Sustainable Intensification of Livestock Systems Using Forage Legumes

Global human population is increasing and expected to reach 9.7 billion people by 2050. Sustainable intensification (SI) of agricultural systems is key to increase food production while minimizing impact on global natural resources. Forage legumes provide a myriad of ecosystem services (ES) and represent an important tool for promoting SI in livestock systems. Forage legumes associate with soil microorganisms to reduce atmospheric N2. This N input represents a valuable contribution to increase net primary productivity with reduced C footprint. In addition, forage nutritive value generally increases, resulting in greater animal performance. When forage legumes are integrated into livestock systems, they complement the essential role of grasses by adding N to the system, improving forage quality, sharing resources with the companion grass, and enhancing soil organic matter. Soil C:N ratio is typically in a narrow range; therefore, input of N is essential to increase C sequestration and maintain the soil C:N ratio. Additional ES provided by forage legumes include enhanced efficiency of nutrient cycling, improved pollinator habitat, medicine/food for humans, timber, wildlife habitat, and shade for livestock (tree legumes). There are options of herbaceous and arboreal legumes, as well as annuals and perennials. In temperate regions, herbaceous legumes are used widely (e.g., Medicago sp, Trifolium sp.) while arboreal legumes are often found in tropical regions. There are a few options of herbaceous perennial warm-climate legumes, and some of them are still underexploited (e.g. Arachis pintoi, Arachis glabrata). Documented examples of forage legumes increasing livestock productivity are available in different regions of the world, and recent progress has been made in developing and managing forage legume germplasm adapted to biotic and abiotic stresses in tropical America, Africa, Southeast Asia, and Australia. Learning past lessons and applying the knowledge to shape the future is essential to achieve SI of livestock systems

Warm-Season Legumes – Challenges and Constraints to Adapting Warm-Season Legumes to Transition Zone Climates with Examples from \u3ci\u3eArachis\u3c/i\u3e

Grass pastures in monoculture are the predominant system in transition zone climates, where warm-season perennial grasses are usually cultivated. Mixed grass-legume pastures are worldwide recognized for having advantages over pure stands, including pasture longevity, N input from biological fixation, efficient nutrient cycling, and greater animal production. The genus Arachis encompasses important and successful warm-season forage legume species cultivated in mixed pastures or in pure stands. Arachis pintoi and Arachis glabrata are potential tropical forage species that can be used in transition zone climates. Mixed pastures with these legumes have been shown to be resilient systems, able to withstand short-term perturbations, like pests, diseases, drought, or flooding. Wide adoption of A. glabrata is constrained by its high cost and slow establishment period. This species has low potential to produce seeds, and rhizomes are required for propagation. Although great seed production is verified in some A. pintoi genotypes, vegetative propagation is also most often used, since seeds are produced underground, and a large-scale commercial seed production depends on the development of an efficient seed harvester. Developing new cultivars with persistent link between seed and peg is a great challenge for breeders. A. pintoi spreads faster than A. glabrata in tropical regions, and the genetic variability for lateral expansion and ground cover in mixed stands must be better understood in humid subtropical climates. The evaluation of Arachis wild germplasm has already shown genetic variability for traits of interest for use in mixed pastures. Studies have also shown that there is genotype x environment interaction considering tropical and subtropical climates. The greatest chances of success in obtaining more adapted, productive, and faster establishing Arachis cultivars for transition zone climates seems to be no longer in the identification of superior wild accessions but in the hybridization and selection through specific breeding programs

New Insights for Benefit of Legume Inclusion in Grazing Systems

The benefits and challenges of legume inclusion in grazing systems have been well documented over time and across different regions. Recent investigations have provided novel insights into the benefits of legume inclusion in grazing systems. Our objective is not to provide a wide overview of the benefits of legume inclusion but to explore novel insights of recent advancements made from studies evaluating legume inclusion in grazing systems. Efficiency of resource use through legume inclusion in grazing systems can reduce the water footprint associated with beef production through improvements in forage nutritive value and animal performance. These efficiencies also translate into improvements in nutrient cycling and nutrient transfer, which are critical for sustaining productivity of grazing systems. Moreover, evidence exists highlighting the importance of root contact between grasses and legumes for sharing N. Provisioning of floral resources from legumes has also been shown to be important for providing habitat for pollinator species. Lastly, soil microbial abundance of microorganisms associated with N2 fixation can be altered according to species present within a pasture, especially when legumes are present. Insights derived from such recent studies continue to provide evidence for the need to continue to develop legume-based grazing agroecosystems

Nutritive Composition and \u3ci\u3eIn Vitro\u3c/i\u3e Dry Matter Digestibility of the Most Browsed Forage Species by Lactating Camels

Camels are both grazers and browsers of a broad spectrum of forages. The objective of this study was to identify and to determine the chemical composition of the most preferred forage species by lactating Somali camels in Laikipia County, Kenya. Lactating Somali camels and their calves were observed during the wet and dry seasons while browsing for a period of two weeks. The forage species were ranked based on the bite count. The most browsed forages identified through observation were sampled for identification by the local and scientific names and laboratory analysis. They were analyzed for proximate composition, detergent fiber fractions, and in vitro dry matter digestibility. The most browsed forage species were Acacia nubica, Acacia seyal, Cucumis aculeatus, Euclea divinorum, Hibiscus parrifolia in the wet season and Barleria acanthoides, Balanites aegyptiaca, Cynodon dactycon, Lycium europium, Pollichia campestris in the dry season. Shrubs constituted 60%, trees 30%, and grasses 10% of the most preferred forage species. The preferred browsed species had high crude protein (7.1±0.4 to 25.7±1.2%) and low neutral detergent fiber concentrations (29.1±2.7 to 74.0±7%). The results of the study show camels fed on different types of forage species and that the forage nutritive value affected the selection

Weed Management Affects Pasture Productivity and Animal Performance

Weed can be defined as any plant growing in undesirable locations. Weeds are considered one of the main challenges in agricultural fields. Weeds affect pasture productivity mainly because of the competition for limited resources such as nutrients, water, and light with forage plants. Weeds encroach pastures spontaneously and spread quickly through the farm and neighboring areas, making their control difficult. In addition, weeds can affect forage nutritive value, grazing behaviour, voluntary forage intake, animal health, and consequently animal performance. The low efficiency of mechanical weeding and the global concern about indiscriminate use of herbicides impose challenges for producers in grazing systems. These factors justify the importance of proper weed management to minimize financial losses and environmental impacts and drive the research effort in this area. Currently, some strategies including grazing management, grass and legumes integration, and site-specific weed spraying have demonstrated potential to improve the efficiency of weed supression and increase the productivity and profitability of livestock systems. This review aims to discuss about the main effects of weed encroachment in grasslands regarding pasture productivity and animal performance, as well as emphasize potential strategies for weed management

Enhancing Milk Production of Lactating Camels in Kenya via Supplementation of the Invasive Cactus (\u3ci\u3eOpuntia stricta\u3c/i\u3e) In the Diet

Climate change leading to prolonged and recurrent droughts, changes in land use, primarily settlement of pastoralists, followed by overgrazing and subsequent land degradation, has made the highly drought resistant opuntia flourish and be aggressively invasive in the Kenya’s rangelands. Camel keeping has increasingly replaced cattle as a climate adaptation strategy and also as a result of a steady increase in demand for camel milk due to the associated nutritional and health benefits,To address the challenge of lack of pasture during prolonged drought, there is the need to utilize the invasive cactus as fodder. The invasive cactus can be a kind of \u27Drought-Insurance\u27 in these regions due to its ability to retain its nutrition and productivity in water deficit conditions. This study reports on the incorporation of the invasive cactus together with a protein source in increasing the milk yield of lactating camels in one of the semi-arid land regions of Kenya

Legume and Nitrogen Fertilization Affect Animal Performance and Enteric Methane Emission of Nellore Heifers

Methane emission from livestock operation is an important source of greenhouse gas and contributes to global warming. Forage legume secondary compounds may mitigate methane emissions by reducing methanogenic population in the rumen. This study evaluated animal performance and methane emission from beef cattle grazing either a mixed pasture [Brachiaria brizantha cv. Marandu (palisadegrass) and Arachis pintoi (forage peanut) cv. BRS Mandobi] or a palisadegrass monoculture with or without nitrogen (N) fertilisation. A 2.5-yr continuous stocking experiment was carried out in southeast Brazil, on a randomized complete block design with three treatments and four replicates. Two Nellore heifers were used as tester animals and additional put-and-takes were used to keep canopy height at 20-25 cm. The treatments comprised three pasture types: 1) palisadegrass-forage peanut mixed pasture (GRASS+LEGUME); 2) palisadegrass + 150 kg N/ha/year (GRASS+N); 3) palisadegrass without N fertilization (GRASS). Response variables included average daily gain (ADG), forage intake, and methane emission. Methane emission was estimated by the sulphur hexafluoride (SF6) tracer technique. There was no difference between grazing systems for the ADG (P = 0.439) and DMI (P = 0.394; averages of 0.433 kg/d and 2.10 %BW/d, respectively). In the GRASS+LEGUME, there was a decrease of 11.7% in methane emission per animal (148 vs. 170 and 165 g/day for GRASS+N and GRASS, respectively; P = 0.001). Grazing systems including legume reduced methane emission per unit of ADG (365 vs. 428 and 398 g/kg for GRASS and GRASS+N, respectively; P = 0.061) and per carcass gain (656 vs. 800 g of methane/kg carcass for GRASS; P = 0.022). Intake of condensed tannins was greater for GRASS+LEGUME (0.61 vs. 0.17 %BW/d, P \u3c 0.001). Forage peanut decreased enteric methane emission intensity, reducing carbon footprint of livestock systems in Southeast Brazil

How Does N Fertilization or Forage Legumes Affect Forage and Animal Production?

Livestock grazing in tropical climates is characterized by low productivity. Forage and animal production can be improved by applying nitrogen (N) fertiliser or using forage legumes. This 2.5-yr study assessed the canopy structure and productivity of beef cattle grazing either a mixed pasture of Brachiaria brizantha cv. Marandu (palisadegrass) and Arachis pintoi (forage peanut) cv. BRS Mandobi or a Marandu palisade grass monoculture with or without N fertilisation. The experiment was carried out in Southeast Brazil, where the canopy structure (herbage mass) and animal productivity (stocking rate and liveweight gain per ha) were compared for three types of pastures: 1) mixed pasture of Marandu palisade grass and forage peanut (GRASS+LEGUME); 2) a monoculture of Marandu palisadegrass fertilised with 150 kg N/ha/year (GRASS+N); and 3) monoculture of Marandu palisadegrass without N application (GRASS), under continuous stocking. A minimum of two Nellore heifers and additional put-and-takes were used to keep canopy height at 20-25 cm. A randomized complete block design was used with four replicates; seasons were considered repeated measurements over time. Herbage mass was greater in the GRASS+N pasture (P \u3c 0.001); however, in the last three seasons (Spring II, Summer III, and Fall III), there was no difference to GRASS+LEGUME pasture. In the GRASS+LEGUME pasture, there was an increase of legume mass (1.260 to 2.565 kg/ha) and botanical composition (23.6 to 39.1% of legume in forage mass) throughout the study. The stocking rate (P \u3c 0.001) and liveweight gain per ha (P \u3c 0.001) were greater in GRASS+N, without difference among GRASS+LEGUME and GRASS pastures in the first seven seasons. In the last three seasons, with an increase of legume proportion, stocking rate and liveweight were intermediate for GRASS+LEGUME pasture. Legume increased herbage mass and animal productivity in the long term. Immediate responses were achieved with N fertilization

Nutrient Cycling and Crop Responses on Integrated Crop-Livestock Systems

Integrated crop-livestock systems (ICLS) can bring numerous benefits to crops or livestock systems, such as increase soil C sequestration, farm profitability, and provisioning of ecosystem services. In a changing world, production systems need to become more resilient and sustainable. Specialized agriculture is characterized by a high level of inputs and outputs, and oftentimes specialize in a single crop to simplify management. However, such operational systems stray away from sustainable standards. Furthermore, specialized cropping systems may face problems such as persistence of pests and diseases, loss of biodiversity, stagnant yields, development of herbicide-resistant weeds, soil erosion and consequently loss of soil organic matter. Recombining crops and livestock in a broad and complementary system is to look back into the past to adopt a practice that used to be common centuries ago. With the advancement of technology and better understanding of this management practice, ICLS appear as an option to provide ecosystem services from agricultural lands, while potentially increasing crop production. Such systems have shown benefits as increasing in soil organic matter, increase in biodiversity, and nutrient cycling. There is an array of ICLS, which may include short and long grazing cycles, more than one animal category, crops from many different functional groups, and trees. Here, we will discuss some of the aspects in nutrient cycling and crop responses on ICLS, giving examples to call attention to some of the advantages ICLS can provide

Herbage and Livestock Responses for N-Fertilized and Grass-Legume Grazing Systems

Forage legumes provide an alternative N source in grazing systems. The objective was to evaluate plant and animal responses in N-fertilized or grass-legume-based systems under continuous stocking during winter and summer, from 2016-2019. The three treatments consisted of year-round forage systems including winter and summer forage components. The first system (Grass+N) included N-fertilized (112 kg N ha-1 yr-1) ‘Argentine’ bahiagrass (Paspalum notatum) pastures during the summer, overseeded with a mixture (56 kg ha-1 of each) of ‘FL 401’ cereal rye (Secale cereale) and ‘RAM’ oat (Avena sativa) during winter with a second application of 112 kg N ha-1 yr-1. Total annual fertilization for this treatment was 224 kg N ha-1 yr-1. System 2 (Grass + clover) included unfertilized Argentine bahiagrass during summer, overseeded with a similar rye-oat mixture, plus a mixture of clovers [17 kg ha-1 of ‘Dixie’ crimson (Trifolium incarnatum), 6.7 kg ha-1 of ‘Southern Belle’ red clover (Trifolium pratense), and 3.4 kg ha-1 ball clover (Trifolium nigrescens), fertilized with 34 kg N ha-1 during winter. System 3 (Grass+CL+RP) included the germplasm Ecoturf rhizoma peanut (Arachis glabrata; RP) and Argentine bahiagrass during the summer, overseeded with the same a similar rye-oat-clover mixture used in System 2 and fertilized with 34 kg N ha-1 during winter. Pastures were continuously stocked using variable stocking rates. Results indicate that clover inclusion during winter improved herbage distribution along the grazing season. Integrating RP during summer increased steer ADG by nearly 80% compared with Grass+N or Grass+Clover (bahiagrass monocultures during summer). While N fertilizer allowed for greater stocking rates, it did not improve animal performance throughout the year. Overall, similar gain per area was achieved in Grass+CL+RP than Grass+N, with lesser N-fertilizer inputs