IAD 202. Livestock Production & Development Wolfgang Pittroff & Girma Getachew Lecture 5

Transcription

1 IAD 202 Livestock Production & Development Wolfgang Pittroff & Girma Getachew Lecture 5

2 Introduction into Tropical Pastures and Browse Resources Tropical grasses, tropical legumes, mixed systems, stability of sown pastures, integrating browse, secondary compounds and their effects on forage quality

3 Forage Tree Resources Great interest: soil improvement, erosion protection, replacement of native trees, reduction of destructive firewood collection, human food, animal feeds, pharmaceutical compounds, living fences, habitat for wildlife, reserve forages

4 Forage Tree Resources - Examples Leucaena (Leucaena leucocephala) Mulberry (Morus spp.) Moringa (Moringa oleifera) Mimosa (Albizia julibrissin)

5 Leucaena (L. leucocephala)

6 Leucaena Origin: tropical Latin-America (Mexico) Used primarily as animal feed, also shade tree Contains an amino acid (mimosine) whose metabolite is toxic. Does not tolerate frost (problem tropical highlands); Does not tolerate well acidic soils (problem tropics)

7 Leucaena Mimosine makes up about 2-5% of leaf dry matter, and up to 9% of the weight of seeds Goitrogenic Ruminants can develop resistance by acquiring rumen microbes that detoxify Feed quality very good, readily eaten, aggressive growth where compatible, repeated defoliation unproblematic

8 Mulberry (Morus alba, M. nigra)

9 Mulberry Origin: China Has been selected for centuries as nutrition for the silkworm (Bombyx mori) Widely distributed, lately increased interest as a forage tree High nutrient requirements, acceptable drought tolerance No negative secondary compounds, excellent forage quality; good reserve forage

10 Moringa (M. oleifera) Origin: mainly E. Africa and W. Asia True multi-purpose plant: human food, oil, water purifier, soap, fire wood, animal feeds Recently strong interest, broad evaluation of genetic resources Used widely in India, Africa, Central America

11 Moringa (M. oleifera)

12 Moringa in silvopastoral system, Nicarargua

13 Mimosa (Albizia julibrissin) Recently discovered forage tree Origin: northern Iran, Turkmenistan towards western China Frost resistant, deeply rooted, tolerates higher levels of soil acidity and salinity than mulberry High value of the wood (hard wood, paper) Rapid growth rates, very high biomass production Excellent forage values

14 Mimosa (Albizia julibrissin) Forage yield up to ~ 10 tons/ha (similar to alfalfa) Very little input required With some coppicing, animals can selffeed Excellent in associations with grasses

15 Mimosa (Albizia julibrissin)

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17 Forage Quality Forage CP CF EE NFE Leucaen a Mora Moringa Albizia 22 NDF: 34.2 ADF: 23.6 DIG: > 70%

18 Tree Forages Species specific disadvantages: Moringa, Mulberry: not legumes, not suited for all soils; Leucaena: not frost resistant, toxin Albizia: largely unknown agronomic properties; reports on toxicity of seeds; unknown pests All: browse may require more labor than other forages resources

19 Tree Forages Recommendations must be site-specific Nutrient requirements and constraints must be known Does the use of tree forages increase labor requirements? Is there education for forage budgeting to go along with the introduction of new species?

20 Harvesting Systems Tree forage can be harvested many different ways: Lopping and feeding of branches Lopping and conservation Browsing alone or in associations Cut and carry systems Collection of seeds Direct grazing of fallen leaves

21 Cut and carry system hair she (Pelibuey) in Mexico

22 Cut and Carry System in Morocco

23 Goat on self-feeding program in Indian railway station

24 Tethered female buffalo (India)

25 Local sheep in Mexico peri-urban system note Pelibuey

26 Secondary Compounds Substances produced by plants that may deter herbivory Hypothesized to be produced for that purpose but no definitive conclusions May be metabolic trashcan, free radical buffer, or serve to reduce damage such as radiation

27 Secondary Compounds Best known group: tannins Hydrolyzable tannins (e.g. gallic acid, ellagic acid); soluble, degradable by rumen microbes, toxic because metabolites (phenol rings) can overwhelm or damage e.g. liver detoxification Catechin tannins Condensed tannins (proanthrocyanidins)

28 Tannins Condensed tannins complex protein CT-P complexes may become unsoluble, or dissociate in the abomasum Level of CT in plant material determines type of effect: < 4% effects mostly beneficial CT s affect protein availability and digestibility May reduce methane output May increase (at lower levels) microbial protein production efficiency (likely a defaunation effect)

29 Tannins Negative effects of tannins can be reduced by supplementation with polymers with a higher affinity for tannins than proteins (PEG, e.g.) Supplementation that combines nutrients with polymers most effective Some herbivore species (not domestic ruminants) developed saliva components that precipitate tannins before they can bind to feed proteins increases amount of essential amino acids available to the animal

30 Tannins The presence of high levels of tannins renders conventional fiber analysis methods useless an important factor in the assessment of nutritional quality of tropical forages that is mostly overlooked

31 Tropical Forage Evaluation Girma Getachew, PhD, PAS

32 Forage Evaluation hagronomic hnutritional h Laboratory h Animal

33 Forages : Edible parts of plants, other than separated grain, that can provide feed for grazing animals or that can be harvested for feeding.

34 Forage and pasture Crops: Generally used 1. As animal feed 2. Soil fertility improvement (N 2 fixation, green manure) 3. Land reclamation (control of wind and water erosion) 4. Stabilizing eco-system

35 Forage based resources include Pasturelands Rangelands Forest range Cultivated forage crops

36 Types of Forage Crops (Taxonomically) 1. Legumes Browse (multipurpose trees MPTs) Herbaceous legumes 2. Grasses Growth habit 1. Annuals 2. Perennials

37 Method of utilization h Cut and carry h Grazing

38 Improving forage production from pasture land Over sowing higher yielding and nutritious species Cultivating forage crops on arable land

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49 Multiple uses of browses h Feed for livestock (fodder banks) h Windbreaks h Fuel h Live fences h Soil fertility improvements h Land reclamation

50 Advantage of browses h Resistance to harsh environmental conditions h Heat h Drought h Salinity h Alkalinity h Grazing h Repeated cutting hhigher nutritional quality (higher CP low fiber) hremain green longer into the dry season

51 Choice of establishing forages species h Soil fertility and species adaptation h Economic benefits h Livestock production systems

52 Germplasm source h Collection Mission h Taxonomy h Accessions Passport h Characterization and Evaluation h Cooperators h Material exchange for research purposes

53 Forage Research Forage Evaluation h Agronomic evaluation h Nutritional evaluation Agronomic Evaluation Centers h Acquisition- Genetic Resource h Germplasm collection mission

54 Screening (Evaluation) 1 m x 1 m plots 5 m strip trials Parameters Survival/ persistence Insect /pest / disease Drought Yield- forage / seed

55 h Reseeding ability Yield trial for basic agronomic studies h Larger plots h Forage yield h Sowing rate & fertilizer application, water requirement etc. h Management (cutting frequencies) h Yield and nutritional quality (chemical and biological assays) Grazing trials h Resistance to grazing and trampling h Recovery after grazing

56 Final acceptability of a given variety Ease of establishment Yield and seasonal distribution of DM Forage quality Chemical composition (nutritional & anti-nutritional components) Intake Digestibility Animal response

57 Choice of species: Method of utilization of forages depends on production systems h Cut and carry- hay, silage h Grazing h Pure stand h Mixture with other forages h Mixture with food crops

58 Forage species adapted to tropical environments

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70 Natural Pasture Improvement: Deterioration of natural pastures ages h Decreasing productivity & nutritional quality as pasture h Deterioration of botanical composition h Decline in soil fertility h Overstocking - over utilization of nutritious plant species

71 Improving natural pastures Existing pastures h Removal of weeds & unwanted species (manual, burning, herbicide h Grazing management h Over sowing with improved varieties h Rotation grazing (stocking rate and carrying capacity of the pasture) With improved species h Without land clearing h With partial clearing h On a prepared seed bed h Establishment on fully cultivated seedbed on new land etc.)

72 Genetic material available for research purposes at ILRI (International Livestock Research Institute) 1. Grasses 59 genus 185 species 2, 191 accessions 2. Legumes 54 genus 321 species 4, 375 accessions 2. Browses 108 genus 287 species 1, 248 accessions , 814 accessions

73 Animal evaluation of forages: Intake- ways to measure Digestibility- ways to measure Animal response- ways to measure

74 Palatability- Intake- Digestibility- Nutrient contentlevel of What is forage quality?? will the animals eat it How much will they eat How much of the forage digested will the forage provide adequate nutrients Anti-quality factors- presence of compounds that either affect Animal Performance- feed quality or animal performance ultimate test of forage quality

75 How can we assess the quality of forages?? Chemical composition- Biological assay- Animal responseproduction the level of useful nutrient Enzymatic, rumen bacteria intake, meat and milk

76 Tropical Forages General Considerations When choosing a tropical forage resource, a set of decision variables apply All objectives must be known and carefully evaluated The target group for the improvement must be consulted, and their needs, constraints and goals must be clearly understood

77 Tropical Forages General Considerations Environmental considerations: Climate: Precipitation: amount Precipitation: distribution Incidence of frost Day length Soils: Acidity Mineral status (Al, P, K) Organic matter content Water holding capacity Soil depth

78 Tropical Forages General Considerations Environmental considerations: Versatility in adaptation vs. specific high performance: the highest yield varieties are often adapted only to a narrow range of environmental conditions high risk

79 Tropical Forages General Considerations Agronomic considerations: Where to be established? After land clearings: timing of clearing; resilience in competition with native species; resistance to fire; responsiveness to inputs and opportunities In integrated systems: As a pioneering crop: Improvement of soil organic matter; reduce competitiveness of natives in subsequent crops; use of legumes in preparation for grass forage grass crops (suppression of native

80 Tropical Forages General Considerations Agronomic considerations: Integrated Systems: In crop rotations: break weed-, pest-, or disease manifestations; improve soil fertility; reduce competition by weeds; improve water holding capacity;

81 Tropical Forages General Considerations Livestock production considerations: Forage quality Timing of availability (reserve forage, complementary forage, supplement forage for better utilization of crop residues and rank native pastures) Sward characteristics (many tropical forages produce swards that are not dense enough for maximum intake (remember properties of the grass-roughage eater feeding type)

82 Tropical Forages General Considerations Livestock production considerations: Production goals must be clear: target livestock (wool production vs. meat or milk; high stocking tolerance required; fencing possible or not (perennial cultivated pastures require fencing); integration with tree crops for either diversification (e.g., palm plantations) or better animal performance (forage trees)

83 Tropical Forages General Considerations Production System/socio-economic considerations: Constraints: is cut and carry possible (labor); can fences be built and maintained (if not, use annual crops); how expensive are seeds or vegetation propagation; how stable is the improved pasture (many perennial legumes are shorter lived than often assumed); is the yield compatible with the production system management (no shortages, no excesses); is there the potential to harm crops if rotations are planned;

84 Tropical Forages General Considerations Management considerations: Integration with weed control; grazing strategy: perennial pastures require careful balance of harvesting efficiency and root care (resilience requires well developed root system); if forage conservation is planned, are skills and available technology sufficient (many tropical grasses and legumes are difficult to hay or ensile)

85 Soil effects of improved pastures (tropical Australia) Soil Property Virgin Soil After 15 yr pasture (grass/legume ph 5.2 mixture) 5.0 Organic carbon (%) Nitrogen (%) Sulfur (ppm) Total Phosphorous (ppm) Total Potassium (ppm) Calcium (ppm) Bulk density Note: bulk density effects might as well be negative! Also, these pastures were grazed and fertilized results not applicable everywhere

86 Effects of use of legumes on forage consumption (sheep, Australia) Diet D. decumbens (only, at lib) D. decumbens (+ 100 g legume) D. decumbens (+ 100 g legume) D. decumbens (+ 400 g legume) Legume only, ad lib DM Intake (g/day, sheep) CP (%) D. M. sativa decumbens Note: observe the clearly synergistic effect in the third treatmen

87 General Conclusions Livestock production in tropical ecoregions is characterized by low productivity Pasture improvement and new crop-pasture integration concepts hold the key to long term sustainable improvement Local conditions are sufficiently diverse to require local experimentation Explicit formulation of goals and constraints is essential for success