Effects of targeted clinical examination based on alerts from automated health monitoring systems on herd health and performance of lactating dairy cows.

Our objectives were to compare the proportion of lactating dairy cows diagnosed with health disorders (HD) and herd performance when using a health monitoring program designed to rely primarily but not exclusively on alerts from automated health monitoring (AHM) systems or a health monitoring program based primarily on systematic clinical examinations, milk yield monitoring, and visual observation of cows. In a clinical trial, at ∼30 d before expected parturition, nulliparous and parous Holstein cows, stratified by parity and days in gestation, were randomly assigned to the high-intensity clinical monitoring (HIC-M; n = 625) or automated monitoring (AUT-M; n = 624) treatment. Cows were fitted with a neck-attached rumination and physical activity monitoring tag, and individual daily milk yield data were collected from parlor milk meters. For cows in HIC-M, clinical examination was conducted daily until 10 d in milk (DIM) and then in response to milk yield reduction alerts or visual observation of clinical signs of HD over the course of 21 DIM. For cows in AUT-M, clinical examination until 21 DIM was because of health index (HI) score alerts and reduced milk yield alerts. The HI score alerts used were generated based on the manufacturer's settings for the system for the last 2-h period before cows were selected for examination. Visual observation of clinical signs of HD was used for identifying cows potentially missed by automated alerts. Binomial and quantitative data were analyzed by logistic regression and ANOVA with repeated measures, respectively. The percentage of cows diagnosed with at least 1 HD during the experimental treatments risk period tended to be greater and the incidence rate ratio of HD diagnosed was greater in the HIC-M than in the AUT-M treatment. We found no difference between treatments for cows that exited the herd up to 60 or 150 DIM, but more cows tended to exit the herd from 61 to 150 DIM in the HIC-M than in the AUT-M treatment. No differences were detectable between treatments in daily or total milk yield to 21 DIM or in weekly mean milk yield and total milk yield to 150 DIM. More cows were inseminated in estrus for first service if in the HIC-M treatment and had no HD diagnosed than if in the HIC-M treatment but with HD diagnosed, or in the AUT-M treatment and had no HD diagnosed. Cows in the AUT-M treatment with HD diagnosed did not differ from other groups. No differences between treatments were observed in pregnancies per artificial insemination or pregnancy loss for first service. Despite a reduction in the risk of diagnosis of HD, no evidence indicated that a health monitoring program that relied on AHM system alerts to select cows for clinical examination reduced herd performance compared with a more intensive program that included systematic clinical examinations of all cows for the first 10 DIM, reduced milk yield alerts, and visual observation. However, to obtain the same herd performance as with the HIC-M treatment, the AUT-M treatment required use of visual observation. In conclusion, a health monitoring program designed to rely primarily on targeted clinical examination based on alerts from automated health monitoring systems might be a feasible alternative to programs that rely more on clinical examination, provided that visual observation is used to identify cows not detected by automated alerts.

Research Note: Validation of a low-cost accelerometer to measure physical activity in 30 to 32-d-old male Ross 708 broilers.

Poultry activity measurements are often associated with expensive equipment or time-consuming behavior observations. Since low-cost accelerometers are available, the current study validated the FitBark (FitBark 2, FitBark Inc., Kansas City, MO) accelerometer for use on 30 to 32-d-old male Ross 708 broilers. The FitBark provides aggregated activity levels based on tri-axial accelerometer technology. Broilers were housed in 5 rooms, each divided into 12 2 × 2.3 m pens (60 birds per pen, 31 kg m-2 final density). From 30 to 32 d, 1 broiler per room (n = 5) was randomly selected and equipped with a 13 g FitBark. Elastic loops were placed around the wings to secure the FitBark medially on the back. During the same time, validity was assessed via ceiling-mounted video cameras. The video recordings were analyzed using 20-min continuous sampling during the photo phase at 8 time periods per bird. Behavior was assessed every second using an ethogram (9,600 data points per bird). In the first step, the FitBark data were matched and correlated with the corresponding video-based observed activity (OA) data. The FitBark and OA data were not normally distributed (1-sample KS test, all n = 800, ZFitBark = 0.21, ZOA = 0.24, all P < 0.001). Therefore, data were transformed, and a repeated measures correlation was performed for each bird, showing a positive correlation between the FitBark and OA data (rrm = 0.76, 95% CI = 0.72-0.78, df = 794, P < 0.001). In the second step, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. The FitBark correctly identified 91% (sensitivity) of the active and 74% (specificity) of the inactive birds. When the FitBark detected an active or inactive bird, there was a probability of 89% (PPV) and 78% (NPV) that the bird was observed to be active or inactive based on the OA data. Accuracy was at 86%. Overall, FitBark are useful for 1-min interval activity measurements in 30 to 32-d-old male Ross 708 broilers. Further research should focus on validating the FitBark at other ages and in different poultry species.

Assessment of gastrointestinal health in racing Alaskan sled dogs using capsule endoscopy and inflammatory cytokines.

OBJECTIVES: Exercise-induced gastrointestinal syndrome occurs in dogs and people and might compromise athlete performance by increasing intestinal permeability and causing gastrointestinal erosions. Racing sled dogs often receive acid suppressant prophylaxis which decreases the incidence of gastric erosions induced by exercise. The objectives were to quantify intestinal injury by measuring serum pro-inflammatory cytokine concentrations before and after exercise and to evaluate gastrointestinal mucosa using video capsule endoscopy after exercise. MATERIALS AND METHODS: Prospective study of 12 racing Alaskan sled dogs receiving approximately 1 mg/kg omeprazole once daily from the day before the race until race completion. Blood was drawn before and 8 to 10 hours after an endurance race for the quantification of cytokines. Gastrointestinal tract mucosa was assessed with video capsule endoscopy immediately post-race. RESULTS: Eight of nine dogs (89%; 95% confidence interval 52 to 100%) had gastric erosions; all dogs (100%, 95% confidence interval 63 to 100%) had small intestinal erosions. Most of the dogs (seven of nine) had straw or foreign material present. Cytokine levels were not different from before to after the race. CLINICAL SIGNIFICANCE: Video capsule endoscopy identified gastrointestinal tract mucosal erosions after exercise in all dogs receiving once-daily omeprazole treatment, though other causes for the lesions besides exercise are possible.

Energy cost of physical activities in growing broilers.

1. The time-energy budget method estimates the energy used for physical activity (PA) by integrating behaviour PA patterns with energy cost for specific PAs. Nevertheless, information about individual energy cost by type of PA are not available and so this study estimated the energy cost of PA for growing broilers.2. An indirect calorimetry system for single birds was constructed to measure the variation in the rate of O2 consumption (V˙O2, L/min) and rate of CO2 production (V˙CO2, L/min) produced by these PAs.3. A total of five birds were used in a replicated trial where their body weight (BW) ranged from 1.5 to 2.5 kg to measure the increase in heat production (HP) above resting levels as a result of PA. The procedure in the chamber was divided into five steps: (1) initial baselining, (2) resting metabolic rate, (3) PA such as feeding, drinking and other standing activities, (4) removal of gas exchange produced in step 3, and (5) final baselining. The PA was recorded using a video camera fixed at the chamber's top (and outside).4. The area under V˙CO2 and V˙O2 curves was used to calculate the CO2 production (vCO2, L) and O2 consumption (vO2, L). Then, the HP (cal/kg-0.75) was calculated according to the Brouwer equation. Two observers analysed the video records to estimate the time spent for each PA (seconds and frequency).5. To calculate the energetic coefficients, the HP was regressed with the function of time spent to perform each PA allowing to estimate the energy cost for eating, drinking and stand activities, which were 0.607, 0.352 and 0.938 cal/kg-0.75/s, respectively.

[Bioactive compounds anthocyanins as a factor in the nutritional recovery of the body's adaptive potential after intense physical activity in the experiment: assessment of immunological and hematological indicators of adaptation].

Restoring the adaptive potential of an athlete is of paramount importance not only for the implementation of his training and competitive activities, but also for maintaining health. One of the leading place in complex recovery programs in sports is given to full-fledged optimal nutrition, which provides for meeting the body's requirements not only in energy, macro- and micronutrients, but also in minor bioactive compounds. The use of anthocyanin-containing products is a promising strategy for the normalization of metabolic and immune disorders that develop as a result of intense physical and neuro-emotional stress not only in athletes, but also in other groups of people exposed to these factors, including military personnel undergoing training in conditions close to combat. This determines the relevance of this study. The aim of the research was to study the effect of an anthocyanin-enriched diet on hematological profile and cellular immunity in rats after intense physical activity. Material and methods. The experiment was carried out for 4 weeks on 4 groups of male Wistar rats with an initial body weight of ~300 g. The motor activity of the animals of the 1st (control) and 2nd groups was limited by the standard keeping animals in the vivarium, while physically active rats of the 3rd and 4th groups received additional physical activity - training on a treadmill. Before the end of the experiment, the animals of 3rd and 4th groups were given debilitating physical activity on a treadmill (until the rats refused to continue the exercise). Rats of all 4 groups received a standard semi-synthetic diet, water ad libitum. Animals in 2nd and 4th groups were additionally fed blueberry and blackcurrant extract (30% anthocyanins) as part of the diet at a daily dose of 15 mg anthocyanins/kg body weight. Hematological parameters were determined on a Coulter ACT TM 5 diff OV hematological analyzer. Expression of CD45R, CD3, CD4, CD8a, CD161 receptors on rat peripheral blood lymphocytes was determined by direct immunofluorescent staining of whole blood cells using a panel of monoclonal antibodies conjugated with fluorescent dyes: APC, FITC, PE. The measurements were carried out on an FC-500 flow cytometer. Results. Intense physical activity in rats of the 3rd group did not lead to a significant change in erythrocyte parameters compared with the control group. Enrichment of the diet with blueberry and black currant extract (the 2nd and the 4th groups) provided a significant (p<0.05) increase in blood content of hemoglobin (Hb) (150.7±0.9 and 154.4±2.0 vs 145.4±0.9 g/l in control), hematocrit (44.95±0.21 and 46.18±0.64 vs 43.78±0.32%) and the average content of Hb in erythrocytes (18.00±0.20 and 18.03±0.24 vs 17.35±0.24 pg). The absolute content of leukocytes and other cellular elements of the leukocyte formula, as well as leukocyte indices in rats of the experimental groups didn't significantly differ from those of the control rats, which confirms the absence of an inflammatory process. Intense physical activity and anthocyanin enrichment of the diet didn't have a significant effect on rat platelet parameters. Enrichment of the diet of rats of the 4th group with blueberry and black currant extract led to the activation of cellular immunity, as evidenced by a significant (p<0.01) increase in the percentage (from the total content of T-lymphocytes) of T-helpers (70.13 ±1.34 vs 63.75±0.99%) and a decrease in the relative content of cytotoxic T-lymphocytes (28.65±1.38 vs 34.71±0.95%) in comparison with those in rats of the 3rd group and at the level of the trend (р<0.1) - from the 1st group indexes (66.87±1.20 and 31.87±1.26%, accordingly). Intense physical activity led to a decrease in immunoregulatory index in rats of the 3rd group (1.86±0.07) compared with the control (2.13±0.12) (p<0.1), and in animals of the 4th group this indicator was significantly higher (2.50±0.14, p<0.05). In animals of the 3rd group a statistically significant (p<0.05) decrease in the relative content of NK cells in peripheral blood was found compared to the control. Enrichment of the diet of physically active rats with blueberry and black currant extract led to a significant (p<0.05) increase in the percentage of NK cells compared to this indicator in rats of the 3rd group (4.87±0.75 vs 2.08±0.18%) and had no significant difference with the indicator in rats of the control group (4.32±0.98%). Conclusion. The enrichment of the rats' diet with blueberry and blackcurrant extract containing a daily dose of 15 mg of anthocyanins per kg of body weight provides an increase in blood Hb content, hematocrit and the average content Hb in erythrocytes. It has been established that intense physical activity induces the cellular immunity suppression. The activating effect of anthocyanins on adaptive cellular immunity and NK cells, which are lymphocytes of innate immunity, was revealed. The data obtained indicate the effectiveness of the use of bioactive compounds (anthocyanins) to increase the adaptive potential of the organism.

Assessment and Management of Declining Physical Function in Aging Dogs.

Aging is the leading cause of disability, disease, and death in adult dogs. One major consequence of aging is diminishing physical function. For normal functioning, basic elements such as strength, balance, and energy must be present. These must then be integrated to enable higher levels of function, from simple walking and feeding to the complex demands of social roles, such as family companion or working search-and-rescue dog. Biological aging processes, such as loss of muscle strength, diminished cardiorespiratory function, chronic inflammation, and age-associated diseases, as well as the adverse effects of medical treatments, all contribute to physical dysfunction. Contextual elements, such as lack of opportunity for physical exercise or restricted access to veterinary care due to owner socioeconomic circumstances, also influence age-associated functional decline in dogs. In humans, well-established clinical assessments are available to evaluate physical function, and these can predict disability, morbidity, and mortality. There are also well-supported interventions that preserve and restore function and reduce the risk of death and disease in the elderly. Because the fundamental biology and the clinical phenotype of aging are very similar in humans and dogs, these assessments and interventions can likely be adapted for use in mitigating declining physical function in geriatric canines. This review evaluates the decline in physical function with age in dogs and the potential utility in this species of clinical assessment tools and interventions developed for humans.

Interactive effect of exercise training and growth hormone administration on histopathological and functional assessment of the liver in male Wistar rats.

BACKGROUND: Abuse of growth hormone (GH) is expanding in exercising populations due to its lipolytic and anabolic actions. The purpose of this study was to examine the interactive effect of exercise training and GH administration on histopathological and functional assessment in the liver of male Wistar rats. METHODS: Forty-eight male Wistar rats were randomly divided into six groups including control + saline group (CS), GH injection group (GI), resistance training + saline group (RS), aerobic training + saline group (AS), resistance training + GH injection group (RG), aerobic training + GH injection group (AG). All groups were injected with either saline or GH 1 h before each training session. RT and AT were performed five days/week for a total of 8-weeks. At the end of the study, blood samples and liver tissue samples were taken to evaluate circulating AST, ALT, and ALP enzymes, as well as albumin protein. Histopathology of liver tissue was performed via qualitative microscopic evaluation. RESULTS: Microscopic evaluation of liver tissue did not show any histopathologic changes. All the groups administered with GH showed a significant increase in ALT, ALP, and albumin protein (P<0.05). However, AST enzyme concentrations increased significantly only in the RG group (P=0.022). In addition, neither RS nor the AS groups showed significant AST, ALT, and ALP changes, but serum albumin concentration significantly increased in the AS group (P=0.033). CONCLUSIONS: The elevation of liver enzymes showed that GH administration with or without exercise training might cause severe liver damage.

The Sound World of Zebrafish: A Critical Review of Hearing Assessment.

Zebrafish, like all fish species, use sound to learn about their environment. Thus, human-generated (anthropogenic) sound added to the environment has the potential to disrupt the detection of biologically relevant sounds, alter behavior, impact fitness, and produce stress and other effects that can alter the well-being of animals. This review considers the bioacoustics of zebrafish in the laboratory with two goals. First, we discuss zebrafish hearing and the problems and issues that must be considered in any studies to get a clear understanding of hearing capabilities. Second, we focus on the potential effects of sounds in the tank environment and its impact on zebrafish physiology and health. To do this, we discuss underwater acoustics and the very specialized acoustics of fish tanks, in which zebrafish live and are studied. We consider what is known about zebrafish hearing and what is known about the potential impacts of tank acoustics on zebrafish and their well-being. We conclude with suggestions regarding the major gaps in what is known about zebrafish hearing as well as questions that must be explored to better understand how well zebrafish tolerate and deal with the acoustic world they live in within laboratories.

A survey on the orthopedic and functional assessment in a Portuguese population of police working dogs.

BACKGROUND: Working dogs are at an increased risk of developing an orthopedic disease compared to companion dogs. This study aimed to evaluate functional and orthopedic index fitness in a Portuguese population of police working dogs. In an observational, prospective study, information on 165 dogs was collected. The age, sex, breed, specific work, and history of previous diagnosis of orthopedic disease were recorded for each patient. A copy of the Canine Orthopedic Index (COI), Hudson Visual Analogue Scale (HVAS), and Functional Assessment (FA) was collected for all dogs. COI, HVAS, and FA scores between breeds, work, age, sex, and history of a previous diagnosis of orthopedic disease were compared. Multiple regression was run to predict COI, HVAS, and FA scores from breeds, work, age, sex, and history of orthopedic disease. Correlations between items were determined with Pearson's correlation. A p < 0.05 was set. RESULTS: The sample was composed of 92 males and 73 females, with a mean age of 5.2 ± 3.2 years. Four main dog breeds were represented, 60 Belgian Malinois Shepherd Dogs, 52 German Shepherd Dogs, 29 Labrador Retrievers, and 14 Dutch Shepherd Dog. A prevalence of diarrhea of 10.6% was determined, with 4% of dogs having liquid diarrhea. German Shepherd Dogs had significantly higher FA scores (p = 0.03). Dogs with a history of previous veterinary assistance due to orthopedic issues had significantly lower HVAS scores and higher scores with all remaining questionnaires (p < 0.01 for all). No differences were found between sexes or specific work. Age and a history of orthopedic disease contributed to the prediction of all scores. FA scores had a good correlation with COI and HVAS. CONCLUSION: This population of police working dogs has a good to excellent level of physical fitness. There was a relationship between increasing age, history of orthopedic disease, and worse scores with all questionnaires. All considered questionnaires could differentiate between animals with a previous history of orthopedic disease and sound dogs.

Simultaneous assessment of spontaneous cage activity and voluntary wheel running in group-housed mice.

Small animal models are frequently used to improve our understanding of the molecular and biological signaling pathways underlying the beneficial effects of physical activity and exercise. Unfortunately, when running wheels are employed, mice and rats are often kept single-housed to determine the individual running distance of each animal. However, social isolation can be stressful for rodents, and may alter an individual's propensity for or response to exercise. For example, increased stress from single housing may significantly affect the results when investigating systemic metabolic responses to exercise. We have combined two already available and well-established systems, a radiotelemetry system and a running wheel, to determine spontaneous cage activity (SCA) as well as voluntary exercise (VE) levels of the individual animal in group-housed rodents. Further, we developed a simple software tool which allows monitoring and analyzing the data. Specifically, the radiotelemetry-system utilizes radio-frequency identification via a small, implanted chip to determine the location of each animal. Since, in addition to the animals' position, also the location of the running wheel in the cage is known, the conclusion of which animal is exercising can be drawn. The developed software enables a fast and reliable assignment of the VE data to the individual animal and a simple analysis of the data collected. Hence, our combined method may be used to investigate the beneficial effects of physical activity, as well as the impact of therapeutic interventions on animal behavior in group-housed rodents.

Intergenerational Costs of Oxidative Stress: Reduced Fitness in Daughters of Mothers That Experienced High Levels of Oxidative Damage during Reproduction.

AbstractParental condition transfer effects occur when the parents' physiological state during reproduction affects offspring performance. Oxidative damage may mediate such effects, yet evidence that oxidative damage experienced by parents during reproduction negatively affects offspring fitness is scarce and limited to early life stages. We show in Japanese quail (Coturnix japonica) that maternal levels of oxidative damage, measured during reproduction, negatively predict the number of offspring produced by daughters. This maternal effect on daughters' reproductive success was mediated by an effect on hatching success rather than on the number of eggs laid by daughters. We also observed a negative association between fathers' oxidative damage levels and the number of eggs laid by daughters but a positive association between fathers' oxidative damage levels and the hatching success of those eggs. These opposing paternal effects canceled each other out, resulting in no overall effect on the number of offspring produced by daughters. No significant association between a female's own level of oxidative damage during reproduction and her reproductive success was observed. Our results suggest that oxidative damage experienced by parents is a better predictor of an individual's reproductive performance than oxidative damage experienced by the individual itself. Although the mechanisms underlying these parental condition transfer effects are currently unknown, changes in egg composition or (epi)genetic alterations of gametes may play a role. These findings highlight the importance of an intergenerational perspective when quantifying costs of physiological stress.

Assessment on In Vitro Probiotic Attributes of Lactobacillus plantarum Isolated From Horse Feces.

This study was designed to assess in vitro probiotic attributes of potent bacterium isolated from the feces of healthy horse. Initially, a total of eight bacteria were isolated from the feces and evaluated their antibacterial activities against indicator bacterial pathogens using agar well diffusion assay. Results showed significant (P < .05) antibacterial property of Lactobacillus plantarum strain LF4 against pathogens tested with maximum growth inhibitory activity of 320.16 ± 3.4 AU/mL against Staphylococcus aureus. Further, in vitro probiotic properties of strain LF4 were determined using standard methodologies. Strain LF4 maintained its viability towards acidic condition (pH 2.0) and simulated gastric juice (pH 2.0) with total cell counts of 1.6 ± 0.18 and 1.7 ± 0.18 log cfu/mL, respectively. Moreover, the strain was observed resistant to oxgall (0.5% w/v) up to 36 hours. The isolate showed significant (P < .05) hydrophobicity property (60.3 ± 1.6%), auto-aggregation trait (41.31 ± 1.5%), and moderate proteolytic activity. Strain LF4 revealed significant (P < .05) rate of DPPH scavenging (15.3 ± 1.3-69.7 ± 1.3%) and hydroxyl radical scavenging (11.3 ± 1.3 to 56.4 ± 1.3%) in a concentration dependent manner. Additionally, the isolate was observed susceptible to all the conventional antibiotics tested, thereby indicating its safer utilization. In conclusion, findings suggested the colossal applications of L. plantarum strain LF4 as an ideal probiotic bacterium in equine industries.

TLR4 deletion increases basal energy expenditure and attenuates heart apoptosis and ER stress but mitigates the training-induced cardiac function and performance improvement.

Strategies capable of attenuating TLR4 can attenuate metabolic processes such as inflammation, endoplasmic reticulum (ER) stress, and apoptosis in the body. Physical exercise has been a cornerstone in suppressing inflammation and dysmetabolic outcomes caused by TRL4 activation. Thus, the present study aimed to evaluate the effects of a chronic physical exercise protocol on the TLR4 expression and its repercussion in the inflammation, ER stress, and apoptosis pathways in mice hearts. Echocardiogram, RT-qPCR, immunoblotting, and histological techniques were used to evaluate the left ventricle of wild-type (WT) and Tlr4 knockout (TLR4 KO) mice submitted to a 4-week physical exercise protocol. Moreover, we performed a bioinformatics analysis to expand the relationship of Tlr4 mRNA in the heart with inflammation, ER stress, and apoptosis-related genes of several isogenic strains of BXD mice. The TLR4 KO mice had higher energy expenditure and heart rate in the control state but lower activation of apoptosis and ER stress pathways. The bioinformatics analysis reinforced these data. In the exercised state, the WT mice improved performance and cardiac function. However, these responses were blunted in the KO group. In conclusion, TLR4 has an essential role in the inhibition of apoptosis and ER stress pathways, as well as in the training-induced beneficial adaptations.

Behavioral Thermoregulation by Mothers Protects Offspring from Global Warming but at a Cost.

AbstractThermal conditions during embryonic development affect offspring phenotype in ectotherms. Therefore, rising environmental temperatures can have important consequences for an individual's fitness. Nonetheless, females have some capacity to compensate for potential negative consequences that adverse developmental environments may have on their offspring. Recent studies show that oviparous reptiles exhibit behavioral plasticity in nest site selection, which can buffer their embryos against high incubation temperatures; however, much less is known about these responses in viviparous reptiles. We subjected pregnant viviparous skinks, Saiphos equalis, to current or projected midcentury (2050) temperatures to test (i) how elevated temperatures affect female thermoregulatory and foraging behavior; (ii) whether temperatures experienced by females during pregnancy negatively affect the morphology, performance, and behavior of hatchlings; and (iii) whether behavioral thermoregulation during pregnancy is costly to females. Females from the elevated temperature treatment compensated by going deeper belowground to seek cooler temperatures and eating less, and they consequently had a lower body mass relative to snout-to-vent length (condition estimator) compared with females from the current thermal treatment. The temperatures experienced by females in the elevated temperature treatment were high enough to affect foraging and locomotor performance but not the morphology and growth rate of hatchlings. By seeking cooler temperatures, mothers can mitigate some of the effects of high temperatures on their offspring (e.g., reduced body size and growth). However, this protective behavior of females may come at an energetic cost to them. This study adds to growing evidence of lizards' vulnerability to global warming, particularly during reproduction when females are already paying a substantial cost.

Rider Energy Expenditure During High Intensity Horse Activity.

Despite the fact that horseback riding is a popular sport, there is little information available on horseback riding as a physical activity. The objective of this experiment was to quantify energy expenditure of participants (n=20) during three riding tests: a 45min walk-trot-canter ride (WTC), a reining pattern ride and a cutting simulation ride while wearing a telemetric gas analyzer. Total energy expenditure (tEE), mean and peak metabolic equivalents of task (MET), heart rate (HR), respiratory frequency (RF), relative oxygen consumption (relVO2), and respiratory exchange ratio (RER) were assessed. Mean MET and HR responses were greater (P < .05) for riders during the long trot portion of the WTC (6.19 ± 0.21 MET, 152.14 ± 4.4 bpm) and cutting (4.53±0.21 MET, 146.88 ± 4.4 bpm) vs the overall WTC (3.81 ± 0.16 MET, 131.5 ± 4.2 bpm). When WTC was evaluated by gait, mean MET increased as gait speed increased. As expected, METs were greater (P < .05) for riders during long trot (6.19 ± 0.21 MET) and canter (5.95 ± 0.21 MET) than during the walk (2.01 ± 0.21 MET) or trot (3.2 ± 0.21 MET). Previous horseback riding studies have not reported METs, but the peaks of all three activities in the present study were similar to METs measured during activities like jogging, playing soccer and rugby. Riders engaged in cutting and reining experienced more intense exercise in short durations, while, as expected on the basis of the duration of the activity, WTC provided a greater overall total energy expenditure. These results suggest that it is possible for health benefits to be achieved through accumulated horseback riding exercise, particularly if riding at the more intense gaits.

Four weeks of high-intensity training in moderate, but not mild hypoxia improves performance and running economy more than normoxic training in horses.

We investigated whether horses trained in moderate and mild hypoxia demonstrate greater improvement in performance and aerobic capacity compared to horses trained in normoxia and whether the acquired training effects are maintained after 2 weeks of post-hypoxic training in normoxia. Seven untrained Thoroughbred horses completed 4 weeks (3 sessions/week) of three training protocols, consisting of 2-min cantering at 95% maximal oxygen consumption V˙O2max under two hypoxic conditions (H16, FI O2  = 16%; H18, FI O2  = 18%) and in normoxia (N21, FI O2  = 21%), followed by 2 weeks of post-hypoxic training in normoxia, using a randomized crossover study design with a 3-month washout period. Incremental treadmill tests (IET) were conducted at week 0, 4, and 6. The effects of time and groups were analyzed using mixed models. Run time at IET increased in H16 and H18 compared to N21, while speed at V˙O2max was increased significantly only in H16. V˙O2max in all groups and cardiac output at exhaustion in H16 and H18 increased after 4 weeks of training, but were not significantly different between the three groups. In all groups, run time, V˙O2max , VV˙O2max , Q˙max , and lactate threshold did not decrease after 2 weeks of post-hypoxic training in normoxia. These results suggest that 4 weeks of training in moderate (H16), but not mild (H18) hypoxia elicits greater improvements in performance and running economy than normoxic training and that these effects are maintained for 2 weeks of post-hypoxic training in normoxia.

Daily energy expenditure in rats following structured exercise training is affected by dietary phosphorus content.

P ingestion has been found to alter energy balance, while regular physical exercise (E) was reported to be associated with energy compensation. However, it is not clear whether dietary P would affect energy compensation following structured E. Two experiments were performed, low P (LP) (0·1, 0·2 and 0·3 %P) and high P (HP) (0·3 , 0·6 and 1·2 %P) diets. In each experiment, male rats were randomly divided into three groups (n 8), in which a sedentary or a moderate-intensity exercise routine (30 min 5 d a week) was implemented. Energy intake (EI); efficiency and stores; body measures and total energy expenditure (TEEx) were monitored for 6 weeks. In the LP experiment, EI and weight gain were the lowest in the 0·1 and 0·2 %P as compared with the 0·3 %P. In the HP experiment, EI was highest in the high P (0·6 and 1·2 %P) groups, while weight gain was reduced. In both experiments, exercise was able to reduce body fat accumulation and to maintain a higher % lean body mass. In the LP diets experiment, the similarity in TEEx between the sedentary and exercising groups suggests the probability of a reduction in normal daily activities, which indicates the presence of compensation for the energy expended during exercise by a subsequent reduction in EE. In contrast, the elevated TEEx in the HP exercising groups (0·6 and 1·2 %P) argue against the presence of energy compensation. In conclusion, high dietary P decreases the body's capability to compensate for the energy deficit induced by E, consequently maintaining an elevated TEEx.

The energy savings-oxidative cost trade-off for migratory birds during endurance flight.

Elite human and animal athletes must acquire the fuels necessary for extreme feats, but also contend with the oxidative damage associated with peak metabolic performance. Here, we show that a migratory bird with fuel stores composed of more omega-6 polyunsaturated fats (PUFA) expended 11% less energy during long-duration (6 hr) flights with no change in oxidative costs; however, this short-term energy savings came at the long-term cost of higher oxidative damage in the omega-6 PUFA-fed birds. Given that fatty acids are primary fuels, key signaling molecules, the building blocks of cell membranes, and that oxidative damage has long-term consequences for health and ageing, the energy savings-oxidative cost trade-off demonstrated here may be fundamentally important for a wide diversity of organisms on earth.

The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days.

The effects of feeding frequency on postprandial response of circulating appetite-regulating hormones, insulin, glucose and amino acids, and on physical activity, energy expenditure, and respiratory quotient were studied in healthy adult cats. Two experiments were designed as a 2 x 3 replicated incomplete Latin square design. Eight cats, with an average body weight (BW) of 4.34 kg ± 0.04 and body condition score (BCS) of 5.4 ± 1.4 (9 point scale), were fed isocaloric amounts of a commercial adult maintenance canned cat food either once (0800 h) or four times daily (0800 h, 1130 h, 1500 h, 1830 h). Study 1 consisted of three 21-d periods. On day 14, two fasted and 11 postprandial blood samples were collected over 24 hours to measure plasma concentrations of ghrelin, GLP-1, GIP, leptin, PYY, insulin and amino acids, and whole blood glucose. Physical activity was monitored from day 15 to 21 of each period. In Study 2 indirect calorimetry was performed on the last day of each period. Body weight was measured weekly and feed intake recorded daily in both experiments. No effect of feeding regimen on BW was detected. Cats eating four times daily had lesser plasma concentrations of GIP and GLP-1 (P<0.05) and tended to have lesser plasma PYY concentrations (P<0.1). Plasma leptin and whole blood glucose concentrations did not differ between regimens (P>0.1). Cats fed once daily had a greater postprandial plasma amino acid response, and greater plasma ghrelin and insulin concentrations (P<0.05). Physical activity was greater in cats fed four times (P<0.05), though energy expenditure was similar between treatments at fasting and in postprandial phases. Finally, cats eating one meal had a lower fasting respiratory quotient (P<0.05). Overall, these data indicate that feeding once a day may be a beneficial feeding management strategy for indoor cats to promote satiation and lean body mass.