Agronomic Potential and Nutritive Value of Promising \u3ci\u3eLeucaena\u3c/i\u3e Species in the Yucatan Peninsula

Two experiments were carried out in order to evaluate the agronomic potential, the nutritive value and the tolerance to psyllid (Heteropsilla cubana) of nine Leucaena species. A randomized block design with four repetitions was used. There were significant (P\u3c 0.01) differences on dry matter production (i.e. leaf and twigs yield ). L. collinsii showed the most promising result, which could be related to its high psyllid tolerance. In a second experiment, the preference indices of Leucaena species was assessed with sixteen male pelibuey sheep in a cafeteria trial. There were significant (P\u3c 0.0001) differences among Leucaena species. L. esculenta paniculata was the species most preferred . There was no relationship between chemical composition (i.e. ADF, NDF, and polyphenols) and preference and psyllid tolerance

Effect of Defoliation Frequency on Forage Yield from Intensive Silvopastoral Systems Compared to a Monoculture Grassland

Livestock production in the tropical regions of the world faces serious constraints as a result of climate change. Monoculture based pastures require the use of large amounts of nitrogen fertilizers to sustain production throughout the year. In general terms, tropical grasses are of low quality and when consumed by ruminant species, contribute to the emission of greenhouse gases (methane, carbon dioxide and nitrous oxide) (Herrero et al. 2009; Place et al. 2009). The establishment of intensive silvopastoral systems (iSPS) with associated shrubs legumes and grasses can increase the yield and quality of forage as well as fixation and transfer of atmospheric nitrogen (N) (Murgueitio et al. 2011). Therefore, the costs of nitrogen fertilizers and the emissions of greenhouse gases under practical conditions can be reduced. The intensive silvopastoral system is a kind of agroforestal practice that it is environmentally friendly and at the same time improves productivity of livestock systems. However, several aspects of its management have not been fully evaluated. This is the case of the response to defoliation, which is an important management factor associated to the overall biomass productivity (Solorio 2005)

Urinary Excretion of Mimosine Derivatives by Cows with and without Experience in Consumption of \u3cem\u3eLeucaena leucocephala\u3c/em\u3e

Leucaena leucocephala is a leguminous tree widely distributed in the tropical regions of the world. In Mexico, it has been incorporated into silvopastoral systems and is highly regarded, owing to its high content of crude protein. Nonetheless, L. leucocephala contains secondary metab-olites, such as mimosine, a non-protein free amino acid, which may induce toxic effects in unadapted ruminants that consume the forage (Hammond 1995). Although Synergistes jonesii, an anaerobic bacterium, has the ability to degrade 3,4-DHP and 2,3-DHP to non-toxic compounds (Allison et al. 1992), in Mexico its presence has not yet been confirmed. Recent work has suggested the occurrence of sub-clinical toxicity to 3,4-DHP and 2,3-DHP in cattle grazing L. leucocephala in Australia and Thailand (Graham 2007; Dalzell et al. 2012; Phaikaew et al. 2012). Several options such as the transfer of rumen liquor and the adaptation of ruminants to the intake of L. leucocephala have been studied in an attempt to reduce the excretion of mimosine and its metabolites (Palmer et al. 2010). The aim of the present work was to evaluate the effect of the experience of consumption of L. leucocephala on excretion of mimosine derivatives (3,4-DHP and 2,3-DHP) in the urine of cattle

Productive Performance of Growing Cattle Grazing a Silvopastoral System with \u3cem\u3eLeucaena leucocephala\u3c/em\u3e

In tropical regions, the feeding of cattle is usually based on the grazing of medium to low quality grasses. Low fertility of soils, changing climatic conditions and the poor management of pastures, have further reduced the quality and forage yield of pastures. The low availability and quality of grasses gives modest weight gains for grazing cattle and this in-turn causes low economical efficiency of cattle production systems (Campos et al. 2011). Silvopastoral systems represent a sustainable option for meat and milk production in the tropics. The association of grasses with legumes such as Leucaena leucocephala (leucaena) supply forage with high concentration of crude protein (Barros et al. 2012). There are reports in the scientific literature which show that intake of leucaena can result in good rates of growth in cattle (e.g. Shelton and Dalzell 2007); however the presence of the free amino acid mimosine and its metabolites (3,4-DHP and 2,3-DHP) in leucaena when the anaerobic bacteria Synergistes jonesii (Allison et al. 1992) is absent from the rumen, may induce subclinical toxicity in grazing ruminants (Graham 2007; Dalzell et al. 2012; Phaikaew et al. 2012). There are no reports in Mexico regarding the rate of growth of cattle grazing silvopastoral systems with leucaena. The aim of the present work was to evaluate the rate of growth of cattle grazing an association of Panicum maximum and leucaena compared to that of cattle fed a high grain ration (feedlot)

Urinary Excretion of Mimosine Metabolites by Hair Sheep Fed Foliage of \u3cem\u3eLeucaena leucocephala\u3c/em\u3e

Leucaena leucocephala is an adapted legume widely distributed in the tropical regions of Mexico. The high crude protein content of leucaena leaves renders it appropriate for ruminant feeding under commercial conditions. However, the foliage contains the non-protein amino acid mimosine, which, if consumed in high amounts, may induce toxicity in animals which have not previously consumed the legume or without microorganisms capable of degrading mimosine and its derivatives 2,3-DHP (dihydroxypyridine) and 3,4-DHP (Hammond 1995, Palmer et al. 2010, Dalzell et al. 2012). Barros-Rodríguez et al. (2012) found that dry matter intake and weight gain were reduced when sheep grazed paddocks with 55,000 plants of leucaena per hectare. Early work in Australia led to the isolation of Synergistes jonesii, an anaerobic bacterium able to degrade 3,4-DHP and 2,3-DHP to non-toxic compounds (Allison et al. 1992). In Mexico, the presence of this microorganism in the rumen has not yet been confirmed. Inoculation of non-accustomed animals with rumen liquor of ruminants adapted to the consumption of leucaena can reduce the impact of mimosine and its metabolites on animal health (Ghosh et al. 2009; Palmer et al. 2010). The aim of the present work was to evaluate the effects of transferring rumen liquor of cows adapted to the consumption of L. leucocephala to sheep without experience of consumption, on urinary excretion of 3.4-DHP and 2.3-DHP by means of a colorimetric technique

Review: Strategies for enteric methane mitigation in cattle fed tropical forages

Methane (CH4) is a greenhouse gas (GHG) produced and released by eructation to the atmosphere in large volumes by ruminants. Enteric CH4 contributes significantly to global GHG emissions arising from animal agriculture. It has been contended that tropical grasses produce higher emissions of enteric CH4 than temperate grasses, when they are fed to ruminants. A number of experiments have been performed in respiration chambers and head-boxes to assess the enteric CH4 mitigation potential of foliage and pods of tropical plants, as well as nitrates (NO3−) and vegetable oils in practical rations for cattle. On the basis of individual determinations of enteric CH4 carried out in respiration chambers, the average CH4 yield for cattle fed low-quality tropical grasses (>70% ration DM) was 17.0 g CH4/kg DM intake. Results showed that when foliage and ground pods of tropical trees and shrubs were incorporated in cattle rations, methane yield (g CH4/kg DM intake) was decreased by 10% to 25%, depending on plant species and level of intake of the ration. Incorporation of nitrates and vegetable oils in the ration decreased enteric CH4 yield by ∼6% to ∼20%, respectively. Condensed tannins, saponins and starch contained in foliages, pods and seeds of tropical trees and shrubs, as well as nitrates and vegetable oils, can be fed to cattle to mitigate enteric CH4 emissions under smallholder conditions. Strategies for enteric CH4 mitigation in cattle grazing low-quality tropical forages can effectively increase productivity while decreasing enteric CH4 emissions in absolute terms and per unit of product (e.g. meat, milk), thus reducing the contribution of ruminants to GHG emissions and therefore to climate change

Forage Yield and Quality of \u3cem\u3eLeucaena leucocephala\u3c/em\u3e and \u3cem\u3eGuazuma ulmifolia\u3c/em\u3e in Tropical Silvopastoral Systems

Low availability and quality of pastures during the dry season are common problems in tropical livestock production systems. However, several studies indicate that the use of trees and shrubs is a good alternative to overcome those problems (Ku-Vera et al. 1999). In fact, the nutritional value of tree foliage is often better than that of forage grasses. In addition, its use could con-tribute to reforestation and restoration of degraded land (Casanova-Lugo et al. 2010). Recently, several reports have focused on the incorporation of Leucaena leucocephala in silvopastoral systems (Murgueitio et al. 2012). Nevertheless, there is little information about other tropical tree species with high forage production potential, such as Guazuma ulmifolia, which is broadly used in Southeast Mexico. In addition, little is known about the effect of season on forage quality of these species under a particular management regime. Therefore, the aim of this study was to evaluate the yield and forage quality of L. leucocephala and G. ulmifolia in the sub-humid tropics during the dry and rainy seasons

Contribution of intensive silvopastoral systems to animal performance and to adaptation and mitigation of climate change

According to FAO, world demand for animal products will double in the first half of this century as a result of increasing population and economic growth. During the same period, major changes are expected in world climate. Food security remains one of the highest priority issues in developing Latin American countries, a region where livestock production plays a fundamental role. Agricultural activities seriously threaten natural resources; therefore, it is necessary to ensure that livestock production contributes to satisfy the demand for animal products in a sustainable manner. Intensive silvopastoral systems (ISS) are becoming the technology of choice for Colombian and regional livestock sectors because it can help reduce the seasonality of plants and animal production, and therefore contribute to mitigate and adapt to the effects of climate change. We have recently gained knowledge on the nutritional and productive attributes of these systems. However, in recent years, the low carbon approach acquired importance in animal agriculture, which seeks to primarily promote the adoption of programs running parallel activities aimed at adapting to and mitigating climate change. This review outlines projections on the effects of climate change on the livestock industry, presents concepts on Greenhouse Gas flow and highlights evidence in support of the conclusion that ISS is an interesting option to allow the livestock sector in the region to adapt to climate change and to mitigate some of its effects. The adoption of ISS may help to remove up to 26.6 tons of CO2 eq/Ha/yr from the atmosphere

Greenhouse Gas Emissions and Crossbred Cow Milk Production in a Silvopastoral System in Tropical Mexico

In Mexico, pasture degradation is associated with extensive pastures; additionally, under these conditions, livestock activities contribute considerably to greenhouse gas (GHG) emissions. Among the options to improve grazing systems and reduce GHG emissions, silvopastoral systems (SPS) have been recommended. The objectives of this work were to quantify the N outflow in a soil–plant–animal interface, as well as the CH4 emissions and milk production in an SPS with woody legumes (Leucaena leucocephala) that is associated with stargrass (Cynodon nlemfuensis). This was then compared with stargrass in a monoculture system (MS) in the seasons (dry and rainy period) over a two-year period. Dung was collected from the animals of each of the grazing systems and applied fresh to the land plots. Fresh dung and urine were collected from the cows of each grazing system and were applied to the experimental plots. In addition, the soil CH4 and N2O contents were measured to quantify the emissions. Average milk yield by seasons was similar: MS (7.1 kg per animal unit (AU)/day−1) and SPS (6.31 kg per AU/day−1). Cows in the MS had a mean N intake of 171.9 g/UA day−1 without seasonal variation, while the SPS animals’ mean N intake was 215.7 g/UA day−1 for both seasons. For the urine applied to soil, the N2O outflow was higher in the MS (peak value = 1623.9 μg N-N2O m−2 h−1). The peak value for the SPS was 755.9 μg of N-N2O m−2 h−1. The N2O emissions were higher in the rainy season (which promotes denitrification). The values for the feces treatment were 0.05% (MS) and 0.01% (SPS). The urine treatment values were 0.52% (MS) and 0.17% (SPS). The emissions of CH4 showed that the feces of the SPS systems resulted in a higher accumulation of gas in the rainy season (29.8 g C ha−1), followed by the feces of the MS system in the dry season (26.0 g C ha−1). Legumes in the SPS helped to maintain milk production, and the N2O emissions were lower than those produced by the MS (where the pastures were fertilized with N)