22421 research outputs found
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Predicting beef diet nutritional composition and intake from rumen metagenomic profiles
Full text linkKnowledge of diet composition and intake levels in beef cattle is valuable for post hoc feed traceability and for more accurate modelling of the diet impact on methane emissions and performance traits. However, a direct measure of this information can be costly and labour-intensive and is not always feasible. In this study, rumen metagenomic data combined with machine learning algorithms were used to predict diet type, nutritional composition, and intake levels. An external validation to assess the generalizability of the models was also performed. Rumen samples were collected from 142 animals belonging to two breeds, Luing (n = 70) and Charolais crossbred (n = 72), with 425.6 ± 43.5 d old and 461.9 ± 70.2 kg body weight. The animals participated in a 56-d feeding trial and were assigned to diets differing in forage-to-concentrate ratio, with 72 animals receiving a concentrate-based diet and 70 receiving a forage-based diet. Liquid ruminal contents were collected immediately postmortem and subsequently subjected to metagenomic sequencing. Based on these sequences, the relative abundance of microbial genes (MGs), microbial genera (MTs), and phyla were determined. The log-ratio between the abundances of Verrucomicrobia and Chlorobi discriminated diet type with an average classification accuracy of 0.86 ± 0.05, while using the log-ratio transformed abundances of 4769 MTs and MGs as predictors reached 0.90 ± 0.05. All this microbiome information was used in a random forest model to predict continuous values for nutritional diet components starch, crude protein, neutral and acid detergent fibre, and metabolizable and gross energy with external validation prediction accuracy values between 0.77 and 0.83. Microbiome features important for prediction of diet components such as fibre and starch included Mitsuokella, Selenomonas, and MGs involved in flagellar assembly and aminoacyl-tRNA biosynthesis. Microbiome data were more informative for predicting the feed composition than the amount of feed consumed, which reached a prediction accuracy of 0.27 ± 0.12 for dry matter intake (DMI). However, microbiome data can still be used as a screening tool to classify DMI into low, medium, or high with a classification accuracy of 0.74. Incorporating dietary information into linear phenotypic and genetic models to predict methane production (MP) and DMI reduced root mean square error (RMSE) by 26.9% and 9.6%, respectively, in the phenotypic model. In the genetic model, only MP showed a reduction in RMSE, with a 31% improvement. These findings highlight rumen microbiome data as a valuable tool for the post hoc prediction of feed composition in beef cattle
Chlorfenapyr bednets effectively overcome pyrethroid resistance escalation in highly resistant Anopheles malaria vectors in Uganda
Full text linkEscalating insecticide resistance threatens the efficacy of LLINs, undermining malaria control in Africa. We conducted the first experimental hut trials in Uganda using highly resistant free-flying wild Anopheles mosquitoes and F2 hybrids of FANG and Uganda An. funestus to evaluate the performance of bednets. The interceptor G2 (chlorfenapyr) bednet demonstrated superior efficacy compared to Interceptor (pyrethroid-only) net [mortality odds ratio (OR): 18.7 (8.05-48.6) P < 0.0001], achieving an overall mortality rate of 70.6% and 63.2% against An. funestus and An. gambiae respectively. In contrast, PermaNet 3.0 and Olyset Plus (piperonyl butoxide (PBO)) and Royal Guard (pyriproxyfen (PPF)-treated) bednets exhibited significantly lower mortality against An. funestus [Olyset Plus: 36.1%, PermaNet 3.0: 31.0% and Royal Guard (37.6%], though performance against An. gambiae was moderate [PermaNet 3.0: 61.4%, Olyset Plus: 50.0%, Royal Guard: 51.6%]. Interceptor net produced the lowest mortality (~ 25%) against both species. Regarding blood-feeding inhibition (BFI), PBO nets, particularly Olyset Plus, outperformed Interceptor G2 and Royal Guard, while Interceptor produced minimal BFI (< 36%). Further evaluation of Royal Guard's PPF effect on oviposition revealed no significant reduction in oviposition rates compared to controls with An. funestus (63.9% vs. 63.3%, P > 0.05). Genetic analysis using the hybrid crosses revealed that pyrethroid resistance markers (4.3 Kb-SV and G454A-Cyp9K1) were significantly associated with mosquito survival and blood-feeding success against PermaNet 2.0 (pyrethroid-only) and PermaNet 3.0 but showed no significant association with Interceptor G2 net. These findings support Interceptor G2 as a promising intervention for regions dominated by both highly resistant An. funestus s.l. and An. gambiae s.l. Piperonyl butoxide and PPF nets emerge as a good alternative for areas mostly dominated by resistant An. gambiae s.l. populations. Critically, the demonstrated variable impact of insecticide resistance on bednet efficacy underscores the imperative need for a comprehensive vector distribution mapping, continuous field efficacy assessments, and systematic resistance monitoring. This evidence-based triad should guide strategic LLIN distribution and rotations to sustain malaria control efficacy in resistance-prone settings.</p
National BVDV eradication programme: Assessing the utility of the spot test
Full text linkWe examined the BVDV test records of 3769 farm holdings from one laboratory involved in a national BVDV eradication programme with the objectives (1) to investigate the utility of the spot test to identify BVDV infected herds correctly; (2) to explore the possible reasons for false positive results and (3) to examine the frequency with which herds subsequently had a BVDV persistently infected (PI) calf born. During the 12-month study, 283 (7.5%) farm holdings were identified as BVD not negative based on the presence of antibodies to BVDV. Follow-up testing was carried out in 131 (3.5%) and in 79 (2.1%) of those, results were not consistent with BVDV infection. The main cause of false positive spot tests was transient antibodies in animals younger than 270 days of age, consistent with the persistence of maternally derived antibodies. BVDV PI births were found on 34 farm holdings (0.9%), in herds that were identified by the spot test as BVD not negative, as well as in herds identified as BVD negative. Farm holdings with spot tests with more than 40% of the samples positive for antibody and those with more than 20% and less than 40% were, respectively, 27.7 and 25.0 times more likely to have a PI born than those that had a negative spot test. However, farm holdings with at least one positive, but no more than 20% of the samples positive for antibody, were 3.9 times more likely to have a PI born than those in which no antibody positive animals were detected. We concluded that ignoring the presence of single antibody positives in the spot test could be counterproductive to the objective of national BVDV eradication
Research on Polysaccharide–Protein Composite Hydrogels for Gastrointestinal Targeted Delivery: A Review
Full text linkPolysaccharide–protein composite hydrogels have demonstrated remarkable potential in targeted gastrointestinal delivery owing to their excellent biocompatibility, adjustable physicochemical characteristics, and intelligent responsiveness. This review provides a comprehensive overview of the underlying mechanisms and diverse applications of these composite hydrogels in gastrointestinal targeted delivery, with a particular emphasis on their stimuli-responsive release behaviors triggered by internal and external factors such as pH, enzymes, magnetic fields. Special attention is also given to their advantages in protecting sensitive bioactive ingredients, including curcumin, EGCG, probiotics. Furthermore, this review highlights their capabilities in achieving high encapsulation efficiency, smart controlled release and targeted delivery, while also presenting current challenges associated with material stability, targeting precision, large-scale production, and clinical translation. Finally, future perspectives are discussed, focusing on the development of multi-response system design, innovative biomaterials, advanced manufacturing technology applications, and AI-assisted optimization. These directions aim to provide theoretical foundations and technical strategies for advanced research and practical applications of polysaccharide–protein composite hydrogels in a targeted gastrointestinal delivery system. Overall, this review underscores the significant promise of polysaccharide–protein composite hydrogels as intelligent gastrointestinal delivery platforms and provides a systematic reference for their rational design and future translational development
Environmental Performance Evaluation Under the Frontier Analysis Framework: A Farm-Level Systematic Review and Meta-Analysis.
Full text linkQuantifying and improving the environmental performance (EP) of agriculture has become an urgent research and policy priority. Over the past three decades, frontier-based analytical frameworks have been widely applied to evaluate farm-level EP. We present a global systematic review and meta-analysis of 121 studies (comprising 800 unique environmental performance estimates) that use a frontier-based approach for farm-level EP evaluation. Adhering to PRISMA guidelines, we extract and synthesise information on modelling approaches, estimation methods, pollutant types, as well as other data and study characteristics. We also consider the determinants for EP. We find that there is inertia in the shift towards more recent and methodologically better environmental performance evaluation techniques, such as the by-production approach and material balance methods, at the farm level. A random effects meta-regression reveals that the methodological approach and estimation methods explain the variation in EP. Farm type and inclusion of determinants are also important. We identify multiple significant determinants of environmental performance across agricultural systems. The findings advance academic understanding of how modelling frameworks shape EP estimates. They also offer practical insights to help policymakers understand specific policy variables and farm-specific factors that could be leveraged to improve environmental performance. For example, fostering pro-environmental attitudes and encouraging the adoption of sustainable agricultural practices through extension services can help enhance environmental performance in farming
Short-term stability over time and across situations of behavioural traits in gestating and lactating sows
Full text linkPersonality consists of the set of traits which show stable individual differences in behaviour over time and across contexts in a species. Personality has been previously studied in pigs, however few studies have focussed on adult females and on both the gestating and lactating phases of their reproductive cycle. The aim of this work was to identify candidate personality traits in breeding females, by assessing temporal stability and associations between situations. Adult female pigs (Sus scrofa) ranging from parity one to seven underwent a series of repeated tests and observations during late gestation (70–110 days after service) and during lactation (1–30 days after farrowing). In gestation, their response to a human in the home pen (n = 55, median 2 repeated tests per individual, ranging from 1 to 4) and social behaviour at feeding (n = 52, median 2 tests, 1–4) were assessed. In lactation their response to a dummy hand (n = 66, median 2 tests, 1–4) and lying down behaviour (n = 68, median 2 tests, 1–6) were recorded as indicators of maternal defence and maternal care. Out of the twelve variables measured in these four different situations, five were consistent over repeated tests at different times (i.e. the posterior distribution of their repeatability excluded values less than 0.01): dominance rank, number of attacks, and number of avoidances during feeding, number of vocalisations when exposed to a dummy hand, and probability of vocalising before lying down. We found correlations with an absolute value higher than 0.30 between number of attacks and number of avoidances during feeding (r = -0.33), number of attacks and number of vocalisations when exposed to the dummy hand (r = -0.52), and between the latter and probability of vocalising before lying down during lactation (r = 0.46). Our results suggest that social behaviour at feeding and acoustic signalling in different contexts are stable traits in adult female pigs. The estimated correlations between the traits might also indicate the presence of a proactive behavioural syndrome
Total replacement of soy with alternative plant-based ingredients, feed enzymes and a probiotic in a mixed-cereal broiler diet fed during an entire growth cycle
Full text linkTotal replacement of soybean meal (SBM) and soy oil with alternative plant ingredients (rapeseed meal, sunflower meal, corn gluten meal, faba beans, lupins, pea flour and potato protein concentrate) plus feed additives was evaluated in broilers. A completely randomized design employed 1440 Ross 308 males (30 birds/pen). Diets were fed ad libitum in 3 phases. Treatments comprised a SBM-control containing phytase (PhyG) at 1000 phytase units (FTU)/kg and xylanase at 1200 xylanase units (XU)/kg, and three alternative (ALT) diets without SBM or soy oil. The three ALT diets contained PhyG at 2000/1500/1000 FTU/kg during starter/grower/finisher phases, respectively, and a probiotic (150,000 colony forming units (CFU)/g), as well as either: 1) a xylanase and β -glucanase co-granule (XB, containing 1200 XU/kg xylanase and 152 U/kg β-glucanase) and 4000 U/kg protease (ALTa); 2) XB at double dose and 2000 U/kg protease (ALTb), or; 3) XB as in 2) and 4000 U/kg protease (ALTc). Increasing both XB and protease dose in ALTc achieved final BW did not differ from the SBM-control, though overall FCR remained higher (P < 0.05), ALTc conferred a ∼57 % reduction in the carbon footprint of production (P < 0.05) and ALTc birds had a more diverse cecal microbiota at family level (P < 0.01, Shannon Diversity Index). Supplementation of these feed additives can enable complete replacement of SBM and soy oil with alternative plant ingredients in an all-vegetable diet, achieving final body weight comparable to a soybean meal- based diet while reducing the carbon footprint of production.</p
Temporal social network structures based on snout contact during group integration in pigs
No full textDuring the formation of new social groups, temporal variations in behavioural associations between individuals can provide insight into the role of behaviours during group formation. While social behaviour during the establishment of new groups has been studied, there is a lack of knowledge on how non-agonistic social patterns change across time. The aim of this study was, therefore, to examine temporal variation in behavioural associations between individuals during the formation and maintenance of social relationships between conspecifics. This was studied in 15 mixed-sex groups of commercial pigs (n = 118 pigs; 8 pigs per group), which were regrouped at the start of the experiment (at weaning). They were studied between 4 and 11 weeks of age to capture variation in group stability. We focused exclusively on snout-directed behaviour given its role in conspecific recognition and affiliative interactions, whereby particularly snout-to-snout contact may contribute to the development of social relationships. Social network analysis (SNA) was used to investigate temporal associations. The results show that pigs made frequent snout contact (avg. 33 times / 15 min.) and that interactions were relatively more affiliative than aggressive (tenor range: 0.52 – 0.61), and were more affiliative in the high as compared to medium social stability phase (p = 0.02). As group integration progressed, the number of social partners involved in snout contact decreased, while the frequency of snout contact per individual increased. There was no evidence of non-random social preferences and no evidence of centralised associations (degree centralisation range: 0–0.3). Pigs showed more snout contact with non-littermates than littermates (i.e. a heterophilic association based on litter origin; assortativity range: −0.34 to −0.08) and between individuals with different early social experiences (assortativity range: −0.45 to −0.07) across all integration phases. Additionally, males initiated contact more frequently than females, whereas females occupied more central positions within the social network. These behavioural processes, which support the formation and maintenance of social relationships, show that non-agonistic behaviours such as snout contact have a prominent role in the social dynamics of pigs.</p
Wetland Archaeology:past, present and future
No full textIn this chapter, we outline the importance of wetland environments for preserving archaeological sites, finds and deposits, especially organic material that rarely survives on dryland (terrestrial) contexts. We briefly review the development of “wetland archaeology” as a sub-discipline and consider the processes that result in the waterlogged, anoxic conditions suitable for the long-term survival (millennia timescales) of such remains. A case study draws on examples from peatlands in northwest Europe, describing the range and character of tangible cultural heritage discovered over centuries of drainage and peat extraction. There is an intrinsic relationship between investigation and excavation of archaeology, and damage and destruction of wetland environments, via drainage, reclamation, urban expansion and related processes. We consider the synergies and conflicts between policies and approaches to wetland rehabilitation and restoration, and the associated protection and management of the archaeological resource. Despite the existence of policies intended to protect and conserve, without appropriate recognition and attention, wetland archaeology can be negatively impacted by interventions and policies intended to rehabilitate and restore wetland environments. Finally, we conclude that cultural heritage represents an under-appreciated and at times woefully ignored, intersection between the “natural” and “cultural” valuation and perception of wetlands, which work needs to better highlight and integrate into future policy directions and decisions
Role of Modern Technologies for Sustainable Genetic Improvement of African Livestock
Full text linkEvidence of the impact of advanced technologies in genetics, nutrition and health management in the last seven decades has led to a twofold increase in the milk produced by a Holstein cow and a fourfold increase in the size of a broiler chicken in Western countries. Therefore, harnessing breakthrough technologies of genomicGenomics breeding, reproductionReproduction, management practices (health and environment), etc., with supporting infrastructure, funding and technical know-how is key to solving current problems and achieving rapid developments in the African livestock sector. This chapter presents an overview of some modern technologiesModern technologies that have played and continue to play significant roles in advancing sustainable genetic improvementSustainable genetic improvement in the livestock sector. Firstly, Section 20.2 presents the key issues impeding sustainable livestock improvement within Africa’s complex livestock production systems. Then the phenomicsPhenomics technologies used for data capture to support genetic selectionSelections are presented in Section 20.3 followed by the breakthrough genomicsGenomics technologies responsible for sustained genetic improvementsGenetic improvements in livestock traits (Section 20.4). The emerging technologies of genome editing (Section 20.4.3) and cellular agriculture (Section 20.4.4) are also presented. Breakthrough reproductive technologies that have been responsible for the spread of high-merit genetics are examined in Section 20.5. This chapter concludes with future perspectives (Section 20.6) on how the adoption and implementation of modern genomicGenomics technologies can accelerate desired improvements in the African livestock sector.</p