Structural-functional brain network coupling predicts human cognitive ability.

Individual differences in general cognitive ability (GCA) have a biological basis within the structure and function of the human brain. Network neuroscience investigations revealed neural correlates of GCA in structural as well as in functional brain networks. However, whether the relationship between structural and functional networks, the structural-functional brain network coupling (SC-FC coupling), is related to individual differences in GCA remains an open question. We used data from 1030 adults of the Human Connectome Project, derived structural connectivity from diffusion weighted imaging, functional connectivity from resting-state fMRI, and assessed GCA as a latent g-factor from 12 cognitive tasks. Two similarity measures and six communication measures were used to model possible functional interactions arising from structural brain networks. SC-FC coupling was estimated as the degree to which these measures align with the actual functional connectivity, providing insights into different neural communication strategies. At the whole-brain level, higher GCA was associated with higher SC-FC coupling, but only when considering path transitivity as neural communication strategy. Taking region-specific variations in the SC-FC coupling strategy into account and differentiating between positive and negative associations with GCA, allows for prediction of individual cognitive ability scores in a cross-validated prediction framework (correlation between predicted and observed scores: r = 0.25, p < .001). The same model also predicts GCA scores in a completely independent sample (N = 567, r = 0.19, p < .001). Our results propose structural-functional brain network coupling as a neurobiological correlate of GCA and suggest brain region-specific coupling strategies as neural basis of efficient information processing predictive of cognitive ability.

Examining the sustainability and effectiveness of co-created physical activity interventions in vocational education and training: a multimethod evaluation.

BACKGROUND: Co-creation approaches are increasingly used in physical activity promotion to develop interventions tailored to the target group and setting. The resulting complexity of such interventions raises challenges in evaluation. Accordingly, little is known about the effectiveness of co-created interventions and the underlying processes that impact their sustainable implementation. In this study, we attempt to fill this gap by evaluating co-created multi-component physical activity interventions in vocational education and training in nursing care and automotive mechatronics regarding (1) their sustainable implementation at the institutional level and (2) the effectiveness of single intervention components at the individual level. METHODS: Following a multimethod design, we conducted a questionnaire survey (n = 7) and semi-structured interviews (n = 4) to evaluate the sustainability of the interventions. Quantitative data were analyzed descriptively, and qualitative data were analyzed using qualitative content analysis. To examine the interventions' effectiveness, we conducted two non-randomized controlled trials (n = 111). Analysis of variance was used to examine differences between groups. RESULTS: At the institutional level, long-term implementation of single intervention components in nursing care was observed; in contrast, long-term implementation in automotive mechatronics was not observed. In this context, various factors at the outer contextual (e.g., COVID-19 pandemic), inner contextual (e.g., health-promoting leadership), intervention (e.g., acceptance), and personal levels (e.g., champion) influenced sustainability. At the individual level, no significant intervention effects were found for changes in physical activity behavior and physical activity-related health competence. CONCLUSION: The role of co-creation on the effectiveness and sustainability of physical activity promotion in vocational education and training cannot be answered conclusively. Only in the nursing care sector, a co-creation approach appeared promising for long-term intervention implementation. Sustainable implementation depends on various influencing factors that should be considered from the outset. Demonstrating effectiveness at the individual level was challenging. To conclusively clarify both the role and impact of co-creation, methodologically complex and elaborate evaluation designs will be required in future research projects. TRIAL REGISTRATION: This study was retrospectively registered at clinicaltrials.gov on 24/08/2021 ( NCT05018559 ).

Relationships between cognitive function, seizure control, and self-reported leisure-time exercise in epilepsy.

Exercise may be a strategy for improvement of cognitive deficits commonly present in people with idiopathic generalized epilepsies (IGE). We investigated the relationship between cognition and level of physical exercise in leisure (PEL) in people with IGE who have been seizurefree for at least 6 months (IGE-) as compared to those who have not been seizurefree (IGE+) and healthy controls (HCs). We hypothesized that higher level of physical exercise is associated with better cognitive functioning in patients with IGE and HCs, and that seizure control affects both PEL levels and cognitive functioning in patients with IGE. We recruited 75 participants aged 18-65: 31 people with IGE (17 IGE-, 14 IGE+) and 44 HCs. Participants completed assessments of quality of life (SF-36), physical activity levels (Baecke questionnaire and International Physical Activity Questionnaire (IPAQ)) and cognition (Montreal Cognitive Assessment (MoCA), Hopkins Verbal Learning Test - Revised (HVLT), and flanker task). Group differences (HCs vs. IGE; HCs vs. IGE+ vs. IGE-) were assessed. Pearson correlations examined linear relationships between PEL and cognitive performance. Groups were similar in age and sex. Compared to HCs, patients with IGE had higher body mass index, fewer years of education, and consistently scored worse on all measures except flanker task accuracy on incongruent trials. When examining IGE- and IGE+ subgroups, compared to HCs, both had higher body mass index, and fewer years of education. Healthy controls scored significantly better than one or both of the IGE groups on SF-36 scores, PEL levels, IPAQ activity level, MoCA scores, HVLT learning and long-delay free-recall scores, and flanker task accuracy on congruent trials. Among patients with IGE, there were no significant differences between age of epilepsy onset, duration of epilepsy, number of anti-seizure drugs (ASDs) currently being used, or the group distribution of type of IGE. In the combined sample (IGE+, IGE- and HCs), PEL positively correlated with MoCA scores (Pearson's r = 0.238; p = 0.0397) and with flanker task accuracy on congruent trials (Pearson's r = 0.295; p = 0.0132). Overall, patients with IGE performed worse than HCs on cognitive and physical activity measures, but the cognitive impairments were more pronounced for IGE+, while physical exercise levels were less for patients with IGE regardless of seizure control. While positive relationships between leisure-time PEL and cognitive performance are promising, further investigations into how exercise levels interact with cognitive functioning in epilepsy are needed.

Co-creating physical activity interventions: a mixed methods evaluation approach.

BACKGROUND: Co-creation strategies, such as cooperative planning, are promising as a means to ensure that physical activity interventions address real-world problems and are tailored to the target group. This has already been validated in diverse settings. However, questions targeting the transferability of cooperative planning to new settings and the key factors influencing its success or failure remain unclear. At the same time, co-creation processes are complex, and evaluation can be challenging. Following calls for detailed reporting, this paper describes the programme activities, the underlying logic, and methodological design of a study that aims to evaluate the transfer of cooperative planning to new settings and to explore the associated key determinants. METHODS: Cooperative planning was utilized as a strategy to target physical activity promotion in three real-world German settings in the nursing care and automotive mechatronics sectors. This involved researchers working alongside stakeholders from practice and policy to conjointly develop new interventions to promote physical activity in physically demanding jobs. A pragmatic approach is used to evaluate both the transferability and key determinants of this strategy. We developed a logic model for this co-creation process that describes the underlying assumptions and guides the evaluation. The evaluation outcomes of this study include planning meetings, newly developed interventions, and the determinants that are likely to affect cooperative planning. Quantitative and qualitative data will be collected using questionnaires, documents, and interviews. The quantitative data will be analysed descriptively, while the qualitative data will mainly be analysed using qualitative content analysis, split by settings. Subsequently, data triangulation will be used to integrate the quantitative and qualitative findings, which will then be compared across all three settings. DISCUSSION: The study findings will contribute to a better understanding of co-creation strategies, their transferability, and key determinants. The practical implications can include a checklist for assessing key determinants and a guideline for transferring cooperative planning into new settings to benefit more people. Ultimately, this study will help to advance co-creation strategies and may be relevant for researchers, practitioners, and policy-makers targeting physical activity promotion in various contexts. TRIAL REGISTRATION: Open Science Framework: https://osf.io/r6xnt/ (retrospectively registered).

Introducing the Practice Dive Approach: an extension of co-creation in physical activity promotion and health promotion.

Recently, there has been increasing interest in co-creation utilized for physical activity (PA) promotion and health promotion. Co-creation involves researchers and non-academic stakeholders conjointly developing and implementing interventions. In addition to the frequently reported benefits of co-creation, critical voices highlight the associated challenges (e.g. different interests that inhibit interaction). So far, research has not identified concrete solutions to these challenges and the limitations of co-creation. This article aims to introduce the Practice Dive Approach as a potential way to strengthen cooperation between researchers and non-academic stakeholders. We build on real-life experiences from a German research project, in which researchers moved into practice to familiarize themselves with the settings and end-users. After conducting a literature search on related concepts in PA/health promotion, we developed a comprehensive approach to fostering multi-sectoral cooperation. The introduced Practice Dive Approach assumes that a significant contribution to better cooperation among co-creators is the temporal immersion of researchers in their setting of interest, which has the potential to improve the success of co-creation in the PA/health promotion field. A four-level typology characterizes the intensity of researcher interactions with the setting and the non-academic stakeholders. Potential beneficial effects for both researchers and non-academic stakeholders can be hypothesized (e.g. familiarity with the setting structures and increased understanding of the end-users), while simultaneously, some challenges need to be considered. Future research should aim to validate the concept and its postulated effects.

Collaboration among researchers and non-academic stakeholders is increasingly used to promote physical activity and health. For example, people involved in such collaborations jointly develop new interventions. Potential challenges include different interests or work routines that can complicate cooperation. This article aims to introduce the Practice Dive Approach as a potential way to improve cooperation between researchers and non-academic stakeholders. We developed the approach based on observations from a German research project and a literature search on related concepts. This approach assumes that the temporal involvement of researchers in their setting of interest can strengthen research-practice cooperation and improve its success. We describe different types of a Practice Dive and the requirements for conducting Practice Dive activities. Furthermore, we present the potential effects of a Practice Dive for the researchers and the non-academic stakeholders, such as increased familiarity between both groups. However, some challenges need to be considered when applying the Practice Dive Approach. Future research should test this approach and its potential effects.

What do we know about physical activity interventions in vocational education and training? A systematic review.

BACKGROUND: Although the health benefits of physical activity (PA) are well known, young people's level of PA is often insufficient and tends to decline in adolescence. Numerous studies have investigated the effectiveness of PA-promoting interventions among young people, but none have reviewed the effectiveness of PA interventions in the vocational education and training (VET) setting. This systematic review aims to (1) synthesize and review the available literature on PA-promoting interventions in VET and (2) examine the effects of these interventions on PA-related outcomes such as PA level, physical fitness, physiological parameters, or psychological factors. METHODS: Five electronic databases were searched for studies involving adolescents aged 15 to 20 years that took place in VET settings and evaluated the effects of interventions with a PA component on PA-related outcomes such as PA level, physical fitness, physiological parameters, or psychological factors. The screening process and the quality assessment were conducted by two independent reviewers; data extraction was conducted by one reviewer and verified by another. RESULTS: The literature search identified 18,959 articles and 11,282 unique records. After the screening process, nine studies, all coming from European or Asian countries, met the pre-defined eligibility criteria and were included in qualitative analyses. All but two studies reported significant improvements for at least one PA-related outcome. The interventions substantially differed in their development approaches (top-down vs. bottom-up approaches), complexity (multi- vs. single-component), and addressed behavior (multi-behavioral vs. single-behavioral). The most conspicuous finding was that bottom-up approaches tend to improve outcomes at the psychological level and top-down approaches at the physical level. Regarding the interventions' complexity and addressed behavior, we did not reveal any conclusive results. CONCLUSION: This systematic review highlights the varying effects of PA-promoting interventions in VET. Nevertheless, heterogeneous effects, overall weak study quality and availability of studies only from two continents limited our ability to draw clear conclusions about the potentially most effective intervention strategies. Therefore, future research should focus on high-quality studies with long-term follow-ups to make recommendations for practical use. TRIAL REGISTRATION: PROSPERO CRD42018109845.

Physical activity promotion in German vocational education: does capacity building work?

Apprentices in many sectors are exposed to increased health risks and show low levels of physical activity (PA). Environmental and policy approaches seem to be promising tools for PA promotion as they can positively influence the context in which PA occurs. This article reports results from a German research project (2015-2018) that developed and implemented measures for PA promotion in the field of vocational education (VE). A participatory approach-cooperative planning (COP)-involving researchers as well as stakeholders from policy and practice was used in two VE settings-nursing care and automotive mechatronics. We assessed the extent to which new capacities for PA promotion were created by conducting semi-structured interviews with stakeholders from both sectors (n = 12) and one group interview with nursing students (n = 4). Transcripts were analysed using qualitative content analysis. Findings show that new capacities were created mainly in the form of resources and opportunities and that several measures for PA promotion (e.g. a regular lesson on the issue of PA and health and a tutoring system) were successfully integrated into VE routines. However, establishing new organizational goals and obligations appeared to be challenging. Moreover, the article presents influencing factors, such as the participation of the main actors that strongly supported the process of capacity building within their organization. We conclude that COP seems promising in creating new capacities for PA promotion in the field of VE, and therefore has the potential to promote a physically active lifestyle among apprentices.

Self-Efficacy for Physical Activity-A Question of Item Framing and Age?

Older adults process and remember positive information relatively better than negative information, compared with younger adults; this is known as the positivity effect. This study examined whether older adults compared with younger adults also respond differently to positively and negatively framed questionnaire items. Participants (N = 275; age = 18-81 years) were randomly assigned to a positively or negatively framed version of a self-efficacy for physical activity questionnaire. Self-efficacy, physical activity intentions, and planned physical activity in the following week were regressed on experimental group and age, controlling for baseline physical activity and covariates. A significant Age × Frame interaction showed that item framing made a difference in planned physical activity for the oldest age group (+350 min compared with the youngest group). This study provides initial support for the positivity effect in item framing on physical activity plans, but not on intentions or self-efficacy. Item framing should be taken into consideration for accurate measurement, but could also be a simple intervention approach.

Implementation and dissemination of physical activity-related health competence in vocational nursing training: study protocol for a cluster-randomized controlled intervention trial.

BACKGROUND: Although the nursing sector gains growing importance in an aging society, students representing the future workforce often show insufficient health. Acknowledging the health-enhancing effects of adequate physical activity, the educational system in Bavaria, Germany, has recently integrated the promotion of physical activity-related health competence (PAHCO) into the nursing curriculum. However, it cannot be assumed that PAHCO has sufficiently permeated the educational practices and routines of the nursing schools. Therefore, the goal of the present study is to examine and compare the effectiveness as well as implementation of different intervention approaches to address PAHCO in the Bavarian nursing school system. METHODS: We randomly assign 16 nursing schools (cluster-based) to four study arms (bottom-up, top-down led by teachers, top down led by external physical activity experts, control group). Schools in intervention group 1 (IG-1) develop multicomponent inventions to target PAHCO via cooperative planning (preparation, planning, and implementation phase). Intervention groups 2 and 3 (IG-2, IG-3) receive both an expert-based intervention (developed through intervention mapping) via trained mediators to address PAHCO. External physical activity experts deliver the structured PAHCO intervention in IG-2, while teachers from the nursing schools themselves conduct the PAHCO intervention in IG-3. In line with a hybrid effectiveness implementation trial, we apply questionnaire-based pre-post measurements across all conditions (sample size calculation: nfinal = 636) to examine the effectiveness of the intervention approaches and, simultaneously, draw on questionnaires, interview, and protocol data to examine their implementation. We analyze quantitative effectiveness data via linear models (times-group interaction), and implementation data using descriptive distributions and content analyses. CONCLUSION: The study enables evidence-based decisions about the suitability of three intervention approaches to promote competencies for healthy, physically active lifestyles among nursing students. The findings inform dissemination activities to effectively reach all 185 schools of the Bavarian nursing system. TRIAL REGISTRATION: Clinical trials NCT05817396. Registered on April 18, 2023.

Neuromorphometric associations with mood, cognition, and self-reported exercise levels in epilepsy and healthy individuals.

Regular physical activity may promote beneficial neuroplasticity, e.g., increased hippocampus volume. However, it is unclear whether self-reported physical exercise in leisure (PEL) levels are associated with the brain structure features demonstrated by exercise interventions. This pilot study investigated the relationship between PEL, mood, cognition, and neuromorphometry in patients with idiopathic generalized epilepsy (IGEs) compared to healthy controls (HCs). Seventeen IGEs and 19 age- and sex-matched HCs underwent magnetic resonance imaging (MRI) at 3T. The Baecke Questionnaire of Habitual Physical Activity, Profile of Mood States, and Montreal Cognitive Assessment (MoCA) assessed PEL, mood, and cognition, respectively. Structural MRI data were analyzed by voxel- and surface-based morphometry. IGEs had significantly lower PEL (p < 0.001), poorer mood (p = 0.029), and lower MoCA scores (p = 0.027) than HCs. These group differences were associated with reduced volume, decreased gyrification, and altered surface topology (IGEs < HCs) in frontal, temporal and cerebellar regions involved in executive function, memory retrieval, and emotional regulation, respectively. These preliminary results support the notion that increased PEL may promote neuroplasticity in IGEs, thus emphasizing the role of physical activity in promoting brain health in people with epilepsy.

Do people with epilepsy want to participate in an exercise intervention randomized controlled trial? - Results of a brief survey and its preliminary application.

Our goal was to survey people with epilepsy (PWE) about their interest in and factors that may influence willingness and ability to participate in an exercise randomized controlled trial (RCT). A brief survey was administered to 100 PWE asking if they would take part in a hypothetical 6-week exercise intervention RCT. Follow-up questions queried reasons for and against participation and why participation would be difficult. Sixty-nine percent of respondents indicated willingness to participate. The top reason for participation was "to improve overall health with exercise" (n = 49). The top reason for why participation would be difficult was they "do not have a reliable source of transportation" (n = 27). The top reason for not participating was "not interested in research participation" (n = 19). Preliminary results were used to budget for transportation in a prospective RCT (NCT04959019). Of the first 27 PWE enrolled (63 % female; 44 % African American/Black), six (50 % female; 50 % African American/Black) have used the transportation service. The majority of PWE surveyed were interested in participating in an exercise RCT, but some indicated barriers. Accommodating transportation in an ongoing RCT has facilitated recruitment of PWE who would otherwise not be able to participate. Barriers to participation should be accounted for when designing studies.

Co-creating physical activity interventions: Findings from a multiple case study using mixed methods.

Introduction: In health and physical activity promotion, there is growing interest in co-creation approaches that involve researchers and non-academic stakeholders in developing new interventions. Previous research has shown the promising results of cooperative planning as a co-creation approach in building new capacities and implementing physical activity-promoting interventions in nursing care and automotive mechatronics. However, it remains unclear whether (1) cooperative planning for physical activity promotion can be successfully transferred to other settings in the nursing care and automotive mechatronic sectors and (2) what key factors influence its success or failure. Methods: We conducted a multiple case study in three settings in the nursing care and automotive mechatronics sectors. Following a mixed methods approach, we collected, analyzed, and triangulated data from documents (n = 17), questionnaires (n = 66), and interviews (n = 6). Quantitative data were analyzed descriptively and through using nonparametric analyses of variance; qualitative data were analyzed using qualitative content analysis by extraction. Results: The transfer of cooperative planning to new settings was realized, though the impact varied by setting. While the interventions were developed and implemented in nursing care settings, interventions were developed but not implemented in the automotive mechatronics setting. In this context, intervention implementation was influenced by 11 key factors: champion, commitment, embedment, empowerment, engagement, health-promoting leadership, ownership, relevance, resources, responsibility, and strategic planning. Furthermore, the transfer of cooperative planning was influenced by different activity characteristics, namely elaboration & reconsideration, group composition, number of meetings, participation, period, prioritization, and researchers' input & support. Discussion: The present article contributes to a better understanding of a co-creation approach utilized for physical activity promotion and provides new insights into (1) the transferability of cooperative planning and (2) the associated key factors influencing intervention implementation. The success of cooperative planning varied by setting and was influenced by several activity characteristics and key factors, some of which showed complex relationships. This raises the question of whether some settings might benefit more from a co-creation approach than others. Therefore, future co-creation initiatives should carefully consider the specific characteristics of a setting to select and apply the most appropriate approach.

Physical Activity Promotion for Apprentices in Nursing Care and Automotive Mechatronics-Competence Counts More than Volume.

Apprentices in the area of nursing care and automotive mechatronics are exposed to increased health risks. In this context, the promotion of physical activity (PA) is considered an effective strategy for the assurance of work ability. The goal of the PArC-AVE study was therefore to better understand the role of PA for apprentices employed in these two sectors. In an exploratory study, 55 apprentices wore an ActiGraph accelerometer over seven consecutive days and were subject to activity analysis. The objective accelerometer data (18,979 ± 3780 steps/day; 471.00 ± 159.75 min of moderate-to-vigorous PA/week), complemented by questionnaire data, indicated that most met the volume-based PA recommendations. Subsequently, we conducted a multicenter study comprising 745 apprentices from six vocational education institutions. Path analyses showed that competencies for health-enhancing PA were significantly related to indicators of work ability (0.180 ≤ b ≤ 0.452) and psychophysical health (0.139 ≤ b ≤ 0.347), whereas mere volume of PA was not (-0.048 ≤ b ≤ 0.080). In summary, apprentices of nursing care and automotive mechatronics showed high levels of PA. However, the results highlight the importance of competencies for health-enhancing PA. The PAHCO model could provide a useful framework for the conceptualization of effective interventions.

Veterinary drug administration in German veal calves: An exploratory study on retrospective data.

The aim of this cross-sectional study was to characterise the usage of antibiotic and non-antibiotic drugs with a withdrawal period in German veal calves in more detail. In Germany, the documentation of the usage of veterinary medicinal products in food producing animals is mandatory. In the German monitoring system antibiotic use in calves under the age of eight months is recorded irrespective of the production type and only some basic measures (50 % and 75 % percentiles of the entire distributions of the treatment frequencies) are published regularly. Within this study 57 farms were included contributing data of 169 veal calf groups with a total of 91,196 individual calves. To assess the drug use the treatment frequency (TF) was calculated. Most treatments were applied in the first weeks after arrival at the farm against respiratory and gastrointestinal disorders, accounting for 65.2 % and 28.6 % of the TF, respectively. Antibiotics account for 91 % of the TF. The antibiotics used most frequently were tetracyclines (35.6 %), beta-lactams (21.9 %), macrolides (12.7 %), sulphonamides (6.0 %) and trimethoprimes (5.3 %). Tetracyclines and polypeptides were administered as group treatments in more than half of the recorded applications. The number of antibiotic group treatments decreased considerably from the first to the second half of the fattening period. Logistic regression analyses revealed no statistically significant association between TF and groups size or mortality. Nevertheless, the results indicate a negative associated between TF and mortality. Concerning non-antibiotics mainly iron compounds, arylpropionic acids, mucolytics and avermectines were applied, accounting for about 5 % of the total TF. The present study provides basic data on antibiotic and non-antibiotic use in German veal calf production.

Effect of ethyl-lauroyl-arginate hypochloride in combination with high hydrostatic pressure processing on the microbial load and physico-chemical characteristics of minced and portioned chicken breast meat.

Campylobacter is an important hazard responsible for many human gastroenteritis cases. As poultry meat is the main source of Campylobacter, many approaches to reduce the Campylobacter load in this meat have been published. In the present study minced and whole broiler breast meat samples were inoculated with Campylobacter (C.) jejuni and treated with different concentrations of the food additive ethyl-Nα-lauroyl-L-arginate hypochloride (LAE, 1,000/1,500 ppm (minced meat); 400/1,000 ppm (whole meat)), with high hydrostatic pressure (HPP, 100/ 200 MPa) or a combination of both preservation methods, followed by vacuum storage up to day 14 after treatment. Aim of the study was to analyze if effects of LAE and HPP alone and in combination on the C. jejuni concentrations and on different meat quality parameters could be found. Analysis of minimal inhibitory and minimal bactericidal concentrations (MIC, MBC) of LAE against 11 C. jejuni and five C. coli strains resulted in MIC/ MBC of 32 ppm for 12 and 64 ppm for four strains investigated. Only 1,500 ppm LAE in minced meat resulted in a significant reduction of the C. jejuni concentrations directly after treatment (day 1) and on day 7 compared to the untreated control samples. Treatment of whole breast meat with 400 and 1,000 ppm LAE resulted in significantly lower C. jejuni concentrations on days 1, 7, and 14 compared to control samples. However, HPP alone and in combination with LAE was not able to reach significant microbial reduction. Whereas LAE only slightly influenced the lightness (L*) results of the minced meat (day 1), HPP treatment with 200 MPa generally increased the L* and yellowness (b*) results of the minced and whole meat on day 1. During further storage, color results were inconsistent in minced and whole meat samples, as well as the myoglobin redox form percentages in the whole meat. In conclusion, a synergistic effect of LAE and HPP could not be proved using the chosen concentrations of LAE and pressure values.

Influence of Different Methionine Sources on Performance and Slaughter Characteristics of Broilers.

Sustainably produced poultry meat with consideration of animal health poses a challenge for broiler production. Low protein diets with high amounts of synthetic amino acids (AAs) like methionine (Met) are the consequence. In a five-week feeding trial, 360 broilers (Ross 308) assigned to four feeding groups were offered protein-reduced complete diets (starter: 20% crude protein (CP); grower: 18.5% CP; finisher: 17.5% CP), supplemented with essential AAs. The "MHA" group received DL-2-hydroxy-4-(methylthio) butanoic acid (DL-HMTBA; trade name: MHA®), groups "L" and "DL" the respective Met source in equivalent concentrations each exceeding the nutritional recommendations. "R-MHA" ("R" for "reduced") received the minimum required level (using MHA as Met source). Performance exceeded performance goals without differences between the groups. The average feed conversion ratio (FCR) amounted to 1.35. The carcass/body weight ratio of R-MHA was significantly lower (0.782) compared to DL (0.808) and L (0.809). Breast meat of R-MHA contained significantly more fat (144 g/kg dry matter (DM)) compared to L (104 g/kg DM) and significantly lower CP content (R-MHA: 838 g/kg DM; L: 875 g/kg DM). The results indicated possible improvement in slaughter yield by protein-reduced diets supplemented with L-Met, thus recommending further research focusing on the Met influence.

Influence of lauric acid on the susceptibility of chickens to an experimental Campylobacter jejuni colonisation.

Among the organic acids, lauric acid has shown a high level of in vitro activity against Campylobacter jejuni. The prevalence and intensity of C. jejuni excretion at slaughter often becomes lower with increasing age. In higher-aged broilers on organic farms which often use other breeds, in turn, the prevalence of C. jejuni is sometimes higher at slaughter. The question then arises as to whether a diet with higher lauric acid concentrations, the age alone or the genetic breed might have an effect in the spread and intensity of an experimental C. jejuni infection in vivo. Therefore, two complete diets with or without 2% lauric acid from palm kernel fatty acids were offered to 450 chickens (ten subgroups à 15 birds, repetitions: n = 3) of two broiler and two layer breeds (Ross 308, Hubbard JA 757, Lohmann Dual and Lohmann Brown-Classic). All breeds were reared for 42 days, Lohmann Brown-Classic also for about 98 days. Twenty-one days before dissection, three seeder birds per subgroup were orally infected with a 1 mL inoculum of C. jejuni (4.46±0.35 log10 CFU/mL). Qualitative detection of C. jejuni in cloacal swabs was performed at days 2, 4, 7, 14 after inoculation and at dissection in all birds. Quantitative detection was performed on excreta samples of seeder birds at days 2, 11 and 17 after experimental challenge and on caecal samples of all birds at dissection. Two days after experimental inoculation, C. jejuni prevalence was higher in control birds without lauric acid supplementation (48.9% vs. 39.6%; P = 0.0462). Depending on age, two days after inoculation the C. jejuni prevalence in young Lohmann Brown-Classic chickens was significantly lower (37.8% vs. 61.1%) whereas at dissection it was higher (99% vs. 67%). At day 2 after inoculation C. jejuni counts in the excreta of young Lohmann Brown-Classic were lower in comparison to those in old ones (log10 CFU/g: 3.30±2.68 vs. 5.24±1.56). Eleven (log10 CFU/g: 5.14±1.13 vs. 4.16±0.82) and 17 days after inoculatioin (log10 CFU/g: 3.77±2.02 vs. 1.72±1.87) it was the reverse situation. At dissection, the carriage of C. jejuni in caecal content was higher in younger than in older birds (log10 CFU/g: 8.57±0.46 vs. 6.66±1.43). An effect of genetic breed on C. jejuni prevalence was seen at dissection, this being lowest in Lohmann Dual chickens (91% vs. 98.9% in other breeds). At d 17 after challenge, C. jejuni counts in the excreta of young Lohmann Brown-Classic were lower in comparison to Ross 308 and Hubbard JA 757 (log10 CFU/g: 3.77±2.02 vs. 5.21±0.85 and 5.62±0.90). Lohmann Dual chickens showed an intermediary excretion, this being only significant lower compared to Hubbard JA 757 (log10 CFU/g: 4.31±0.89). In summary, the effect of lauric acid is limited to the initial phase after experimental inoculation. A higher age at infection seems to lead to a more rapid limitation of the infection. The excretion of C. jejuni appears to decrease more rapidly in layer breeds than in broiler lines after experimental inoculation.

Effects of parsley extract powder as an alternative for the direct addition of sodium nitrite in the production of mortadella-type sausages - Impact on microbiological, physicochemical and sensory aspects.

Increasing concern about chemical additives in processed meat has led to an increased market of uncured and alternatively cured meat products. However, the use of vegetable extracts or the exclusion of curing salt may increase the risk of greater bacterial growth and alteration of several physicochemical parameters. Therefore, in this study mortadella-type sausages, manufactured with 1.07 (V3), 2.14 (V4) and 4.29 (V5) g parsley extract powder/kg sausage meat were produced. These sausage variants were compared to an uncured (V2) and a traditionally nitrite-cured control (V1). A significantly lower Listeria monocytogenes growth was observed for V5 compared to all other variants during the storage time of 28days (P<0.05). Compared to V1, V5 presented a residual nitrite content reduced by 40% and similar a* values until day 21. Concerning texture parameters, L* and aw values, no differences between the variants were detected. Sensory analysis showed that overall acceptance of V4 and V5 was comparable with V1.

Lauric acid as feed additive - An approach to reducing Campylobacter spp. in broiler meat.

The increasing prevalence of Campylobacter spp. within broiler populations is a major problem for food safety and consumer protection worldwide. In vitro studies could already demonstrate that Campylobacter spp. are susceptible to lauric acid. The purpose of this study was to examine in vivo the influence of lauric acid as a feed additive on slaughter parameters, muscle fatty acid profile, meat quality traits and the reduction of Campylobacter coli in inoculated meat of Ross 308 (R308) and Hubbard JA 757 (HJA) broilers in three independent trials (n = 3). Although slaughter parameters did not show any significant differences, the fatty acid profile of both breeds revealed significantly higher lauric acid concentrations (P < 0.0001) in the Musculus pectoralis superficialis of treated broilers. Comparing both tested breeds, R308 test broilers had significantly higher lauric acid concentrations than HJA test broilers (P < 0.0001), indicating a higher conversion rate in those animals. The meat quality traits showed no differences in the R308 breed (P > 0.05), but HJA test broilers had higher values for drip loss, electrical conductivity, CIE color values L* and b*, and lower pH values. The inoculation trials of R308 showed that initial bacterial loads of 5.9 log10 cfu/g were reduced during six days of storage (4°C) to approximately 4.3 log10 cfu/g in the control groups compared to 3.5 log10 cfu/g in the treatment groups (P = 0.0295), which could be due to antimicrobial effects of lauric acid within the muscle. This study therefore suggests that lauric acid as a feed additive has the potential to improve food safety by reducing the numbers of Campylobacter coli in broiler meat. However, this effect seems to be dependent on the breed determining the feed intake capacity, the fat deposition and therefore the ability to incorporate lauric acid in the muscle.