, W. G. P. (2002). Decision support system for overall welfare assessment in pregnant sows A: Model structure and weighting procedure. J. Anim Sci., 80(7), 1819–1834.
Abstract: The problem of how to objectively assess the overall welfare status of animals under farming conditions has contributed to an ongoing debate that has hampered actual decision making on animal welfare. For this reason we constructed a model based on the assumed hierarchical organization of the animals' needs for overall welfare assessment in the case of pregnant sows. This model is implemented in a computer-based decision support system that takes a description of a housing and management system as input and produces a welfare score as output. A formalized procedure was used to construct the model for welfare assessment in pregnant sows on the basis of available scientific knowledge. This SOWEL (from SOw WELfare) model contains 37 attributes that describe the welfare-relevant properties of housing and management systems. In the decision support system these attributes are linked to scientific statements and a list of needs to provide a scientific basis for welfare assessment. Weighting factors that represent the relative importance of the attributes are derived from the scientific statements about the various welfare performance criteria that have been measured by scientists. The welfare score is calculated as the weighted average score. All information in the decision support system is stored in tables in a relational database such that newly available knowledge and insights can be incorporated to refine the model. The model has been developed in line with several existing models but it differs from these models in that it is the first to provide a formalized procedure to explicate the reasoning steps involved in welfare assessment based on available scientific knowledge. N1 -
|
|
|
|
Lanier, J. L., Grandin, T., Green, R. D., Avery, D., & McGee, K. (2000). The relationship between reaction to sudden, intermittent movements and sounds and temperament. J. Anim Sci., 78(6), 1467–1474.
|
|
|
|
Olesen, I., Groen, A. F., & Gjerde, B. (2000). Definition of animal breeding goals for sustainable production systems. J. Anim Sci., 78(3), 570–582.
|
|
|
|
Marc, M., Parvizi, N., Ellendorff, F., Kallweit, E., & Elsaesser, F. (2000). Plasma cortisol and ACTH concentrations in the warmblood horse in response to a standardized treadmill exercise test as physiological markers for evaluation of training status. J. Anim Sci., 78(7), 1936–1946.
Abstract: Reliable physiological markers for performance evaluation in sport horses are missing. To determine the diagnostic value of plasma ACTH and cortisol measurements in the warmblood horse, 10 initially 3-yr-old geldings of the Hannovarian breed were either exposed to a training schedule or served as controls. During experimental Phase 1, horses were group-housed, and half of the horses were trained for 20 wk on a high-speed treadmill. During Phase 2, groups were switched and one group was trained for 10 wk as during Phase 1, whereas the control group was confined to boxes. During Phase 3 horses were initially schooled for riding. Thereafter, all horses were regularly schooled for dressage and jumping, and half of the horses received an additional endurance training for 24 wk. During all phases horses were exposed at regular intervals to various standardized treadmill exercise tests. During and after the tests frequent blood samples were taken from an indwelling jugular catheter for determination of ACTH and cortisol. Treadmill exercise increased both hormones. Maximum ACTH concentrations were recorded at the end of exercise, and maximum cortisol levels were recorded 20 to 30 min later. Except for one test there were no differences in ACTH levels between trained horses and controls. There was no significant effect of training on the cortisol response (net increase) to treadmill exercise in any of the tests during Phase 1. During Phase 2 higher cortisol responses were recorded in controls than in trained horses (P < .05) after 10 wk of training (controls confined to boxes). During Phase 3 plasma cortisol responses were also higher in controls than in trained horses (P < .05 after 6, 18, and 24, P < or = .07 after 12 wk of training) when the inclination of the treadmill was 5%, but not at 3%. There was no overlap in net cortisol responses at 30 min between trained and untrained horses. An ACTH application after 24 wk of training resulted in higher cortisol responses in controls than in trained horses (P < or = .05), without any overlap between the groups at 30 min after ACTH. Plasma cortisol responses to either treadmill exercise or ACTH injection may be a reliable physiological marker for performance evaluation. Prerequisites are sufficient differences in training status and sufficient intensity of exercise test conditions.
|
|
