Animal Production Systems Research Articles

How closely do ecosystem services and life cycle assessment frameworks concur when evaluating contrasting animal-production systems with ruminant or monogastric species?

Life cycle assessment (LCA) and ecosystem services assessment (ESA) are often used for environmental assessment. LCA has been increasingly used over the past two decades to assess agri-food systems and has established that ruminant products have higher impacts per kg of protein than products from monogastric species. Conversely, ESA is used less but is likely to rank ruminant systems higher than monogastric systems, as the former often include grasslands that can provide high levels of regulating ecosystem services (ES). Here, we applied both methods to a selection of contrasting meat-oriented animal-production systems that included either ruminants or monogastrics (6 of each). We considered 16 environmental impact categories in the LCA and two functional units: 1 kg of human-edible protein (HEP) and 1 m2yr of land occupied. We used the life-cycle inventory step of LCA to characterize the land occupation of the systems, i.e. the land cover types used, such as croplands and grasslands. Based on these land covers and quantification of the ES they provide, we performed ESA. We estimated that ruminant systems had higher environmental impacts than monogastric systems per kg of HEP for all 16 LCA impact categories studied. For example, for ruminants and monogastrics, mean greenhouse gas (GHG) emissions were 280 vs. 32 kg CO2-eq., respectively (P = 0.002), and mean fossil energy use was 351 vs. 189 MJ, respectively (P = 0.009). The trend was the opposite for impacts per m2yr, with mean GHG emissions of 0.50 vs. 0.57 kg CO2-eq. (P = 0.485) and mean fossil energy use of 0.71 vs. 3.63 MJ (P = 0.002) for ruminants and monogastrics, respectively. We also estimated that ruminant systems had a higher capacity to supply regulating ES than monogastric systems did, with mean scores of 2.4 and 1.2, respectively (P = 0.002), due to multiple types of grasslands in ruminant systems. Applying both LCA and ESA to a range of contrasting animal-production systems was a novelty of this study, and ESA indicated that ruminant systems have higher positive environmental contributions than monogastric systems. The study also found that LCA and ESA frameworks can agree or disagree on the assessments of animal-production systems depending on functional unit used (i.e. agreement per unit of land occupied but disagreement per unit of HEP).

Principles, barriers and enablers to agroecological animal production systems: a qualitative approach based on five case studies

Agroecology is among the most promising options to alleviate the negative impacts of animal farming on the environment and build local food systems based on ethically-acceptable production methods. So far, most of the research on agroecological animal production systems was conducted at farm scale, and the potential of agroecological principles addressing social dimensions and food system level approaches has been underexplored. Here, we analyze how the whole set of agroecological principles was mobilized in five case studies on grassland-based, silvopastoral or integrated crop-livestock systems in Switzerland, Guadeloupe, French uplands, Bulgaria and Andalucía. Following a multilevel perspective, we propose a new eight-category framework to categorize barriers and enablers in these different socioecological contexts, and discuss the implications of these results for scaling out and scaling up agroecological niche innovations in animal production areas. Though we could observe activities related to each agroecological principle in each case study, the relative importance of each principle differed. For instance, in Switzerland the focus was on ecological processes operating in multi-species mixtures, and therefore on mobilizing principles of input reduction, synergy, soil health and biodiversity, while in Andalucía, a civil society organization, a regional agricultural office, researchers, and farmers mainly mobilized transformational principles at the food system level, e.g. social values, connectivity and participation. Such contrasts highlight how agroecology allows different equilibria among principles, adapting to the needs of farmers and local communities. Inadequate infrastructure and lack of technology were frequently reported as barriers to agroecological transitions. Policy needs to go beyond the mere support of agroecological practices on livestock farms and adopt a systems approach looking downstream and upstream if it is to enable a large-scale agroecological transition with EU public policies. Market as an enabler was linked to direct sales and short distribution circuits, generating added value to the benefit of local communities. Most agroecological systems benefited from a positive image among citizens and consumers, but cultural barriers resulted from change in product characteristics, e.g. veal meat color in dairy system that promote long-lasting cow-calf contact. All case studies were very advanced in the social dimensions of agroecology, and cooperation networks were always reported among the enablers for scaling out. The multi-actor network approach fostered knowledge exchange between farmers, researchers and citizens, and allowed participants to share values. Long-term commitment from local practitioners is required so that co-designed solutions are implemented, which can strengthen the economic and social viability of animal production areas.

Feeding Strategies and Quality Assessments of Animal-Derived Products

Feeding strategies play an important role in animal production systems by directly influencing animal health, productivity, and the quality of animal-derived products (meat, eggs, and milk) [...]

The need for high-resolution gut microbiome characterization to design efficient strategies for sustainable aquaculture production

Microbiome-directed dietary interventions such as microbiota-directed fibers (MDFs) have a proven track record in eliciting responses in beneficial gut microbes and are increasingly being promoted as an effective strategy to improve animal production systems. Here we used initial metataxonomic data on fish gut microbiomes as well as a wealth of a priori mammalian microbiome knowledge on α-mannooligosaccharides (MOS) and β-mannan-derived MDFs to study effects of such feed supplements in Atlantic salmon (Salmo salar) and their impact on its gut microbiome composition and functionalities. Our multi-omic analysis revealed that the investigated MDFs (two α-mannans and an acetylated β-galactoglucomannan), at a dose of 0.2% in the diet, had negligible effects on both host gene expression, and gut microbiome structure and function under the studied conditions. While a subsequent trial using a higher (4%) dietary inclusion of β-mannan significantly shifted the gut microbiome composition, there were still no biologically relevant effects on salmon metabolism and physiology. Only a single Burkholderia-Caballeronia-Paraburkholderia (BCP) population demonstrated consistent and significant abundance shifts across both feeding trials, although with no evidence of β-mannan utilization capabilities or changes in gene transcripts for producing metabolites beneficial to the host. In light of these findings, we revisited our omics data to predict and outline previously unreported and potentially beneficial endogenous lactic acid bacteria that should be targeted with future, conceivably more suitable, MDF strategies for salmon.

Consumers’ Perceptions and Behaviors Regarding Honey Purchases and Expectations on Traceability and Sustainability in Italy

Traceability is a cornerstone of sustainable honey production and consumption. Honey fraud and a lack of traceability have been recently highlighted by the European Commission. Innovative systems aimed at guaranteeing food safety ’from farm to fork’ and improved controls are highly recommended. Within the framework of the BPRACTICES project, part of the European Union’s Horizon 2020 research and innovation program, and the ERA-Net SusAn initiative—focused on Sustainable Animal Production Systems—an advanced traceability system has been developed. This system utilizes QR code and radio-frequency identification (RFID) technology, along with a user-friendly web application, to facilitate direct interactions between producers and consumers. Despite existing research, studies on the information needs of Italian consumers regarding honey and its traceability remain limited. Understanding these needs is vital for creating effective communication strategies that enhance consumer satisfaction and trust. This study aims to identify the needs of Italian consumers’ honey during the purchasing and consumption decisions. To explore consumer perceptions, behaviors, expectations, and needs regarding honey, we employed diverse social research methodologies, including a quantitative online survey, paper-and-pencil interviews, and focus groups. The results of this study indicate a robust demand for more information on honey’s origin, production processes, and beekeeping practices, aligning with the recent EU Directive 2024/1438, which mandates clear labeling. Italian consumers would be willing to pay a premium for honey that offers detailed information about production practices and transparency. The positive reception of QR code technology by consumers suggests a growing openness to digital tools that enhance transparency and access to information. Ultimately, this research emphasizes the need for the beekeeping sector to adopt sustainable practices, improve traceability systems, and actively engage with consumers to foster trust and ensure long-term viability in the honey market. By addressing these information needs, the sector can align itself with increasing consumer demand for quality, sustainability, and transparency.

Near-Infrared Spectroscopy in Animal Nutrition: Historical Insights, Technical Principles, and Practical Applications

Optimizing forage quality is vital for enhancing animal performance and supporting the global animal production industry. Near-infrared (NIR) spectroscopy offers a rapid, non-destructive alternative to traditional, time-intensive laboratory analyses, enabling the on-site assessment of forage properties with significant advantages in cost, speed, and environmental impact. This review traces the development of NIR spectroscopy, outlines its core principles, and highlights its applications in animal nutrition. Additionally, it discusses the current technological state, challenges, and future prospects, emphasizing NIR’s growing role in promoting more sustainable and efficient animal production systems.

PSXIII-16 Kinematics and viability of spermatozoa from Criollo and Angus bulls in a low-input system

Abstract The Chihuahuan Criollo cattle is a genetic resource with special adaptive characteristics to rough, arid and semi-arid ecosystems. There is a great interest in incorporating such adaptations into beef production systems as one of the strategies for sustainable production to face the climate change challenge. Reproductive success is determinant to achieve sustainability in animal production systems. Most research efforts to improve reproductive efficiency have focused on the study of females. However, it has been shown that much of the economic losses caused by embryonic deaths are due to the bull. The aim of this study was to evaluate the quality of thawed semen from Angus and Criollo bulls kept in a low-input system. Thirteen healthy bulls (n = 7 Angus and 6 = Chihuahuan Criollo), with an average age of 4.3 ± 0.48 yr, grazing in the same rangeland and subjected to natural pasture conditions, were studied. Semen obtained by electroejaculation, were frozen and subsequently thawed for analyses. Characteristics of motility, vitality (V), morphology (M) and plasma membrane integrity (PMI) were evaluated in fresh and thawed semen, whereas movement kinetics (MK) and acrosome reaction (AR) were evaluated in thawed semen. Statistical analysis was performed using the PROC GLM of SAS Studio 2022 including the fixed effects of breed, semen condition and their interaction for variables of progressive motility (PM), V, M, PMI and the effect of breed for variables of MK and AR. As expected, PM and V were less (P < 0.05) in thawed (57.93 ± 4.1 and 53.69 ± 2.7) compared with fresh (72.64 ± 3.9 and 74.98 ± 2.6) semen, whereas no differences (P > 0.05) were found in M. However, the interaction between semen condition and breed for PMI tended to the significance (P = 0.08) with a PMI of 68.95 ± 4.6 and 58.98 ± 4.3 for Criollo and Angus, respectively, in fresh semen, whereas in thawed semen this difference was inverted (52.08 ± 4.6 and 58.40 ± 4.6). It is important to note that the semen retained quality traits with values above the minimum accepted for use in artificial insemination, despite the scarcity of resources of the system in which the animals were kept. There were no differences by breed in the main MK variables; however, AR reported as live unreacted sperm was less (P < 0.05) in Criollo (40.49 ± 4.49) compared with Angus bulls (58.48 ± 4.49). In conclusion, it is important to incorporate the assessment of membrane integrity and acrosome reaction in thawed semen evaluation to obtain a more accurate prediction of the potential fertility of samples, even if motility parameters appear to be optimal.

3 Hands -on 1: Applying system dynamics to develop “Flight Simulators” for sustainable animal production

Abstract Solving complex livestock production problems is a pressing issue for achieving long-term sustainability and profitability and often requires modeling techniques. The use of mathematical models is undoubtedly a daily practice in the livestock industry, especially nutrition, and has improved animal performance, productivity, and environmental sustainability while maintaining or reducing costs. Although many students and professionals use spreadsheets and existing empirical models for nutrition and management [NASEM (2016)], there is still a need to understand the complexity of livestock systems and the utility of flight simulator models. At the same time, more complex models (although robust) may fail to provide new insights for experienced nutritionists due to poor user-friendliness. A systems understanding goes beyond simply obtaining a desired output, such as optimizing a total mixed ration, but instead leads to identifying high-leverage solutions and gaining insight. Further, parameterizing and calibrating variables and equations and testing management scenarios is straightforward. However, developing causal feedback linkages (A to B and B to A) and identifying time delays is less intuitive and more challenging for novices. Model flight simulators grounded in fully documented, calibrated models provide a means to introduce practitioners to a methodology of insight generation because the user designs and runs the model scenarios for themselves, challenging their mental models. Such approaches are generally more impactful (compared with someone telling them) because they have gained insight into the system themselves, and, in the case of open source (white box models), they can explore equations and parameters. Therefore, understanding how to utilize dynamic models in scenario-based simulations is critical in training current and future modelers in animal science. This hands-on model training will cover the basics of System Dynamics modeling and allow participants to run real-time animal production simulations. Finally, participants will be “debriefed” to unpack “ah ha” moments that were unexpected. The debrief will include using models to develop accurate guidelines and recommendations for those who cannot use computer models and developing experimental designs to test hypotheses and “validate” model recommendations (proof in the pudding). Participants will gain knowledge of System Dynamics applications for animal production systems, experience using flight simulators, and their utility in teaching, informing, and guiding their livestock production or that of a client. The “flight simulator” will focus on production and nutrition with species-agnostic principles. Participants will also have a new tool to identify areas for improvement in model development (i.e., what is missing?), research questions, or industry needs. The need for modelers who can turn big data into insight, knowledge, and wisdom using a systems approach is becoming even more critical due to the increasing use of precision livestock farming. Thus, providing the livestock industry with trained systems modelers will help achieve current and future sustainability challenges.

Evaluating Biosecurity on Selected Commercial Pig Farms in Serbia

Abstract Biosecurity measures, coupled with effective on-farm management, encompass all aspects aimed at preventing the entry of pathogens into pig farms and their subsequent spread within the facility. This study assessed biosecurity practices on commercial pig farms in Serbia by surveying farm veterinarians/managers. To evaluate biosecurity on these farms, a Biocheck online survey (https://biocheckgent.com) was conducted across ten commercial pig farms in Northern Serbia, where the highest concentration of industrial pig production occurs. The average overall biosecurity score was 65.56 ±11.65. External biosecurity scored higher (75.56 ±9.39), whereas internal biosecurity scored lower (54.89 ±16.92). Within external biosecurity, the weakest scores were observed in categories such as feed, water, and equipment supply (47 ±25.48), showing considerable variation among farms, particularly in feed, water, equipment supply (54.22), and farm location (57.65). Regarding internal biosecurity, the lowest scores were noted during the farrowing and suckling period (37.22 ±15.08) and the finishing unit (37.66 ±24.12). This study reveals that biosecurity measures in commercial pig farms in Serbia are slightly below the global average. Given the predominance of extensive production systems in Serbia, urgent improvements in biosecurity practices on industrial farms are essential. Identification and implementation of appropriate biosecurity measures tailored to existing animal production systems are urgently needed.

Genetic regulation of ovulation rate and multiple births.

Ovulation rate in many mammalian species is controlled to regulate the numbers of offspring and maximise reproductive success. Pathways that regulate ovulation rate still respond to genetic and environmental factors and show considerable variation within and between species. Genetic segregation, positional cloning, and association studies have discovered numerous mutations and genetic risk factors that contribute to this variation. Notable among the discoveries has been the role of mutations in bone morphogenetic protein 15 (BMP15 ), growth differentiation factor 9 (GDF9 ) and bone morphogenetic protein receptor type 1B (BMPR1B ) from the intra-ovarian signalling pathway contributing to the evidence that signalling from the oocyte is the key driver in follicle regulation rather than circulating gonadotrophin concentrations. Multiple variants in different domains of BMP15 and GDF9 result in partial or complete loss of function of the proteins providing insights into their functional roles and differential regulation contributing to species differences in ovulation rate. Early success encouraged many more studies in prolific strains of sheep, cattle and goats providing a valuable catalogue of genetic variants of large effect increasing ovulation rate and litter size. More recently, genetic association studies are beginning to identify genetic risk factors with smaller effects. Most genes implicated are from pathways with defined roles in regulation of the ovarian function. However, some genomic regions suggest regulation by novel genes. Continuing genetic and related functional studies will add further to our understanding of the detailed regulation of ovulation rate and litter size with implications for health and animal production systems.

The paradoxes of the protein transition maintain existing animal production and consumption systems.

The shift towards reduced consumption of animal-based products, referred to as the protein transition, is increasingly viewed as an opportunity to drive sustainable food systems transformations. Here we explore three central paradoxes of the protein transition. The first underscores the focus on substituting animal proteins with alternative sources, rather than reducing overall protein consumption. The second focuses on the search for new protein sources, rather than tackling overconsumption and overproduction. The third involves the continued export of animal proteins from Europe, a practice defended under the guise of food security, efficiency and comparative advantage. These narratives dominate public discourse, justifying existing production and consumption patterns, shaping perceptions and influencing decisions and policies that impact the future direction of our food systems. Given the influence of stakeholders' narratives in the transition, we advocate for a holistic and systemic perspective that transcends isolated and quick-fix solutions to foster coherent strategies to advance the protein transition.

Addressing residue and resistance in food animals: a policy imperative in Southeast Asia

SummaryResidue and resistance in food animals pose significant challenges to Southeast Asia's public health, animal welfare, agricultural productivity, and sustainability. This article emphasises the need for policy interventions to address these issues effectively. Residue, the presence of harmful substances in animal products, is a concern due to the misuse of veterinary drugs and pesticides. Robust surveillance programs, risk assessment, and enforcement of maximum residue limits are crucial to ensure food safety. Antimicrobial resistance (AMR) is another critical challenge in the region, driven by intensive animal production systems and disproportionate antimicrobial use. Responsible antimicrobial use, surveillance systems, and alternative production practices like vaccination, enhanced animal husbandry, and improved biosecurity a re essential to combat the menace. Addressing residue and resistance requires a comprehensive mindset and policy approach, including strengthening regulatory frameworks and inter‐agency collaboration, including a One Health approach. Governments, farms, veterinarians, and other stakeholders must work together to develop and enforce effective policies. Education and awareness campaigns can promote responsible practices throughout the food‐animal production chain. By prioritising the reduction of residue and resistance, Southeast Asian countries can safeguard public health, ensure sustainable agriculture, and contribute to global efforts in tackling AMR. Policymakers supported by academia, industry, and other stakeholders play a crucial role in effectively shaping and implementing policies to address these challenges.

Selection for yield in elephant-grass forage genotypes using GGE Biplot analysis

Elephant grass is among the most used forages in intensive animal production systems due to its high productive potential, carrying capacity and nutritional quality. Because of the existing interaction between genotypes and environments, it is essential to select and develop materials that are not only high-yielding but also adaptable and stable. In this context, this study was developed to analyze the performance and select genotypes of elephant grass simultaneously for dry matter yield, performance stability and adaptability. Fifty-three elephant grass genotypes with forage potential were evaluated in four environments (rainy and dry seasons in years 1 and 2), defined according to the time at which the harvests occurred. A randomized-block design with two replicates was adopted. Dry matter yield (t.ha-1) was measured at each assessment (harvest). Adaptability and genotypic stability were evaluated using the GGE biplot methodology and R software. In the overall classification, genotypes 53, 22, 29, 17 and 33 showed the best average performance. Regarding dry matter yield, adaptability and phenotypic stability, genotype 53 was classified as the ideotype.

Conventional and unsupervised artificial intelligence analyses identified risk factors for antimicrobial resistance on dairy farms in the province of Québec, Canada

Antimicrobial resistance (AMR) is one of the greatest threats to global health worldwide and is threatening not only humans, but also animal production systems, including dairy farms. The objective of this paper was to describe risks factors associated with AMR on dairy farms in Québec, Canada. This observational cross-sectional study included 101 commercial dairy farms and took place between the springs of 2017 and 2018 for a one-year period. We explored risk factors such as farm practices and producer's knowledge (measured using a questionnaire), antimicrobial use (quantified using veterinary invoices), and the presence of Salmonella Dublin (tested by serology). We evaluated AMR with fecal Escherichia coli retrieved from pre-weaned calves and lactating cows using the following outcomes: the presence of extended-spectrum-β-lactamase/AmpC resistance and the number of resistances to antimicrobial classes. We used logistic regression models to evaluate the association between each risk factor and the 2 outcomes for the 2 types of samples (pre-weaned calves and lactating cows). Furthermore, we explored the relationships between these risk factors utilizing data dimensionality reduction and hierarchical clustering. Outputs of these analyses were used as regressors for AMR in regression models. While the results for univariate analyses were ambiguous, the unsupervised analysis naturally categorized the sample of farms according to their health/treatment status (dimension 1, explaining 12.9% of the variance) and herd size (dimension 2, explaining 7.8%). Three clusters of farms were identified (cluster 1: mainly healthy herds and low ceftiofur users, cluster 2: relatively high ceftiofur users, cluster 3: farms with a higher incidence of diseases and higher antimicrobial treatment rates). Dimension 1 and cluster membership were statistically associated with the presence of extended-spectrum-β-lactamase/AmpC resistance in lactating cows and in pre-weaned calves. Dimension 1 was also statistically associated with the number of resistances in lactating cows and in pre-weaned calves. This study highlights the complexity of analyzing risk factors associated with AMR. Our results suggest that the herd health status and the AMU-related practices used are associated with AMR in dairy farms. However, prospective studies are needed to confirm a causal relation.

Exploratory study for implementing a Global Burden of Animal Diseases case study in Senegal.

Senegal is a West African country with both extensive animal production systems, representative of the environmental, economic and animal health constraints specific to the Sahel region, and thriving commercial poultry and dairy production. An exploratory study was conducted in Senegal between 2021 and 2022 as a prelude to a case study of the Global Burden of Animal Diseases (GBADs) programme. An overview of existing animal production systems as well as the main priorities and issues in animal health on a national level was developed. A national workshop gathering representatives from the livestock production and academic sectors took place in Dakar in June 2022 with the objective of jointly developing a case study. The participants prioritised pastoralist production systems for cattle and agropastoral systems for small ruminants for the application of the GBADs programme. Through a series of activities, the participants highlighted the health, environmental, economic and socio-political challenges surrounding these systems, all of which limit their contribution to the well-being of pastoralist households, consumers and other stakeholders. While Senegal has in the past hosted a large number of research and cooperative projects on these two livestock systems, participants noted difficulties in obtaining, centralising and harmonising the existing data. This exploratory study led to the funding of a focused case study of the agropastoral small-ruminant sector that was carried out in 2023 in partnership with national and international organisations.

The application of Global Burden of Animal Diseases methodology to aquatic animal production.

The Global Burden of Animal Diseases (GBADs) programme's key objective â€" to provide a systematic approach to determine the burden of animal disease â€" is as relevant to aquatic as to terrestrial animal production systems. However, to date GBADs methods have mainly been applied to terrestrial animal production systems. The challenges in applying GBADs methods, notably the Animal Health Loss Envelope (AHLE), vary considerably by production system. The authors demonstrate how the AHLE can be calculated for rainbow trout production in England and Wales and acknowledge that its application to other systems (e.g. hatchery production, polyculture and no-feed mollusc production) is more complex. For example, in small scale tropical fish production the impact of suboptimal nutrition on production would need to be addressed. Recirculating aquaculture systems have inherent high levels of biosecurity and disease control, and thus low levels of disease. Removing the capital and running costs associated with biosecurity fundamentally changes the system and invalidates the AHLE calculation. Lack of data from many systems, notably small-scale tropical finfish farming, means that expert opinion will be needed to support the application of GBADs methods. While calculation of the AHLE is the focus of this article, it should be noted that attribution to causes and value chain modelling are needed to generate data on the wider societal impact of aquatic animal diseases (and possible interventions), which governments require to support decision-making about resource allocation.

Interpretation and utility of the Animal Health Loss Envelope as part of the Global Burden of Animal Diseases analytical process.

The Global Burden of Animal Diseases (GBADs) programme follows a multistage process to produce disease burden estimates in livestock and farmed aquatic animal production systems. The GBADs programme has broad goals of inclusivity, transparency and rigour. Meeting those goals means providing users of all levels of technical expertise with a clear explanation of the programme's output. In this way, the meaning and limitations of those results are clearly communicated, minimising the risk of misinterpretation. The first published estimates of disease burden have been calculated at farm level using a new metric called the Animal Health Loss Envelope. This metric estimates the cost of lost productivity and expenditure on disease control for profit-maximising producers by comparing current system performance to a hypothetical ‘ideal health'scenario. This ideal is a farm-specific concept and is critically different from an ideal health state when physiologically defined. The metric and its key concepts are described in this article.

Effect of butyrine glycerides on the performance metrics and egg quality in laying pullets

The chicken feed industry is very much interested in creating innovative solutions to address the issue of safer animal products due to the increasing customer demand and the prohibition on utilizing antibiotic growth boosters. Organic acids, especially butyric acid, when added to chicken diets, have several beneficial effects on health, productivity, and egg quality. These factors may lead to their substitution in animal production systems for antibiotics. The study was determined the effects of butyrine glycerides (BAG) supplementation on various aspects of egg production and egg quality in laying pullets. Three dietary treatments were randomly assigned to 48 NovoGen Brown laying pullets at 24 weeks of age. For eighteen weeks, the chickens were kept in a three-tiered pyramid-style cage. The chickens in the control group (T1) were fed a basal diet; in groups T2 and T3, the basal diet was supplemented with 0.033% and 0.066% butyrine glycerides, respectively. Throughout the 12 weeks trial, measurements were made of the quantity and weight of eggs laid, feed conversion, and egg quality. Dietary supplementation of butyrine glycerides contributed to a significantly (p<0.001) increased in the egg production, egg weight and egg mass in laying pullets. Similarly, egg quality parameters did not affect significantly except shell percentage, albumen index and Haugh unit at 28th weeks of supplementation. Taken altogether, it is said that BAG positively impacted the laying performances and egg quality of laying pullets. Bangladesh Journal of Animal Science 53 (2): 31-39, 2024

Productivity and quality of Mulato II grass (Urochloa híbrido) alone and silage with agroindustrial by-products

The use of silage is considered as a feeding strategy in animal production systems with ruminants during dry periods. The objective was to evaluate the yield and nutritive value in forage and silage of Mulato II grass (Urochloa hybrid) and two additives, at different regrowth ages. Ages of 3, 6 and 9 weeks and additives (orange peel and molasses) were evaluated in silages: 1) Mulato II (ME); 2) Mulato II + orange peel; 3) Mulato II + molasses and 4) Mulato II + orange peel + molasses. The variables were: yield (kg ha-1) of total dry matter (TDM) and by morphological component, plant height (PH, cm), leaf area index (LAI), CP, NDF, ADF and lignin in forage and silage; pH, brix degrees and DM (%) in silage. When the forage was harvested at nine weeks of regrowth, the highest DM yield was obtained (7 508 kg ha-1), while the CP content was higher in week three of regrowth (201 g kg-1), exceeding by 10 and 29% that found in the sixth and ninth weeks. The silages with additives presented the highest CP values and the lowest values of ADF, NDF and pH. The higher the age of regrowth, the higher the dry matter yields, while the nutritive value decreased; however, the use of orange peel and molasses in grass silages improved the nutritive value.

Comparative susceptibility of adult house fly (Diptera: Muscidae) and an important predator, Carcinops pumilio (Coleoptera: Histeridae), to Beauveria bassiana (Hypocreales: Cordycipitaceae).

House flies (Musca domestica L.) (Diptera: Muscidae) are challenging pests to control. Biological control using Carcinops pumilio beetles may help to reduce house fly populations. However, it is unknown if C. pumilio beetles are compatible with Beauveria bassiana, another house fly biological control option. Five strains of commercially available (GHA, HF23, and L90) and newly discovered (NFH10 and PSU1) strains of B. bassiana were used to test the comparative susceptibility of adult house flies and adult C. pumilio using different laboratory exposure methods. Adult house flies were susceptible to B. bassiana in contact filter paper assays (89%-98% mortality) and immersion assays (100% mortality) at the same 108 conidia suspension using 0.1% CapSil as an aqueous surfactant. Carcinops pumilio were less susceptible than flies to B. bassiana infection using the contact and immersion assays at the same 108 conidial concentration, with 4.4%-12.2% and 8.3%-24.6% mortality, respectively. Immersion in an aqueous conidial suspension resulted in higher mortality compared to contact with treated filter papers at the same 108 concentration with house flies and beetles. We conclude that C. pumilio can safely be used as a biological control agent for house flies with B. bassiana in animal production systems.