scholarly journals Effects of incremental exercise and dietary tryptophan supplementation on the amino acid metabolism, serotonin status, stool quality, fecal metabolites, and body composition of mid-distance training sled dogs

2020 ◽  
Vol 98 (5) ◽  
Author(s):  
James R Templeman ◽  
Emma Thornton ◽  
Cara Cargo-Froom ◽  
Eli J Squires ◽  
Kelly S Swanson ◽  
...  

Abstract Exercise improves the health of dogs; however, the extreme exertion experienced by sled dogs may lead to variable metabolic and fecal characteristics. Nutritional interventions, such as dietary tryptophan (Trp), may reduce the prevalence of these exercise-induced disturbances. Sporting diets tend to have high crude protein concentrations in contrast to adult maintenance diets and this results in less Trp relative to other amino acids (AA). Therefore, sporting dogs represent an ideal cohort to assess the effects of supplemental Trp. The objective was to evaluate the effects of supplemental dietary Trp and an incremental training regimen on AA and serotonin status, fecal scores and metabolites, and body composition in client-owned Siberian huskies. Sixteen dogs (nine females and seven males) were used, with a mean age of 4.8 ± 2.5 yr and body weight (BW) of 24.3 ± 4.3 kg. Dogs were blocked for sex, age, and BW and randomly allocated into two groups with eight fed a dry extruded control diet (Ctl) and eight fed Ctl supplemented with Trp to reach a Trp:large-neutral AA (LNAA) ratio of 0.075:1 (treatment, Trt). The exercise regimen was designed to increase in distance each week, but weather played a role in setting the daily distance. Each week BW was recorded and food allotments were adjusted to maintain initial BW. Pre and post-exercise blood samples were taken every 3 wk, dogs then received a meal followed by 1, 2, and 4 h post meal blood collections (serum AA, serotonin). Stool collection and scoring occurred each week and body composition was measured on weeks −1 and 11. Serotonin, AA, fecal metabolite, and body composition data were analyzed using PROC MIXED of SAS with dog as a random effect and week and Trt as fixed effects. Stool score data were analyzed using PROC FREQ to compare stool score and Trt, and PROC CORR was used to analyze associations between fecal score, temperature, humidity, and run distance. Dogs on Trt had greater fasted Trp compared with baseline, greater post-meal Trp and serotonin compared with baseline, greater post-meal Trp compared with fasted, and greater post-meal Trp and serotonin compared with Ctl (P < 0.05). Fecal data indicated that Trp improved stool scores (P < 0.05) yet had no effect on fecal metabolites. An overall increase in lean and decrease in fat mass was found (P < 0.05), but Trt had no effect on body composition. Optimization of the dietary Trp:LNAA ratio may help to improve GI health without compromising performance in actively training sled dogs.

2020 ◽  
Vol 7 (3) ◽  
pp. 97 ◽  
Author(s):  
Emma Thornton ◽  
James R. Templeman ◽  
Michael Bower ◽  
John P. Cant ◽  
Graham P. Holloway ◽  
...  

Tryptophan (Trp), an indispensable amino acid for dogs, is the precursor of serotonin, a neurotransmitter with a variety of effects throughout the body, including the ability to modulate cardiac and pulmonary activity. This study aimed to investigate the effects of a 12-week incremental exercise regimen and supplemental dietary Trp on heart rate (HR) and respiratory rate (RR) in client-owned sled dogs. Sixteen Siberian huskies were randomly allocated to either treatment or control diet groups. Both groups were fed a control diet (Trp to large neutral amino acid ratio of 0.047:1); however, treatment dogs received a Trp supplement to achieve a Trp to large neutral amino acid ratio of 0.075:1. Every three weeks, external telemetry equipment was used to non-invasively measure and record HR and RR at a resting, working, and post-exercise state in a controlled exercise challenge. A mixed model was used to test differences between diet, activity parameter, and week. Dietary Trp supplementation had no effect on HR or RR. Independent of diet, resting, working, post-exercise HR, and time to recover post-exercise HR decreased from week −1 to week 11 (p < 0.05). Resting HR had the greatest reduction from week −1 to week 11 (21%, p < 0.05). Working RR did not change with exercise (p > 0.10), but rRR and postRR decreased from week −1 to week 11 (p < 0.05). These data suggest that the exercise regimen the dogs were subjected to may have positively impacted the dogs’ capacity to sustain aerobic exercise, whereas Trp supplementation had no effect on HR or RR.


2021 ◽  
Vol 8 ◽  
Author(s):  
Emma Thornton ◽  
Eve Robinson ◽  
James R. Templeman ◽  
Lindy Bruggink ◽  
Michael Bower ◽  
...  

Dietary fiber affects canine physiology in many ways, such as increasing colonic absorption of water and improving gut health, both of which may positively impact exercise performance. The objectives of this study were to investigate the effects of increased dietary soluble fiber and incremental training on respiratory rate (RR), internal body temperature (BT), body composition, and fecal metabolites in mid-distance training sled dogs. Fourteen dogs (12 Siberian and 2 Alaskan Huskies) were blocked by age, sex, and body weight (BW) and then randomly allocated into one of two diet groups. Seven dogs were fed a dry extruded control diet (Ctl) with an insoluble:soluble fiber ratio of 4:1 (0.74% soluble fiber on a dry-matter basis), and seven dogs were fed a dry extruded treatment diet (Trt) with an insoluble:soluble fiber ratio of 3:1 (2.12% soluble fiber on a dry-matter basis). Fecal samples were taken once a week. All dogs underwent 9 weeks of incremental exercise conditioning where the running distance was designed to increase each week. Every 3 weeks, external telemetry equipment was used to non-invasively measure and record RR and internal BT at resting, working, and post-exercise recovery states. Body composition was measured on weeks −1 and 9 using quantitative magnetic resonance. Body composition, RR, BT, and fecal metabolites were analyzed using a mixed model with dog as a random effect and week and diet group as fixed effects. Dogs on Trt had lower working and post-exercise BT than Ctl (P &lt; 0.05). In addition, Trt dogs had lower recovery BT at weeks 2 and 5 than Ctl dogs (P &lt; 0.05). Treatment dogs had greater fecal short-chain fatty acid concentrations than Ctl (P &lt; 0.05). Diet had no effect on RR or body composition (P &gt; 0.10), but exercise resulted in an overall 7% increase in lean and 3.5% decrease in fat mass (P &lt; 0.05). These data suggest that increasing dietary soluble fiber may positively influence BT and gut health; however, it has no effect on RR or body composition. Soluble fiber did not negatively impact any measures of overall health and performance and should be considered for use in performance dogs.


2018 ◽  
Vol 18 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Mervyn Travers ◽  
Penny Moss ◽  
William Gibson ◽  
Dana Hince ◽  
Sheree Yorke ◽  
...  

Abstract Background and aims: Exercise-induced hypoalgesia (EIH) is a well-established phenomenon in pain-free individuals that describes a decrease in pain sensitivity after an acute bout of exercise. The EIH response has been demonstrated to be sub-optimal in the presence of persisting pain. Menstrual pain is a common recurrent painful problem with many women experiencing high levels of pain each cycle. However, the EIH response has not been examined in a cohort of women with high levels of menstrual pain. This research aimed to examine whether EIH manifests differently in women with varying levels of menstrual pain. The primary hypothesis was that women with high levels of menstrual pain would demonstrate compromised EIH. Secondary aims were to explore relationships between EIH and emotional state, sleep quality, body mass index (BMI) or physical activity levels. Methods: Pressure pain thresholds (PPT) were measured in 64 participants using a digital handheld algometer before and after a submaximal isometric-handgrip exercise. EIH index was compared between low (VAS 0–3), moderate (VAS 4–7) and high (VAS 8–10) pain groups, using a linear mixed model analysis with participant as a random effect, and site, menstrual pain category and the interaction between the two, as fixed effects. Results: EIH was consistently induced in all groups. However, there was no statistically significant difference between the pain groups for EIH index (p=0.835) or for any co-variates (p>0.05). Conclusions: EIH was not found to differ between women who report regular low, moderate or high levels of menstrual pain, when measured at a point in their menstrual cycle when they are pain free. Implications: This study provides insight that EIH does not vary in women with differing levels of menstrual pain when they are not currently experiencing pain. The current findings indicate that, although menstrual pain can involve regular episodes of high pain levels, it may not be associated with the same central nervous system dysfunctions as seen in sustained chronic pain conditions.


2020 ◽  
Vol 98 (10) ◽  
Author(s):  
Brooke N Smith ◽  
Melissa Hannas ◽  
Catiane Orso ◽  
Simone M M K Martins ◽  
Mei Wang ◽  
...  

Abstract This study investigated the effects of dietary osteopontin (OPN)-enriched algal protein on growth, immune status, and fecal fermentation profiles of weaned pigs challenged with a live infection of F18-fimbriated enterotoxigenic E. coli (ETEC). At 21 d of age, 54 pigs (5.95 ± 0.28 kg BW; blocked by BW) were allotted to 1 of 3 experimental groups combining dietary and health statuses. A control diet, containing 1% wild-type algal protein, was fed to both sham-inoculated (NC) and ETEC-inoculated (PC) pigs, while the test diet contained 1% OPN-enriched algal protein as fed only to ETEC-inoculated pigs (OA). All pigs received their assigned dietary treatment starting at study initiation to permit a 10-d acclimation period prior to inoculation. Growth performance, fecal dry matter, as well as hematological, histopathological, immune, and microbiota outcomes were analyzed by ANOVA, where treatment and time were considered as fixed effects and pig as a random effect; significance was accepted at P &lt; 0.05. Overall, ETEC-inoculated pigs (PC and OA) exhibited decreased (P &lt; 0.05) ADG and G:F, as well as increased (P &lt; 0.05) peripheral blood helper T-cells and total leukocyte counts, compared with NC pigs during the postinoculation period. The OA treatment also elicited the highest (P &lt; 0.05) concentrations of circulating tumor necrosis factor-α and volatile fatty acid concentrations in luminal contents at various postinoculation time-points, compared with other treatments. A principal coordinate analysis based on Unifrac weighted distances indicated that NC and OA groups had similar overall bacterial community structures, while PC pigs exhibited greater diversity, but infection status had no impact on α-diversity. Osteopontin-specific effects on microbial community structure included enrichment within Streptococcus and Blautia genera and decreased abundance of 12 other genera as compared with PC pigs. Overall, ETEC-infected pigs receiving 1% OPN-enriched algal protein exhibited changes immunity, inflammatory status, and colonic microbial community structure that may benefit weanling pigs experiencing F18 ETEC infection.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 219-220
Author(s):  
Ezequias Castillo-Lopez ◽  
Raul Rivera-Chacon ◽  
Sara Ricci ◽  
Nicole Reisinger ◽  
Qendrim Zebeli

Abstract The aim was to evaluate the effect of changing from forage to a high grain diet on chewing, feed sorting and lying behavior of cows supplemented with or without a phytogenic feed additive. Nine cows were blocked in two groups and used in a change-over design. Each experimental run consisted of one week of forage feeding, one week of diet transition, and four weeks of high grain feeding (65% concentrate). During the washout period of 10 weeks between the two runs, cows grazed on pasture. Cows were fed either a control diet (CON) or a diet with a phytogenic additive (PHY) based on menthol, thymol and eugenol. Data on chewing, feed sorting and lying behavior were analyzed using SAS with week of feeding and supplementation as fixed effects, and cow as random effect. Data across weeks from the same cow were processed using a first order variance-covariance structure matrix taking into account that the covariance decays with time. We found a reduction (P &lt; 0.01) in rumination time by 53% with diet change. Within the high grain feeding, rumination reached lowest value in the second week (160 min/d). The high grain diet increased (P &lt; 0.01) selection for long size particles by 20%. Although lying time was not affected immediately after diet change, it increased (P &lt; 0.01) by 8% from the second week of high grain consumption. In the fourth week of grain feeding, there was a tendency for PHY to increase rumination (P = 0.07) and total chewing time (P = 0.10), but with no effect on sorting for fiber or lying time. The high grain diet decreased chewing and standing time, and increased sorting for fibrous ingredients especially after one week of feeding. The phytogenic feed additive may contribute to stimulate chewing in long term supplementation.


2018 ◽  
Vol 14 (2) ◽  
pp. 91-97 ◽  
Author(s):  
J.A. Baker ◽  
M.S. Davis

Our objective was to evaluate the effect of conditioning and hypoxia on rectal and gastrointestinal temperature changes in dogs exercising at cold ambient temperature. Six Alaskan Husky sled dogs, each in a physically conditioned and unconditioned state, were used in the prospective study. Dogs in peak physical condition were run untethered on a treadmill under normoxic and hypoxic conditions of 20 and 12.5% environmental oxygen concentration, respectively, on separate days. After undergoing a deconditioning period of four months, the same dogs were run again under the same environmental conditions of 20 and 12.5% O2. Body temperature measurements were obtained via digital rectal thermometer and ingestible gastrointestinal thermistor at baseline, every 5 min for 30 min of exercise, and for 15 min following cessation of exercise. Under hypoxic conditions, peak gastrointestinal temperature was lower in conditioned vs unconditioned dogs. Gastrointestinal cooling was faster in conditioned dogs under normoxic conditions only. There was no difference in the peak rectal temperature, or rate of rectal temperature cooling in either normoxic or hypoxic conditions. 3 of 6 (50%) of the conditioned dogs reached a plateau temperature after approximately 20 to 25 min. This was observed less frequently when the dogs were unconditioned. Gastrointestinal and rectal temperatures reacted differently to exercise depending on conditioning or environmental oxygen concentration and this suggests that they cannot be used interchangeably to assess body temperature. Under these conditions, conditioning had no effect on rectal temperature. Presence of a plateau effect of rectal or gastrointestinal temperature may demonstrate a thermoregulatory balance of heat production and heat loss and may be a helpful measure in assessing individual dogs’ level of conditioning with regard to resistance to thermal stress.


2015 ◽  
Vol 11 (4) ◽  
pp. 245-248
Author(s):  
H.W. Huneycutt ◽  
M.S. Davis

Previous necropsy studies have shown that up to 60% of sled dogs competing in endurance sled dog races have areas of muscle damage. Human athletes and trainers have maintained a strong belief, based mostly on personal experiences, that massage can be effective for pre-race preparation and expedited recovery between consecutive events. We proposed that massage could lessen the degree of creatine phosphokinase (CPK) release when utilised prior to endurance activities. A randomised crossover study was performed using minimally conditioned sled dogs from a sled dog racing kennel. Each dog in the treatment group received a 14 min massage immediately prior to controlled endurance exercise. The pre-exercise CPK activity was 64±11 IU/l (mean ± standard deviation). The difference between pre-exercise CPK and post-exercise CPK for both groups was expressed as delta CPK. The delta CPK for the massage group was 62±22 IU/l and 74±55 IU/l for the control group. There was no significant change in concentration of CPK between pre- and post-exercise in the treatment and control group (P=0.2282). The lack of a significant difference between the control and massage group suggests that pre-exercise massage may not reduce the severity of exercise-induced muscle damage.


2012 ◽  
Vol 69 (11) ◽  
pp. 1881-1893 ◽  
Author(s):  
Verena M. Trenkel ◽  
Mark V. Bravington ◽  
Pascal Lorance

Catch curves are widely used to estimate total mortality for exploited marine populations. The usual population dynamics model assumes constant recruitment across years and constant total mortality. We extend this to include annual recruitment and annual total mortality. Recruitment is treated as an uncorrelated random effect, while total mortality is modelled by a random walk. Data requirements are minimal as only proportions-at-age and total catches are needed. We obtain the effective sample size for aggregated proportion-at-age data based on fitting Dirichlet-multinomial distributions to the raw sampling data. Parameter estimation is carried out by approximate likelihood. We use simulations to study parameter estimability and estimation bias of four model versions, including models treating mortality as fixed effects and misspecified models. All model versions were, in general, estimable, though for certain parameter values or replicate runs they were not. Relative estimation bias of final year total mortalities and depletion rates were lower for the proposed random effects model compared with the fixed effects version for total mortality. The model is demonstrated for the case of blue ling (Molva dypterygia) to the west of the British Isles for the period 1988 to 2011.


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 54-55
Author(s):  
Leigh Ruckman ◽  
Stacie Gould ◽  
John Patience

Abstract Mycotoxins may not be an issue every year, but the proper environmental conditions can cause a spike in contaminated grains and cause severe economic impact on pork producers. The objective of this study was to determine the effect of naturally occurring infections of deoxynivalenol, zearalenone and fumonisins (DZF) on growth performance and carcass parameters in grow/finish pigs. One hundred pigs (BW 34.0 ± 0.9 kg; L337 × Camborough, PIC, Hendersonville, TN) were randomly assigned to 1 of 2 dietary treatments with 10 split-sex pens/treatment. The control diet (CTL) contained low levels of DZF and the CTL+DFZ diet contained high levels of DZF. Diets were fed in 4 phases over the 126-d experiment period. The CTL diet contained 1.6, 1.6, 1.8 and 1.2 mg deoxynivalenol/kg and CTL+DZF contained 9.2, 6.9, 5.8 and 3.8 mg deoxynivalenol/kg in the 4 diet phases, respectively. The CTL contained 0.30, 0.32, 0.51 and 0.32 mg zearalenone/kg and 0.7, 0.8, 0.8 and 0.9 mg total fumonisins/kg; CTL+DFZ contained 0.59, 0.72, 0.86 and 0.57 mg zearalenone/kg and 1.0, 1.1, 1.2 and 0.9 mg total fumonisins/kg for phases one through four, respectively. Data were analyzed using PROC MIXED of SAS (9.4) with treatment, sex, and their interaction as fixed effects. Compared to CTL, feeding CTL+DFZ decreased final BW (130.3 vs 120.5 kg; P&lt; 0.001), ADG (0.95 vs 0.79 kg/d; P&lt; 0.001), ADFI (2.73 vs 2.49 kg/d; P=0.016), and G:F (0.35 vs 0.32; P=0.043). Feeding CTL+DFZ decreased HCW (92.3 vs 89.4 kg; P=0.024) and increased dressing percentage (70.9 vs 74.3%; P=0.009) and tended to reduce loin depth (7.0 vs 6.8 cm; P=0.057) compared to CTL. Diet did not affect backfat depth or lean percentage (P &gt;0.10). In conclusion, diets naturally contaminated with multiple mycotoxins reduced growth performance and adversely affected carcass parameters; pigs did not adapt over time to the mycotoxins.


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