Effect of Feeding Graded Levels of Wild Silver Leaf Desmodium (Desmodium Uncinatum) on Growth and Bodyweight Change of Horro Sheep Fed Basal Diet of Natural Pasture Hay

This experiment was conducted at Nedjo ATVET College with the objective of evaluating the effects of graded levels of wild silver leaf desmodium (Desmodium uncinatum) on growth and body weight change Horro sheep fed a basal diet of natural pasture hay. Twenty intact male Horro sheep with intact milk teeth and an average initial weight of 18.28±1.47 kg (mean± SD) were used. The experimental sheep were blocked into 5 blocks of 4 animals based on initial body weight and randomly assigned to one of the four treatments within a block. The treatments were natural pasture hay ad libitum (T 1 ) and wild silver leaf desmodium supplement at levels of 200(T 2 ), 300(T 3 ), 400(T 4 ) g/head/d on dry matter bases. The basal diet had DM, CP and OM of 91.2, 75.5 and 9.3, respectively while the corresponding values for Desmodium were 89.8, 77.8 and 16.8. Desmodium supplementation resulted in significantly higher (p<0.01) final body weight and average daily gain (15.6, 38.9, 45.6 and 68.9 g/d in T 1 , T 2 , T 3 and T 4 respectively) (p<0.001) than the sheep in the control treatment. Therefore, supplementation with 400 g/d Desmodium improved body weight of sheep and correspondingly increased the net income from the sale of sheep at the end of the feeding trial. Therefore, in the present study supplementation of wild silver leaf desmodium to natural grass hay at 400 g appears to be the best level for Horro sheep in growth and daily body gain.

gown and is widely used by farmers as feed resource for animals either as grazing or hay forage. However, effect of feeding this legume on growth and body weight gain of sheep has not been evaluated for its proper utilization. The present study was therefore designed with the following objectives.

Objective of the study
 to evaluate growth and body weight change of Horro sheep fed a basal diet of natural pasture hay and supplemented with graded levels of Silver leaf desmodium (Desmodium uncinatum)

MATERIALS AND METHODS Experimental Feeds and Feeding
Wild silver leaf desmodium and natural pasture hay were harvested from the campus of Nedjo ATVET College. The Desmodium was grown naturally under the coffee plant, at the edge of crop farm and livestock protected areas. Desmodium and hay was chopped to an approximate size of 5 cm for ease of consumption by animals, dried under shade on a plastic sheet and stored at the experimental site. The animal was offered natural pasture hay as a basal diet, common salt as mineral lick, and water ad libitum. The desmodium was given according to the treatments and offered to the animals in two equal halves at 0800 and 1600 hours daily.

Experimental Animals and their Management
Twenty intact male yearling Horro sheep were purchased from the nearby local market. Age was determined by dentition and information obtained from the owner. The animals were used in a digestibility trial of 10 days followed by a feeding trial of 90 days. The experimental animals were de-wormed with albendazole against common internal parasites and sprayed with deiazinon against common external parasite, and vaccinated against common diseases in the area like ovine pasteurellosis, sheep pox and anthrax with 1 ml ovine pasteurellosis vaccine, 1 ml sheep pox vaccine and ½ ml anthrax vaccine per sheep, during the quarantine period of 21 days, which was followed by an adaptation period of 15 days to the experiment feed and procedure. All animals were housed in individual pens throughout the experiment.

Experimental Design and Treatments
The experimental design was randomised complete block design (RCBD) that consists of four treatments. The treatments were supplementation of graded levels of wild silver leaf desmodium to natural pasture hay. The animals were blocked based on initial live weight into five blocks of four animals per block. The live weights of animals were determined by two consecutive weighing after overnight fasting. The four treatments were randomly assigned to each experimental animal in a block. The experimental design used is therefore, completely randomized block design. Ad libitum 400

Growth Trial
The growth trial was conducted for 90 days. All animals in the respective treatments used in the digestibility trial were used for growth trial too. There was no randomization of animals, i.e. animals used for digestibility were maintained in the respective treatment. During this period, the following data were collected.

Body weight gain
Initial body weight of animals was determined by taking the mean of the two consecutive weights after overnight fasting and subsequent body weight measurements were made at ten days' interval throughout the experimental period. Average daily body weight gain was calculated by dividing the weight difference by the number of feeding days. Feed conversion efficiency was estimated as a ratio of daily body weight gain and daily dry matter intake.

Statistical Analysis
Data collected was analyzed using the General Linear Model procedure of SAS (SAS, 2008). Treatment means were compared using Tukey adjustment. The model used for data analysis was Yij=µ + ti + bj +eij Where: yij = response variable Journal of Biology, Agriculture and Healthcare www.iiste.org ISSN 2224-3208 (Paper) ISSN 2225-093X (Online) Vol.10, No.17, 2020 µ = overall mean ti = treatment effect bj = block effect eij = random error

RESULTS AND DISCUSSIONS Chemical Composition of the Experimental Feeds
The results of the chemical composition of wild silver leaf desmodium and hay (offered and refused) are shown in Table 2. The CP content of silver leaf desmodium in the current study was comparable with 17.5% CP reported by Taye (2004)) for samples of silver leaf desmodium collected from different sites, but higher than the CP Content of 10.2% reported by Negussie (2008). The OM was lower than the OM value of 89.1 reported by Ngussie (2008) for desmodium. The NDF component is higher than the NDF content of 50.9% reported by Taye (2004). The ADF and ADL content is lower than the ADF and ADL value of 38.3% and 8.3% reported by Taye (2004). The high ash content of silver leaf desmodium used in the current study implies that it contains enough amounts of minerals.
The hay used in the present study has DM content, which was comparable to the DM contents of 91.8%, 91.4, 91.6, and 91.8% reported by Asnakew (2005) (2010), respectively. The CP content of hay offered to the experimental animals in the current study is higher than 4.2%, 6.6%, 6.9%, and 7.9% CP reported by Mulu et al. (2008), Simret and Solomon (2008), Simachew (2009), and Amansisa (2010), respectively. But it is comparable to the value of 9.2% CP reported by Bimrew (2008). It has been noted that CP value ranging from 7-7.5% is needed to satisfy maintenance requirement of ruminant animals (Van Soest, 1982). Hence, the CP content of the mixed sward grass hay used in the current study is above the value demanded for maintenance requirements of sheep. he higher CP content of hay in the current study might be attributed to the good environmental condition in which the grass was grown, proper drying of the hay, early harvesting time, and the observed better mixtures of legumes. Forage maturity stage at harvest is identified as the most important factor affecting the composition and nutritive value of pastures (Adane, 2003). The same authors described that the CP content of most grass species is adequate to meet minimum nutritional requirements for livestock if harvested at early stage, but CP content declines below this requirement at latter stages of harvesting. Based on the study conducted to compare the cutting dates on chemical composition of forages, Kidane (1993) also noted that early harvested hay gave high CP percentage than delayed harvest. However, at early age, the digestible crude protein (DCP) and total digestible nutrient (TDN) values of the legumes are very high, but the DM yield per hectare is very low (Ranjhan, 1980) indicating the need to balance for this phenomenon.
The NDF component of hay used in the current study is lower than the NDF content of 74.2%, 69.7%, 67.2%, and 71.8% reported by Simret and Solomon (2008), Bimrew (2008), Simachew (2009), and Amansisa (2010), respectively. Pond e al. (1995) noted that NDF portion of feed is only partially digestible by any species of animals, but can be used to greater extent by ruminants, which depend on microbial digestion for utilization of most fibrous plant component. The ADF content of hay used in the present experiment was lower than the ADF content of 38.4 and 46.4% reported by Bimrew (2008)  . The ADL content of hay used in the present experiment was lower than the ADL content of 11.0, 9.8 and 9.0% reported by Bimrew (2008), Simret and Solomon (2008) and Simachew (2009), respectively. The DM, OM, CP, ADF, ash and ADL content of the hay refusals were almost similar among all treatments. This may be due to the feeding habits of sheep which selected the most nutritious parts of the grass such as leaves and shoots and left the relatively non-edible parts like stems in similar fashion among treatments. The higher the NDF and or the ADF composition of a feedstuff, the lower the nutritive value of that feedstuffs and vice versa (Beyene, 1976). The chemical composition of the hay used in this experiment could be characterized by its acceptable CP (9.3%), NDF (60.8%), which is lower than the minimum (45-65%) reported to affect intake and digestibility (Singh and Oosting, 1992) and relatively lower ADF (32.6%) contents. This low content of NDF and ADF may imply high intake and digestibility of the basal diet

Body Weight Change and Feed Conversion Efficiency
The body weight change, average daily gain (ADG), and feed efficiency of Horro sheep fed basal diet of natural pasture hay and graded level of silver leaf desmodium are given in Table 5. The final body weight of the sheep in the control group (T1) was lower (P<0.01) than final body weights of sheep fed graded level of wild silver leaf desmodium at all levels. Among the groups supplemented with wild silver leaf desmodium hay the lower and medium supplemented groups (T2 and T3) had lower (P<0.01) final body weights than the highest level (T4). In accordance with the variations in the final weights of sheep fed the experimental diets, there were also significant (P<0.01) difference in average daily weight gain (ADG) of sheep in the different treatments. Accordingly, sheep fed the basal diet, that is natural pasture hay alone (T1), has significantly lower (P<0.01) ADG than sheep supplemented with wild silver leaf desmodium in addition to ad libitum consumption of natural pasture hay diets (T2, T3 and T4). There were also significant (P<0.01) differences in ADG among sheep fed the different levels of wild silver leaf desmodium as a supplement to natural pasture hay. Accordingly, T4 has the highest ADG as compared to T2 and T3 which are not statistically different from each other Similar to the current study, Mtenga and Mafweress (1992) showed that supplementation increased DM intake of sheep fed hay supplemented with lablab meal and maize bran, which correspondingly increased body weight gain in sheep. The increase in ADG by sheep supplemented with wild silver leaf desmodium agrees with Kariuki et al. (1999) who reported that heifers fed natural pasture hay as a sole diet gained 0.41 kg per day, while those on natural pasture hay intercropped with desmodium, natural pasture hay alone, and Napier grass supplemented with desmodium hay gained 0.45, 0.52 and 0.42 kg per day, respectively showing the positive effect of desmodium as a supplement to grass hay. The current finding revealed that supplementation with legume forage increased the average daily body weight gain. However, the gain attained is lower than that reported for small ruminants supplemented with different concentrate diets in previous studies (For example, Asnakew, 2005;Abebaw, 2007;Mulat, 2006;Fentie, 2007). Demissie et al. (1987) reported a daily body weight gain of 72g in yearling Horro lambs supplemented with 300 g/day concentrate, which is only slightly higher than the gain obtained in groups supplemented with the highest level of the legume forage in the present study. On the other hand, Solomon (1996) reported a range of 90-131 g/day gain in Horro sheep under free grazing. Melese et al. (2001) indicated that Horro lambs have the potential of gaining more when they are managed under improved forage and concentrate supplementation. The authors reported a range of 30-121 g/day gain in Horro lambs when natural hay is supplemented with 216g ground maize and 150 noug seed cake under indoor feeding condition. Gebregziabher et al. (2002) also noted that Horro rams perform better in terms of body weight gain when supplemented either concentrate or herbaceous legumes.
Feed conversion efficiency was higher (P < 0.001) in the order of T3= T4> T2= T1. The results of this study explicitly revealed the advantages of supplementation of legume hay to natural pasture based diet in improving total DM, OM and CP intakes, digestibility, live weight gain, and feed conversion efficiency. In general, the supplemented sheep had better body weight gain and nutrient intake than the non-supplemented groups. This is an attribute of better availability of nutrients to animals', particularly crude protein, which is in line with the Journal of Biology, Agriculture and Healthcare www.iiste.org ISSN 2224-3208 (Paper) ISSN 2225-093X (Online) Vol.10, No.17, 2020 established fact that supplementation results in improved animal performance in several ways, such as by providing essential nutrients for rumen microorganisms, enhancing the microorganism activities in the rumen and providing nutrients for the sheep (Van Soest, 1994). For the supplemented group of sheep in the current study, a gradual and continuous increment of weekly body weight was observed at higher rate than that of the control group. Figure 2 Trends in body weight change across the experimental period for Horro Sheep fed Natural pasture hay and graded level of wild silver leaf desmodium T1=natural pasture hay alone ad libitum; T2= Natural pasture hay ad libitum + 200 g wild silver leaf Desmodium; T3= Natural pasture hay ad libitum + 300g wild silver leaf Desmodium; T4= Natural pasture hay ad libitum +400 g wild silver leaf Desmodium. . CONCLUSIONS Generally, the results of the study revealed that the supplementation of legumes in improving growth and body weight change and nutrient utilization than feeding sole natural pasture hay due to better availability of nutrients to animals' particularly crude protein. Therefore, supplementation with 400g/day desmodium hay higher improved Average daily body gain(ADG) of sheep. Hence, in the present study, it was concluded that supplementation of hay with 400 g /day/head is biologically efficient in feeding of growing Horro sheep. weight and carcass characteristics of Washera sheep fed urea treated rice straw. Adane Kitaba, 2003  Journal of Biology, Agriculture and Healthcare www.iiste.org ISSN 2224-3208 (Paper) ISSN 2225-093X (Online) Vol.10, No.17, 2020