Genetic Determinants of Skin Color, Aging, and Cancer

Chapter 1 gives a general introduction to this thesis. In Chapter 2 we validated perceived skin color as skin color measurement. In Chapter 3 we investigated whether digitally quantified skin color was a suitable measure to discover new skin color genes. In Chapter 4 we investigated the genetic basis of skin color by a genome-wide association study followed by a replication analysis in 17,262 individuals of European ancestry from the Netherlands, UK and Australia. In Chapter 5 we validated a new digital image analysis technique to measure severity of different skin aging features including wrinkling, pigmented spots and telangiectasia. In Chapter 6 we have used the digitally quantified pigmented spots measures to search for associated genetic variants. In Chapter 7 we studied intrinsic and extrinsic risk factors for the skin aging feature sagging eyelids. In Chapter 8 we investigated genetic susceptibility to the pre-malignant actinic keratosis. In Chapter 9 we have summarized the pattern of genetic association between 13 genes and pigmentation traits, pigmented spots, and cutaneous malignancies. In Chapter 10 we discuss the results of all studies in this thesis

Welfare impact of social breeding value and straw for growing-finishing pigs

Animal welfare is of increasing concern in present society. In commercial pig farming, animal welfare problems are common. One of the causes for these problems is the barren environment in which pigs are housed, which can cause oral manipulation of pen mates. Providing straw might be one solution to this problem. Another solution could be reached through genetic selection. Present breeding schemes are only focused on direct production characteristics of the individual, like growth performance. Welfare, as well as production, might be improved by including the effect an animal has on its pen mates in the selection criteria. However, effects on welfare of selection for the so called Social Breeding Value (SBV), which is based on growth, are largely unknown. This study investigated the direct welfare effects induced by straw as well as SBV and the possible interaction between both. In a one generation selection experiment, 192 finishing pigs with either a high or low SBV, were housed in barren or straw pens. In this 2x2 experimental design, pigs were studied from weaning until slaughter. Welfare status was assessed using a protocol that was partly based on the Welfare Quality® protocol. Results show that straw had a positive welfare effect regarding tail biting and exploration. Straw housed pigs had less infections and greater body weight at slaughter age than barren housed pigs. Pigs in enriched pens did show more lesions than barren housed pigs, probably due to raised overall activity in enriched pens. No welfare effect was found due to SBV, besides an effect on the occurrence of a rough hair coat. No interactions were found. It can be concluded that the welfare impact of SBV for growing-finishing pigs is not yet proven

Killing individual poultry on-farm-a survey among veterinarians and farmers

To date, information about reasons to select and kill poultry on-farm and which method veterinarians and poultry producers preferably use is scarce. Little is also known about their knowledge of the legislation regarding on-farm killing methods and of methods alternative to the one(s) they use, as well as their perception of those alternatives. In this study, Flemish poultry veterinarians (n = 13), broiler chicken producers (n = 27), and turkey producers (n = 4) were surveyed on killing methods they currently use in practice and alternative methods, on their opinion about what constitutes an appropriate method for on-farm killing of poultry, and on their reasons for killing. All poultry veterinarians and chicken producers who filled out the survey kill poultry by manual cervical dislocation (CD), whereas some turkey farmers also indicated killing by percussive blow to the head (n = 1) or exsanguination (n = 1). Turkey producers seem to be more inclined not to kill animals with injuries or symptoms of disease as compared to veterinarians or chicken producers, such that moribund turkeys are more likely to remain in the flock. Veterinarians considered the following properties of a killing method important: animal friendliness, applicability inside the stable, a high success rate, and time efficiency. Producers ranked the properties similarly, but for them, ease of performance and cost efficiency were more important than applicability inside the stable. Producers scored those killing properties rather positively for manual as well as mechanical CD. Veterinarians and chicken producers considered the captive bolt method to be easy to perform, to have a high success rate, to be feasible to perform in the stable, and to be animal friendly. Turkey producers, however, had doubts about the latter 2 properties. Gas, injection, and electrocution were inferior methods to kill poultry according to producers. In conclusion, manual CD is the most common method for killing broiler chickens and turkeys, and knowledge of, and experience with, alternative methods is very limited, both among veterinarians and producers. Informing them about legislation and training for the use of alternative killing techniques are recommended

A Phase IIIb, Multicentre, Randomised, Parallel-Group, Placebo-Controlled, Double-Blind Study to Investigate the Efficacy and Safety of OROS Hydromorphone in Subjects with Moderate-to-Severe Chronic Pain Induced by Osteoarthritis of the Hip or the Knee

Background. Opioid analgesics are included in treatment guidelines for the symptomatic management of osteoarthritis (OA). Starting with a low dose of opioid and slowly titrating to a higher dose may help avoid intolerable side effects. Methods. Subjects aged ≥40 years, with moderate to severe pain induced by OA of the hip or knee not adequately controlled by previous non-steroidal anti-inflammatory drugs (NSAIDs) or paracetamol treatment, were enrolled. Subjects received OROS hydromorphone 4 mg or placebo once-daily. The dose was titrated every 3-4 days in case of unsatisfactory pain control during the 4-week titration phase. A 12 week maintenance phase followed. The primary efficacy endpoint was the change in “pain on average” measured on the Brief Pain Inventory (BPI) scale from baseline to the end of the maintenance phase. Results. 139 subjects received OROS hydromorphone and 149 subjects received placebo. All efficacy endpoints showed similar improvements from baseline to end of study in the 2 groups. The safety results were consistent with the safety profile of OROS hydromorphone. Conclusion.The study did not meet the primary endpoint; although many subjects' pain was not adequately controlled at inclusion, their pain may have improved with continued paracetamol or NSAID treatment

Remedying contact dermatitis in broiler chickens with novel flooring treatments

Simple Summary Contact dermatitis is an overarching term for inflamed or necrotic lesions after contact with an allergen or irritant. Broiler chickens commonly experience these lesions due to prolonged contact with moisture, feces, and ammonia within litter. This study aimed to find methods to prevent and remedy lesions on broilers' feet, hocks, and breast. Furthermore, the impact of treatments on plumage cleanliness, gait, and body weight was investigated. We applied novel flooring treatments consisting of plastic slats and disinfectant mats containing povidone-iodine, which we compared to the industry control (used litter) and a positive control (clean litter). Weekly measurements on a sample of birds in each pen showed us the impact of both flooring treatments and age (weeks) on animal welfare outcomes. Contrary to expectations, the novel flooring treatments did not prevent or remedy contact dermatitis. In fact, the positive control, consisting of replacing litter every four days, resulted in the best welfare condition, with limited to no contact dermatitis at week seven of age. Contact dermatitis (footpad dermatitis (FPD), hock burns, and breast dermatitis) is a welfare issue for broiler chickens, causing pain and behavioral restrictions. Once lesions develop, often nothing is done to remedy the issue for the affected flock. Our objective was to evaluate novel flooring treatments at the flock level by providing preventative and remedial treatments against contact dermatitis, plumage soiling, and gait impairment. Broilers (n = 546) were housed in 42 pens, with 13 birds/pen. The flooring treatments (four) included used litter (NEG), new pine shavings replaced regularly (POS), a mat filled with 1% povidone-iodine solution (MAT), and the iodine mat placed on a slatted floor (SLAT). Flooring treatments were provided from day one of age (preventative approach; PREV) or day 29 (remedial approach; REM). Contact dermatitis, soiling, gait, and weight were recorded weekly (seven birds/pen). Results showed a treatment effect for all measures, dependent on bird age. Overall, the POS treatment resulted in the best welfare outcomes (FPD, hock burns, and gait). The worst contact dermatitis was found in the MAT and SLAT groups. NEG birds showed little contact dermatitis, opposite to expectations. Weights were lower for PREV-POS in week seven only. The treatments with povidone-iodine were deemed ineffective against contact dermatitis. Access to clean litter prevented and remedied contact dermatitis, and a comparable approach may be commercially feasible

Stakeholder perceptions on broiler chicken welfare during first-day processing and the pre-slaughter phase : a case study in Belgium

Day of hatch and pre-slaughter processing are stressful events (involving selection, handling and transport) for broiler chickens, putting pressure on welfare, which has economic consequences. This case-study documented common industry practices and evaluated poultry industry stakeholder perceptions related to broiler welfare during day-of-hatch processing and the pre-slaughter phase. Twenty-three individual in-depth interviews were conducted with representatives of key stakeholders in the Flemish poultry sector: hatchery personnel (five), farmers (six), poultry catchers (two), transporters (three) and slaughterhouse personnel (seven). The findings showed various factors influencing broiler welfare during day of hatch processing and the pre-slaughter phase, with some discrepancies between stakeholder views and the scientific evidence. While stakeholders perceived the day of hatch processing procedures of chicks to be relatively under control, with no major issues, literature points out several issues, including first-week mortality and time without feed and water as major welfare problems. For broilers at slaughter age, the industry stakeholders' views aligned well with scientific evidence on major welfare issues, such as injuries, thermal stress, mortality during fasting, catching, loading, transportation and lairage. This study provides novel insights in stakeholder perceptions, and potential avenues for future research and actions to reduce animal welfare problems in the poultry sector

Effect of environmental complexity and stocking density on fear and anxiety in broiler chickens

Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety) and tonic immobility (measure of fear). In Experiment 1, individual birds were tested for attention bias (n = 60) and in Experiment 2, groups of three birds were tested (n = 144). Tonic immobility testing was performed on days 12 and 26 (n = 36) in Experiment 1, and on day 19 (n = 72) in Experiment 2. In Experiment 1, no differences were observed in the attention bias test. In Experiment 2, birds from high-complexity pens began feeding faster and more birds resumed feeding than from low-complexity pens following playback of an alarm call, suggesting that birds housed in the complex environment were less anx-ious. Furthermore, birds housed in high-density or high-complexity pens had shorter tonic immobility durations on day 12 compared to day 26 in Experiment 1. In Experiment 2, birds from high-density pens had shorter tonic immobility durations than birds housed in low-density pens, which is contrary to expectations. Our results suggest that birds at 3 weeks of age were less fearful under high stocking density conditions than low density conditions. In addition, results indicated that the complex environment improved welfare of broilers through reduced anxiety

Effect of post-hatch transportation duration and parental age on broiler chicken quality, welfare, and productivity

Broiler chicks are transported to production sites within one to 2 d post-hatch. Possible effects of this transportation are poorly understood and could vary among chicks from breeder flocks of different ages. The aim of the present study was to investigate the effects of transportation duration and parental flock age on chick welfare, productivity, and quality. After hatch in a commercial hatchery, 1,620 mixed-sex chicks from 29-wk old (young) and 1,620 chicks from 60-wk old (old) breeders were subjected to transportation of 1.5 h or 11 h duration. After transportation, 2,800 chicks were divided among 100 pens, with each pen containing 28 chicks from one transportation crate (2 or 3 pens per crate). From the remaining chicks, on average 6 chicks (min 4, max 8) per crate (n = 228) were randomly selected and assessed for chick quality, weighed, and culled for yolk sac weighing (one d). Chicks that had not been assigned to pens or were not used for post-transportation measurements, were removed from the experiment (n = 212). Mortality, ADG, BW, and feed conversion (FC) of the experimental chicks were recorded until 41 d. Meat quality was measured for breast fillets (n = 47). No interaction effect of parental age and transportation duration was found for any variables. BW and yolk sac weight at one d were lower for chicks transported 11 h than 1.5 h and for chicks from young versus old breeders. The effect of parental flock age on BW persisted until slaughter. Additionally, parental age positively affected ADG until slaughter. Chick quality was lower in chicks from old versus young breeders. Chick quality and productivity were not affected by transportation duration. Mortality and meat quality were not affected by either parental age or transportation duration. To conclude, no long-term detrimental effects were found from long post-hatch transportation in chicks from young or old parent flocks. Based on these results, we suggest that 11 h post-hatch transportations under similar conditions do not impose long-term welfare or productivity risks