The impact of bio-logging on body weight change of the Eurasian beaver

Bio-logging is a common method to collect ecological data on wild animals, but might also induce stress, reduce body condition, and alter behavior. Eurasian beavers (Castor fiber) are a semi-aquatic and nocturnal species that are challenging to observe in the wild. Bio-loggers are hence useful tools to study their behaviour and movements, but this raises concerns of potential negative impacts of tagging. To investigate the potential negative impacts of glue-on tags, we compared body weight change for tagged and untagged Eurasian beavers. We hypothesized that tagged beavers would gain less body weight compared to untagged beavers, and that weight change might be affected by tagging length, tag weight, water temperature and the season of tagging. Daily percentage body weight change in relation to initial body weight during the first capture was compared during 57 tagging periods (18±7 days) and 32 controls periods (64±47 days). Body weight change varied between the two groups, with untagged beavers on average gaining daily weight whilst tagged beavers on average lost weight daily, indicating a negative effect of tagging. The average reduction in percentage body weight change per day for tagged beavers was small (0.1 ± 0.3%), and with large individual variation. Neither tag weight, number of tagging days, nor season were important in explaining body weight change of tagged animals. In other words, we found that tagging reduced daily body weight during the tagging period but were unable to determine the mechanism(s) responsible for this decline. Detrimental effects of tagging have important implications for animal welfare and can introduce bias in data that are collected. This calls for careful consideration in the use of tags. We conclude that studies investigating the effects of tagging should consider individual variation in the effects of tagging and, where possible, compare tagged animals with a control group.

Association of long-term body weight variability with dementia: a prospective study

Background Body weight variability (BWV) refers to intraindividual weight loss and gain over a period. The association of long-term BWV with dementia remains unclear and whether this association is beyond body weight change is undetermined. Methods In the Health and Retirement Study (HRS), a total of 5,547 dementia-free participants (56.7% women; mean [SD] age, 71.1 [3.2] years) at baseline (2008) were followed up to 8 years (mean=6.8 years) to detect incident dementia. Body weight was self-reported biennially from 1992-2008. BWV was measured as the coefficient of variation utilizing the body weight reported 9 times across 16 years before baseline. Cox proportional hazard model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI). Results Among the 5,547 participants, a total of 427 incident dementia cases were identified during follow-up. Greater long-term BWV was significantly associated with a higher risk of dementia (HR comparing extreme quartiles: 2.01, 95% CI: 1.48-2.72; HR of each SD increment: 1.21, 95% CI: 1.10-1.32; P-trend<0.001) independent of mean body weight and body weight change. This significant association was even observed for BWV estimated approximately 15 years preceding dementia diagnosis (HR of each SD increment: 1.13, 95% CI: 1.03-1.23) and was more pronounced for that closer to diagnosis. Conclusions Our prospective study suggested that greater BWV may be a novel risk factor for dementia.

509 Late-Breaking: Effect of a Sensory Additive on Sow Reproductive Performance

The addition of a sensory additive to sow diets during the summer improved feed intake during lactation, and litter performance. The aim of this study was to evaluate the impact of the sensory additive on sow lactation performance during cooler temperatures. Three consecutive groups (n = 61 total) of sows were farrowed during winter (October, December and January). Sows were weighed, and back fat depth was measured, at 110 d of gestation prior to entering the lactation room, and again at weaning. The sows were sorted by parity, and then allotted by BW at d 110 to Control or 0.075% sensory additive (Luctamax® SowVive, Lucta S.A., Spain). Experimental diets were offered upon entry to the lactation room and fed through weaning. Feed disappearance was recorded every three days. Sows were fed 2.72 kg/head/day until farrowing, and then allowed to eat ad libitum from 24 hours post-farrowing until weaning. Data were analyzed using the PROC MIXED procedure of SAS as an RCBD with treatment as the fixed effect and group as a random effect. No differences were observed on sows feed intake (P > 0.4), 10th rib backfat thickness change (P = 0.632) and body weight change from d 110 of gestation to weaning (P = 0.65, Table 1). Sows fed the sensory additive lowered preweaning mortality by 4.9% (P = 0.051), and weaned an additional 1.42 piglets (P = 0.026) with similar weaning weights (P = 0.86) when compared to control. In conclusion, in the current study, lactation diets supplemented with a sensory additive improved litter performance and helped maintain sow body condition.

Longitudinal Body Weight Change, Visit-To-Visit Body Weight Fluctuation, and Cognitive Decline Among Older Adults

Background: The evidence regarding dementia and late-life weight change is inconsistent, and data on body weight fluctuation and dementia are limited. Objective: To test the hypothesis that weight loss and substantial weight fluctuation predict cognitive decline independent of body weight and traditional risk factors of dementia. Methods: This study utilized longitudinal data from the National Alzheimer’s Coordinating Center for 10,639 stroke- and dementia-free older adults (60.9%female, mean age 71.6 years, median follow-up 5.5 years). Trends in weight change and weight fluctuation were estimated for each individual by regressing repeated body weight measurements on time. Cognitive decline was examined as diagnostic progression from normal to mild cognitive impairment (MCI) or dementia and from MCI to dementia. Results: Compared to participants with stable weight, those with weight loss had increased odds of diagnostic progression (adjusted OR = 1.35, 95%CI [1.21, 1.51]). Also, large weight fluctuation was associated with increased odds of diagnostic progression (OR comparing the extreme quartiles = 1.20, 95%CI [1.04, 1.39]) after adjusting for traditional risk factors for dementia and body weight change. The magnitude of the association appeared larger among those older than 80 and those with 3 or more cardiometabolic risk factors at baseline (both p for interaction < 0.05). Conclusion: Weight loss and substantial weight fluctuation during late-life were associated with increased odds of cognitive decline independent of body weight and traditional risk factors of dementia. Our results suggested the linkage between late-life body weight instability and cognitive decline especially among those with greater age or higher cardiometabolic risk.

Attitude Matters! How Attitude towards Bariatric Surgery Influences the Effects of Behavioural Weight Loss Treatment

<b><i>Introduction:</i></b> Multidisciplinary obesity services at university hospitals usually treat patients with more complex and severe obesity. In addition, patients with Class 3 obesity, in particular, have different attitudes regarding the choices of therapy. <b><i>Methods:</i></b> This explorative study investigated the effect of patient attitudes towards bariatric surgery on body weight change (primary outcome) and psychological improvement (secondary outcomes: quality of life, depression, anxiety, and eating behaviour) in a 6-month moderate behavioural weight loss (BWL) programme in a university outpatient setting. <b><i>Results:</i></b> 297 patients with mostly Class 3 obesity participated in the programme. The patients did not yet have any indications for bariatric surgery. Of the participants, 37% had a positive attitude towards bariatric surgery (POS), whereas 38% had a negative attitude (NEG). The drop-out rate was 8%. NEG participants lost significantly more body weight than the POS participants (intention-to-treat population: 4.5 [SD: 6.3] kg versus 0.4 [SD: 5.8] kg; <i>p</i> &#x3c; 0.001). In both subgroups, anxiety, depression, the mental score for quality of life, and eating behaviour improved. <b><i>Conclusion:</i></b> A BWL treatment in a clinical setting identified 2 distinct groups with different attitudes towards bariatric surgery that were associated with different body weight change outcomes. These groups may require differently targeted programmes to achieve the best body weight loss results.