Feeding Prosopis juliflora pod’s flour as a substitute for wheat bran on body weight and carcass parameters of Hararghe highland bulls

Yohannes Dagnew, Mengistu Urge¹ and Meseret Molla

Department of Animal Science, College of Veterinary Medicine and Animal Sciences, University of Gondar, P O B 196, Gondar, Ethiopia
yohanesdagnew@yahoo.com
¹ School of Animal and Range Sciences, Haramaya University, P O B 138, Dire Dawa, Ethiopia

Abstract

Replacing cereals and expensive and less available agro-industrial by products by unconventional source of raw materials, which are less exploited by man, is one of the solutions to reduce cost of production and contribute to increased supply of animal protein. Therefore, this study aimed to generate basic information on chemical composition and to evaluate the effect of replacing wheat bran by ground Prospis juliflora pod (GPJP) flour on body weight change and carcass characteristics. Bulls within the block were assigned randomly to one of the four dietary treatments, and within each treatment there were 6 animals. Grass hay was offered ad libitum to all animals, and a supplement of 3kg concentrate according to the established ratio between wheat bran (WB) and noug seed cake (NSC), i.e. 70:30, respectively were used as a supplement. The difference between the treatments is therefore, the amount of GPJP that substituted the wheat bran portion of the concentrate. Thus, treatment one (GPJP0) bulls received 3 kg of mixtures of WB and NSC. In treatments (GPJP15), three (GPJP30), and four (GPJP45), the WB portion of the concentrate mix were substituted by 15, 30, and 45% of GPJP. The result in the present experiment showed a positive effect of substituting of WB by GPJP up to 30% on average daily gain (ADG), final body weight and FCE. ADG was highest for bulls in GPJP30 (935.18±27.72 g), while differences were not observed between bulls in GPJP45 (766.6 ± 46.1g), GPJP15 (696.3±67.9g) and GPJP0 (683.3±50.20g). Feeding bulls with GPJP30 and GPJP45 diet improved empty body (P<0.01) and hot carcass weights (GPJP30= (185.7±4.23); GPJP45= (172.1±1.46); P<0.001, GPJP0) compared to GPJP15 (158 ± 5.52) and GPJP0 (157.3±4.95). Dressing percentage was higher (P<0.01) for bulls in GPJP30 (57.17±0.85) and GPJP45 (55.7±0.50%) compared to bulls in GPJP15 (52.13±1.46) and the control group (52.18±1.44%). Based on the results, it can be concluded that inclusion of GPJP up to 30% of the wheat bran in the concentrate mixture could be recommended as optimal level for better live weigh gain and carcass parameter in feeding of Hararghe highland bulls.

Keywords: body weight, bulls,carcass, Hararghe, prosopis, wheat bran

Introduction

Animal protein deficiency today is one of the worlds’ serious health problems, especially for children in developing counties, which is aggravated by rapid increasing population growth. Most of the population depends on cereals as stable foods which are deficient in certain amino acids resulting in serious protein deficiency as compared to animal origin food. Livestock are essential components of Ethiopian agriculture and the country is reported to have the largest livestock resource than any other African country with about 52 million heads of cattle (CSA 2010). Among these, cattle kept especially as beef animals either for home consumption or for sale account for only about 0.65 percent of all cattle (CSA 2010). Though, Ethiopia is known for its huge cattle population, most of the beef is produced under an extensive low input system and in conjunction with crop and small ruminant production, as a result of which, beef production and productivity are very low as compared to the African average (CSA 2006). Therefore, low growth rate of livestock output and high human population growth rate become one of the major causes of concern similar to what is occurring in other countries with developing economy (IBC 2004).

In recent years, cattle fattening has gained prominence as an important business project of the livestock industry in Ethiopia (Abera et al 2007). However, the practice is constrained by high feed cost, poor quality and low availability of feed resources, inadequate veterinary service, weak extension service as well as absence of good management and proper policy support for livestock development (Anteneh et al 2010). Among these factors, feed shortages are root causes for the poor performance of livestock sector in general and fattening in particular (Admasu 2006). Therefore, improvement of traditional beef cattle production system through introduction of better feeding strategy is very important (Abera et al 2007). Among the various suggested strategies, replacing cereals and expensive and less available agro-industrial by products by unconventional source of raw materials, which are less exploited by man, is one of the solutions to alleviate this situation and contribute to increased supply of animal products. In this context, P. juliflora pods are a valid option for animal feed, mainly as a result of its availability, low cost and good nutrient content of these feeds. In Ethiopia, P. juliflora was introduced in the eastern part in 1970s during the establishment of irrigation water development project at Middle Awash as wind break, shade and shelter (EARO and HADRA 2005; Abiyot et al 2006). Since then, the tree has been rapidly invaded vast areas of agro-and silvo-pastoral lands in Afar and eastern Hararghe (Shiferaw et al 2004; Worku et al 2004; Mwangi and Swallow 2005). This species is now commonly found in Afar and spreading to Oromia, Amhara, Somalia, and Dire Dawa administrative zone. It grows out of control and covers approximately 800,000 hectares of land in Ethiopia. It is suggested that it is spreading at an alarming rate of about 18% per annum. Despite these controversies, the tree has promising prospects in the future as livestock feed. It grows and flourishes in areas receiving rainfall below 100 mm which many plant species do not. P. juliflora pods have been said having high nutritional value and being palatable for livestock (Benedito 1988; Paseicznik et al 2004; Esther and Brent 2005). There are controversial issues regarding eradication and usefulness of the plant, and currently there seems a consensus in how the expansion of the plant can be halted. One of these is utilizing the plant pod as animal feed. However, there is limited information on the potential use and level of inclusion of Prosopis juluflora pod flour in fattening rations of cattle under Ethiopian condition in the past. Better management of P. juliflora can greatly reduce its invasiveness (Pasiecznik 2001). Its utilization can also offer additional income (i.e, by collecting and selling the pod) for smallholder farmers and pastoralists. Thus, this research was conducted to determine the effect of different levels of inclusion of ground Prosopis juliflora pod flour as a substitute for wheat bran on body weight change and carcass parameters.

Material and methods

Description of the study area

The experiment was conducted at Haramaya University Beef farm. The University is located at 521 km east of Addis Ababa. The area lies at latitude of 9° 20’ North of equator and 42^o 03’ longitude east of meridian and at an altitude of 1980 meter above sea level. It has a moderate average temperature of 16^oC, and the maximum and minimum monthly temperatures are 4.5 to 14.8ºC and 21 to 25.5ºC, respectively. The mean annual rainfall is 780 mm (Bobe et al 2004).

Management of experimental animals

Immediately after selection, animals were identified with ear tag, weighed, and randomly assigned to the treatments according to their weight. The bulls were offered the treatment ration according to the treatment plan during the 15 days of adaptation period. The bulls were offered hay ad libitum, but the concentrate was offered on increasing base, so that the bulls receive the total amount of the planned supplement at the end of the adaptation period.

Experimental feeds and feeding

Natural grass hay was used as a basal diet for the experiment. Concentrate supplements were prepared from noug seed cake, wheat bran and P. juliflora pod (GPJP) flour. Adequate amount of mature P. juliflora pods were collected from P. juliflora trees grown in Dire Dawa and Bordede areas. The collected pods were crushed (hand broken) and sun dried and hammer milled to pass through 5 mm sieve to produce ground Prosopis juliflora pods (GPJP). The GPJP were hand sieved (2 mm) and intact seeds, and large sized pods that did not pass through the sieve were reground at Haramaya University feed processing unit. The hay was offered ad libitum allowing a minimum of 20% refusal based on previous day’s intake. The daily concentrate supplements were limited to 3 kg per day as recommended earlier (Emebet 2008). Common salt block (Amole) was available to the bulls all time and water was given twice a day, in the morning and afternoon throughout the experiment.

Experimental design and treatments

The experiment was conducted using a randomized complete block design (RCBD) with four treatments. After randomization, there was no difference (p<0.05) in mean initial body weight among bulls assigned into the different treatments. The concentrate feeds were formulated to provide nutrient that can meet a body weight gain of 0.5-1kg/day. Dietary treatments consisted of grass hay offered ad libitum to all treatment bulls and a supplement of 3kg concentrate according to the established ratio between wheat bran (WB) and noug seed cake (NSC), i.e. 70:30, respectively. The difference between the treatments is therefore, the amount of GPJP that substituted the wheat bran portion of the concentrate. Thus, treatment on (GPJP0) bulls received 3 kg of mixtures of WB and NSC. In treatments two (GPJP15), three (GPJP30), and four (GPJP45), the WB portion of the concentrate mix were substituted by 15, 30, and 45% of GPJP. The proportion of the ingredients for each treatment is presented in Table 1.

Measurements and observations

Body weight gain

Animals were weighed at the beginning of the trial and at fifteen days interval after overnight fasting and before the daily meal were offered by using weighing scale (True test digital balance). Average daily weight gain was calculated as the difference between final and initial weight of the animal divided by the number of feeding days. The fortnightly body weights were used to draw growth curve during the experiment.

Body condition scoring

Body weight scores of individual animals were taken by external visual examination of those parts of the body which best indicates the animal’s condition (over hump, ribs, transverse processes, lumbar fossa, tail head, brisket and cod). Body condition score was assessed on scale of 1 to 9 (1=Emaciated and 9=Obese) according to the procedure described by Nicholson and Butterworth (1986).

Evaluation of carcass characteristics

At the end of the fattening trial, all bulls were kept without food overnight and slaughtered. Immediately before the slaughter, bulls were weighed (pre-slaughter weight). The EBW was calculated as the difference between SW and gut content. Dressing percentage was calculated as proportion of hot carcass weight to slaughter weight and empty body weight.

Data Analysis

Data from the digestibility and feeding trials such as feed intakes, live weight gain, and carcass parameters were subjected to analysis of variance (ANOVA) using the General Linear Model of SAS (SAS 2002). When treatment effect was found significant, least significant difference (LSD) were employed to detect differences among treatment means.

The model used for data analysis was:

Model Yij= µ + αi + bj + eij

Where, Yij= Response variable

µ= over all mean

αi = i^th treatment effect

bj = block effect

eij = random error

Result and discussion

Live weight change

Initial and final live weight, average daily gain and feed conversion efficiency are shown in Table 2. The initial body weight were not significantly different among treatments (P>0.05). The current study revealed that final BW, ADG and FCE were positively affected by inclusion of GPJP. The mean daily weight gain (770.34 g/day) of Hararghe highland bulls in the present study is higher than average daily gain reported by Chala et al (2004) for Horro steers (642g/day) fed different levels of molasses in a concentrate ration. It was also higher than average daily gain reported by Mekasha et al (2010) for Ogaden bulls (503g/day) grazing native pasture and supplemented with different proportion of agro-industrial by products and grass hay. However, it was slightly lower than the daily average gain of 829.88g/day reported by Fekadu (2010) for same bull breed type fed maize stover basal diet and supplemented with 3 kg concentrate mixture fortified with different levels of yeast. The gain recorded in the present trial was also lower than the range (900-1050 g/day) reported by Lamidi et al (2001) in Sudanese bulls.

Results of final body weight, average daily gain and feed conversion efficiency showed that GPJP30 (P<0.001) bulls has significantly heavier weight than the other treatments. No difference (P<0.001) was observed between bulls in GPJP45 (308±3.5), GPJP15 (302±9.7) and GPJP0 (301±3.5). The result in the present experiment showed a positive effect of substituting WB by GPJP up to 30% on final body weight, ADG, and FCE. These results agree with previous similar works. Shukla et al (1984) reported that Kakrei bullocks fed with concentrate ration containing 0, 15 and 30% GPJP has heavier weight gain, but increasing the substitution of WB to 45% resulted in reduced body weight gain due to slight negative N and P balance. Similarly, Mahgoub et al (2004) reported that sheep fed ration containing 45% GPJP gained significantly lower weight than those with 15, 30 and 0% GPJP. In follow up study, Mahgoub et al (2005) reported lower weight gains in goats fed 30% GPJP compared to that consumed 20%. Buzio et al (1972) noted no effect on feed intake, but reduced weight gain in rams when larger proportion of sorghum is

replaced with GPJP (60%). Furthermore, feeding increased level of crushed pods of P. chilensis to desert Sudanese goats resulted in linear body weight decrease. Supplementing grazing steers with mature pods of P. caldenia (DM digestibility of 63.8%) also resulted in weight gains (Menvielle and Hernandez 1985). Similarly, Lima et al (1984), working with Sheep fed combinations of Opuntia and elephant grass and supplemented with 500g GPJP gained more than the control. Moreover, GPJP successfully replaced wheat bran at varying levels in diets for crossbred calves and lambs, but no significant differences were observed between the levels on daily gain (Rao and Reddy 1983).

The increased live weight gain and average daily gain in animals supplemented with different levels of GPJP can be explained by the higher total DM and CP intake, which in turn attributed to the fact that GPJP provided adequate energy to protein ratio, which not only increased the essential nutrients to maintain optimal rumen activity, but also more rapidly degraded in the rumen. Moreover, GPJP consists high content of succharose, calcium, phosphorous, iron, vitamin B1 and vitamin B6, which enhance total DM intake of the feed (Andrew 1992).

These results indicated that diets, which have higher digestibility values, result in higher final body weight, average daily gain and feed conversion efficiency. This also confirmed that the supplements have relatively higher nutrient concentrations that contributed to the increments in body weight gain. On the other hand, the low feed conversion efficiency for GPJP15 and GPJP0 may be due to low intake of nutrient. Similar to the present result, Mahgoub et al (2004) reported lower feed conversion ratio in sheep fed with P. cineraria pods at 0 and 150 g/kg while the ratio increased as p. cineraria increased. Moreover, Belal et al (2008) noted increased feed conversion ratio in Awassi lambs fed diet containing 100 and 200 g/kg PJP when compared to the control diet.

The body weight of the experimental animals in all treatments increased throughout the experiment. However, body weight of GPJP0 remained lower during each weighing as compared to the others. This is related to the higher feed intake by the groups supplemented with P. juliflora pod flour than diets with no GPJP. The GPJP30 treatment group had the highest mean weight, and hence the best performance. This can be attributed to a higher total feed intake. The results in the present study are similar with that recorded by Shukla et al (1984), who found an increase in live weight gain in Kakrei bullocks supplemented with 30% of GPJP. Shukla et al (1984) also observed that feed with diet containing 45% GPJP lost weight. Thus, the present result confirmed that upto 30% of replacement of wheat bran with GPJP improved live weight and feed conversion efficiency of bulls, but higher level reduced performance

Figure 1. Live weight prosopis pod % replacing	Figure 2. FCR prosopis pod % replacing

Body Condition Score

Logistic regression of body condition scoring (BCS) did not show significant difference among the treatments (P r>ChiSq >0.05 at α =0.05. The mean body condition score for GPJP0, GPJP15, GPJP30 and GPJP45 were 5.68, 5.94, 5.98 and 5.91, respectively. GPJP0 and GPJP30 recorded numerically the lowest and the highest scores, respectively. Similar to the current study, Tsigereda (2010) noted no significant difference in BCS between Hararghe highland bulls fed maize Stover and 3 kg of concentrate feed fortified with different levels of yeast. Unlike the present study, the mean BCS was the highest (p<0.05) in Ogaden bulls grazing native pasture and supplemented with different proportion of agro-industrial by products and grass hay (Yosef et al 2010).

Carcass Characteristics

Mean values of main carcass components of Hararghe highland bulls fed ration containing GPJP are presented in Table 3. Similar to live body weight, most of the carcass components of Hararghe highland bulls were influenced by dietary treatments. Both the pre-slaughter and empty body weight follow the same trend, and bulls in GPJP30 exhibited significantly (P<0.01) better weights than other groups. There were no significant (P> 0.05) differences among GPJP0, GPJP15 and GPJP45 for these parameters. But, numerically GPJP45 and GPJP15 groups recorded higher value than the control group indicating that partial substitution of WB with GPJP improved performance of bulls. Hot carcass weight was significantly higher (P<0.01) for GPJP30 when compared to other groups, with no differences between the control and GPJP15 groups. Similar to the present result substitution of corn-cotton bran mix concentrate with 37.5% GPJP yielded significantly higher hot carcass in goats as compared to 12.5, 25 and 50% replacement levels (Primo et al 1984). Moreover, Nagpal et al (1995) noted that growing lambs fed GPJP had higher live weight and increased hot carcass weight than diets free of GPJP. Dressing percentage on slaughter weight basis was significantly higher (P<0.001) for GPJP30 and GPJP45 as compared to GPJP15 and GPJP0, where as dressing percentage on empty body weight basis was not significantly different (P>0.05) among all treatment groups. In other study, replacement of part of the barley grains with GPJP (100 and 200g/kg) had no effect on dressing percentages, non-carcass components, carcass cut weights and loin cut tissues percentages of lambs (Belal et al 2008). The mean dressing percentage (slaughter weight basis) recorded for Hararghe highland bulls in the present study was 54.3% (range 52.2 to 57.2%). This value was superior compared to the dressing percentage of 50.5% reported for Ethiopian Boran zebu bulls kept only on natural pasture. Tsigereda (2010) reported 51.3% for Hararghe highland breed bull fed maize stover and concentrate mix fortified with different levels of yeasts. But, it was slightly lower than 57.5 and 55%, reported for Boran bulls fed hay and concentrate, and grazed pasture and supplemented with concentrate, respectively. It was also lower than 56% reported for Ogaden bulls’ grazed native pasture and supplemented with different proportion of agro-industrial by products and grass hay (Yosef et al 2010).

Primal cuts component of Hararghe highland bulls fed ration containing different levels of GPJP are presented in Table 3. There was a significant (p<0.01) difference among treatment groups in major carcass components except for hump. Backbone, lumbar and loin were the highest for GPJP45 and GPJP30 groups compared to the control (p<0.01), with no difference between the control and GPJP15 group. Among the treatment groups, GPJP30 had heavier forequarter, hindquarter, ribs and brisket meat than the other treatments, with no significant difference between the control, GPJP15 and GPJP45. There was a significant (p<0.001) difference between treatment groups in total usable carcass, which is higher in GPJP30 and GPJP45 groups than the control, with no significant difference between GPJP0 and GPJP15. The higher carcass traits in GPJP30 compared with other groups might be due to higher DM intake, FCE and body weight gain. Similar to the present study, increasing ME levels in Omani goats increased most of the carcass parameters recorded (Mahgoub et al 2005). The result of the present experiment is in agreement with the reports of Tesfaye et al (2007) who noted significant difference in total loin weights among rations. Not in accord with the present finding, primal carcass cut was not significantly different (P>0.05) among Boran finishing bulls fed four different basal diets and supplemented with equal amount of concentrate with different protein and energy sources.

In general, results of final body weight, average daily gain and feed conversion efficiency showed that GPJP30 (324.6± 3.15) (P<0.001) bulls had significantly heavier weight than the other treatments. Control treatment had significantly lower (P<0.01) dressing percentage (52.18±3.52) on slaughter weight basis than GPJP30 (57.17±0.85) and GPJP45 (55.7±0.50), with no significant difference between GPJP15 (52.13±1.46) and the control group. There was a significant (P<0.01) difference among treatment groups in major carcass components except for hump. Backbone, lumbar and loin were the highest for GPJP30 and GPJP45 groups compared to the control (P<0.01), with no difference between the control and GPJP15 group. Among the treatment groups, GPJP30 had heavier forequarter, hindquarter, ribs and brisket meat than the other treatments, with no significant difference between the control, GPJP15 and GPJP45. There was a significant (P<0.001) difference between treatment groups in total usable carcass, which is higher in GPJP30 (185.7±4.23) and GPJP45 (172.1±1.46) groups than the control, with no significant difference between GPJP0 (157.3±4.95) and GPJP15 (158 ± 5.52). The study showed that inclusion of GPJP in the concentrate mixture resulted in better utilization of nutrients and bulls performance. Feeding concentrate mixture containing up to 30% GPJP had higher effect on final body weight, average daily gain and carcass parameter. This implies that there is great opportunity in utilizing GPJP as a substitute for wheat bran, since it avoids competition with monogastric animals and could contribute to the control of prosopis expansion.

Conclusion

• Inclusion of GPJP in the concentrate mixture resulted in better utilization of nutrients and bulls performance.
  
  
• Feeding concentrate mixture containing up to 30% GPJP had higher effect on feed intake, digestibility, final body weight, average daily gain and carcass parameter.
  
  
• This implies that there is great opportunity in utilizing GPJP as a substitute for wheat bran, since it avoids competition with monogastric animals and could contribute to the control of prosopis expansion.

Acknowledgements

We would like to thank Ethiopian Agricultural Research Institutes (EARI) for the financial support. The project cost was covered by National Agricultural Research Fund (NARF).

Conflicts of interest

The authors declare no conflicts of interest

References

Abera H, Kebede M, Meresa C, Gembere A, Galmessa U, Gember T, Ayana T and Lemma T 2007 On farm demonstration and population of back yard oxen fattening technologies in Dano district, Western Oromia. 103-108p In: Proceedings of the 13^th National Conference of Ethiopian Society of Animal Production (ESAP).

Abiyot B and Getachew T 2006 The Prosopis dilemma, Impacts on dryland biodiversity and some controlling methods. Journal of the Drylands, 2:158-164. https://www.researchgate.net/publication/267951814_

Admasu D 2006 Impacts of prosopis juliflora invasion and control using charcoal production in Afar National Regional State, Ethiopia. MSc Thesis, University of Walls, Bangor, UK.

Andrew S 1992 The genous Prosopis and its potential to improve livestock production in: legume trees and other fodder trees as protein sources.

Anteneh B, Tegegne A, Beyene F and Gebremedhin B 2010 Cattle milk and meat production and marketing systems and opportunities for market orientation in Fogera woreda, Amhara region, Ethiopia. IPMS (Improving Productivity and Market Success) of Ethiopian Farmers Project Working Paper 19. ILRI (International Livestock Research Institute), Nairobi, Kenya

Belal S O, Abdullah A Y and Fatima A A 2008 The effect of partial replacement of barley grains by Prosopis juliflora pods on growth performance, nutrient intake, digestibility, and carcass characteristics of Awassi lambs fed finishing diets. Animal Feed Science and Technology. 146: (1-2):42-54.

Benedito VM 1988 Potential offered by Prosopis juliflora (Sw) DC in the Brazilian semi-arid region. In A. H. Mario an C. S. Julio (Eds.), The Current State of Knowledge on Prosopis juliflora. 61-62p. Recife, Brazil.

Butterworth M H and Mosi A K 1986 The intake and digestibility by sheep of oat straw and maize stover offered with different levels of noug (Guizotia abyssinia) meal. Animal Feed Science Technology, 16: 99-107.

Buzo J, Avilla R and Bravo FD 1972 Effect of substitution of progressively sorghum by P. juliflora pod flour. Technical Pecuaria in Mexico, 20: 23–27.

CSA (Central Statistical Agency) 2006 The Federal Democratic Republic of Ethiopia. Report on Livestock Characterstics. Agricultural sample survey 2005/06, vol 2. Statistical Bulletin No. 36.

CSA (Central Statistical Agency) 2010 The Federal Democratic Republic of Ethiopia. Statistical Abstract (2009/10). CSA, Addis Ababa, Ethiopia.

EARO and HADRA 2005 Controlling the spread of Prosopis in Ethiopia by its utilisation. Addis Ababa: Ethiopian Agricultural Research Organization (EARO) and Henry Doubleday Research Association (HADRA).

Esther M and Brent S 2005 Invasion of Prosopis juliflora and local livelihoods: Case study from the lake Baringo area of Kenya, ICRAF Working paper no.3, 66p. Nairobi: World Agroforestry Center.

Fekadu T 2010 Assessment of traditional cattle fattening practices and feed lot performance of Hararghe highland cattle. Msc Thesis Presented to School of Graduate Studies of Haramaya University.65p.

IBC (Institute of Biodiversity Conservation) 2004 The State of Ethiopia's Farm Animal Genetic Resources: Country Report. A contribution to the first report on the state of the World's Animal Genetic Resources. IBC. May 2004. Addis Ababa, Ethiopia.

Lamidi OS, Adamu D, Oni OO, Ehoche OW and Alawa CBI 2001. Value of sundried layer manure as protein source in fattening Bunaji bulls. Journal of Sustainable Agriculture Enviroment, 3: 211-216.

Mahgoub O T I, Kadim S D, Al-Ajmi M N, Al-Saqry S A, Al-Abri R A, Richie A l, Halhali S A and Forsberg E N 2004 Use of local range tree (Prosopis pods in feeding sheep and goats in the Sultanate of Oman. Aseminaires Meditterraneennes ressources.ciheam.org.

Mekasha Y, Urge M, Bayissa M and Yusuf M 2010 Body weight and carcass characteristics of Ogaden bulls subjected to differential levels of supplementation. Department of Animal scince, Haramaya University, 2010 completed Research Report, Ethiopia.

Mishra B, Kidan H, Kibret K, Hassen M and Eshetu B 2004 Soil and land resource inventory at Alemaya University research farm with reference to land evaluation for sustainable agricultural management and production. Synthesis of working papers, Soil Science. Bulletin No. 1, 123p. Alemaya University, Dire Dawa, Ethiopia.

Mwangi E and Swallow B 2005 Invasion of Prosopis and local livelihoods: Case studyfrom the lake Baringo area of Kenya. ICRAF Working Paper – no. 3, Nairobi, World Agroforestry Centre.

Nagpal A K D, Singh V S S and Prasad P C 1995 Effects of weaning age and feeding system on growth performance and carcass traits of male kids in three breeds in Indian. Small Ruminant Research, 17: 45–50p.

Pasiecznik N M, Felker P, Harris P J C, Harsh L N, Cruz G, Tewari J C, Cadorer K and Maldonado L J 2001 The Prosopis juliflora-Prosopis pallida Complex: A Monograph. UK: HADRA Coventry. 172p.

Pasiecznik N M, Harris PJC and Smith SJ 2004 Identifying Tropical Prosopis Species: A Field Guide. UK: HADRA Coventry.36p.

Primo G B, Lima M A, Coelho M J, Silva R F, Mirnda M E and Santos M 1984 Part and total replacement of corn-cotton bran mix by pods of Prosopis juliflora (sw) DC in rations for caged goats during the dry season. Brazilian Journal of Animal Science.

SAS 2002 Statstical Analysis System Software, Version 9.0, SAS Institute, inc., cary, NC, USA.

Shiferaw H, Teketay D, Nemomissa S and Assefa F 2004 Some biological characteristics that foster the invasion of Prosopis (Sw) DC at Middle Awash Rift Valley Area. Northeastern Ethiopia Journal of arid environment, 58:135-154.

Shukla P C, Talpada P C and Pande M B 1984 Prosopis juliflora pods, a new cattle feed source. Animal Nutrition Department, Gujarat Agriculture University, Anand, India. Http:www.fao.org/docrep/006/Ad321e/ad321e0f.htm#bm15.3.

Tesfaye L, Tesfa G, Amsalu S and Tekle A 2007 Effects of four different basal diets on the carcass composition of finishing Borana bulls. Adami Tulu Agricultural Research Center, Ziway, Ethiopia. Journal of Cell and Animal Biology 1:2, 15-18.

USFS (United States forestry service) 2006 The United States Department of Agriculture (USDA) forestry service technical assistance trip report to the Federal Democratic Republic of Ethiopia (FDRE).

Worku A, Tessema T and Engeda G 2004 Biological impact assessment of selected invasive alien plant species on native species biodiversity in Rift valley, Ethiopia. Proceeding of symposium on the rehabilitation of dry land forests in Ethiopia: Ecology and management, Mekele, Ethiopia.

Worku A, Tessema T and Engeda G 2004 Biological impact assessment of selected invansive alien plant species on native species biodiversity in Rift valley, Ethiopia. Proceeding of symposium on the rehabilitation of dry land forests in Ethiopia: Ecology and management, Mekele, Ethiopia.