Food for rumination : developing novel feeding strategies to improve the welfare of veal calves

Summary of thesis entitled: “Food for Rumination – Developing novel feeding strategies to improve the welfare of veal calves”, Laura Webb Veal calves are typically fed high levels of milk replacer supplemented with solid feed, which tends to contain a relatively small roughage component. Feeding strategies used in veal production have been associated with welfare issues, including the development of abnormal oral behaviours (AOB) and poor gastrointestinal health. AOB include tongue playing, excessive oral manipulation of the environment, grazing of the coat of other calves, and sham chewing, and are thought to develop in calves when chewing activity (i.e. eating and rumination) is not adequately stimulated. Common gastrointestinal health issues include poor rumen development and lesions in the abomasum. The aim of this thesis was to develop novel feeding strategies to improve the welfare of veal calves, i.e. to minimise the development of AOB and gastrointestinal health disorders as well as maximise chewing activity. The EU legislation stipulates a minimum of 250 g of `fibrous feed' for 20 week-old calves, but this amount does not seem supported by previous research in terms of it optimising calf welfare. In addition, it does not specify what fibrous feed refers to in terms of source and particle length of roughage. Developing novel feeding strategies for calves necessitates a better understanding of how different roughage characteristics might affect behaviour and gastrointestinal health, and this is what was investigated in Chapter 2. Because none of the single roughage sources investigated were able to improve both behaviour and health, it is likely that a combination of roughage sources would be optimal. For example, an appropriate diet choice may include a combination of roughage sources that facilitate good ruminal papillae development (e.g. maize silage), minimise plaque formation, and encourage both rumen muscularisation and rumination (e.g. straw). This chapter also suggested that hay, as a roughage source with both high levels of structure and high levels of fermentable fibre, could achieve both objectives of encouraging rumination and rumen development. Hay, however, is not used in veal production due to its high iron content that would lead to darker meat colour, which is less preferred by consumers. In Chapter 3, different amounts of a solid feed mixture were fed to calves and behaviour was monitored. The results showed that calves fed no solid feed on top of their milk replacer still displayed a rumination-like behaviour, which was in previous literature referred to as `sham chewing'. This result gives an indication as to the importance of rumination in calves. Moreover, this chapter failed to find a straightforward linear relationship between amount of solid feed provided and level of AOB displayed. Certain amounts of solid feed were found to initially stimulate chewing activity to a high level, but later, as calves grew older and more experienced with roughage, failed to stimulate chewing above the level displayed by calves fed no solid feed. Providing such an amount of roughage seemed to be more detrimental in terms of behaviour than providing an amount that results in a constant level of chewing activity throughout the fattening period. In order to develop animal-friendly feeding strategies, it is important to know what the animals would choose when given free choice. Therefore, in Chapter 4, the feed preferences of calves for milk replacer, concentrate, hay, straw and maize silage were investigated. This study showed that at 6 months, calves selected on average approximately 1250 g dry matter (DM) milk replacer, 1000 g DM roughage and 2000 g DM concentrate. Although all calves with free choice showed high levels of chewing activity and subsequently low levels of AOB, large individual differences existed in intake levels and feed preferences. Moreover, outcomes were dependent on the variable used to assess preferences: i.e. intake (in g DM relative to metabolic body weight), duration of feeding, or number of visits to each diet component. On average, however, calves showed a preference for milk replacer, concentrate and hay, over straw and maize silage. In contrast to free choice testing, as was used in Chapter 4, double demand operant conditioning gives an indication as to the strength of a preference. In Chapter 5, different methods to analyse data collected from double demand operant conditioning studies were investigated. Due to the dependence level between the two resources presented simultaneously, i.e. at any given time the test animal can only work for one resource, it would seem that proportions of rewards achieved for one resource over the total number of rewards achieved for both resources would be an adequate dependent variable in this type of analysis. In Chapter 6 the statistical method developed in Chapter 5 was used to assess the preference of calves for long and chopped hay and straw, and their preference for hay versus straw. Two to five month-old calves learned the double demand operant task and were motivated to work for roughage on top of a high energy diet of milk replacer and concentrate. They showed a preference for long over chopped hay, but not for long over chopped straw, and showed a strong preference for hay over straw. In Chapter 7 it was investigated whether temperament might affect learning of a double demand operant task in calves. Studies in horses and voles previously found that certain individuals seemed unable to learn certain tasks. If one could find out why, individual training programs could be designed and non-learners would not be removed from studies, potentially avoiding biases in data due to only certain temperament profiles making it through the learning criteria. Chapter 7 gave some indication that temperament may affect learning in calves, and it is the first study in calves to do so. However, due to the low number of animals used, further research is necessary to confirm which temperamental traits affect learning ability in calves. Relationships between tongue playing and: 1) hypothesised measures of chronic stress, and 2) hypothesised temperamental traits were investigated in Chapter 8. Large individual differences in the performance of tongue playing in calves subjected to similar husbandry conditions were found. This suggests that although tongue playing might well be a warning sign for chronic stress, and hence poor welfare, individual variation in the propensity to tongue play in response to stressful conditions exists. This could be due to differences in temperament. In contrast to what theoretical papers suggest, calves that showed more tongue playing showed characteristics of a reactive coping style. This result is, however, consistent with previous experimental papers on calves and other species. Results from Chapters 2 to 8 were combined into the design of the experiment described in Chapter 9. In this chapter, various feeding strategies (i.e. different amounts of solid feed combined with different concentrate to roughage ratios, different types of ad libitum choice diets, and feeding milk replacer via an open bucket or automated milk dispenser[AMD]) were applied and the effect on behaviour was recorded. Rumination was mainly affected by roughage provision, regardless of concentrate provision. Therefore, increasing solid feed provision without increasing the roughage content would most likely have little effect on rumination, although it would probably increase eating time to a certain extent. Because of the timing of tongue playing and oral manipulation of the environment (found in both Chapters 3 and 9), we suggest that the first of these two AOB is related to chewing activity in general, whereas the second may be more related to anticipation of an upcoming meal and positive reinforcement of feeding behaviours following an unsatisfactory meal. Calves provided ad libitum access to long straw in racks showed high levels of chewing activity and low levels of AOB relative to calves that did not have access to a straw rack but otherwise received the same diet. Six-month-old calves with ad libitum access to straw, maize silage and concentrate (but a restricted milk replacer allowance of 1050 g DM/d) consumed on average approximately 900 g DM/d roughage and 2300 g DM concentrate at 6 months of age. Feeding milk replacer via an AMD seemed to have little impact on behaviour, although it led to lower levels of tongue playing at 15 wk relative to bucket-fed calves. In Chapter 10, I first reflect on possible underlying mechanisms of AOB and on the best methods to assess animal preferences. AOB seem to develop in veal calves due to a number of factors, starting with the thwarting of chewing activity, of which rumination at least is most likely a behavioural need. Other factors involved in the development of AOB include chronic stress resulting from the thwarting of chewing activity, anticipation of an upcoming meal, and positive reinforcement of feeding behaviours following a meal that was unsatisfactory. Of great importance is the understanding of individual variation in the propensity to develop AOB, because stereotypic behaviours in sub-optimal environments have been linked to improvements in welfare (relative to non-stereotyping animals). Ruminants seem to be able to select a diet that maximises their comfort. Developing feeding strategies to improve veal calf welfare, therefore, requires the assessment of calf feed preferences. Choice tests and cross point analysis of double demand functions are two possible methods for the assessment of animal preferences, and both these methods include drawbacks and benefits. In contrast to choice tests, double demand offers a setting that closer mimics the complexity of natural environments by imposing a cost on access to resources and enables quantification of the strength of preferences. However, this procedure requires appropriate statistical methods, which take into account the dependence structure between the two simultaneously available resources. Finally, practical implications of the research presented in this thesis are described in Chapter 10. The development of novel feeding strategies to improve the welfare of veal calves is challenged by individual differences in feed preferences, chewing efficiency, and behavioural response to chronic stress caused by inadequate feeding. The latter is demonstrated by only certain calves developing AOB when chewing activity is not stimulated enough by the feeding strategy, whilst others do not develop such behaviours. This complicates the evaluation of the effects of feeding strategy on veal calf behaviour. However, based on the results of this thesis and previous research it seems that young calves should first receive a diet that optimises rumen development, before receiving coarser roughages that stimulate chewing activity, rumen muscularisation, and minimise plaque and hairball prevalence in the rumen. Adequate amounts of roughage and concentrate at 6 months of age seem to be 1000 and 2000-3000 g DM, based on voluntary intake. </p

Perceptions and experiences of appetite awareness training among African-American women who binge eat

Introduction: Binge eating may contribute to the prevalence of obesity in African-American women. Yet, there has been scant intervention research on the treatment of binge eating in this population. We tested the feasibility of an appetite awareness training (AAT) intervention in a sample of African-American women with binge and overeating behaviors. Participants who completed AAT were recruited to participate in focus groups to elicit information about their perceptions and experiences with this intervention to inform the design of future interventions to treat binge eating and obesity in African-American women. Methods: African-American women, aged 18–70 years, who had completed an 8-week randomized AAT intervention, were invited to attend a focus group discussion. Session content was recorded and transcribed. Data were analyzed by use of open coding. Themes were identified that described their perceptions and experiences of participating in the intervention. Results: Seventeen women participated in three focus group discussions. Pertinent themes identified included: paying attention to internal cues of hunger and satiety, influence of culture on eating patterns, breaking patterns of disordered eating, and perceptions about weight. Overall, participants were satisfied with their experience of AAT, and reported they found it valuable to learn about listening to biological signals of hunger and satiety and to learn specific strategies to reduce maladaptive eating patterns. Conclusion: AAT was acceptable and provided helpful eating behavior instruction to African-American women with reported binge and overeating behaviors. Future research should examine the potential of AAT to improve weight management in this underserved population. Level of evidence: Level V, qualitative descriptive study

Neighborhood Factors and Six-Month Weight Change among Overweight Individuals in a Weight Loss Intervention.

The purpose of this study was to examine the neighborhood environment and the association with weight change among overweight/obese individuals in the first six months of a 12-month weight loss intervention, EMPOWER, from 2011 to 2015. Measures of the neighborhood environment included neighborhood racial composition, neighborhood income, and neighborhood food retail stores density (e.g., grocery stores). Weight was measured at baseline and 6 months and calculated as the percent weight change from baseline to 6 months. The analytic sample (N = 127) was 91% female and 81% white with a mean age of 51 (± 10.4) years. At 6 months, the mean weight loss was 8.0 kg (± 5.7), which was equivalent to 8.8% (± 6%) of baseline weight. Participants living in neighborhoods in which 25–75% of the residents identified as black had the greatest percentage of weight loss compared to those living in neighborhoods with 75% black residents. No other neighborhood measures were associated with weight loss. Future studies testing individual-level behavioral weight loss interventions need to consider the influence of neighborhood factors, and how neighborhood-level interventions could be enhanced with individual-level interventions that address behaviors and lifestyle changes

Sun exposure behaviour, seasonal vitamin D deficiency, and relationship to bone health in adolescents

YesContext: Vitamin D is essential for bone health in adolescence, where there is rapid bone mineral content accrual. As cutaneous sun-exposure provides vitamin D, there is no recommended oral intake for UK adolescents. Objective: Assess seasonal vitamin D status and its contributors in white Caucasian adolescents, and examine bone health in those found deficient. Design: Prospective cohort study. Setting: Six schools in Greater Manchester, UK. Participants: 131 adolescents, 12–15 years. Intervention(s): Seasonal assessment of circulating 25-hydroxyvitamin D (25OHD), personal sunexposure and dietary vitamin D. Adolescents deficient (25OHD <10 ng/mL/25 nmol/L) in ≥one season underwent dual-energy X-ray absorptiometry (lumbar spine, femoral neck), with bone mineral apparent density (BMAD) correction for size, and peripheral quantitative computed tomography (distal radius) for volumetric (v)BMD. Main Outcome Measure: Serum 25OHD; BMD. Results: Mean 25OHD was highest in September: 24.1 (SD 6.9) ng/mL and lowest in January: 15.5 (5.9) ng/mL. Over the year, 16% were deficient in ≥one season and 79% insufficient (25OHD <20 ng/mL/50 nmol/L) including 28% in September. Dietary vitamin D was low year-round while personal sun-exposure was seasonal and predominantly across the school week. Holidays accounted for 17% variation in peak 25OHD (p<0.001). Nineteen adolescents underwent bone assessment, which showed low femoral neck BMAD versus matched reference data (p=0.0002), 3 with Z≤ -2.0 distal radius trabecular vBMD. Conclusions: Sun-exposure levels failed to provide adequate vitamin D, ~one-quarter adolescents insufficient even at summer-peak. Seasonal vitamin D deficiency was prevalent and those affected had low BMD. Recommendations on vitamin D acquisition are indicated in this age-group.The Bupa Foundation (Grant number TBF-M10-017)

What is animal happiness?

Today, we see a growing concern for the quality of life of nonhuman animals and an accompanying call for viable means of assessing how well animals thrive. Past research focused on minimizing negatives such as stress, while more recent endeavors strive to promote positives such as happiness. But what is animal happiness? Although often mentioned, the term lacks a clear definition. With recent advances in the study of animal emotion, current interest into positive rather than negative experiences, and the call for captive and domesticated animals to have good lives, the time is ripe to examine the concept of animal happiness. We draw from the human and animal literature to delineate a concept of animal happiness and propose how to assess it. We argue that animal happiness depends on how an individual feels generally—that is, a typical level of affect

Marine conservation : towards a multi-layered network approach

Valuing, managing and conserving marine biodiversity and a full range of ecosystem services is at the forefront of research and policy agendas. However, biodiversity is being lost at up to a thousand times the average background rate. Traditional disciplinary and siloed conservation approaches are not able to tackle this massive loss of biodiversity because they generally ignore or overlook the interactive and dynamic nature of ecosystems processes, limiting their predictability. To conserve marine biodiversity, we must assess the interactions and impacts among biodiversity and ecosystem services (BD-ES). The scaling up in complexity from single species to entire communities is necessary, albeit challenging, for a deeper understanding of how ecosystem services relate to biodiversity and the roles species have in ecosystem service provision. These interactions are challenging to map, let alone fully assess, but network and system-based approaches provide a powerful way to progress beyond those limitations. Here, we introduce a conceptual multi-layered network approach to understanding how ecosystem services supported by biodiversity drive the total service provision, how different stressors impact BD-ES and where conservation efforts should be placed to optimize the delivery of ecosystem services and protection of biodiversity

Chopped or long roughage: what do calves prefer? Using cross point analysis of double demand functions

The present study aimed to quantify calves'(Bos taurus) preference for long versus chopped hay and straw, and hay versus straw, using cross point analysis of double demand functions, in a context where energy intake was not a limiting factor. Nine calves, fed milk replacer and concentrate, were trained to work for roughage rewards from two simultaneously available panels. The cost (number of muzzle presses) required on the panels varied in each session (left panel/right panel): 7/35, 14/28, 21/21, 28/14, 35/7. Demand functions were estimated from the proportion of rewards achieved on one panel relative to the total number of rewards achieved in one session. Cross points (cp) were calculated as the cost at which an equal number of rewards was achieved from both panels. The deviation of the cp from the midpoint (here 21) indicates the strength of the preference. Calves showed a preference for long versus chopped hay (cp ¿=¿14.5; P ¿=¿0.004), and for hay versus straw (cp ¿=¿38.9; P¿=¿0.004), both of which improve rumen function. Long hay may stimulate chewing more than chopped hay, and the preference for hay versus straw could be related to hedonic characteristics. No preference was found for chopped versus long straw (cp ¿=¿20.8; P¿=¿0.910). These results could be used to improve the welfare of calves in production systems; for example, in systems where calves are fed hay along with high energy concentrate, providing long hay instead of chopped could promote roughage intake, rumen development, and rumination

Fractional Sunburn Threshold UVR Doses Generate Equivalent Vitamin D and DNA Damage in Skin Types I-VI but with Epidermal DNA Damage Gradient Correlated to Skin Darkness

Dermatology-oncolog

Menus for Feeding Black Holes

Black holes are the ultimate prisons of the Universe, regions of spacetime where the enormous gravity prohibits matter or even light to escape to infinity. Yet, matter falling toward the black holes may shine spectacularly, generating the strongest source of radiation. These sources provide us with astrophysical laboratories of extreme physical conditions that cannot be realized on Earth. This chapter offers a review of the basic menus for feeding matter onto black holes and discusses their observational implications.Comment: 27 pages. Accepted for publication in Space Science Reviews. Also to appear in hard cover in the Space Sciences Series of ISSI "The Physics of Accretion onto Black Holes" (Springer Publisher