Research Article

Sustainable Improvement of Reproductive Efficiency in Smallholder Cattle and Swine Systems

Ferdinand Bizimana1,2*, Bonnet Irakoze Dushime3, John Makuza2, Luis Mckie1, Bobwealth Oakina Omontese1, Roderick Tubbs1, David Mckenzie1, Martin Ntawubizi2

1Department of Large Animal Clinical Science, College of Veterinary Medicine, Tuskegee University, Tuskegee, AL, United States; 2School of Veterinary Medicine, University of Rwanda (UR), P.O Box 57, Nyagatare, Rwanda; 3School of Medicine and Pharmacy, University of Rwanda (UR), P.O Box 3286, Kigali, Rwanda.

Received | july 15,2026; Accepted | August 11, 2026; Published | August 29, 2026

*Correspondence | Ferdinand Bizimana, Department of Large Animal Clinical Science, College of Veterinary Medicine, Tuskegee University, Tuskegee, AL, United States; School of Veterinary Medicine, University of Rwanda (UR), P.O Box 57, Nyagatare, Rwanda; Email: [email protected]

Citation | Bizimana F, Dushime BI, Makuza J, Mckie L, Omontese BO, Tubbs R, Mckenzie D, Ntawubizi M (2026). Sustainable improvement of reproductive efficiency in smallholder cattle and swine systems. Adv. Anim. Vet. Sci., 14(9):2094-2107.

DOI | https://dx.doi.org/10.17582/journal.aavs/2026/14.9.2094.2107

ISSN (Online) | 2307-8316

Copyright: 2026 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

INTRODUCTION

Reproductive efficiency is a central determinant of productivity, profitability, and long-term sustainability in livestock systems (Bang et al., 2021; Menchaca, 2023). Its importance is particularly pronounced in smallholder cattle and swine enterprises, where herd growth, milk production, piglet output, and replacement dynamics directly influence household income, food security, and asset accumulation (Nkadimeng et al., 2022). In many low- and middle-income countries (LMICs), livestock serves multiple roles beyond food production, including savings, insurance, draft power, and nutrient cycling within mixed crop-livestock systems (Banda and Tanganyika, 2021; Chen et al., 2021; Nkadimeng et al., 2022). Consequently, even modest improvements in reproductive performance can substantially enhance smallholder resilience, livelihood stability, and market participation (Nkadimeng et al., 2024; Yousif et al., 2025). Globally, smallholder or family farms dominate numerically, accounting for approximately 84% of farms and more than 500 million holdings, most operating on less than 2 hectares (Giller et al., 2021; Ritchie, 2021). Although they manage a smaller share of total agricultural land compared with large commercial systems, smallholders contribute significantly to domestic food supply in LMICs (Garzón Delvaux et al., 2020). In sub-Saharan Africa, smallholders represent nearly 80% of farms and produce the majority of locally consumed food (Garzón Delvaux et al., 2020; Giller et al., 2021b). Across Asia, including China, India, and Vietnam, small and medium-scale livestock producers remain structurally important despite sectoral intensification (Giller et al., 2021a). Similarly, in Latin America and parts of Eastern Europe, smallholder systems coexist with commercial enterprises (Ibarrola-Rivas et al., 2023; Schneider, 2014). Even in high-income countries, small family farms dominate numerically, representing approximately 86% of farms in the United States and over 60% in the European Union (Lim et al., 2024). The livestock sector contributes approximately 40% of global agricultural gross domestic product (GDP) and about 30% in developing countries (Salmon et al., 2020; World Bank, 2021). Cattle and swine populations are substantial across production systems worldwide, with rapid expansion in LMICs driven by increasing demand for animal-source foods (Henchion et al., 2021; Van Eenennaam, 2024). This growth further emphasizes the need to improve reproductive efficiency, particularly in smallholder livestock systems where productivity gaps remain substantial. Despite the fundamental contribution of smallholder cattle and swine production to global food security and rural livelihoods, reproductive inefficiency remains one of the principal constraints limiting livestock productivity, profitability, and sustainability.

Conception rates under field conditions are often low and highly variable due to poor estrus detection, suboptimal timing of breeding, and limited access to quality reproductive services (Nkadimeng et al., 2024; Ojango et al., 2017). Extended calving and farrowing intervals are commonly reported in smallholder systems, reflecting prolonged days open and delayed return to estrus, which reduce lifetime productivity and herd turnover (Ill-Hwa and Jeong, 2018; Mutenje et al., 2020). In response to these challenges, several reproductive and precision livestock technologies have been developed to improve reproductive performance. These inefficiencies contribute to marked productivity gaps between smallholder and commercial systems. While commercial operations achieve higher and more consistent reproductive performance due to better nutrition, genetics, and management, smallholders often face compounded constraints that limit reproductive outcomes (Felix, 2025; Lucy, 2025). Multiple interacting factors, including inadequate nutrition, endemic diseases, poor management practices, and climate-related stressors, further depress fertility and increase embryonic and pre-weaning losses (Sumi et al., 2022; Thornton et al., 2021). Biological factors such as genetics, reproductive disorders, and disease burden significantly influence fertility outcomes. Infectious and parasitic diseases remain major causes of reproductive failure in smallholder systems (Nkadimeng et al., 2024). Environmental stressors, particularly heat stress, combined with inadequate nutrition and poor feed quality, negatively affect reproductive physiology, estrus expression, and embryo survival (Acosta et al., 2024; North et al., 2023). Management practices, including estrus detection, breeding timing, and record keeping, are critical determinants of reproductive success. Limited access to veterinary services, extension support, and breeding infrastructure further constrains performance in smallholder settings (Mutenje et al., 2020). Over recent decades, reproductive technologies such as artificial insemination (AI), estrus synchronization, embryo transfer (ET), and advanced techniques including multiple ovulation and embryo transfer (MOET) and in vitro fertilization (IVF) have demonstrated potential to improve fertility, genetic gain, and productivity (Dhangada et al., 2024; Menchaca, 2023; Sharifuzzaman et al., 2024). In parallel, emerging precision livestock technologies, including electronic heat detection systems, mobile-based advisory tools, and portable diagnostics, offer new opportunities to enhance reproductive management and decision-making (Merkelytė et al., 2025). However, adoption of these technologies remains limited because of financial, infrastructural, institutional, and knowledge-related barriers that restrict access by smallholder farmers (Huang and Wang, 2024; Nxumalo and Chauke, 2025). Although numerous studies have investigated individual reproductive constraints or technologies, the available evidence remains fragmented across livestock species, production systems, and geographical regions. Consequently, there is no comprehensive synthesis integrating biological, environmental, technological, and socioeconomic determinants of reproductive efficiency in smallholder cattle and swine systems. Furthermore, variability in study settings, methodologies, and outcome measures has limited the identification of scalable and context-appropriate interventions.

Therefore, a comprehensive systematic review is needed to consolidate current evidence, evaluate the effectiveness of available interventions and identify practical strategies for improving reproductive efficiency in low-input livestock systems. Accordingly, this systematic review was conducted to: (i) identify the predominant constraints affecting reproductive performance in smallholder cattle and swine systems; (ii) evaluate the effectiveness of reproductive technologies and management interventions reported between 2020 and 2026; and (iii) highlight practical, scalable strategies for improving reproductive efficiency in smallholder production systems. By integrating multidisciplinary evidence, this review provides comprehensive information to support future research, policy formulation, veterinary extension services, and interventions aimed at enhancing productivity, resilience, and sustainable livestock development in smallholder cattle and swine systems.

MATERIALS AND METHODS

Review design and protocol

We conducted a systematic review to synthesize evidence on the major constraints affecting reproductive efficiency in smallholder cattle and swine production systems and to evaluate practical interventions and emerging innovations aimed at improving reproductive performance. The review focused on low-input, smallholder, and LMIC livestock systems where reproductive inefficiency remains a key limitation to productivity. The review was implemented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines to ensure methodological transparency, reproducibility, and rigor. The final literature search was completed in April 2026, covering contemporary evidence while retaining key foundational studies where necessary for conceptual and methodological context.

Eligibility criteria

Studies were considered eligible if they met the following criteria: published between January 2020 and April 2026, with selected earlier studies included for foundational relevance; focused on cattle and/or swine production systems; conducted in smallholder, family-based, low-input, tropical, or LMIC systems, or had findings transferable to such contexts; examined at least one determinant of reproductive efficiency, including biological, nutritional, environmental, welfare, management, technological, logistical, or socioeconomic factors; reported reproductive performance indicators, such as conception or pregnancy rate, calving-to-conception interval, days open, farrowing rate, litter size, piglet survival, embryo yield, or embryonic loss; evaluated reproductive technologies or interventions, including artificial insemination (AI), estrus synchronization, embryo transfer (ET), multiple ovulation and embryo transfer (MOET), heat detection methods, semen handling and transport, reproductive monitoring tools, and precision livestock technologies, included peer-reviewed empirical studies, systematic reviews, or high-value contextual literature relevant to reproductive outcomes. Studies were excluded if they: focused exclusively on non-target species or human/biomedical reproduction; were conducted under highly intensive or laboratory conditions without relevance to smallholder systems; did not address reproductive performance or fertility-related outcomes; were duplicate records or lacked sufficient methodological or contextual relevance.

Search strategy

This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Page et al., 2021). The review aimed to address the question: “What are the key determinants, technological interventions, and practical strategies influencing reproductive efficiency in smallholder cattle and swine production systems?”

A comprehensive literature search was performed across multiple electronic databases, including PubMed, Scopus, Web of Science, and CAB Abstracts, to identify relevant peer-reviewed studies. The search was limited to publications written in English and published between January 2020 and April 2026 to capture recent advances and evidence.

The search strategy was structured around four main domains: animal species, reproductive outcomes, production systems, and interventions and technologies. Keywords and Boolean operators were adapted for each database. Truncation (*) and phrase searching were applied where appropriate to maximize retrieval. Representative search domains and terms are presented in Table 1.

Study selection process

All records retrieved from the database search were compiled and subjected to a structured, multi-stage screening process. In the first stage, titles and abstracts were independently assessed for relevance based on predefined criteria, including livestock species (cattle or swine), production system (smallholder), and focus on reproductive performance or efficiency. Studies that met these preliminary criteria were retained for full-text evaluation.

Full-text articles were subsequently reviewed against established inclusion and exclusion criteria to determine eligibility. Duplicate records arising from overlapping database indexing or citation inconsistencies were identified and removed before screening.

 

Table 1: Domains and search terms used in database queries.

Domain	Search Terms
Animal	cattle OR cow* OR dairy cattle OR bovine OR pig* OR swine OR sow* OR gilt* OR porcine
Reproductive outcome	“reproductive efficiency” OR “reproductive performance” OR fertility OR infertility OR conception rate OR pregnancy rate OR litter size OR calving interval
Production system	smallholder OR “small-scale” OR backyard OR extensive OR semi-intensive OR “family farm*” OR low-input
Intervention/technology	“artificial insemination” OR “estrus synchronization” OR “embryo transfer” OR “heat detection” OR “precision livestock” OR “technology adoption”
Final string	#Animal AND #Reproductive outcome AND #Production system AND #Intervention

 

Table 2: Major constraints, prevalence, and reproductive impacts in smallholder cattle and swine systems with supporting evidence.

Constraint category	Specific constraint	Prevalence	Reproductive consequence	Productivity impact	Evidence
Management	Poor estrus detection	45% of heats missed (cattle)	Incorrect timing of breeding	Conception rate reduced to 35%	(Becker et al., 2020; López-Gatius, 2022; Lucy, 2025)
Technological access	Limited access to artificial insemination	55% (cattle); 40% (swine)	Limited genetic improvement	Lower productivity and slower herd growth	(FAO, 2021; Tola an Deresa, 2025; Van Eenennaam, 2025)
Nutrition	Nutritional deficiencies (low body condition score)	35% below optimal BCS	Delayed puberty and silent estrus	Extended calving interval (420–600 days)	(Fantuz et al., 2024; Kang et al., 2025; Weiss, 2021)
Health	Reproductive diseases (e.g., brucellosis, leptospirosis)	15% prevalence	Embryonic loss and abortion	Pregnancy rate reduced by 10–25%	(Marami et al., 2021; Mercadante et al., 2020; Qiu et al., 2023)
Institutional	Limited veterinary service access	60% lack adequate services	Untreated reproductive disorders	Reduced fertility and herd expansion	(Burgos-Paz et al., 2025; Doyle et al., 2025; Jiang et al., 2023)
Environmental	Heat stress (>30°C seasonal exposure)	Common in tropical systems	Reduced oocyte quality	Fertility reduced by 10–25%	(Gupta et al., 2025; Khaliq et al., 2025; Khan et al., 2023; Pasha et al., 2024)
Genetic	Predominance of low-productivity local breeds	>70% of herds	Lower reproductive potential	Reduced milk yield and litter size	(Assefa et al., 2026; Barłowska et al., 2025; Sawicka-Zugaj et al., 2025)
Management (swine)	Suboptimal pig management	6-9 piglets/litter (vs 10-14 commercial)	High piglet mortality and poor sow performance	Lower weaned piglets per sow per year	(Estienne & Niblett, 2024; Jongbo et al., 2026; Peltoniemi et al., 2021)

 

To ensure methodological consistency and transparency, a standardized evidence-screening matrix was developed to document bibliographic information, study characteristics, and relevance to the review objectives. Based on their relevance and contribution to the research questions, studies were classified into four categories: (i) core empirical evidence, comprising primary studies reporting quantitative reproductive outcomes; (ii) supportive contextual evidence, providing complementary insights; (iii) background literature, including reviews and conceptual frameworks; and (iv) excluded studies, which did not meet the inclusion criteria. Greater emphasis

was placed on peer-reviewed empirical studies conducted

under field conditions, reflecting practical reproductive performance in smallholder livestock systems.

The study identification and selection process, including identification, screening, eligibility assessment, and final inclusion, was documented using a PRISMA flow diagram(Figure 1). The diagram presents the number of records identified from each source, screened after duplicate removal, excluded at each stage, and ultimately included in the review.

 

Table 3: Adoption of reproductive technologies and associated pregnancy outcomes in smallholder (LMIC) and commercial livestock systems.

Technology	Adoption in LMIC (%)	Pregnancy Rate (LMIC – field conditions)	Pregnancy Rate (Commercial systems)	Citations
Artificial insemination (cattle)	<20%	25-48%	40-60% (dairy); 50-80% (beef)	(Garcia et al., 2020; Lucy, 2025; Speckhart et al., 2023; Tadesse et al., 2022; Tola & Deresa, 2025)
Artificial insemination (swine)	≈16%	70-80%	80-90%	(Falceto et al., 2023; Haile et al., 2025; Mellagi et al., 2023; Sharma et al., 2020)
Cow estrus synchronization	≈5%	25-45%	50-70%	(Cabrera, 2026; Kibre et al., 2022; Kouamo, 2025)
Cow embryo transfer (ET)	≈5%	30-50%	50-70%	(Lee et al., 2026; Park et al., 2023; Pérez-Mora et al., 2020; Xie et al., 2024)
Precision livestock monitoring	Extremely low	30-55%	50-75%	(Agrawal & Arafat, 2024; Betti Sorbelli, 2024; Korir et al., 2023; Tadele et al., 2025)

 

LMIC- low and middle-income countries

 

Table 4: Impact of reproductive technologies on cattle and swine reproduction with supporting evidence.

Technology	Pregnancy improvement	Litter size change	Adoption	Citations
Cow Artificial insemination	+10-20%	N/A	Moderate	(Kasimanickam et al., 2025; Mikkola et al., 2024; Naniwa et al., 2026; Tadesse et al., 2022)
Swine Artificial insemination	+5-15%	+0-0.3	Moderate	(Boonkum et al., 2025; Jochems et al., 2025; Makuza et al., 2025; Peltoniemi et al., 2021)
Cow Estrus synchronization	+8-15%	N/A	Low	(Bai et al., 2021; Cooke, 2023; Kasimanickam, Harting, et al., 2025; Kathambi et al., 2025)
Swine Estrus synchronization	0-10%	Not consistent	Very low	(Kousenidis et al., 2021; Li et al., 2025; Shi et al., 2025)
Cattle Embryo transfer	+20-30%	N/A	Very low	(Bizimana et al., 2025a; Hansen, 2020; Park et al., 2023; Pereira et al., 2024)
Precision monitoring	+5-12%	—	Emerging	(Aparicio et al., 2024; Das et al., 2023; Džermeikaitė et al., 2023)

 

Data extraction and management

Data were extracted using a standardized framework developed specifically for this review to ensure consistency and reproducibility. The following information was systematically collected from each included study: author(s) and year of publication, geographic location, livestock species (cattle or swine), production system characteristics, study design, sample size, type of reproductive constraint or intervention investigated, and reproductive technology or management practice evaluated. In addition, studies were thematically classified according to their focus, and their relevance to smallholder production systems was assessed. The primary reproductive performance outcomes extracted included conception or pregnancy rate, calving-to-conception interval, days open, farrowing rate, farrowing interval, litter size, piglet survival, embryo yield, embryonic loss, offspring survival, and weaning rate. All extracted data were organized into standardized summary tables

to facilitate comparison across studies and to support a

comprehensive thematic synthesis of the evidence.

Because of substantial methodological heterogeneity in study design, livestock species, production systems, interventions, and reported reproductive outcomes, a formal meta-analysis was not appropriate. Instead, the evidence was synthesized using descriptive statistical methods, including frequencies, percentages, ranges, and thematic classification. Reproductive outcomes were summarized according to livestock species, intervention type, reproductive constraint, and geographic region. Findings were integrated through narrative synthesis and presented in summary tables and figures, enabling systematic comparison of the available evidence while preserving methodological rigor and ensuring appropriate interpretation across diverse study designs.

 

Table 5: Quantitative synthesis of reproductive efficiency gains in smallholder cattle and swine systems.

Output Indicator	% Change (Range)	Supporting Evidence
Cow conception rate	+5% to +30%	(Bizimana et al., 2026; Diffe, 2026; Lucy, 2025)
Sow conception rate	+5% to +15%	(Bai et al., 2021; Makuza et al., 2025; Putri & Poetranto, 2021)
Calving interval	-10% to -20%	(EFSA et al., 2025; FAO, 2024; Hansson et al., 2025)
Farrowing interval	-10% to -20%	(Buoio et al., 2022; Knox, 2024; Shirley et al., 2021)
Litter size (swine)	+5% to +12%	(Carnevale et al., 2024; Sanz-Fernández et al., 2024; Tucker et al., 2022)
Weaned piglets	+5% to +15%	(Carnevale et al., 2024; Knox, 2024; Yu et al., 2024)
Cattle Embryo/ET success rate	+20% to +30%	(Bizimana et al., 2025a; Park et al., 2023; Sartori et al., 2025)
Overall productivity	+10% to +25%	(FAO, 2024; Thornton et al., 2021; Xiao et al., 2022)

 

RESULTS

Study selection and characteristics

A total of 185 records were identified through database searching. After removal of duplicates, 182 studies were screened based on titles and abstracts. Of these, 95 articles were retained for full-text assessment. Following eligibility evaluation, 50 studies were excluded due to insufficient relevance or lack of focus on smallholder systems. Ultimately, 45 studies were included in the final synthesis (Figure 1).

 

 

Geographic distribution of evidence

The included studies represented diverse geographical regions, with a strong emphasis on smallholder-dominated systems. Africa and Asia together accounted for nearly 60% of the evidence base, reflecting the high concentration of smallholder livestock systems in these regions and enhancing the contextual relevance of the findings (Figure 3).

 

Table 2 summarizes the major biological, management, environmental, and institutional constraints affecting reproductive efficiency in smallholder cattle and swine systems, highlighting their prevalence, reproductive consequences, productivity impacts, and supporting evidence.

Table 3 presents the adoption levels of key reproductive technologies in smallholder (LMIC) systems alongside corresponding pregnancy rates under field conditions and in commercial systems, supported by relevant empirical evidence.

Table 4 summarizes the reported impacts of key reproductive technologies on pregnancy outcomes, litter size, and adoption levels in cattle and swine systems, supported by empirical evidence.

Table 5 presents the quantitative improvements in reproductive efficiency achieved in smallholder cattle and swine systems through enhanced reproductive technologies and management practices.

Figure 3 illustrates an integrated framework showing how nutrition, breeding strategies, animal health, and service delivery collectively contribute to improved reproductive efficiency in livestock systems.

DISCUSSION

The present review synthesizes evidence on the biological, nutritional, environmental, and management factors influencing reproductive efficiency in smallholder cattle and swine systems. The findings demonstrate that reproductive performance is shaped by complex interactions among these determinants, which also influence the effectiveness of reproductive technologies under field conditions. The review further highlights persistent challenges related to technology adoption, infrastructure, and technical capacity.

Major constraints of cattle and swine reproductive efficiency in smallholder systems

The review results confirm that biological constraints, including genetic limitations, reproductive disorders, and infectious and parasitic diseases, remain key drivers of reduced reproductive performance in smallholder systems. In LMICs, diseases such as brucellosis (≈5-15%), leptospirosis (≈10-20%), trypanosomiasis (≈15-30%), bovine tuberculosis (≈3-10%), and mastitis (>20-40%) are widely reported to impair fertility through embryonic loss, abortion, anestrus, and reduced conception rates (Aymée et al., 2024; Burgos-Paz et al., 2025; Lokamar et al., 2020). High endemic disease burden, coupled with limited veterinary services, contributes to conception rates often below 40% in smallholder herds across sub-Saharan Africa and South Asia (Nkadimeng et al., 2024; Thornton et al., 2021). Breed-related differences further exacerbate these constraints, with indigenous breeds such as Ankole cattle or zebu typically achieving lower conception rates (≈30-45%) under low-input conditions, reflecting adaptation to harsh environments but limited genetic potential for productivity (Martyniuk, 2021; Mavunga et al., 2025). In contrast, improved dairy breeds such as Holstein-Friesian cattle (50%) and Jersey cattle (60%) generally achieve higher conception rates under adequate nutrition and health management, as documented in Rwanda, Kenya, and India (Chawala et al., 2021; Opoola et al., 2022). Crossbred cattle (e.g., Local x Friesian or Jersey) frequently outperform both parental lines (70%), benefiting from heterosis and improved adaptability (Bizimana et al., 2026; Quénon and Magne, 2021). Nutritional deficiencies and environmental stressors, particularly heat stress, emerged as critical constraints affecting reproductive physiology. Inadequate energy intake and poor feed quality impair estrus expression and embryo survival, while heat stress negatively affects oocyte quality and early embryonic development (Kasimanickam and Kasimanickam, 2021; Thornton et al., 2021). Additionally, improved body condition score significantly increased pregnancy rates in embryo transfer programs, supporting previous reports linking nutritional status with reproductive success (Khan et al., 2022; Lucy, 2025). Management-related factors, including poor estrus detection, suboptimal timing of insemination, and lack of record-keeping, were consistently identified as major contributors to reproductive inefficiency. Evidence from Bezdíček et al. (2020) and Haile et al. (2023) demonstrated that inaccurate estrus detection is one of the primary causes of AI failure in smallholder systems.

Technology adoption gaps and barriers to the adoption of reproductive technologies

Despite demonstrated benefits, adoption of reproductive technologies remains low across LMICs. The AI adoption rates below 20% in cattle and approximately 16% in swine suggest that technological effectiveness alone is insufficient to improve reproductive performance. Successful implementation also depends on affordable infrastructure, reliable veterinary services, and sustained producer training. These findings indicate that the challenges identified in this review are not unique to the included studies but are widely observed across LMIC smallholder production systems (FAO, 2024; Mendizabal-Ruiz et al., 2025). Limited infrastructure, including inadequate cold-chain systems, poor transport logistics, and insufficient veterinary coverage, significantly hinders technology uptake. High costs and financial constraints further limit adoption among smallholders (Gadea et al., 2020; Mansour, 2025). Knowledge deficits and weak extension services represent major barriers to effective implementation, consistent with previous studies reported by Huang and Wang (2024) emphasizing the role of training and extension in enhancing technology effectiveness.

Comparative performance of cattle and swine reproductive efficiency in smallholder versus commercial systems

The gap in reproductive performance between smallholder and commercial systems is largely explained by differences in nutrition, genetics, health management, and infrastructure. This is consistent with previous reports by Knox (2024) and Lucy (2025) confirming that commercial farms benefit from controlled environments and consistent management, resulting in higher and more stable reproductive outcomes. Management precision, particularly estrus detection and timing of insemination, is a critical determinant of reproductive success. López-Gatius (2022) and Merkelytė et al. (2025) demonstrated that optimal timing relative to ovulation significantly improves conception rates.

Effectiveness of reproductive technologies in cattle and swine

Among the reproductive technologies evaluated, artificial insemination offers substantial advantages in genetic improvement and disease control; however, its effectiveness is highly dependent on management quality (Singh et al., 2022). In some smallholder contexts, natural mating may outperform AI (Mathewos et al., 2023; Singh et al., 2022). This observation is further reported by Mahbubiy et al. (2026), indicating that AI success is strongly influenced by technical execution and farmer skill. Estrus synchronization and embryo transfer technologies have demonstrated substantial potential to improve reproductive efficiency. Evidence synthesized in this review supports the effectiveness of estrus synchronization in improving reproductive control and conception rates under appropriate management conditions (Menchaca, 2023). Fresh embryos significantly outperform frozen embryos, consistent with findings in the literature reported by Fattahpour et al. (2025) and Pavlovic et al. (2024), highlighting higher viability and pregnancy success rates for fresh embryos. More recently, precision livestock technologies, including electronic heat detection and digital advisory systems, are emerging as promising tools for improving reproductive management. Although adoption remains limited, early evidence suggests improvements in estrus detection accuracy and reproductive outcomes (Merkelytė et al., 2025).

Integrated approach to improving cattle and swine reproductive efficiency

An important finding emerging from this review is that reproductive efficiency improvements are maximized when interventions are integrated (Ayantoye et al., 2025). Similar integrated approaches have also been recommended by Yousif et al. (2025) focusing on smallholder livestock systems. Findings on embryo transfer recipients showed that improved feeding and housing conditions significantly increased pregnancy success, reinforcing the importance of holistic management (Bizimana et al., 2025b). Reproductive performance should be addressed within a systems framework that considers interactions among biological, environmental, and socioeconomic factors. Isolated interventions are less effective than coordinated strategies combining feed improvement, disease control, breeding services, and farmer training (Thornton et al., 2021).

Policy and development implications for improving cattle and swine reproductive efficiency in LMICs

The findings suggest that improving reproductive efficiency in LMICs smallholder systems requires coordinated investments in producer education, veterinary services, and reproductive technologies rather than focusing on a single intervention. Training programs targeting estrus detection, AI timing, and herd management can significantly improve reproductive outcomes (FAO, 2024). Investment in veterinary infrastructure and access to skilled reproductive services is critical for improving fertility outcomes in smallholder systems (World Bank, 2021). Innovative delivery models, including mobile-based services and digital platforms, can improve access to reproductive technologies (Vithalrao et al., 2025).

Strengths and limitations of the review

Several limitations should be acknowledged. First, heterogeneity in study designs and outcome measures limited the feasibility of formal meta-analysis, consistent with similar reviews in livestock systems (Uttley et al., 2023). Second, variability in reporting standards may affect comparability across studies. Third, although grey literature provided valuable contextual insights, it was not weighted equally to peer-reviewed empirical evidence.

Despite these limitations, this review provides a comprehensive synthesis of current evidence and identifies practical strategies that can improve reproductive efficiency in smallholder cattle and swine systems. The findings provide a useful foundation for future research, policy development, and the implementation of integrated reproductive management programs in LMICs.

Conclusions and practical implications

This review demonstrates that reproductive efficiency in smallholder cattle and swine systems is influenced by interconnected biological, nutritional, environmental, managerial, and institutional factors. Persistent challenges, including low conception rates, prolonged calving and farrowing intervals, and poor reproductive performance, continue to limit livestock productivity and the livelihoods of smallholder farmers. Although reproductive technologies such as artificial insemination, estrus synchronization, and embryo transfer can improve reproductive outcomes, their effectiveness depends on effective herd management, adequate nutrition, accurate estrus detection, technical expertise, and accessible veterinary services. The evidence indicates that integrated reproductive management strategies are more effective than isolated interventions. Combining improved nutrition, disease prevention, reproductive technologies, farmer training, and extension support offers the greatest potential for improving reproductive performance sustainably under smallholder conditions. From a practical and policy perspective, strengthening veterinary and extension services, improving farmer capacity, and expanding access to affordable reproductive technologies should be prioritized, particularly in low- and middle-income countries. Future research should evaluate scalable, context-specific integrated approaches and generate high-quality evidence to support their implementation. Overall, sustainable improvements in reproductive efficiency will require coordinated, evidence-based strategies that integrate science, management, extension, and policy to enhance livestock productivity and resilience.

ACKNOWLEDGEMENTS

The authors of this manuscript are grateful to their respective universities for their valuable support in completing this review.

NOVELTY STATEMENT

This review provides a comprehensive synthesis of recent evidence (2020–2026) integrating biological, nutritional, environmental, managerial, technological, and socioeconomic determinants of reproductive efficiency across smallholder cattle and swine systems. Unlike previous reviews that largely address individual species, reproductive constraints, or technologies separately, this study comparatively evaluates reproductive technology adoption and performance under smallholder and commercial conditions and identifies critical implementation gaps in low- and middle-income countries. Importantly, the review advances an integrated, systems-based framework that combines improved nutrition, herd health, reproductive technologies, veterinary and extension services, and farmer training as a practical strategy for sustainably improving reproductive performance in resource-limited livestock systems.

AUTHORS CONTRIBUTIONS:

Conceptualisation: F.B. Methodology: F.B. Investigation: F.B. Data curation: F.B. and B.I.D. Formal analysis: F.B. Visualization: F.B. Writing-original draft preparation: F.B. Writing-review and editing: F.B., B.I.D., L.M., J.M., B.O.O., D.M., R.T., and M.N. Scientific review: B.O.O., D.M., R.T., and M.N. Correspondence: F.B. All authors have read and agreed to the published version of the manuscript.

Declaration of generative ai and ai-assisted technologies in the writing process

During the preparation of this work, the author(s), in some sentences, used Google Gemini, Grammarly, and ChatGPT to improve the readability and language of the manuscript, as well as create an illustrative image. After using this tool/service, the author(s) reviewed and edited the content as needed and take full responsibility for the content of the publication

Conflict of interest

The authors declare no competing interests.

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