Cross-amplification and characterization of polymorphic microsatellite markers from Acacia (Senegalia) mellifera and Acacia brevispica to Acacia senegal (L.) Willd.

Seven polymorphic microsatellite markers isolated from Acacia brevispica and Acacia mellifera were successfully cross-amplified in Acacia senegal. The loci were surveyed for polymorphism using 30 samples. Allelic diversity ranged from 4 (Ame02, Ab06 and Ab18) to 13 (Ab26) per locus. The expected heterozygosity (HE) ranged from 0.543 (Ame02) to 0.868 (Ab26) while observed heterozygosity (HO) ranged from 0.516 (Ame05) to 0.800 (Ame03). Cross amplification of these loci represents a potential source of co-dominant marker and will be useful in the study of genetic diversity, structure, gene flow and breeding systems of this important Acacia species

Evaluation of the Nutritional Composition of Selected Indigenous Fodder Trees and Shrubs in Daro Labu District, Eastern Ethiopia

Low availability of quality fodder particularly in the dry season is a major factor constraining livestock production in Ethiopia. Therefore, a study was conducted in Daro Labu District of West Hararghe Zone, Eastern Ethiopia to evaluate the nutritional composition of selected indigenous fodder trees and shrubs as a feed resources. Three Rural Kebeles (villages) were purposively selected in the highland, midland, and lowland in the district. Chemical analysis of leaves of selected fodder trees and shrub samples, namely, Acacia brevispica L., Combretum molle, Erythrina abyssinic (Lam), and Cordia africana (Lam) were analyzed for their chemical composition. The results of chemical analysis of feed samples of the selected fodder trees and shrubs revealed that the dry matter of Combretum molle was found to be significantly higher (P<0.01) than that of Accia brevispica. The ash content of the selected fodder trees and shrubs ranged 7.3-16.6%. The ash content of Cordia africana was significantly higher (P<0.01) than that of Combretum molle. The crude protein contents of Acacia brevispica L., Combretum molle, Erythrina abyssinic (Lam) and Cordia africana (Lam) were 17.51, 15.84, 14.04 and 8.89%, respectively. The neutral detergent fiber was greater (59.14%) in Cordia africana and lower (47.49%) in Acacia brevispica. The relative feed value of Acacia brevispica, Combretum molle, Erythrina abyssinica and Cordia africana were 136.3, 121.26, 112.9 and 74.8, respectively. The crude protein (CP) content and relative feeding value (RFV) of Acacia brevispica was significantly higher (P< 0.05) than the crude protein contents and relative feeding values of the other fodder tree/shrub species. This closely followed by the crude protein and feeding value of the leaves of Erythrina abyssinica. Generally, Acacia brevispica and Erythrina abyssinica had higher potential as animal feed in terms of crude protein contents and relative feeding value. In conclusion based on these results, Acacia brevispica and Erythrina abyssinica species could be recommended as potential animal feed resources in the study area. Keywords: Chemical analysis, feed resources, fodder trees and shrub

Nutritional and anti-nutritional quality of range vegetation in southern Ethiopia and supplementary values of selected browse leaves to goats

Livestock are reared in all agroecological zones of Ethiopia under various production systems. Goats, although found in all agroecological zones, are popular in the drier environments since they adapt well in harsh condition better than sheep and cattle. Natural vegetation comprised of both woody and herbaceous species provides the feed base year round in such environments. Due to seasonal variations, a marked fluctuation in feed resource exists in quantitative and qualitative terms. The herbaceous particularly the grasses, are faster in deteriorating while most of the woody (browse) species maintain greenness and are able to provide higher level of crude protein and minerals to animals. In areas where crops and livestock are integrated, crop residues provide substantial amount of feed to animals. However, cereal straws are inherently low in crude protein and high in fibre which results in low intake and digestibility. Thus such feeds cannot even meet maintenance requirement of animals and should be supplemented to enhance their nutritive value. Supplementation with browse foliage and fruits could be a viable alternative in smallholder livestock-crop mixed production systems. The study was comprised of four individual works. In experiment I, nutritional quality of some important browse and grass species collected from Borana rangeland during the hot dry and main rainy seasons were evaluated in terms of chemical composition, in vitro digestibility and in sacco degradability potentials. In experiment II, the effect of polyethylene glycol (PEG) on feed intake, digestibility, ammonia nitrogen concentration, nitrogen balance and body weight gain of Borana goats was evaluated. Goats were fed a basal diet of Rhodes grass (Chloris gayana) hay supplemented with either Acacia brevispica or Acacia seyal leaves with or without PEG addition. The concentrate replacement value of Balanites aegyptiaca leaves was evaluated in experiment III. The concentrate was replaced at 25, 50, 75 and 100 percent by Balanites aegyptiaca and feed intake, digestibility, nitrogen balance, excretion of purine derivatives and microbial nitrogen supply and average daily body weight gain were evaluated using Arsi-Bale goats fed barley straw as a basal diet. The fourth component of the study was a survey conducted in the southern rangelands to assess the perception of pastoralists towards dry season feed shortage and associated livestock poisoning in the rangeland. The browse foliage had higher crude protein content (>10%) during both seasons with higher values in the main rainy season (except for A. seyal). On the other hand, crude protein content of grass species was only slightly above the critical limit required to maintain proper functioning of rumen microbes. The fibre content was lower in the browses and higher in the grasses. The concentration of condensed tannins was variable among the browses ranging between negligible levels to over 30%. The in vitro and in sacco digestibility values were generally higher for browses, which shows their potential to be used as supplements to poor quality fibrous feeds. Experiment II showed that addition of PEG did not result in significant differences in feed intake, digestibility of dry matter, organic matter, and neutral detergent fibre as well as in nitrogen excretion and retention, and average daily weight gain. However, goats receiving PEG had higher crude protein digestibility, ammonia nitrogen concentration, and urinary nitrogen excretion. Goats without PEG addition had higher faecal nitrogen loss. When the type of Acacia was considered, A. seyal supplemented goats had higher feed intake while crude protein digestibility and ammonia nitrogen concentration were higher for A. brevispica supplemented goats. Higher average daily body gain was recorded for A. seyal supplemented goats. Experiment III showed that B. aegyptiaca had a potential to be used as supplement to cereal straw based diets. This was evident from the performance of the animals even when the concentrate was replaced completely by B. aegyptiaca. All animals had positive average daily body weight gain although it was lowest in animals supplemented with sole leaves of B. aegyptiaca. The survey revealed that the pastoralists in the southern rangelands are knowledgeable in allocation of resources, animal husbandry and ethnoveterinary practices. It also showed the concern of pastoralists about the changes in vegetation that favors woody and some unpalatable herbaceous species. Twenty two plants were identified by pastoralists as causes of livestock poisoning when ingested which usually occurs when animals are hungry and thirsty.Husdyrhald er vanleg under ulike produksjonssystem i alle agroøkologiske soner i Etiopia. Sjølv om geiter er finst over heile landet, er dei mest vanlege i tørre strok. Dei kan, betre enn sau og storfe, utnytta ein stor del av vegetasjonen, inkludert gras, urter og lauvfôr og har difor lettare for å livnæra seg gjennom heile året. Sesongvariasjonar med regn- og tørketid, gjer at det er stor variasjon i fôrtilgang og fôrkvalitet gjennom året. Normalt vil kvaliteten på fôr frå urter og spesielt gras avta mykje raskare enn for lauvfôr. I område med både åkerbruk og husdyrhald er halm og andre biprodukt ein viktig fôrressurs. Men halm er eit proteinfattig fôr med høgt trevleinnhald. Det har difor låg næringsverdi og opptaket er avgrensa. Dyra kan knapt dekka vedlikehaldsbehovet på ein slik rasjon. Tilskotsfôring med lauvverk og frukter frå tre og buskvegetasjon kan difor vera eit viktig tiltak for å auka produktiviteten i husdyrhaldet i små driftseiningar med åkerbruk. Dette arbeidet er samansett av fire artiklar. I forsøk I samla vi inn fôrprøvar i den varme tørketida og i hovedregntida frå viktige tre- og grasartar i beite i Borana-regionen i det sørlege Etiopia. Fôrverdien vart bestemt ved analysar for kjemisk innhald, in vitro fordøyingsgrad og in sacco nedbrytingsgrad. I forsøk II såg vi på verknaden av polyethylene glycol (PEG) på fropptak, fordøyingsgrad, konsentrasjon av ammonium-nitrogen, nitrogenbalanse og levandevektendring hos boranageiter. Geitene fekk høy laga av Rhodes-gras (Chloris gayana) med tilskot av enten Acacia brevispica eller Acacia seyal lauv med og utan tilskot av PEG. Fôrverdien til lauv frå Balanites aegyptiaca samanlikna med kraftfôr vart studert i forsøk III. Kraftfôret vart erstatta med lauv i forholdet 25, 50, 75 and 100% i ein fôrrasjon med bygghalm til Arsi-Bale geiter. Effekten av behandlinga vart studert med omsyn til fôropptak, fordøyingsgrad, nitrogenbalanse, ekskresjon av purin-derivat, tilgang på mikrobiell nitrogen og fôropptak. I del fire av dette arbeidet gjennomførte vi ei spørjeundersøking for å finna ut kva utfordringar pastoralistar i dei sørlege heieområda har med å skaffa fôr til buskapen i tørketida og om giftige planter er eit problem for husdyr. Proteininnhaldet i lauvfôr var høgt (>10%) både i tørke- og regntid. Med unntak av A. seyal, var innhaldet av protein høgast i hovedregntida. For grasartane derimot var proteininnhaldet lågt og berre tilstrekkeleg for å dekka vedlikehaldsbehovet til dyra. Fiberinnhaldet i lauv var også lågare enn for gras. Innhaldet av kondenserte tanniner varierte frå nesten ingenting til over 30%. Generelt var verdiane for fordøyingsgrad (in vitro og in sacco) høgre for lauv enn for gras. Lauvfôr har difor eit potensiale som tilskotsfôr i trevlerike fôrrasjonar. Tilskot av PEG i fôrrasjonen hadde ingen effekt på fôropptak, fordøyingsgrad av tørrstoff, organisk materiale, eller trevler (NDF), eller på nitrogenekskresjon og retensjon, eller middel dagleg tilvekst hos dyra (Forsøk II). Men geiter med PEG i fôrrasjonen hadde høgre fordøingsgrad med omsyn til råprotein, konsentrasjon av ammonium-nitrogen og utskiljing av nitrogen i urinen. Geiter utan PEG i rasjonen hadde høgare tap av nitrogen i møkka. Vi fann også skilnad i fôrverdi mellom ulike akasie-treslag. Geiter med tilskot av A. seyal i fôret hadde høgre fôropptak, medan fordøyingsgrad for råprotein og konsentrasjon av ammonium-nitrogen var høgast for geiter som fekk tilskot av A. brevispica. Tilveksten var også større for geiter som fekk A. seyal. Forsøk III syner at B. aegyptiaca har eit potensiale som tilskotsfôr til halmbaserte fôrrasjonar, til og med når alt kraftfôret i rasjonen vart erstatta med lauvfôr. Alle dyra hadde positiv middel dagleg tilvekst, men vektendringane var minst for geiter som berre fekk tilskot av lauv frå B. Aegyptiaca. Spørjeundersøkinga synte at pastoralistane Borana-regionen sit inne med stor kunnskap om resursallokering beitebruk og -planter, husdyrhald og sjukdomsbehandling basert på lokal kunnskap. Dei uttrykte uro over at vegetasjonen har endra seg, frå opnare beitemark til tettare buskvegetasjon med større innslag av beiteplanter som ikkje høver til fôr. Pastoralistane identifiserte 22 planteslag som kan vera giftige for husdyr dersom dei blir etne. Forgifting er vanlegast i periodar med fôrmangel og når dyra er tørste.NORA

The influence of polyphenolics on the nutritive value of browse: A summary of research conducted at ILCA

Summarises ILCA's findings over several years of research on the nutritive value of browse plants. Discusses nitrogen metabolism in ruminants and tannin chemistry. Examines the effect of browse on animals, i.e., feed intake, growth, digestion of fibre fractions and utilisation of nitrogen. Discusses factors affecting the use of browse. Presents data on the contents of soluble phenolics and insoluble proanthocyanidins, browse and roughage intakes and growth rate in sheep, digestibility of organic matter, neutral detergent fibre & acid-detergent lignin for sheep. Also examines digestibility of dry matter, rumen ammonia and plasma urea nitrogen concentrations and daily urinary nitrogen loss, and nitrogen digestibility and contents of soluble phenolics and insoluble proanthocyanidines

A thorny issue: Woody plant defence and growth in an East African savanna

Recent work suggests that savanna woody plant species utilise two different strategies based on their defences against herbivory; a low nutrient/high chemical defence strategy and a nutrition paired with mostly architectural defences strategy. The concept that chemical and structural defences can augment each other and do not necessarily trade-off has emanated from this work. In this study, we examine woody plant defence strategies, how these respond to herbivore removal and how they affect plant growth in an East African savanna. At three paired long-term exclosure sites with high browser and mixed-feeder densities at Mpala Ranch, Kenya, we investigated: (a) whether defences employed by the dominant fine- and broad-leaved woody savanna species form defence strategies and if these align with previously proposed strategies, (b) how nine key plant defence traits respond to herbivore removal and (c) how effective the different defence strategies are at protecting against intense herbivory (by measuring plant growth with and without herbivores present). We identified three defence strategies. We found a group (a) with high N, short spines and high N-free secondary metabolites, a group (b) with high N, long spines and low N-free secondary metabolites and a group (c) with moderate N, no spines and low N-free secondary metabolites (most likely defended by unmeasured chemical defences). Structural defences (spine length, branching) were generally found to be induced by herbivory, leaf available N increased or did not respond, and N-free secondary metabolites decreased or did not respond to herbivory. Species with long spines combined with increased “caginess” (dense canopy architecture arising from complex arrangement of numerous woody and spiny axis categories) of branches, maintained the highest growth under intense browsing, compared to species with short spines and high N-free secondary metabolites and species with no spines and low N-free secondary metabolites. Synthesis. At our study site, structural traits (i.e. spines, increased caginess) were the most inducible and effective defences against intense mammalian herbivory. We propose that high levels of variability in the way that nutrient and defence traits combine may contribute to the coexistence of closely related species comprising savanna woody communities

Rangeland dynamics in South Omo Zone of Southern Ethiopia: Assessment of rangeland condition in relation to altitude and Grazing types

A study was undertaken in Hamer and Benna-Tsemay districts of the Southern Ethiopia with the objective to determine the condition of the rangelands for grazing animals as influenced by altitude and grazing types. The rangelands in each of the study districts were stratified based on altitude and grazing types. In the study districts, a total of 32, 3, 2, 7 and 29 species of grasses, legumes, sedges, other herbaceous plants and woody species were identified, respectively. The common and/or dominant grass species in the enclosures was Cenchrus ciliaris while in the communal grazing areas they were Cynodon dactylon and Tetrapogon tennulis. In riverside grazing areas, the common and/or dominant grass species was Cynodon dactylon. The total grass biomass of communal, riverside and enclosure areas found in the different altitude categories of the study districts ranged from 398-503; 98-626, and 1,132 – 1,209 kg/ha, respectively. The common and/or dominant woody species in the communal grazing areas were highly palatable species of Acacia tortilis and Grewia bicolor and less palatable Solanum species. In riverside grazing areas, the common and/or dominant woody plants were species of Acacia tortilis, Grewia bicolor, and Solanum species while in the enclosures; Acacia brevispica and Acacia tortilis were found. The woody vegetation density per hectare of communal, riverside and enclosure areas in the different altitude categories of the study districts ranged from 2,501-3,021; 2251-3,021, and 201-700,wd/ha respectively which showed that the communal and riverside grazing areas were bush encroached. The range condition scores ranged from 17.87-20.38 (communal), 22-27 (riverside), 31.05-31.2 (enclosures) which were poor, fair and good condition classes, respectively. Similarly, with regard to the same variable the scored varied from 22-32.87, 19.73-31.43, 17.97-31.44 and 17.87-31.28% in altitudes >1550m, 1250-1550m, 900-1250m, and 550-900m, respectively. The result indicated the need for rangeland improvement measures in communal and riverside grazing areas, in order to attain sustainable livestock production from these areas. Establishment of community based enclosures was found to be one of the ways to improve the condition of the rangelands. The result indicated the need for rangeland improvement measures in communal and riverside grazing areas, in order to attain sustainable livestock production from these areas. Establishment of community based enclosures was found to be one of the ways to improve the condition of the rangeland

Some Makueni birds

Volume: XXII