Factors influencing how Canadian dairy producers respond to a downer cow scenario.

Understanding how downer cattle are managed allows for the evaluation of strengths and weaknesses in these practices, which is an important step toward improving the care these animals receive. The objective of this cross-sectional study was to analyze factors associated with the care and management of downer cattle by Canadian dairy producers. Data were obtained from the 2015 National Dairy Study, and analysis was limited to the 371 respondents completing the downer cow scenario. The scenario described a downer cow that the producer wanted to keep in their herd but must be moved, and was followed by questions addressing the cow's care and management. Using multivariable logistic regression models, associations between respondent demographics and farm characteristics, and the presence of downer cow protocols, we assessed decisions regarding euthanasia and use of behavioral prognostic indicators. Written downer cow protocols were reported by 18.2% of respondents, 67% indicated that they had a nonwritten protocol, and 14.8% reported that they did not have a protocol (either written or nonwritten). Respondents from western provinces were more likely to have a written protocol than those from Ontario. Nineteen percent of the respondents with a written or unwritten protocol reported veterinary involvement in developing their downer cow protocol, which occurred more commonly on farms with more frequent herd health visits and a good producer-veterinarian relationship. An area to move a downer cow to was present on 88% of farms, with respondents who were farm staff being less likely to report having knowledge of a designated area than respondents who were the farm owner. In addition, approximately half (45%) of respondents reported moving downer cattle with hip lifters as their most common method. Behavioral prognostic indicators chosen by respondents were associated with the respondent's geographic region, age, farm size, and education. Most notably, older respondents were more likely to use appetite, and less likely to use attitude, as a prognostic indicator compared with younger respondents. Using perceived pain as a prognostic indicator was more common among respondents from western and Atlantic provinces compared with respondents from Ontario, and more common among respondents with a college or university education. These results highlighted herd and farmer demographics that were associated with how Canadian dairy producers managed downer cattle in 2015 and could be used as a benchmark for evaluating how these management practices compare with those currently implemented.

A scoping review of the analytical literature concerning nonambulatory dairy cattle.

Nonambulatory dairy cattle pose a complex problem due to the challenges associated with prevention, appropriate treatment and management, and arriving at an accurate prognosis. There is a breadth of literature regarding this topic, of which there is currently no formal synthesis. The objective of this scoping review was to describe and characterize the literature investigating risk factors, sequela, preventions, treatments, and prognostic factors for nonambulatory conditions in dairy cattle, with the intent of qualitatively synthesizing knowledge of the topic and identifying gaps in the literature. A literature search was conducted in 6 databases and 2 conference proceeding archives, which returned 7,568 unique articles. Initial screening of abstracts resulted in 1,544 articles reviewed at the full-text stage, of which 379 were included for data extraction. Over 75% of the included literature was published after 1980, and the most common countries in which these studies took place were the United States (n = 72), Canada (18), Sweden (17), and Germany (17). Common eligibility criteria used for inclusion were geographic region (97) and parity (92). Of the 379 studies included in this review, 144 were randomized controlled trials and 235 were observational studies. The majority of the controlled trials assessed prevention of nonambulatory conditions (116), most commonly through supplementation of vitamin D (27) and calcium (25) or the provision of anionic salts (22). Of the 28 studies focusing on treatment of nonambulatory conditions, 26 focused on calcium administration. Becoming nonambulatory was evaluated as an outcome in 165 of the observational studies. Frequently measured risk factors for becoming nonambulatory included hematological variables, such as blood calcium (73), phosphorus (53) and magnesium (42), and other factors such as parity (35) and breed (22). Recovery from a nonambulatory condition was the outcome in 31 of the observational studies, with commonly measured prognostic indicators being calcium (9), phosphorus (9), and duration of recumbency (7). Nonambulatory disorders were measured as risk factors in 53 of the observational studies, with the most commonly assessed outcomes including disorders of the transition period (11), and death or euthanasia (11). The most common terms used to describe nonambulatory conditions were "milk fever" (199) and "parturient paresis" (147). These terms were only further defined with explicit symptomatic criteria in 193 of the 379 studies in this review. Recumbency was the most commonly used of these criteria (144), followed by inability to rise (55). Potential gaps in the literature concerning nonambulatory dairy cattle that were identified in the present review included investigation of prognostic indicators for recovery from nonambulatory conditions that are applicable on farm, treatment alternatives to calcium administration, and guidance regarding the appropriate usage of terms meant to categorize nonambulatory dairy cattle.

The relationships among sprint performance, voluntary swimming activity, and social dominance in juvenile rainbow trout.

The specific objectives of this study were to determine whether sprint performance in juvenile rainbow trout is correlated with either voluntary swimming activity or aggressive behaviors and to determine the reciprocal: the effect of swimming activity and aggression on sprint performance. Sprint performance was assessed by rapidly accelerating trout (5-7-cm fork length) to a fixed velocity (40, 42, or 45 cm s(-1)) and then holding them at that velocity until fatigue. There was considerable interindividual variation in sprint performance not explained by variations in body size, but intraindividual performance was highly repeatable over at least 2 mo. Voluntary swimming was measured as the frequency of transits (voluntary transit activity, VTA) between two identical tanks via a connecting channel with two different flow regimes: zero or minimum velocity (0 or 2.5 cm s(-1)) and high velocity (84 cm s(-1)). There was a strong correlation between sprint performance and VTA in minimal current but no correlation in high current. Furthermore, sprint performance did not predict the outcome of dominance encounters. Experience with rapid acceleration, especially when voluntary, led to a pronounced improvement in sprint performance in proportion to the number of acceleration events. Social dominance encounters had a more complex effect: a significant reduction in sprint performance in previously high-performance sprinters and the reverse for low performers. We propose that there are four independent axes of interindividual variation in juvenile rainbow trout: spontaneous and rheotaxis-stimulated locomotor activity, aggressive activity, and the trainability of sprint performance. The independence of these axes has the potential to produce a much larger diversity in behavioral and ultimately physiological phenotypes than would be produced if the axes were linked.

Relating intramuscular fuel use to endurance in juvenile rainbow trout.

This study examined fuel depletion in white muscle of juvenile rainbow trout sprinted to fatigue to determine whether the onset of fatigue is associated with a measurable metabolic change within the muscle and whether muscle glycogen levels influence endurance. In this study, "fuels" refer to any energy-supplying compounds and include glycogen, phosphocreatine (PCr), and ATP. Fuel depletion in white muscle was estimated by the calculation of the anaerobic energy expenditure (AEE; in micromol ATP equivalents g(-1)) from the reduction of PCr and ATP and the accumulation of lactate. Progression of fuel use during sprinting was examined by sampling fish before they showed signs of fatigue and following fatigue. Most of the AEE before fatigue was due to PCr depletion. However, at the first signs of fatigue, there was a 32% drop in ATP. Similarly, when fish were slowly accelerated to a fatiguing velocity, the only significant change at fatigue was a 30% drop in ATP levels. Muscle glycogen levels were manipulated by altering ration (1% vs. 4% body weight ration per day) combined with either daily or no exercise. Higher ration alone led to significantly greater muscle glycogen but had no effect on sprint performance, whereas sprint training led to higher glycogen and an average threefold improvement in sprint performance. In contrast, periodic chasing produced a similar increase in glycogen but had no effect on sprint performance. Taken together, these observations suggest that (i) a reduction in ATP in white muscle could act as a proximate signal for fatigue during prolonged exercise in fish and (ii) availability of muscle glycogen does not limit endurance.

Creatine supplementation affects sprint endurance in juvenile rainbow trout.

Fingerling rainbow trout were supplemented with equal amounts of creatine (Cr) by two routes: dietary (12.5 mg Cr per g food); or intraperitoneal injection (0.5 mg Cr per g fish). Endurance in a fixed velocity sprint test (at a speed of 7 BL s(-1)), and resting levels of white muscle metabolites (total creatine [a measure of free creatine plus phosphocreatine (PCr), ATP, lactate and glycogen] were assessed following 7 days of supplementation and compared to controls. None of the treatments had a significant effect on growth, muscle total creatine, percent phosphorylation of creatine, ATP or lactate. However, resting muscle glycogen was elevated in creatine-supplemented fish. Higher muscle glycogen corresponded to significantly greater endurance in creatine-supplemented fish. Although fish do not actively transport additional creatine into the muscle, a mechanism whereby circulating creatine acts to enhance muscle glycogen is present. These results suggest that the improved endurance may be due to an insulin-dependent mechanism (similar to that elucidated in mammalian studies) that allows fish to supercompensate muscle glycogen stores, thus extending endurance through enhanced glycolytic flux.

Short-term effects of 3,5,3'-triiodothyronine on the intermediary metabolism of the dogfish shark Squalus acanthias: evidence from enzyme activities.

Plasma 3,5,3'-triiodothyronine (T3) concentration decreased significantly (P < 0.05), during 1-5 days of captivity, from levels in the freshly caught dogfish shark Squalus acanthias. The short-term effects of T3 treatment on the intermediary metabolism of S. acanthias were measured in the gill, kidney, liver, and white muscle. Animals were kept for 1-5 days before experimentation. Three hours after an intraperitoneal injection with either a low T3 dose (8.3 pmol T3/kg fish) or a high T3 dose (830 pmol T3/kg fish), selected enzymes of amino acid metabolism, lipid catabolism, ketone body metabolism, glycolysis, and oxidative metabolism were measured. Activity of enzymes of amino acid metabolism and lipid catabolism increased significantly (P < 0.05) in the liver of fish treated with a low T3 dose. The low dose of T3 apparently influences glycolysis as pyruvate kinase activity significantly increase (P < 0.05) in the kidney and white muscle.

Patient access to hospital records: a pilot project.

The results of granting hospitalized psychiatric patients the right of access to their current hospital record were investigated. Thirty-nine percent of the patients granted that right utilized it. No statistically significant difference between the patients granted this right and those not granted the right of access were detected in the measures of the effectiveness of the treatment program, the patient's attitude towards hospital or its staff, or the actual content of the record. Patients availing themselves of the right of access, however, did have a greater awareness of the treatment program and the content and purpose of the record, although in the main these differences were not statistically significant. Staff were comfortable with open charting and felt it could be used as a therapeutic tool.