Effect on performance of Hararge Highland sheep of feeding “Kocho” waste as part of the concentrate supplement

Kochito Wolde, Mengistu Urge¹ and Meseret Girma¹

Department of Animal Sciences, Mizan Tepi University, P O Box 260, Mizan Tepi, Ethiopia
¹ School of Animal and Range Sciences, Haramaya University, P O Box 138, Dire Dawa, Ethiopia
meseretgirma4@gmail.com

Abstract

A study was conducted to evaluate the effect of feeding Kocho waste (KW) as a substitute for part of the concentrate mixture (a 2:1 ratio of maize and wheat bran) on growth performance of Hararghe Highland sheep. Twenty-four yearling intact male sheep with initial body weights of 16.3±2.08 kg were assigned to four dietary treatments in a completely randomized block design. The treatments were: replacement levels of ECM of 0, 25, 50 and 75% by kocho waste, the other components of the diet being noug seed cake and natural grass hay.

Over a 90 day growth period, there were positive responses in live weight gain and feed conversion to inclusion of kocho waste at the 20% level of the diet. However, when the kocho waste reached 30% of the diet DM, growth rate and feed efficiency became worse. It is postulated that at low levels, kocho waste provides benefits due to the prebiotic effect resulting from its content of autolyzed yeast cells but at high levels this did not compensate for the superior value of maize as source of glucose precursors, which are a major determinant of growth rate and feed efficiency in ruminant animals.

Key words: Ensete ventricosum, fermentation, prebiotics

Introduction

The Enset plant (Ensete ventricosum), known as “false banana” , is widely grown in southern and southwestern parts of Ethiopia (Admasu 2002). Different parts of Enset are used as feed for livestock (Brandt et al 1997; Mohammed et al 2013). One of these products is “Kocho” produced by scraping the starchy pulp from the Enset stem and fermenting it in a pit in the ground (Photo 1; Admasu 2002). The product of the fermentation is primarily used for human consumption. In 2017, from 123,479,334.00 enset plants 3,162,563 tonnes of kocho were produced (CSA 2017). However, the upper layers of the fermented mass are usually discarded due to discoloration. This component which is not suitable for human consumption is traditionally fed to livestock.

Photo 1. Ensiling “Kocho” in a “pit” about 1.2m deep

The objective of the present study was to evaluate Kocho waste (Dupo) as a partial replacement for the concentrate (a mixture of maize, wheat bran and noug seed cake) used to supplement grass hay for fattening sheep.

Materials and methods

Starter culture for Kocho

The corms (Photo 2) of selected Enset plants are traditionally used as substrate for the preparation of a starter culture (gamancho). The corm is pulverized with a serrated and sharp-edged tool made from animal bone (scapula) to make it ready for fermentation. The prepared corms are then wrapped with fresh enset leaves and left at ambient temperature for 8 days. On the 5th day, the ground corm is exposed to the sun for 5 to 12 hours and again wrapped with fresh enset leaves and allowed to ferment for 3 to 5 days more (Tiruha et al 2014).

Preparing Kocho

Mature enset plants are selected chopped and the starchy internal part pounded into “dough”. The fermented starter culture is mixed with the fresh dough and left to ferment in a pit for 3-5 days or more (Tiruha et al 2014).

Experimental animals

The experiment was conducted at Haramaya University sheep farm, Ethiopia. Twenty-four intact male yearling Hararge highland sheep were purchased from a local market. They were quarantined for 3 weeks and treated against internal and external parasites. They were adapted to the experimental diets for 15 days before data collection.

Feed preparation

The Kocho waste was collected from house-holders in Keffa and Bench Maji zones of SNNPR. It was sun-dried by spreading over a clean mat until it became safe for storage.

Photo 2. The Enset plant in the natural state (A) and shown diagrammatically (B)

Experimental design and treatments

The experiment was conducted according to a randomized block design with four treatments and six replicates. The sheep were blocked based on their initial body weight and allocated to 4 treatments within each block. The treatments consisted of increasing levels of Kocho waste ( Dupo) replacing the energy concentrate at 4 levels: 0, 25, 50 and 75% on DM basis (Table 1). The energy concentrate (ECM), kocho waste (KW) and noug cake (NSK) were mixed together and fed ad libitum along with natural grass hay also ad libitum. All animals had free access to water.

Digestibility measurement

This was for 7 days after the 90-day feeding trial when the sheep were harnessed with fecal collection bags for total fecal collection. Representative samples of feces were dried at 60°C for 72 hours prior to analysis.

Growth performance and feed conversion

Live weights were taken every 10 days in the morning before the daily feed offer. Live weight gains were estimated from the linear regression of liveweight (Y) at 10-day interval s (X). Feed conversion was calculated by dividing ADG (g/day) by DMI (g/day).

Chemical Analysis

The chemical analysis of feeds and feces followed AOAC (1990) procedures. Neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) were determined by procedures in reported by Van Soest and Robertson (1985).

Statistical Analysis

The final data were subjected to analysis of variance in a randomized complete block design using the general linear model procedure of the ANOVA program in the software of SAS (2002). The model for ANOVA analysis was: Yij= µ + ti + bj + eij

Yij= the response variable; µ= overall mean; ti = treatment effect (feed); bj = block effect (initial body weight) and eij = random error

Results

Chemical composition of feeds

The crude protein content of Kocho waste (Dupo) was 7.1% (in DM) and lower than in maize (Table 2). Temesgen (2013) reported lower values of 4.42 - 5.09% of crude protein in Kocho waste. The NDF and ADF in Kocho waste were lower than in maize.

Feed intake , live weight gain and feed efficiency

Feed intake and DM digestibility did not vary among treatments (Table 3). Live weight gain and feed conversion efficiency showed curvilinear responses to inclusion level of kocho waste in the diet (Figures 1 and 2) with improvements in both criteria with up to 20% kocho waste in the diet but with no further improvement when the kocho waste reached 31% of the diet DM.

Figure 1. Relationship between live weight gain and proportion of the maize-wheat bran concentrate replaced by kocho waste	Figure 2. Relationship between feed conversion efficiency and proportion of the maize-wheat bran concentrate replaced by kocho waste

The performance response curves observed in this experiment bear a close resemblance to the responses observed in a previous experiment in which a byproduct (Atella) from local brewing of sorghum grain was fed to sheep (Ayfokir et al 2020). In that instance the initial response to the supplement was attributed to a prebiotic effect induced by the products (β-glucan and related products) derived from the autolysis of the residual yeast cells at the end of the brewing process. The subsequent decline in animal performance with more than 30% replacement of the concentrate by Atella was attributed to the decline in availability of essential nutrients (glucose precursors and amino-acids) as the Atella replaced the nutrient-rich concentrate. We propose that a similar relationship existed between the Kocho waste and the maize grain-wheat bran part of the concentrate that it replaced. Thuy Hang et al (2018) reported a similar curvilinear response to brewers’ spent grain fed at 0, 2, 4 and 6% the diet of growing goats. The maximum response in growth rate was with 4% of the supplement with a major decrease in response as the level of the supplement was raised to 6% (Figure 3).

Figure 3. Curvilinear relationship between growth rate of goats and level of brewers’ grains in the diet (Thuy Hang et al 2018)

The inflexion point for any given supplement thought to provide “prebiotic” properties will be determined by the concentration in the supplement of the compounds responsible for the ”prebiotic” effect. In ruminants this research area is still poorly understood.

Conclusions

Live weight gain and feed conversion efficiency showed curvilinear responses to inclusion level of kocho waste in the diet with:

• major improvements (+60%) when Kocho waste was 20% of the diet;
  
  
• no further improvement (in growth rate), and a decrease in feed conversion efficiency, when the kocho waste was fed at 30% of the diet.

References

Admasu Tsegaye 2002 On indigenous production, genetic diversity and crop ecology of enset ( Ensete ventricosum) (Welw.) Cheesman. PhD Thesis, Wageningen University.

AOAC (Association of Official Analytical Chemists) 1990 Official methods of the analysis 15th ed. AOAC. Arlingston, USA.

Ayfokir Tadesse, Mengistu Urge and Meseret Girma 2020 Effects of replacing concentrates with Atella (a byproduct of local beer) on growth performance of Hararghe Highland sheep in Ethiopia. Livestock Research Rural Development. 32(7) # 109. http://www.lrrd.org/lrrd32/7/meser32109.html

Brandt S, Spring A, Hiebsch C, McCabe J, Tabogie T and Diro M 1997 The "Tree against hunger": Enset based agricultural systems in Ethiopia, Washington: American Association for the Advancement of Science.

CSA (Central Statistical Agency) 2017 Central Statistical Agency Agricultural Sample Survey Report on area and Production of Major Crops (Private peasant holding, Meher season). Addis Ababa.

Mohammed B Gabel M and Karlsson L 2013 Nutritive value of drought tolerant food and fodder crop enset. African Journal of Agricultural Science 8(20): 2326-2333.

SAS 2002 SAS User’s Guide. Statistics. SAS Institute, Inc., Cary, NC. USA.

Temesgen Melese 2013 Improving the Indigenous Processing of kocho, an Ethiopian Traditional Fermented Food. Journal of Nutrition and Food Sciences 3: 182.

Thuy Hang L T, Preston T R, Ba N X and Dung D V 2018 Digestibility, nitrogen balance and methane emissions in goats fed cassava foliage and restricted levels of brewers’ grains. Livestock Research for Rural Development. Volume 30, Article #68. http://www.lrrd.org/lrrd30/4/thuy30068.html

Tiruha Habte Karssa Kebede Abegaz Ali and Edessa Negera Gobena 2014 The microbiology of Kocho: An Ethiopian Traditionally Fermented Food from Enset (Ensete ventricosum). International Journal of Life Sciences 8(1): 7-13.

Van Soest PJ and Robertson JB 1985 Methods of analysis of dietary neutral detergent fiber and non-starch polysaccharides in relation to animal nutrition. Journal of Diary Science 74:358-359.