Growth of Washera ram lambs fed on Napier (Pennisetum purpureum) and Sesbania (Sesbania sesban) mixture at different levels of combination

Mengistie Taye

Andassa livestock research center, P.O.Box 830, Bahirdar, Ethiopia
mengistietaye@yahoo.com

Abstract

An experiment to evaluate the growth of Washera ram lambs fed on different combinations of fresh Sesbania (Sesbania sesban) and Napier grass (Pennisetum purpureum) and to determine the appropriate level of combination for maximum growth was conducted at Andassa Livestock Research Center. The treatments were 55N45S (55-45 Napier-Sesbania Mixture), 70N30S (70-30 Napier-Sesbania Mixture), 85N15S (85-15 Napier-Sesbania Mixture), 100N0S (Sole Napier), Grazing + 400 gm concentrate (45:55 ground maize-grass pea grain mixture) and Grazing alone.

Average initial body weight (23.11 kg) was not different between feeding treatment groups. The mean final weight (Kg), total body weight gain (Kg) and average daily weight gain (gm) obtained were 28.28±0.31, 5.17±0.29 and 49.27±2.77, respectively. Final body weight and average daily body weight gain were significantly different (p<0.05) between treatments. The group fed on grazing plus concentrate supplement had better final body weight and average daily body weight gain. Average daily dry matter (DM) intake was calculated only for those groups fed indoor because of the difficulty of determining feed intake in grazing animals. The groups fed on 55N45S and 70N30S Napier-Sesbania mixture had higher daily DM intake while those fed on 85N15S and sole Napier had better feed conversion efficiency.

The results indicated the possibility of increasing sheep production in areas where grazing land is a problem while the production of these forage species is possible. For a fattening practice, these forage feeds should be supplemented with concentrate feed for which the level of supplementation needs to be set. In addition the economics should be seen under the farmer’s condition.

Key words: Dry matter intake, feed conversion efficiency, Napier, Sesbania, Washera

Introduction

Sheep production is an integral component of the mixed crop-livestock production systems in Ethiopia. Sheep contribute as a source of cash income, food, manure and fiber for smallholder farmers. Sheep production in the mixed crop-livestock production system is based on communal grazing land which is shrinking due to cropping encroachment and gully erosion (Benin et al 2002; Mengistie 2008). There is therefore a need for an alternative feeding strategy which could alleviate livestock feed problem.

The use of cut and carry system is a key principle for the successful integration of livestock and cropping systems to control grazing of stock exclusion and cropping areas and to preserve uplands, catchments and recharge areas essential for sustainable water supplies (Alemayehu 2003). Napier grass is being adopted owing to its high dry matter, palatability and suitability to cut and carry system. Napier grass has a mean CP level of 5.9-13.8 % (Kahindi et al 2007; Kanyama et al 1995). However, this level is below the ARC (1980) recommended dietary CP levels of growing lambs (167 gm CP/kg DM). Sesbania sesban is one of the exotic multipurpose fodder tree species that have been introduced in the Ethiopian highlands to alleviate feed shortages, maintain soil fertility and prevent land degradation. Sesbania is a potential source of protein having 24.0 - 31.9 % CP (Mekoya 2008; Kanyama et al 1995). Feeding of Sesbania forages have desirable characteristics as a potential feed supplement to improve the utilization of Napier grass to ruminant animals. Nutrient content and digestibility could be enhanced by feeding Sesbania with Napier grass (Tessema and Baars 2004). The objective of the current experiment was therefore, to evaluate the growth of Washera ram lambs fed on different combinations of Sesbania and Napier grass and develop Napier grass based feeding strategy for cut and carry system.

Material and methods 

Study area

The experiment was conducted at Andassa livestock research center. The center is located between 11^Ο 29’N latitude and 37^Ο29’E longitude, 20 km south west of Bahir Dar on the way to Tissisat fall. The altitude is 1750 m a.s.l. and the mean annual rainfall is 1496 mm (Yihalem 2003).

Forage production and management

Napier grass (Acc. Number 19383) and Sesbania (Sesbania sesban) were planted at Andassa livestock research center. It was irrigated in 7-15 days interval when the soil gets dry. Poultry litter and cow dung was applied in addition to Urea and di-ammonium phosphate (DAP).

Animals and experimental design

Fifty-four Washera ram lambs aged approximately 7 months were purchased from Adet market and stayed for two months at the center before getting to the trial. They had an average initial body weight of 23.6±2.2 kg. They were all treated for internal and external parasites and vaccinated for pasteurellosis and sheep pox.

The experimental design employed was a Completely Randomized Design. Experimental animals were grouped in to nine groups (six animals in each group) according to their body weight. The animals were then randomly distributed into six feeding treatments by allocating one animal from each of the nine weight groups. Therefore, each treatment had a total of nine animals.  There were three replications (pens) in each treatment with three animals per replication.

The treatments were:

1.                  55N45S (55-45 Napier-Sesbania Mixture)

2.                  70N30S (70-30 Napier-Sesbania Mixture)

3.                  85N15S (85-15 Napier-Sesbania Mixture)

4.                  100N0S (Sole Napier)

5.                  Grazing + 400 gm concentrate (45:55 ground maize-grass pea grain mixture)

6.                  Grazing alone

Feeding management

Treatment groups 5 (Grazing + 400gm concentrate supplement) and treatment 6 (Grazing alone) graze during the day for about 8 hours. Supplementation of concentrate feed for treatment 5 was half in the morning before they got out to grazing and half in the afternoon after they got into their pen. Treatment groups 55N45S, 70N30S, 85N15S and 100N0S were fed fresh Napier-Sesbania mixtures at different combinations indoor. Napier grass and Sesbania were chopped, weighed and mixed according to the percent proportion (treatment) and offered ad libitum. Napier-Sesbania combination was based on the dry matter content. Average DM content of Napier grass was 22% and that of Sesbania was 26%. The ingredients of the concentrate were grass pea (Lathyrus sativus) 55% and maize (Zea mays) 45%.  Grass pea and maize contains 21% and 9% CP, respectively.  Water and salt were provided for all animals ad libitum.

Data collection and analysis

Body weight of animals was taken every fifteen days interval with a Salter balance (50 kg capacity of 200 gm precision). Feed offered and refusals were collected and weighed daily. Data were analyzed using the general linear model procedure of SAS (SAS 9.1). The model used for the analysis of growth and feed intake was:

Y_ij = µ + T_i + e_{ij .}  

Where:

Y_ijk = The observation on growth and feed intake;
µ = Overall mean
T_i = The fixed effect of treatment and
e_ij = effect of random error.

Result and discussion 

Growth

The overall mean final weight, total weight gain and average daily weight gain (ADG) were 28.28 kg, 5.17 kg and 49.27 gm, respectively (Table 1). Final weight was significantly (p<0.05) different between treatment groups. Ram lambs fed on grazing plus concentrate supplementation were superior over the rest of the treatment groups. Total weight gain and average daily weight gain were also significantly different between the treatments. Ram lambs fed on grazing plus concentrate feed supplementation performed better than other treatment groups while those with grazing alone had the least total weight  gain (kg) and average daily body weight gain (gram per day) (8.02±0.70 vs. 3.48±0.70; p<0.05 and  76.40±6.71 vs. 33.23±6.71; p<0.05), respectively. There were no significant differences in final weight, total weight gain and average daily weight gain between the different Napier-Sesbania combination treatment groups. It is unlikely that animals fed different level of Sesbania performed similarly. This effect might be because of the nutritional value of the Napier grass was better. This type of effect is also reported in the literature (Manaye et al 2009).

The growth performance obtained in the Napier-Sesbania fed treatment groups is below the expected given that Sesbania has high values of dry matter digestibility and better nutrient content (Nguyen 1998a; Wambui et al 2006; Nguyen et al 2009). However, the weight gains obtained in the Napier-Sesbania fed treatments is consistent with the results reported in the literature for goats (Lam and Ledin 2004; Wambui et al 2006). Moreover, Kanyama et al (1995) found out that goats fed on above 30% Sesbania lost weight. The relatively low weight gain in Sesbania supplemented treatment groups might be related to the protein binding effect of tannins in the Sesbania (Kanyama et al 1995; Wambui et al 2006). On the other hand, Nguyen (1998b) and Manaye et al (2009) reported much higher weight gains from supplementing Sesbania.

As can be seen in Figure 1 below, the Napier-Sesbania treatment groups lies between the concentrate fed group (which is a positive control) and the grazing group (negative control). The weight gains attained in all Napier-Sesbania fed groups were well below the potential of Washera sheep for growth and fattening. The expected weight gain for a profitable fattening should be around the weight gains achieved from concentrate feeding in this experiment (Treatment 5). However, Napier-Sesbania feeding could be comparatively economical feeding and fattening strategy compared to concentrate feeding. Moreover, Napier-Sesbania feeding results indicate the possibility of increasing sheep production in areas where grazing land is a problem, in stock exclusion areas, and in areas where there is irrigation. Inclusion of a certain amount of concentrate in Napier-Sesbania based fattening rations may improve fattening practices based on these forage feeds.

Feed intake

Average dry matter intake and feed conversion efficiency were calculated for indoor fed treatment groups (Napier-Sesbania fed treatments) only and are presented in Table 2. There was significant difference (p<0.05) in average daily dry matter intake (DM) between the treatments. Increased supplementation of Napier with Sesbania forage increased total DM intake, that treatment groups fed on 55N45S and 70N30S Napier-Sesbania mixtures had higher DM intake than the other low Sesbania mixture treatments. This might partly be due to the higher Sesbania content in the mixture which might be liked by the sheep and the higher protein content of the diet. Protein intake and DM intake has a close relationship (Nguyen 1998a). This result is inconsistent with literature that Sesbania increased total DM intake (Mekoya 2008; Manaye et al 2009). Kahindi et al (2007) reported that, the increase in supplementation of Napier grass with Madras thorn forage legume had increased DM and CP intake by growing goats.

Treatments with higher Sesbania percentage (55N45S and 70N30S) had higher DM intake, but lower average daily body weight gain. This may partly be due to the deleterious effect of Sesbania on growth of sheep when fed in a large proportion (Mekoya 2008). In addition, though data were not collected, there was an observation of bloating in the treatment groups with high Sesbania proportion (55N45S and 70N30S) which might be because the feed was offered fresh.

Feed conversion efficiency calculated as gram body weight gain per kg feed was significantly higher for treatment groups fed on Sole Napier and 85N15S mixtures (see Table 2 above). That is animals fed on higher proportion of Napier and thus lower proportion of Sesbania had higher conversion efficiency. This is in agreement with the above discussion that higher level of Sesbania (though it has higher protein content) depresses feed utilization because of its higher alkaloid content.
 

Conclusions

• All the Napier-Sesbania combinations were above the maintenance level and the animals performed better than the animals on grazing alone treatment. The experiment indicated that feeding of Napier-Sesbania mixtures for sheep can overcome the problem of feed shortage in areas where production of these forage plants is possible and where grazing is limited. To use these combination as a fattening diet, supplementation of concentrate feed is needed which needs to be set. To recommend to a larger scale adoption, the economics of the result need to be seen under the farmers’ condition.

Acknowledgements 

The financial assistance provided by the Andassa Livestock Research Center is gratefully acknowledged.

References 

Alemayehu Mengistu 2003 Country Pasture/Forage Resource Profiles, Ethiopia. http://www.fao.org/ag/AGP/AGPC/doc/Counprof/Ethiopia/Ethiopia.htm

ARC (Agricultural research council) 1980 The nutrient requirements of ruminant livestock. Commonwealth Agricultural bureaux, Farnham Royal, UK. 351 p

Benin S, Ehui S and Pender J 2002 Policies for livestock development in the Ethiopian highlands. Socioeconomics and Policy research working paper 41. ILRI (International Livestock Research Institute), Addis Ababa, Ethiopia. 29 p  http://www.ilri.org/Infoserv/webpub/Fulldocs/WP41/Toc.htm

Kahindi R K, Abdulrazak S A and Muinga R W 2007 Effect of supplementing Napier grass (Pennisetum purpureum) with Madras thorn (Pithecellobium dulce) on intake, digestibility and live weight gains of growing goats. Small Ruminant Research 69: 83–87

Kanyama Phiri G Y, Powell C and Gill M 1995 The effect of levels of supplementation with Sesbania sesban foliage on intake and live weight changes in goats. African Feed Resources Network. pp. 117-121

Manaye T, Tolera A and Zewdu T 2009 Feed intake, digestibility and body weight gain of sheep fed Napier grass mixed with different levels of Sesbania sesban. Livestock Science 122: 24–29

Mekoya A K 2008 Multipurpose fodder trees in Ethiopia; Farmers’ perception, constraints to adoption and effects of long-term supplementation on sheep performance. PhD thesis, Wageningen University, Wageningen, The Netherlands. 220 p http://library.wur.nl/wda/dissertations/dis4369.pdf

Mengistie Taye 2008 On-farm performances of Washera sheep at Yilmanadensa and Quarit districts of the Amhara National Regional State. M. Sc. Thesis. Hawassa University, Awassa. 133 p

Nguyen Thi Hong Nhan 1998a Effect of Sesbania grandiflora, Leucaena leucocephala, Hibiscus rosa-sinensis and Ceiba pentadra on intake, digestion and rumen environment of growing goats. Livestock Research for Rural Development (10) 3: http://www.lrrd.org/lrrd10/3/nhan1.htm

Nguyen Thi Hong Nhan 1998b Utilization of some forages as a protein source for growing goats by smallholder farmers. Livestock Research for Rural Development (10) 3:  http://www.lrrd.org/lrrd10/3/nhan2.htm

Nguyen Thi Hong Nhan, Ngo Van Man and Preston T R 2009 Biomass yield of Hymenachne acutigluna and Paspalum atratum in association with Sesbania sesban on seasonally waterlogged soils and their use as feeds for cattle in the Mekong delta, Vietnam. Livestock Research for Rural Development (21) 8: http://www.lrrd.org/lrrd21/8/nhan21121.htm

SAS 2003 SAS User’s Guide: Statistics. Version 9.1. Cary, NC: Statistical Analysis System Inc.

Tessema Z and Baars RMT 2004 Chemical composition, in vitro dry matter digestibility and ruminal degradation of Napier grass (Pennisetum purpureum (L.) Schumach.) mixed with different levels of Sesbania sesban (L.) Merr. Animal Feed Science and Technology 117: 29–41

Vo Lam and Ledin Inger 2004 Effect of feeding different proportions of sweet potato vines (Ipomoea batatas L. (Lam.)) and Sesbania grandiflora foliage in the diet on feed intake and growth of goats. Livestock Research for Rural Development (16) 10  http://www.lrrd.org/lrrd16/10/lam16077.htm

Wambui C C, Abdulrazak S A and Noordin Q 2006 The effect of supplementing urea treated maize stover with Tithonia, Calliandra and Sesbania to growing goats. Livestock Research for Rural Development (18) 5: http://www.lrrd.org/lrrd18/5/abdu18064.htm

Yihalem Denekew 2003 Effect of stage of harvesting on botanical composition of selected natural pasture for optimum hay production at Andassa, North Western Ethiopia. MSc thesis. Alemaya University, Dire-dawa. 90 p

Received 8 August 2009; Accepted 10 October 2009; Published 3 December 2009

Go to top