Species-Specific Feeding Strategies

*Ruminants:* Buffalo, cattle, sheep, and goats are the major ruminant animals raised for meat or milk production in Nepal. One of the major challenges for improvement of productivity in the Nepalese ruminant livestock sector is to provide quality feed to the animals all year round, which is an important issue, since feed costs can amount to ~60% of total production costs in a typical livestock production system [45]. Due to land occupation and degradation, land availability for grazing is diminishing so the livestock sector relies more heavily on crop residues, by-products, and (novel) fodder and forage plants. For example, hempseed meal, a by-product of hemp oil production, was shown to be an alternative feeding resource for small ruminants [46]. Thus, strategies to supply sufficient amounts of nutritious feeding material all year-round should be a major strategic focus for the development of ruminant production in Nepal.

Crop–animal interaction is an integral component of mixed farming systems in Asia, including Nepal, where both crop and livestock complement resources to establish and sustain such farming systems [9]. A typical rice–wheat–maize cropping system in Nepal generates a substantial amount of straw and other by-products, which can be utilized for livestock feed. However, the nutritional quality of straw is low and methods to enrich such by-product nutrient content and use it efficiently have not been commonly practiced. It has been shown that urea treatment (up to 4% on a weight basis) enhances the voluntary intake of by-products like straw, and urea treatment can increase milk production in lactating buffalo [47]; this is due to an improved ability of microorganisms in the rumen to utilize fiber and synthesize protein for the animal, when the non-protein–nitrogen source, urea, is added to the diet. However, urea is not readily available to farmers. Alternatively, such by-products can also be pre-treated with sugar molasses [48] to increase feed intake and animal productivity. The nutritionally deficient crop by-products, such as rice straw (with high lignin and silica contents) could be enriched with the addition of alternative nutrient sources to stimulate microbial fermentation in the forestomach, such as urea, sugar molasses, ligninolytic enzymes, or microbial treatments [49].

In Nepal, precipitation during the rainy monsoon season (June–August) allows different grasses, pasture, and other fodder plants to grow, which represent substantial natural plant biomass of good nutritional quality and which can be used to feed ruminant livestock. However, in other seasons of the year (such as in winter or spring conditions), natural biomass availability is low, and particularly larger ruminants hardly ge<sup>t</sup> anything to eat other than the dried crop by-products of low nutritional quality. This seasonal deficit of feed materials is probably the major constraint for the improvement of ruminant production [30] and must be overcome to improve the productivity of ruminant livestock production systems. Preservation/conservation of plant biomass during the season, when it is available, is an important strategy to ensure more consistent availability of feed for

ruminants throughout their production cycle. The substantial amount of biomass available during the rainy season could be stored as hay or silage, thus preserving the available nutrients for use during the dry season, with a positive impact on overall annual animal productivity. It is noteworthy that it is not feasible to operate ensiling on a larger scale in all regions of Nepal due to topographical constraints, space limitations, and the lack of proper technologies to harvest and chop the harvested plant biomass. However, the application of low-scale ensiling techniques, such as using synthetic plastic bags or pits, could be an economical option also for small-scale farmers [50]. However, the implementation of such technologies is presently hindered by ineffective extension services and hence knowledge transfer.

In Nepal, more than 170 different species of trees, shrubs, and vine are used to provide fodder for ruminants [51]. However, there is limited information on their nutritional contents and potential biomass yields; nevertheless, three different commonly used fodder species had a large annual biomass yield of ~26–39 kg dry matter (DM)/tree [52]. Chemical analyses of ~30 different types of fodder-tree leaves revealed a relatively high crude protein content of ~10–22%, but also high contents of neutral detergent fiber (~27–74%) and acid detergent lignin (~6–30%) on a DM basis; these have strong negative impacts on DM digestibility [53]. In the hilly regions, the fodder species available for ruminant feeding as green feed will only support moderate levels of growth and milk production [54] due to the high content of indigestible components, such as lignin, which also limit the availability of protein and other nutrients for the animal [53]. Detailed chemical and nutritional characterization of various forage and fodder species potentially available as ruminant feeds are ye<sup>t</sup> to be performed, and this knowledge is needed for estimations of possible improvements in productivity in the ruminant livestock sector.

*Non-ruminants:* Poultry and pigs are the major land-based non-ruminant species being raised in Nepal. The poultry sector is, as mentioned before, the most commercialized animal production sector, although people, particularly in rural areas, still keep a small number of local poultry breeds as a source of quality food protein, as well as for additional income from sales of eggs and meat [55]. Like in many other countries, poultry feed can contain up to 65% of corn [56]; corn is a significant energy source used for poultry production in Nepal. Corn is also one of the staple foods for human consumption in Nepal, and corn productivity is low despite some efforts in the past to try to increase productivity [57]. Due to the competition for corn for human food versus animal feed, the total annual demand for corn is growing, and thus ~45% of total corn used for animal feed is imported from India [57]. There have been some research efforts made by the National Maize Research Program, under the Nepal Agricultural Research Council, Government of Nepal, to increase the productivity of corn by developing more stress-tolerant corn varieties [58]. However, they are ye<sup>t</sup> to be tested and commercialized under farm conditions in different agro-ecological zones. Pig production is still at an infant stage, although recent trends show that pork consumption is rising, particularly in urban areas, and this will call for even more efforts to improve the production of suitable feeds for monogastric animals, without competing for arable land needed for the production of food for human consumption.

In Nepal, various grain legumes are available in the winter (such as lentil, chickpea, etc.) and summer (such as soybean, black gram, etc.) seasons and they are important components of the cropping systems but are mostly used for human consumption, and their productivity is remarkably low (<1 ton/ha) [59]. Hence, overall availability of soybean for animal feeding in Asian regions is generally low [60], but soybean is, nevertheless, the major and probably most expensive feed resource used in Nepal for poultry and swine to fulfill their protein requirements. Grain legumes, including soybean, are mostly cultivated under an intercropping system, but they also have the potential to be grown as sole crops, particularly in the lower plain areas of the Terai region. Diseases and pests, soil moisture deficits in winter crops, and the unavailability of high-yielding varieties appear to be the major constraints for the upscaling of grain legume production [61]. To increase the productivity of Nepalese poultry and swine production systems, it is, therefore,

imperative to find alternative sources of feed protein to partially replace the expensive soybean meal as a protein source. Such alternative feed items could be of both animal or plant origin. One alternative protein source for non-ruminant animals, which presently is attracting interest in more developed regions of the world, is insects. Nepal hosts a diverse range of insect species [62,63], and they could become alternative sources of protein in diets for non-ruminants in the future [64]. This requires that insects depending on their growth substrate can be safely added to livestock diets without compromising the quality, safety, or palatability of meat and milk [65]. Insects can be grown on different cheap organic substrates, such as household wastes. This is an important feature in relation to the development of a more circular bioeconomy, where unutilized waste is converted into valuable protein food sources and the pollution load is reduced.

Other alternative sources of protein could be plant-based feed materials. Sunflower or mustard meals also contain high levels of protein. In one study, sunflower meal (with the addition of microzyme) could substitute up to 35% of soybean meal in the feed without compromising the growth performance of broilers [66]. Additionally, the water plant Azolla, like terrestrial legumes, can fix atmospheric nitrogen and convert it into protein. Azolla has been identified as a possible economical substitute for soybean-based poultry feed and can replace up to 10% of soybean meal in the overall diet [67].

The availability of quality feeds all year round is important to sustain animal production and exploit the genetic potential of livestock. Specific research and extension services should be prioritized in Nepal to effectively utilize current feed resources and formulate implementable, alternative, and efficient new feeding strategies. Particular attention should be paid to enrich the nutritional values of various plant-based by-products. Also, cost-effective small-scale technologies should be developed to preserve the chemical and nutritional properties of seasonally available surplus plant biomass. Additionally, a detailed evaluation of biomass yields, chemical and nutritional properties, and digestibility of a broader range of available forage and fodder species is vital to optimize future feed formulations. Future strategies should also be directed towards identifying alternative nutritious feed resources, such as insects, and assessing them for palatability, utilization, and impacts on animal health, growth, and performance. While formulating future livestock strategies, it is noteworthy that ruminants have advantages over non-ruminants, since they are not necessarily in direct competition with humans for food resources, which is critical for a developing country like Nepal, but feed resources for ruminant animals should nevertheless have a reasonably high digestibility to achieve significant improvements in animal production.

#### *5.3. Feeding Strategies for Reduced Climate Impact*

The livestock sector's contribution to climate change has become a global issue, as the livestock sector alone accounts for about one-fifth of total GHG emissions [68]. In Nepal, it has been estimated that agriculture and forestry, and other land-use sectors account for >80% of national GHG emissions [69]. Enteric emissions from ruminant livestock and emissions from agricultural soils are the major contributors [70]. The climate mitigation policies directed at GHG emission from the livestock sector and particularly enteric methane emission from ruminant livestock should be implemented with extreme caution. Assessing the negative impact of livestock-derived GHGs should be balanced against the positive benefits relating to food security and poverty alleviation since livestock is a vital source of nutrition and livelihood for many low-income people in countries like Nepal [71,72]. The global average meat consumption is ~100 g per person per day with an about ten-fold variation between the highest and lowest consuming parts of the population [68]. In Nepal, with a transition in socio-economic status and income rise, per capita meat consumption will increase, which is expected to lead to beneficial trade-offs in terms of improvements in nutritional status. However, this also calls for a transition of livestock production systems from the traditional extensive production system to more intensified and resource-efficient systems to ensure increments in productivity are achieved without associated increments

in GHG emissions. Improving livestock production efficiency through better breeding techniques and feed utilization strategies is essential in this respect since the most important determinant for methane emission per kg produce is animal productivity [73].

Other possibilities to reduce emissions from the ruminant livestock sector could be to exploit feed additives with anti-methanogenic properties in diets for ruminants. This is becoming a topic of interest in the European Union, where climate policies dictate a 40% reduction in GHG emissions by the year 2030 compared with 2014, which is likely to be backed by political instruments, such as taxation on livestock production [74]. Various types of plants have been shown to contain bioactive, anti-methanogenic compounds, but to the best of our knowledge, no research has been conducted in this field on indigenous plants from Nepal.

To sum up, long-term strategies to minimize GHG emissions from the livestock sector in a developing country like Nepal should involve (1) the transition of particularly the existing ruminant livestock sector towards more productive systems, and (2) identification of potential anti-methanogenic plants/compounds suitable to use as feed additives for ruminant livestock.

The livestock sector is not only a culprit, but also itself becoming a victim, of climate change; it is vulnerable to the adverse impacts of climate change on the environment and feed availability for livestock in the developing world [75]. In Nepal, the livestock sector is, as already mentioned, an integral component of mixed farming systems. The increased frequency of drought, extreme rain, hailstorms, floods, erratic rainfall patterns, etc., are some of the observed effects of climate change with negative impacts on the existing farming system [76,77]. Thermal stress has direct adverse effects on animal health, reproductive, and productive performances of livestock, whereas adverse abiotic conditions, such as droughts and heat stress, lead to undesirable impacts on forage and crop production, thus limiting plant biomass supply for feeding of production animals [78,79]. Although there are some early indications of adverse climate change impacts, it is ye<sup>t</sup> too soon to fully understand the extent of climate change impacts on the livestock sector in different regions of Nepal with its diverse agro-climatic conditions and agro-livestock systems. Climate impacts on livestock production may, therefore, be very different in different areas [80]. In Nepal, limited research has been conducted concerning livestock adaptation to climate change, and most research efforts have taken only ruminant species into account. Thus, future studies are needed to acquire a better understanding of the impacts of climate change on different livestock production systems, taking both ruminants and non-ruminants into account, and considering key issues, such as forage and pasture availability, animal performance characteristics (meat, milk, and egg production and feed conversion efficiency). Such information is essential to perform a holistic economic analysis of livestock systems under climate change and develop the most appropriate region-specific future strategies for adaptation and reduction of GHG emissions.

#### **6. Future Livestock Policies**

In Nepal, the Ministry of Agriculture and Livestock Development (MOALD) (http: //moald.gov.np/, accessed on 8 December 2021) is responsible for the formulation, implementation, monitoring, and evaluation of livestock-related policies, plans, and programs, and the Department of Livestock Services (DLS) is mainly liable for livestockrelated extension activities. Moreover, the Nepal Agricultural Research Council (NARC) (www.narc.gov.np, accessed on 8 December 2021) carries out major agricultural research activities at the National Animal Science Research Institute (NASRI), with various disciplinary divisions targeting different livestock sectors. Agricultural universities, mainly the public Agriculture and Forestry University (AFU) and Tribhuvan University (TU), and some private institutions carry out teaching activities to fulfill academic requirements for various study programs in animal and veterinary sciences. In Nepal, collaboration within and across governmental livestock bodies and industry sectors could generate needed

synergies to improve livestock productivity. Unfortunately, such coordinated efforts have been missing so far.

Detailed analysis of the national agricultural policies of Nepal have been reported elsewhere, suggesting a need for a separate livestock policy rather than the previously formulated common agricultural policies (see review by [37]) and agriculture perspective plans (1995/96–2014/2015) [81]. In this paper, we propose that a future separate livestock policy should be formulated, which (a) acknowledges animal feed as a pivotal component to improve livestock productivity, (b) prioritizes the capacity building of research institutions to uplift livestock research, and (c) recognizes the industry sector as a key player in Research– Academia–Industry (RAI) partnerships to promote future research and sector development activities (Figure 5).

**Figure 5.** Formulation of future livestock policies in Nepal. Future livestock policies should focus on creating a better research environment and collaborative networks among research, academic, and industry sectors where animal nutrition should be recognized as a central player to improve existing production systems and exploit the genetic potentials of future livestock production systems.

#### *6.1. Animal Feed—A Pivotal Component of the Future Livestock Policies*

Poor animal productivity is recognized as a major issue in Nepal, like in many other developing countries [82]. We highlight that providing quality feed for livestock is probably the first and most important factor in improving animal productivity in Nepal as this strategy is also helpful in reducing methane production by increasing the production per unit of animal [83]. This is particularly important because feed costs account for ~60% of total livestock production costs [45], and the provision of quality feeds is necessary to fully exploit the genetic potential of production animals. Thus, any breeding program, particularly for ruminants, would not succeed without ensuring the availability of quality feed year-round. In this context, Nepal's future national livestock policies should identify production, supply and optimized use of quality animal feeds as the central focal point.

Compiling information about feed quality in the form of feeding tables is a critical step in ensuring that proper feeding plans can be formulated to fulfill the nutritional requirements of specific animals. Such tables should integrate nutrition characteristics of (a) existing commonly used feedstuffs and the impact of post-harvest processing, (b) identify alternative feedstuffs, and (c) encompass seasonal and regional/geographical variations and other potential factors that could influence the nutritional values of the feedstuffs. Presently, planning of animal feeding in Nepal is rarely based on scientific knowledge about the feed, but rather on the livestock farmers' experiences, which may not always ensure the most resource-efficient outcomes.

To improve the preservation, quality, and utilization of existing feedstuffs for ruminant species, preservation, and storage of seasonally available forage and fodder biomass should be a top priority. Farmers must have easier access to nutrient enrichment technologies to improve the nutritional values of crop residues and by-products. The use of marginal or underutilized lands, where virtually no crop production is possible, for growing grasses, forages, and fodder trees should be prioritized, and potentials for the utilization of forest biomass and new plant species under agroforestry models should be evaluated.

As an immediate action, the livestock sector should collaborate with crop development companies and research divisions to increase maize productivity and expand legume cultivation to ensure a greater future reliance on home-grown energy and protein resources. Expanded productivity of these crops is imperative to prevent increased competition from livestock for these crops that are primarily utilized as foods for humans. The utilization of natural pastures and meadows in hilly areas can also improve the export potential of organic livestock products in the future. The long-term policy strategy should focus on the potential for producing novel protein sources that can be less competitive with humans for food, and insects and Azolla are fascinating in this regard. Proper capacity and infrastructure building of research institutions are crucial to identify and evaluate the suitability of existing and novel feed resources, as discussed in the following sections.

#### *6.2. Capacity and Infrastructure Building of Research Institutions*

Like in many other developing countries, an insufficient research capacity, not least in the livestock field, is a significant concern in Nepal. Future livestock policies should be directed towards developing better research environments to address upcoming vital issues associated with livestock production and management, particularly efficient utilization of existing and alternative feedstuffs and the development of new feed resources. Traditionally, the NARC has been the only institution devoted to livestock research. Its available laboratory facilities and human resources should be upgraded to perform, for example, large-scale in vitro analyses to characterize feed digestibility, which is the major determinant of energy and protein value of feeds. Besides, animal experimental facilities should be equipped to enable in vivo studies that characterize the impacts of existing and novel feeding resources on animal performance. Facilities to assess potential anti-methanogenic properties of existing or novel feedstuffs are also highly relevant in this context, so as to be able to design the most productive, as well as climate-friendly, strategies for livestock sector development.

Historically, Nepalese academic institutions are dedicated to fulfilling only the academic requirements of various study programs, including animal and veterinary sciences. Future livestock education policies should aim to transform the existing universities into more research-based institutions, thus prioritizing both research and teaching as their major activities. This will help to uplift the research capability and contribute to establishing research-based university education training and teaching programs. This will also strengthen positive collaborations between universities and research institutions to develop joint project proposals and establish a research-based, potentially international, learning environment in animal science.

#### *6.3. Research–Academia–Industry (RAI) Collaborations*

In Nepal, research and academia are separate pillars, and neither appear to have strong traditions for research collaboration with the industry sector. Livestock industries are currently in a growing phase, and many feed industries of different sizes are already in existence, mainly focusing on poultry feed formulations. Research efforts in Nepal are poorly connected with business sectors, which makes it difficult to commercialize research outputs to promote industrial growth in the livestock sector. Industry sectors can provide important tools for livestock research, such as animals and animal facilities, as well as resources to carry out different research activities. Both research and the academic level in Nepal could benefit from such collaborations with the industry sector, as international

experiences have shown in other parts of the world. Thus, integrated future livestock policies should include instruments (e.g., National research funding) to promote research– academia–industry (RAI) collaborations to develop a sustainable livestock industry sector.
