Advances in smallholder large ruminant production and profitability in Southeast Asia over the past decade – lessons from the Mekong region: a review

Forages

The uptake of high yielding forages has been a major advancement in improving large-ruminant production in Southeast Asia over the past decade. Although forage-growing technology is not new (Stür and Horne 2001; Stür et al. 2002), the widespread uptake and utilisation is more recent and likely due to an increase in the demand and value for large ruminants as well as time savings for all members of the household, including women and children (Bush et al. 2014a; Ashley et al. 2016, 2018a). This is especially the case for areas where rainfall is limiting during the dry season and grazing of rice stubble and cut-and-carry of poor-quality roadside grasses are the only options (Horne et al. 2005). In addition, cattle and buffalo are restricted from free grazing in the wet season to prevent damage to growing crops (Devendra and Thomas 2002). The uptake of introduced forages can be more challenging in regions where free grazing of natural grasses maintains livestock weight and body condition without the associated costs and labour, such as in northern Laos (Phouyyavong et al. 2019).

The improvements in nutritional value associated with growing introduced forages are evident in productivity gains. Feeding introduced forages to cattle in Cambodia achieved weight gains of 0.19 kg/day over a 104-day period compared with traditional cut-and-carry feeding practices where animals lost on average 0.04 kg/day with forage-fed animals gaining, on average, 25.9 kg more weight than animals fed in a traditional manner (Bush et al. 2014b). Similar outcomes were achieved in Lao People’s Democratic Republic (PDR), where cattle and buffalo in fattening stalls gained 0.32 and 0.22 kg/day respectively over a 4-month period, and 0.04 and 0.09 kg/day when free-grazing (Bush et al. 2014b). It is suggested greater weight gains are possible if farmers feed forages at the recommended 15% of bodyweight on a fresh-weight basis per day (Bush et al. 2014b).

In addition, the feeding of introduced forages grown close to the household results in time savings of up to 3 h per day (Dimang et al. 2009; Ashley et al. 2016, 2018a; Le Phi Khanh et al. 2020). These time savings enable children to spend more time at school and adult household members to seek off-farm income or spend more time conducting household duties or socialising (Dimang et al. 2009; Ashley et al. 2016, 2018a; Le Phi Khanh et al. 2020).

Rice straw

Rice is readily grown throughout Southeast Asia to provide a base diet for the human population (Fukagawa and Ziska 2019). However, the intake of rice straw by ruminants is limited as although it is rich in polysaccharides, it has a high lignin and silica content, reducing degradability by ruminal microorganisms (Sarnklong et al. 2010). Treatments to improve voluntary intake of rice straw are physical or chemical. Physical treatments require machinery that can be expensive and prohibitive to smallholder farmers; whereas chemical treatments such as NaOH, NH₃ or urea are more accessible and practical for on-farm use (Sarnklong et al. 2010). Rice straw has delivered productivity gains in large ruminants with increases in crude protein content from 4.7% to 7.9% and the DM digestibility from 47% to 55% reported when treated with a urea–molasses solution (Aquino et al. 2020) and increases in ADG of 18.9–28.9% when treated and fed with byproducts (Aquino et al. 2020). Although the benefits are apparent, the sustainability of feeding rice straw is limited, likely due to the labour intensiveness of preparing the straw as well as the cost of machinery and chemical treatments such as urea (Aquino et al. 2020).

Crop byproducts, residues and supplements

Crop byproducts and residues are readily available and regularly fed to large ruminants throughout Southeast Asia. Large ruminants require energy and protein in their ration to stimulate rumen function and enhance productivity (Wanapat 2009). An example of a byproduct commonly fed to large ruminants is cassava roots fed as dry chips or pellets to provide energy and dried leaves (hay) for protein (Wanapat 2009). Hence, cassava provides a year-round feed source that can be used when seasonal conditions result in feed gaps. There are also other readily available byproducts in the tropics that can be used to feed large ruminants (Wanapat 2009) with the most common crop residues and agro-industrial byproducts being rice straw, cassava pulp and wet brewers’ grains, providing a source of roughage, energy and protein sources, respectively (Napasirth and Napasirth 2018).

The use of lick blocks, with or without molasses, has demonstrated improved growth rates (measured as ADG) during the dry season when nutrition is limiting in young calves (251–265 g/day), growing calves (198–237 g/day) and lactating cows (187–190 g/day) (Windsor et al. 2021). Accompanying surveys confirmed farmers using blocks stated their animals were calmer and healthier and had better coat condition with minimal external parasites (Windsor et al. 2021). There is also evidence to suggest the use of high-quality molasses blocks will inhibit greenhouse gas (GHG) emissions (Windsor and Hill 2022) and control internal parasites when containing fenbendazole (Olmo et al. 2020).

Foot and Mouth Disease (FMD)

FMD is endemic throughout the region (Rweyemamu et al. 2008) and considered the most important transboundary animal disease (TAD), representing a failure of the global food security system (Rushton 2009) with the economic impact estimated to be USD6.5–21 billion per year in the endemic regions of the world (Knight-Jones and Rushton 2013). Seroprevalences for FMD (nonstructural protein) NSP in large ruminants, reported at 50.5% (95% CI: 49.0, 52.0), are high compared to Q fever and brucellosis; which are low at 1.7% (95% CI: 1.3, 2.1) and 0.7% (95% CI :0.5, 1.0) respectively (Siengsanan-Lamont et al. 2022). Losses of annual household income due to FMD of 16–60% have been reported in northern Laos (Nampanya et al. 2015) and are likely similar throughout the region where FMD is endemic.

Several regional programmes were introduced to reduce the impacts of emerging infectious and transboundary animal diseases on food security, public health and livelihoods in Southeast Asia (Hampshire 2014). These include the Stop Transboundary Animal Diseases and Zoonoses (STANDZ) project from 2011 to 2016 and the Southeast Asia FMD (SEAFMD) campaign initiated in 1997 to facilitate a strategic and collective approach to FMD control in the region (MacPhillamy et al. 2021b). The SEAFMD programme expanded to became SEACFMD with the inclusion of China (Hampshire 2014). Aims of the programmes include strengthening national animal health and veterinary services, improving regional and international coordination for animal health, and supporting Office International des Epizooties (OIE)-led subregional activities (MacPhillamy et al. 2021b). Through the STANDZ and SEACFMD programmes, approximately 1.6 million doses of FMD vaccination were administered to large ruminants in northern Laos under the National Lao FMD Plan from 2013 to 2016, reducing the incidence of FMD outbreaks and increasing farmer incomes (Nampanya et al. 2018).

Other diseases

In addition to FMD, health and production diseases impacting large ruminants throughout the region have also been investigated. A key disease often mistaken for FMD is haemorrhagic septicaemia (HS), which is an acute fatal infectious disease of mainly cattle and buffalo (Kawasaki et al. 2015). A study in Cambodia found 24% of all household large ruminants were affected with an estimated mean village herd morbidity of 10.1% and mortality of 28.8% (Kawasaki et al. 2015). Buffalo had higher morbidity and mortality compared with cattle, and unvaccinated large ruminants a higher morbidity. HS was found to cause substantial financial losses for smallholders and remains a critical constraint to improving large-ruminant productivity and profitability (Kawasaki et al. 2015).

Studies in Cambodia on pathogens causing reproductive losses in cattle and buffalo detected antibodies to Neospora caninum, bovine viral diarrhoea virus (BVDV), Leptospira interrogans serovar Hardjo and Brucella abortus in buffalo samples at 79.3% (95% CI 64.6–94.0), 3.4% (95% CI 0–10.0), 0% and 0%, respectively, and in cattle at 4.2% (95% CI 2.4–6.0), 6.4% (95% CI 4.2–8.6), 8.1% (95% CI 5.6–10.6) and 0%, respectively (Olmo et al. 2021). This provides important awareness of the presence of pathogens responsible for potentially compromising bovine fertility and creating a zoonotic risk for smallholders. In addition, information on the absence of pathogens provides incentives to implement strategies designed to prevent introduction. Large-ruminant reproductive management skills of smallholder farmers and parameters of reproductive efficiency in cattle and buffalo were studied in northern Laos (Matsumoto et al. 2017). The surveys included female farmers to provide gender-disaggregated data, with females making up 38.3% of participants (Matsumoto et al. 2017). Results confirmed low knowledge levels amongst smallholder farmers in relation to reproductive management of large ruminants (34–46%) and poor reproductive parameters were identified: with low calving percentages of 54–75 and 45–54% in cattle and buffalo groups respectively, and prolonged intercalving intervals of 14.1–19.8 and 26.0 months for the cattle and buffalo groups respectively (Matsumoto et al. 2017).

Internal parasites impacting large-ruminant productivity also have the potential to impact humans. An example is Fasciolosis, caused by Fasciola hepatica and Fasciola gigantica. The rapid detection requires species-specific assays for an antemortem diagnosis in both humans and animal. A new molecular workflow was developed in Laos to provide a sensitive and quantitative diagnostic approach for the rapid testing of medium to large sample sizes (Calvani et al. 2017). This approach provides a quicker alternative to the traditional sedimentation and faecal egg count (FEC) technique, enabling surveillance programmes in locations where animal and human health funding is limited (Calvani et al. 2017). Another study in Laos investigated the potential translocation of parasites from endemic to nonendemic areas, via associated international livestock movements (Calvani et al. 2020). The presence of F. hepatica DNA was confirmed through qualitative and quantitative sequencing (Calvani et al. 2020). From this work a protocol was developed for the rapid detection of Fasciola species eggs, their coinfection and/or infection with F. hepatica/F. gigantica hybrids from faecal samples (Calvani et al. 2020).

Biosecurity

The concept of biosecurity is relatively new in countries such as Cambodia and Laos, where traditionally vaccination is the main approach to disease control. However, globalisation has resulted in an increased risk of disease transmission to livestock and humans through the worldwide trade in livestock and livestock products (Manuja et al. 2014). In addition, vaccine efficacy and a reliable cold chain for vaccine storage can be problematic. Examples of highly contagious diseases of livestock and poultry include FMD, peste des petits ruminants, African swine fever (ASF), Newcastle disease, avian influenza and zoonotic diseases caused by viruses like Nipah, Hendra and swine influenza (H1N1) (Manuja et al. 2014). Biosecurity measures are designed to prevent the introduction of disease through understanding the risks associated with the introduction of infections through livestock and livestock products as well as routes of transmission (Manuja et al. 2014).

A study in Cambodia demonstrated smallholder farmers adopted biosecurity practices, including a willingness to vaccinate for FMD and HS at their own cost, separate sick from healthy cattle, grow and feed forages and awareness of the benefits of building fattening pens (Young et al. 2014). Further, smallholder farmers that adopted these practices significantly increased annual household income (Young et al. 2014). In Cambodia it was demonstrated that positive biosecurity and disease reporting behaviours by village animal health workers (VAHWs) are correlated with high levels of knowledge (MacPhillamy et al. 2021a). This provides evidence that improved training of VAHWs, with regular monitoring and evaluation of training programmes, will likely further strengthen the livestock sector through improved disease surveillance and management (MacPhillamy et al. 2021a).

Forages and weigh tape

The benefits of forages to improve large-ruminant productivity and household livelihoods have been discussed in detail previously. An example of the success of forage growing was observed in Cambodia, where an initial establishment of 52 fodder plots covering 2.6 ha in 2008 expanded to 1306 plots covering 45 ha by 2011, including nonproject farmers from surrounding areas (Bush et al. 2014a). Although the establishment of forages did not have a significant effect on reducing the use of traditional feed sources such as rice straw, crop byproducts and crop residues, grazing of cattle on native pastures proved to be less common among adopter households (Ashley et al. 2016). Coupled with a significant reduction in daily time spent sourcing feed, average costs of fodder plot establishment of USD6.10 per 100 m² and the potential increased household income from forage establishment and forage feeding provided incentive for uptake (Ashley et al. 2016). To further enhance the benefits of improved nutrition from forage feeding for large-ruminant production and address a lack of farmer and trader knowledge of animal weights due to limited availability of liveweight scales, an accurate weigh tape was developed specific to cattle and buffalo to provide a cheap and easy tool to monitor animal production and health, and to assist in negotiating a fair sale value (Bush et al. 2014b).

Vaccination programmes

Demonstrating the successful use of vaccination for disease control has proven to be an effective farmer engagement tool (Young et al. 2014; Nampanya et al. 2018; Blacksell et al. 2019). However, it is important to note that success of vaccination programmes requires maintenance of cold chains, selection of the appropriate vaccines, correct vaccine administration, efficient vaccination programme strategies and sufficient quantities of vaccine (Blacksell et al. 2019). If any of these requirements are not met, the success of the programme is compromised, resulting in farmer distrust and a delay in vaccination uptake.

Lick blocks

Another engagement tool is the distribution of high-quality molasses lick blocks, which have demonstrated improvements in weight gain and parasite control in large ruminants in Laos (Windsor et al. 2019; Olmo et al. 2020). Blocks are easily fed out so require minimal labour, are suited to the tropical environment, and can have urea included to provide additional growth benefits, particularly in the dry season (Windsor et al. 2021). In addition, the blocks provide immediate benefits for the farmers through improved herd management, as animals were calmer and easier to muster, and had improvedcondition and coat, increasing saleability (Windsor et al. 2021). This successful engagement can then lead to promotion and uptake of other strategies such as forage growing and vaccination programmes.

Knowledge

Although monetary and material handouts are often eagerly sought by potential participants in research for development projects and associated training, the benefits are short-term and only last the length of the project. A longer-term and more sustainable approach is to promote knowledge as a beneficial commodity, where skills and understanding are obtained and utilised into the future. However, the topic of knowledge and how it interacts with intervention uptake or on-farm practice change is complex. It is well established that ‘knowledge’ or ‘understanding’ are not always enough for stakeholders to make changes in their own lives (or on their own farms). Other barriers to practice change include not fully understanding the benefits, concern about the time and costs involved and wanting to see successful implementation before committing (Ashley et al. 2018a). This requires all or a combination of the engagement approaches above to be implemented. In addition, identification of a ‘champion’ smallholder farmer who is respected by others and can visualise how the improvements will benefit their situation is required (Turner et al. 2021). This person will be an early adopter, with other farmers likely following and implementing the initiatives themselves.