Comparative evaluation of Tree Lucerne (Chamaecytisus palmensis) over conventional protein supplements in supporting growth of yearling Horro lambs

Getu Kitaw, Mesfin Dejene, Aemiro Kehaliw and Getnet Assefa*

Ethiopian Institute of Agricultural Research (EIAR), Holetta Research Center, P.O. Box 2003, Addis Ababa, Ethiopia
* Ethiopian Institute of Agricultural Research, P.O. Box 2003 Addis Ababa, Ethiopia
kitaw2006@yahoo.com

Abstract

A feeding trial was conducted for 90 days on yearling Horro lambs with a mean body weight of 18.5±0.05kg (mean ±SD) to investigate the effect of supplementation of conventional  oil seed cakes and  the comparative advantage they have over a fodder legume (Chamaecytisus palmensis) commonly known as Tagasaste supplementation. Six experimental sheep per treatment were arranged in completely randomized design to receive dietary treatments formulated to the nearest iso-nitrogenous and iso-caloric in order to achieve a daily growth rate of 100g. In addition to being fed to an ad libitum natural pasture hay the sheep were supplemented with a concentrate mix composed of 180g noug seed (Guizotia abyssinica) cake + 180g wheat bran (NC), 180g linseed cake + 180g wheat bran (LC), 160g cotton seed cake + 200g wheat bran (CS), 250g Tagasaste leaf on dry matter bases + 150g wheat bran (TL) while the control group (CTL)  was allowed to graze 8 hours a day according to the farmer's practice with out supplementation.

Supplementation with cotton seed meal followed by linseed cake has substantially improved feed dry matter and nutrient intake (P<0.05), and significantly (P<0.05) promoted daily body weight gain and feed conversion efficiencies. For almost all measured parameters in general no appreciable differences (P>0.05)  in terms of sheep performance were observed among experimental sheep receiving  noug cake meal and Tagasaste forage leaf signifying the need to capture the opportunity to replace conventional and  most widely used purchased protein supplement with cost effective on-farm grown multi-purpose forage legume under Ethiopian condition . Even though, part of the work related to the carcass quality deserves special attention in the up-coming future research work the data set from the current study favors the use of the protein supplements in the order of CS, LC, TL, NC, respectively. 

Keywords: Forage legumes, iso-caloric, iso-nitrogenous, natural pasture hay, nutrient intake, oil seed cakes, tagasaste, wheat bran

Introduction

There are about 25.02 million heads of sheep (CSA 2009) in the country, playing an important role in the livelihood of resource poor farmers. This number would seem to be doubling in the near feature because sheep have higher survival rates and can restore stocks very rapidly under drought conditions compared to cattle. Moreover, prolific nature and higher incidence of multiple births in these animals would enable us to have higher annual off take than we used to have from cattle. In fact in some areas of the country, small ruminants have been described as the “village bank”. It has to be noted that this is beyond the cash value of the animal. Small ruminants represent only 7% of the average total capital invested in livestock in mixed crop livestock production system; but they account on average for 40% of the cash income and 19% of the total value of subsistence food derived from all livestock production (Adane and Girma 2008). According to same authors sheep and goat contribute to a quarter of the domestic meat consumption; about of half of the domestic wool requirement; 40% of fresh skin and 92% of the value of semi-processed skin and hide export trade. There is also a growing export market for sheep and goat meat in the Middle East Gulf States and African countries. The export to mutton and lamb by the year 2003 approached to generally a figure above 1500 metric tones (FAO 2004). The current annual off take rates of sheep and goats is, however, only 33% and 35% respectively. The average carcass weight of Ethiopian sheep and goat is only 10kg, which is the second lowest in sub-Saharan Africa.   

Although many factors constrained sheep production and reproduction in the country feed shortage both in terms of quantity and quality constituted the lion's share. In economic terms, feed cost accounts for about 70% of the cost of livestock production under Ethiopian condition. The feasibility of livestock enterprise is, therefore, a function of the type of feed and feeding system. Sheep and goat production in Ethiopia suffers from feed shortages at all levels with an estimated 40% deficit in the national feed balance. This is aggravated by seasonal availability of forage and crop residues; an increasing demand for crop production and recurrent droughts particularly in the low lands. Poor nutrition results in low rates of production, often defined by growth rates and reproduction. From the feed resource base it can be understood above all that most basal feeds for sheep and goat suffer from low crude protein (CP) contents. This suggests the need for additional protein supplementation for efficient utilizations of the basal feed resources and subsequent betterment of sheep production in the country. The objective of the current study was to find out the effects of locally produced oil seed cake supplementation on the performance of local yearling lambs and evaluate their comparative advantage over a forage legume supplementation. 

Materials and Methods

Study site 

The feeding trial was conducted at Holetta Research Center (HRC) located at some 30km West of Addis Ababa along the main road to Ambo. It is situated at 93^o N latitude and 38^o 30’ E longitude at an altitude of 2400m.a.s.l. Metrological data indicates that the center receives an annual rain fall of 1000 mm with the minimum and maximum temperature of 6^oC and 22^oC, respectively.  

Animal and feeding management 

A total of 32 ram lambs were purchased from West Shewa, Ethiopia at local markets around Bako area where the local breed "Horro sheep" predominantly exits. The sheep were then transported back to HRC where they were housed in individual pens. Among these 30 lambs were selected, drenched against internal and external parasites to be used as experimental animals while the remaining 2 ram lambs were used as replacement stock. The experimental lambs were systematically grouped in to five treatments (6 lambs per treatment) with similar initial live weight (mean 18.45±0.05) and randomly assigned to one of the four dietary treatments formulated to the nearest iso-nitrogenous and iso-caloric according to Kearl (1982). The treatments were:

• Natural pasture hay ad libitum + 180gm noug seed cake + 180gm wheat bran (NC)
• Natural pasture hay ad libitum + 180gm Linseed cake + 180gm wheat bran (LC)
• Natural pasture hay ad libitum + 160gm cotton seed cake + 200gm wheat bran (CS)
• Natural pasture hay ad libitum + 250gm fresh Tagasaste leaf and edible branches + 150gm wheat bran (TL)
• Grazing alone for 8 hours/day (CTL)

Native grass hay and the natural pasture composition consisting mainly of Andropogon, Pennisetum and clover species. The trial was conducted for 100 days out of which the first 10 days were allocated for adaptation to the experimental diets while the remaining 90 days were used for actual data collections. During the experimental period ram lambs were fed natural pasture hay collected from the station as basal feed at the rate of 20% refusal of the previous day offer to ensure ad libitum feeding. Similarly, the animals were watered twice a day with out any restrictions. Daily allowance of the supplements that consists of the different oil seed cakes and fresh leaves from a forage tree shrub Tagasaste (Chamaecytisus palmenesis) which were calculated on dry matter basis were offered together with wheat bran in two equal portions during the morning (8:00am) and around the dusk (5:00pm). The amount of feed offer and refusal was recorded every day with feed intake being adjusted according to fortnightly live weight changes. Degradability characteristics of the different protein sources were carried out using three different fistulated 50% (Boran X Friesian) steers that received a maintenance diet (ad libitum natural pasture hay + 2kg concentrate mix per day). Duplicate samples of each feed type grounded to pass through a 2mm sieve size were incubated in each animal for 6, 12, 24, 48, 72 and 96 hours. The bags containing the residues were hand washed dried in an oven for 72 hours at 65^oC to calculate dry matter and nutrient disappearance from the bag up on incubation. Linear models of Ørskov and McDonald (1979) was used to calculate the different degradability constants. Feed samples from the feeding trial were used for laboratory analysis of DM, total ash and CP (AOAC 1990); NDF, ADF and permanganate lignin (Van Soest and Robertson 1991); and in-vitro organic matter digestibility (DOMD) (Tilley and Terry 1963). The data set from animal feed and nutrient intake, Daily weight gains and feed conversion efficiency were subjected to statistical software (SAS 2002) using a model for completely randomized design (CRD).

Results and Discussion

Availability of experimental feed supplements 

Agro-industrial byproducts are the byproducts of the primary processing of crops, including bran and related byproducts of flour mills, oil seed cakes from small and large scale oil processing plants, brewery byproducts and byproducts of the sugar factory such as molasses. They make up part of concentrate ration in the country. However, the supply of these byproducts is unpredictable and their use is limited to urban and pre-urban livestock producers. Varela-Alvarez (2006) compiled the designated capacity and actual annual production capacity of 9 state-owned and 181 private flour mills found in different parts of the country. Accordingly, the total annual production of wheat bran was estimated to be 269,238 tons of which 14% and 86% were produced by the state owned and private flour mills, respectively. The actual production performance of flour mills lies around 20-50% of their capacities due to shortage and high price of wheat among other factors. On the other hand, oil seed cakes are the residues or cakes that are produced as byproducts during extraction of oil from oilseeds. Under Ethiopian condition these includes: Noug cake, Cottonseed cake, ground nut cake, Linseed cake, Sesame cake, Sunflower cake and others. All oil processing plants, except Addis-Modjo oil factory, use the expeller (mechanical) methods of extraction. Adugna (2009) estimated the country’s total annual production of the different oil seed cakes to approach 102,225 metric tones. Noug seed cake with 39,348 metric tones stands in the first place while linseed cake and cotton seed cake are placed on the second and third place with total annual production rate of 921,889 and 20,017 metric tones, respectively. From these figures it is possible to judge that Ethiopia is producing a broad range of potential livestock feed supplements that could supply both the macro and micro nutrients. Thus, there is a need for adoption of the use of balanced "best cost" rations for more efficient and effective utilization of the available feed resources to attain the desired level of productivity.  According to Adugna (2009) most of the oil mills are operating at less than 50% of their capacity due to various problems. Some of the constraints faced by oil processing plants include:

• Inadequate supply of raw materials (oilseeds) because of competition from other uses such as export and direct use of the seeds locally
• High price of oilseeds exacerbated by increased export of oilseeds
• Availability of cheaper imported oil in the market

Hence, locally grown fodder trees like Tree Lucerne have a potential to replace the conventional protein sources which are becoming expensive and unavailable for small holder farmers (Mesfin et al 2011).

Photo 1. Tree Lucerne ((Chamaecytisus palmensis).	Photo 2. Natural grazing pasture.

Nylon bag degradability characteristics of experimental feed supplements

Nylon bag CP degradability characteristics for the different protein supplements are shown in Table 2. The rapidly soluble fraction "a" (t=0 hour) was highest for Tagasaste leaf followed by noug seed cake. Cotton seed cake coming immediately after linseed cake was the lowest in the series. A reversed trend has been found to be true for slowly but potentially degradable fraction "b" with considerably lower fraction being recorded for Tagasaste leaf (514g/kg DM). Part of the CP that effectively degraded at a digesta passage rate of 3% per hour was observed to be higher for noug cake (612g/kg CP) with Tagasaste leaf, Linseed and Cotton seed cake holding the 2^nd, 3^rd and 4^th place in the series, respectively. In general CP from noug cake and Tagasaste were degraded at rate faster than (0.05 and 0.07) the remaining protein supplements. The higher rate constant "c" and effectively degradable fractions "ED" recorded for noug cake and Tagasaste leaf (Table 2 and Figure 1) is a clear indication of the fact that these protein supplements are very good sources of fermentable nitrogen while still with their lower values cotton and linseed cakes can be used as sources of escape nitrogen which we can see later on in tables 3 and 4 how this has affected the level of sheep performance in the current trial. The most important thing we can perhaps notice from this nylon bag trial is that Tagasaste which can adapt and is found widely distributed in the highlands of Ethiopia was observed to be almost similar in all degradability parameters with popularly used but costly noug cake. This could even have further implication in that Tagasaste may be used as cost effective protein supplement in the diet of ruminant animals.

The higher "c" value for noug cake and Tagasaste might have increased the total "ED" for CP. Degradability constants from the current study lie within the range  reported earlier for most oil seed cakes and tree shrubs by Seyoum (1995). However, lack of standard procedure for washing loss coupled with the difference in the method of oil seed extraction slightly contributed to the marked differences in the rapidly soluble fraction among the oil seed cakes. The mean “c" value except for noug cake was higher for Tagasaste as compared to the oil seed cakes and lies wiin the range 0.027-0.053 that reported by Getnet (2007) for Tagasaste leaf harvested under different stage of growth and also coincides to values reported earlier by Mupangwa (2000) for tropical herbaceous legumes. The "a" fraction of 196g/kg CP is again with in the range of 214 to 496g N/kg DM reported by Mgheni et al (1993) for tropical herbaceous legumes. The “PD” value for CP of Tagasaste (710g/kg CP) was slightly above the range of 269-550g/kg CP reported by Mgheni et al (1993) for Desmodium intortum and D. uncinatum owning to the difference in the species and harvesting stage.  This shows that Tagasaste is a suitable protein supplement to low quality roughages. Figure 1 illustrates the slower rate at which cotton and linseed cakes have disappeared further implying the potential of these feed supplements to be used as escape nitrogen sources. However, this fact should not be confused with the nitrogen disappearance curve displayed by Tagasaste in the same figure as this is not translated to a significantly modest level of daily growth comparable to that recorded for the two feed supplements. The reason could be attributed to the effects of condensed tannins and soluble phenolics contained in Tagasaste that imposed limitations on the utilization of the CP. The negative effect of high levels of tannins on feed protein digestibility is well documented even under Ethiopian condition (Asfaw et al 2007; Getnet 2007).

Figure 1. Effect of incubation hours on nylon bag CP disappearance of supplemental diets

Feed dry matter intake  

Natural pasture hay and total dry matter intake differed with type of protein supplement (Table 3). Lambs supplemented with cotton and linseed cake had superior daily total dry matter intake over those supplemented with noug seed cake and Tagasaste forage legume.

Supplementation with cotton seed cake improved basal feed and total dry matter intake (TDMI) by 37.7 and 19.9% over Tagasaste and 31.5 and 19.6% over noug seed cake respectively. Expressed as percent body weight the quantity of total dry matter consumed was 3.1, 3.3, 3.2 and 3.0 for lambs on NC, LC, CS and TL, respectively. This is in consistent with a similar report by Solomon et al (2006) who reported the TDMI as percent body weight of local Menz sheep with in the range of 3.2 to 3.4. The TDMI as percent body weight from the present trial is also with in the range of recommendation (2-6%) by ARC (1980). On the other hand, the total supplemental feed supplements constitute 47.9, 40.6, 38.5 and 53.4% of the total daily dry matter intake while the share of protein supplements (oil seed cake) as percent total daily intake was less than 30% except for Tagasaste leaf which constituted 33% owning to its high substitution effect. This was in line with the contention that bypass protein sources should be given in amount not to exceed 30% of the total diet DM to prevent depression in the total DM intake of the poor quality basal roughage feed. The increase in the basal feed or total feed intake with cotton and linseed cake agree with the finding of Bonsi et al (1996) who observed in Menz sheep that finely ground cotton seed meal provide animals with by pass protein resulting in increased total feed intake. The same improvement in terms of daily grass hay (1147 vs. 1274) and total dry matter intake over the control group was reported by Yilala (1990). Improved intake after supplementation with cotton and linseed cake from the present trial clearly suggests the importance of availability of source of nitrogen for effective utilization of the basal diet which is again in agreement with previous reports that dietary CP levels and quality of protein in the feed supplement influence DM intake in sheep positively (Badamana and Sutton 1992). Even though noug seed cake and Tagasaste leaf supplementation were found to be inferior in terms of feed intake against their counter part feed supplements the major finding as far as wide scale on-farm application of these feed supplements concerned is the lack of significant difference (P>0.05) for both basal and total daily feed intake between noug cake and Tagasaste forage leaf. Noug is the most abundant and widely used oil seed cake in the country despite it’s on- farm use is somehow constrained by its cost which can easily be off-set by replacing with a relatively cheaply grown forage protein source. Previous results by Leng and Preston (1983) and Lemma (1993) also confirmed higher basal and total feed intake with forage legume than noug based concentrate mixes. On the contrary, while Gebregziabher et al (2003) found low Rhodes grass hay intake (10 to 115g/d) for Sesbania sesban supplemented Horro sheep at the rate of 1.6 kg/d , Umunna et al (1995) and Getnet  (2007) with Tagasaste leaf reported very exaggerated basal feed intake that is almost twice compared with that seen in the current trial. As opposed to the present study lower intakes were definitely related to substitution effects while larger intake were possibly linked to the difference in the breed used in each case, age of the experimental sheep, stage at which the forage legume harvested (Polyphenolic effect) and the quality of basal feeds used.  

Crude protein and metabolisable energy intake  

The CP (g/d) and ME (MJ/d) intake of experimental sheep are indicated in Table 3. Mean daily CP and ME intakes were 107g 7.5 MJ, respectively. Sheep on cotton seed meal supplementation consumed more (P<0.05) CP and ME than those in the other protein meals. The CP intakes as percent TDM intakes were 14.1, 12.1, 12.3 and 13.4 for noug, linseed, cotton seed cake and Tagasaste supplemented group, respectively. Similarly, sheep supplemented with cotton seed cake comparably consumed the same amount of ME/d (P>0.05) with that of sheep supplemented linseed cake. However, intake was considerably higher (P<0.05) with an additional daily intake of 1.5 and 1.9 MJ over the noug seed cake and Tagasaste-supplemented groups, respectively. The average daily CP intake (129.11g/kg DM) of experimental sheep was comparable to the 124g CP/kg DM) recommended for a 20 kg growing lambs (ARC, 1980). Moreover, the daily CP intakes of sheep across all dietary treatments agree with the CP requirements recommended for a 20kg-growing sheep (Kearl 1982). More CP intake (P<0.05) by sheep in cotton seed cake supplemented group could be justified by the quality of nitrogen (see slower rate of degradation and lower ED values in Table 2 and Figure 1) and relatively higher CP content (Table 1) of the cake both of which have contributed to the correspondingly higher basal feed intake. In general, owing to the higher CP contents of the supplement diets all supplemented sheep obtained CP above that set for their daily allowance (72g/d) according to Kearl (1982). In the present study the total dry matter intake and ME intakes were positively favored the level of CP intake which indeed agree with previous reports by Solomon et al (2004) and Getnet (2007) that increased protein intakes improve total DM and ME intake. However, the daily average CP (107.2g) and ME intakes (7.5MJ) from the current trial was a little bit more than that reported by Getnet (2007) for Menz sheep (72.5 vs. 5.94) and Fantie and Solomon (2008) for a yearling Farta sheep (90.2 vs. 6.8) presumably because these local sheep breeds are small body sized with a relatively smaller feed intake compared to Horro breeds. The daily CP intake reported as percent total DM intake (8.3-11.2%) for Menz sheep by Solomon et al (2004) earlier was even smaller than the observed CP intake from the present trial that ranges between 12.1-14.1% for same reason given above. On the other hand, sheep on cotton seed (1.35MJ/d) and linseed meal (0.85MJ/d) remained on positive energy balance while those on noug seed cake and Tagasaste suffered from negative energy balance of 0.15MJ/d and 0.55MJ/d, respectively. The over all mean daily ME intake per gram growth in the current study (0.08MJ/d) was almost more than double than the 0.035MJ/d of ME requirement needed to support a gram growth according to ARC (1980). However, because the sheep were brought from their normal hot-humid environment and exposed to cool environment in the middle of Ethiopian winter, the cost of maintenance was so much higher that mean daily gain was not as formerly anticipated according to Kearl (1982). Supplementation with Tagasaste resulted to a marked improvement in CP and ME intakes comparable to the noug cake supplemented group. This concurs with the finding of Getnet (2007) that supplementation of Menz sheep with Tagasaste significantly (P<0.01) improved daily CP intakes (72.5 vs. 70.2) over the noug based concentrate mix while the variation in terms of daily ME intake in the same experiment remained to be same (5.94 vs. 5.74). The importance of Tagasaste to replace the most abundantly used but still costly protein supplement dictates that there should always a need to survey such forage as they could represent cost effective supplements for ruminants that subsist on poor quality pasture and/or crop residues. 

Live weight change 

Cotton seed cake supplemented group had noticeably higher growth rates and final live weight  followed by linseed cake as compared to the control group (Table 4).  Sheep on cotton seed meal gained 17.4, 43.7, 34.8 and 42.0 g extra growth per day than that recorded for sheep on linseed cake, noug cake, Tagasaste forage leaf supplementation and the control group  respectively. Similarly the amount of feed consumed per gram daily growth was smaller for sheep supplemented with cotton seed cake followed by linseed cake, Tagasaste and noug seed cake, respectively.

The sheep across all dietary treatments were fed the different protein supplements at iso-nitrogenous and iso-caloric base with an expected daily growth rate of 100g according to Kearl (1982). Even though the daily CP and ME requirements for a 20 kg growing sheep (72g Vs 7.07MJ) were closely met for all experimental sheep it was only those sheep supplemented with cotton and linseed cake that produced higher growth rates than 100g per day. However, the most interesting finding of this study was the existence of huge potential to finish and attain local yearling sheep at an export market weight of 25-30kg. All treatment diets positively promoted daily live weight gain which indicates the higher nutritional values of these supplements to local lambs fed on poor quality basal feed resources. In general, the average daily growth rates 93.4g in the present study can fairly be compared with earlier results reported for yearling Horro lambs supplemented with noug seed cake based concentrate mixes and/or forage legume hays (Lemma 1993; Melese et al 2002; Temesgen et al 2007). The tendency of higher daily live weight gain and change in the final live weight for lambs on cotton and linseed cake supplemented group was a reflection of higher CP and ME intakes above their maintenance and better feed conversion all of which can be positively correlated to DMI and live weight gain in many other studies (Fantie and Solomon 2008; Getnet 2007). Owen and Zinn (1988) on the other hand after reviewing a large set of data concluded that added dietary protein resulted in increased rate of weight gain in over 85% of the feeding trials.

Conclusions

• Supplementation of local sheep breeds with some of the most commonly available oil seed cakes and forage legume "Tagasaste" to the basal grass hay based die improved feed intake, growth rates and feed conversion.

• The supplements considered in this study could be recommended in the order of: cotton seed cake > linseed cake > noug seed cake = Tagasaste forage leaf.

References

Adane Hirpa and Girma Abebe 2008.  Economic Significance of Sheep and Goats. Sheep and Goat Production Hand Book For Ethiopia. 

Adugna Tolera 2009 Livestock feed supply situation in Ethiopia. In: Commercialization of Livestock Agriculture in Ethiopia (Taddelle Dessie, ed.). 16th annual conference of the Ethiopian Society of Animal Production (ESAP) held in October 8-10, 2008. Addis Ababa, Ethiopia. 

AOAC 1990 Official Methods of Analysis, 15th (ed). Assoaciation of Analytical Chemists, Inc, Arlington, Virginia, USA. 

ARC 1980 The Nutrient Requirement of Ruminant Livestock. Agricultural Research council  

Asfaw Yimegnuhal, McCrabb Graemep and Amere Feleke 2007 Effect of Acacia angustissima on feed intake, feed digestibility, nitrogen retention, animal performance and carcass quality of Arsi sheep. 14th annual conference of the Ethiopian Society of Animal Production (ESAP), held in September 5-7, 2006. Addis Ababa, Ethiopia.     

Badamana M S and Sutton J D 1992 Hay intake, milk production and rumen fermentation in British Saanen goat given concentrates varying widely in protein concentration. Anim. Prod., 54:395-403.   

Bonsi M L K, Tuah A K, Osuji P O, Nsahlai  I V and Umunna N N 1996 The effect of protein supplement source or supply pattern on the intake, digestibility, rumen kinetics, nitrogen utilization and growth of Ethiopian Menz sheep fed Tef straw. Anim. feed Sci. and Technol., 64:11-25. 

CSA (Central Statistics Agency) 2009 Agricultural Sample Survey. Report on livestock and Livestock characteristics. Addis Ababa, Ethiopia. 

FAO (Food and Agricultural Organization) 2004 FAO production year book, http://faostat.fao.org 

Fantie Bishaw and Solomon Melaku 2008 Effect of supplementation of Farta sheep fed hay with sole or mixture of noug seed meal and wheat bran on feed intake, digestibility and body weight change. Trop. Anim. Health and Prod. 40:597-606. 

Gebregziabher Gebreyohannes, Driba Geleti, Lemma Gizachew, Yohannes Gojam and Gemeda Duguma 2003 Effect of noug cake and Sesbania sesban supplementation on the growth performance and carcass characteristics of Horro rams. ESAP (Ethiopian Society of Animal Production). 10^th proceedings, 22-23 August, 2003. Addis Ababa, Ethiopia. 

Getnet Assefa 2007 Evaluation of Tagasaste (Chamaecytsis palmensis) as forage for ruminants. PhD Dissertation. Humbold University, Berlin, Germany.  

Kearl L C 1982 Nutrient requirements of ruminants in developing countries. International  Feed Staffs Institute, UTAH State University, Logan, 381pp.  

Lemma Gizachew 1993 Comparison of legume hay, urea and noug cake as protein supplements to Horro sheep fed on Tef straw. 4^th NLIC (National Livestock Improvement Conference), 13-15 November, 1991. Addis Ababa, Ethiopia.  

Leng R A and Preston T R 1983 Nutritional strategies for the utilization of agro-industrial byproducts by ruminants and extension of the principles and technologies to the small-scale farmers in Asia. Proceedings of the 5th World conference on Animal production, 1:310-318. 

McDonald P, Edwards R A, Greenhalgh J F D, Morgan, C A 2002 Animal Nutrition (6^th Edition). Pearson Educational Ltd. Edinburgh, Great Britain. 544pp.  

Melese Abdisa, Driba Geleti, Lema Gizachew, Temesgen Driba and Adane Hirpa 2002 The effect of improved forages and/or concentrate supplementation on live weight of Horro lambs and growing bulls. ESAP (Ethiopian Society of Animal Production). 9^th proceeding, 30-31 August 2001. Addis Ababa, Ethiopia. 

Mesfin Dejene, Seyoum Bediye, Dawit Alemu, Getu Kitaw, Aemiro Kehaliw, Getnet Assefa and Getaw Tadesse 2011 Livestock Feed Marketing in Ethiopia: Challenges and Opportunities. Commercialization of Livestock Agriculture in Africa: Challenges and Opportunities. In: Proceedings of 5^th All Africa Conference on Animal Agriculture and 18^th annual conference of the Ethiopian Society of Animal Production (ESAP) held in Addis Ababa, Ethiopia, October 25-28, 2010 (In press). 

Mgheni D M, Hvelpluned T, and Weisbjerg M R 1993 Rumen degradability of dry matter  and protein in tropical grass and legume forages and their protein values expressed in the AAT-PBV protein evaluation system. Proceedings of the 2^nd biennial conference of AFRNET held in Harare, Zimbabwe, 6-10 Dec. 1993. 

Mupangwa J F 2000 Nutritive value, intake and utilization of forage legumes in ruminants. D Phil Thesis. University of Zimbabwe, Harare, Zimbabwe. 

Ørskov E R and McDonald I 1979 The estimation of protein degradability in the rumen  from incubation measurements weighed according to the rate of passage. J. Agric. Sci. Cambridge. 92:499-503.  

Owen F N and Zinn R 1988 Protein metabolism of ruminant animals. In: D.C. Church (ed.) The Ruminant Animals Digestive Physiology and Nutrition. Waveland press Inc; prospect Hights, Illinios, USA. Pp 227-249.  

SAS Statistical Software 2002 Version 9.0, 2002.

Seyoum Bediye 1995 Evaluation of nutritive value of herbaceous legumes, browse species and oil seed cakes using chemical analysis, In vitro digestibility and nylon bag techniques. MSc. Thesis, Alemaya University of Agriculture, Ethiopia. 209p.                                                                      

Solomon Melaku, Peters K J, Azage Tegegne 2004 Effect of supplementation with L.  purpureus, L. pallida and S. sesban on feed intake and live weight gain of Menze sheep . 10^th annual conference of the Ethiopian Society of Animal Production held in August 21-23, 2003. Addis Ababa, Ethiopia.  

Solomon Melaku, Peters K J and Azage Tegegne 2006 Intake, digestibility and passage rate in Menz sheep fed tef straw supplemented with dried leaves of selected multi-purpose trees, their mixture or wheat bran. Small Ruminant Research, 56:139-149. 

Temesgen Jembere, Gemeda Duguma, Ketema Demissie and Driba Geleti 2007 Evaluation of cow pea hay (V. unguaculata) Vs noug cake supplementation of Cynodon dectylon on growth performance and carcass characteristics of Horro rams at Bako. ESAP (Ethiopian Society of Animal Production). 15^th proceeding, 4-6 October, 2007. Addis Ababa, Ethiopia.  

Tilley J M A and Terry R A 1963 A two-stage technique for in Vitro digestion of forage  crops. Journal of the British Grassland Society 18:104. 

Umunna N N, Nsahlai I V and Osuji P O 1995 Degradability of forage protein supplements and their effect on the kinetics of digestion and passage. Small Ruminant Research, 17:145-152. 

Van Soest P J, Robertson J B and Lewis B A 1991 Methods for dietary neutral detergent fibre and non-starch poly-saccarides in relation to animal nutrition. Journal of dairy science, 74:3583-3597. 

Varela-Alvarez H 2006 Availability and utilization of   alternative feeds. Report prepared for ACDI/VOCA., Addis Ababa, Ethiopia. 

Yilala K 1990 The effect of supplements of oil-seed byproducts on the utilization of low nitrogen fibrous diets by sheep. Proceeding of the 1^st joint workshop held in Lilongwe, Malawi, 5-9 Dec., 1988. Addis Ababa, Ethiopia.

Received 22 June 2011; Accepted 5 November 2011; Published 4 January 2012

Go to top