Livestock Research for Rural Development 23 (2) 2011 Notes to Authors LRRD Newsletter

Citation of this paper

On-farm experience of feeding urea-molasses treated barley straw to crossbreed dairy cows in Jeldu District, highlands of Ethiopia

Rehrahie Mesfin and Getachew Kebede

Ethiopian Institute of Agricultural Research (EIAR),
Holetta Research Center. Addis Ababa, Ethiopia.
Y_takele@yahoo.com

Abstract

An on-farm study was carried out with Boran-Friesian and Boran-Jersey crossbred dairy cows maintained under smallholder farmers’ condition in mixed farming production system at Jeldu District in West Shoa zone, highlands of Ethiopia. The objective was to demonstrate feeding of urea-molasses treated straw to dairy cattle under farmers’ management, to demonstrate improved utilization of crop residues as strategy of improved management of dairy cows for sustainable milk production & reproduction performance and to evaluate the response of smallholder farmers’ urea-molasses treatment and feeding of urea-molasses treated straw to dairy cattle. The study was implemented on farmer’s management with full follow-up on the research side. Finally, the practice was evaluated based on the analyzed data collected from farmers. A total of 16 households each having improved crossbred dairy cows were selected and the intervention tested. The cows were weighing in a range of 400 20 kg. The experiment was handled in Latin square design. The different breeds were equally distributed between the treatments. The proportions of the ingredients that have been used for the treatment process were a solution of 5kg urea and 10-liter molasses per 100kg barley straw. The cows were fed urea treated straw adlib as basal diet. They were also supplemented with commercial concentrate feeds including mix of 64% wheat bran 35% noug cake and 1% common salt.

No statistical difference (P = 0.23) was observed between groups of cows that were fed urea-treated barley straw and those ones fed hay based diet. Fifty percent of the farmers used this technology, have accepted and were willing to continue. The result of this study revealed that feeding urea-molasses treated straw as supplemented with concentrate feeds under on-farm condition could replace the conventional roughage based diet which is hay in feeding milking cows. This is possible provided that the price of urea is affordable and molasses is accessible to the farmers. 

Key words: Boran-Friesian, Boran-Jersey, feed intake, hay, noug cake, Oromiya, smallholder farmers


Introduction

Ethiopia holds huge potential for livestock development due to its large livestock population, favorable climate for improved animal breeds and the relatively disease-free environment for livestock (Mohamed et al 2004). The supply of feed both in quantity and quality however is declining from time to time. Natural pastures (including hay), crop residues, aftermath grazing are the predominant roughage sources (Jutzi et al 1987; Getnet and Ledin 1999). Because of the expansion for cultivation of food crops and shrinkage of traditional grazing areas, crop residues are assuming greater importance as source of roughage than natural pasture and hay. The price of hay is becoming expensive from time to time owing to the scarcity of land. Agro industrial by products (oil seed cakes, various flour milling by-products such as wheat bran and wheat middlings as well as molasses (the energy feed resource produced from sugar factory) are the existing supplemental feed resources in the country. However the supply of these by-products is un-predictable and their use is limited to urban and peri-urban livestock producers (Adugna 2009). Crop residues are available in all agro ecologies of the country and belong to every farmer every year. Crop residues however contain poor nutrient content. They are low in nitrogen and the carbohydrate part is too fibrous which makes the straws less digestible and energy is not readily available to rumen microorganisms. Due to the unbalanced nutrient content, straw by it self cannot support ruminants, more than providing for maintenance (Kudo et al 1994; Nuwanyakpa and Butterworth 1987; Michael et al 1989).  

Urea treatment is important for improving nutritive value of cereal straws and stovers. It has been used in tropical and in developing countries. Straw treatment with urea has advanced from providing for maintenance toward improvement of production. It is the ammoniating effect that improves nutrient content and intake of straw (Willie 2001; Chesson and °rskov 1984; °rskov 1987; Kristensen 1984). Treatment of crop residues with urea is particularly adapted to the needs of small farms and producers, and can be undertaken within a family with out calling in help from externally paid labor (Djajanegra and Doyle 1989; O’ Donovan et al 1997; Chenost and Kayouli 1997).

Beyond improving the nutrient content, urea - molasses treatment withstands previous loss of crop residue and consequently save the bulk which leads to improved utilization of feed proper to the feeding calendar (Rehrahie and Ledin 2001). The practice of straw treatment in Ethiopia was mainly concentrated on research stations level with little or no on-farm application. There is a need to demonstrate the technology under farmers’ management with intention of developing a system which is both practical and easy for farmers adopt. There fore, the objectives of this study were to demonstrate feeding of urea molasses treated straw to dairy cattle under farmers’ management and to evaluate the response of smallholder farmers to urea-molasses treatment and feeding of urea-molasses treated straw to dairy cattle. 
 

Materials and methods

Site of the study

The study was conducted in a mixed crop-livestock production system using two breeds: Boran-Friesian and Boran-Jersey crossbred dairy cows maintained under smallholder farmers’ condition at Jeldu District. Jeldu is a district found in West Shoa zone of Oromiya Regional State which represents typical highland environments. It is situated about 125 km SW of Addis Ababa on the road from Ginchi to Gindeberet. The altitude ranges from 2900 to 3200 m.a.s.l. The rainfall pattern is bimodal. The soil is characterized as Haplic Luvisols. The main rainy season is from June to September with a mean annual rainfall of 1399 mm. Like other places in the highlands, crop- Livestock production is the mode of farming. Cereals pulses and oil crops were grown in the area. Among them, barley is the most dominant crop. The study was conducted at five peasant association (PA’S): Chlanko, Shkutie, Tulu Bultema, Adensa Gelan and Kolu Gelan. As Alemu et al. (1991) reported the availability of crop residues were closely related to the farming system and the crop produced and the intensity of cultivation. Thus barley straw is the main crop residue produced in the district.

Almost all common Livestock species including cattle, small ruminants, equines and poultry are raised in the study area. In addition, crossbred dairy cows were which previously demonstrated by the dairy research at Holetta, Ethiopia were benefiting to some selected model/participating farmers. The district was selected for the study as it represented the barley-based crop-livestock production typical of the central highlands of Ethiopia.  

Selection of farmers and training

Sixteen participating farmers having crossbred dairy cows were selected to verify the effect of feeding urea-molasses treated straw to dairy cows using a participatory approach. The cows were of two breeds: crosses of Friesian and Jersey. Theoretical and practical training was given to 16 farmers and five development agents. The training was focusing on procedures of urea-molasses treatment; amounts of the ingredients used during the treatment practice and care to be taken while carrying out the treatment process and feeding the treated feed to corresponding animals. In addition, farmers were advised to properly collect, bale and reserve the untreated straw in a well-shaded place which they will be used for the preplanned treatment. They were advised to reserve some area and woods that will be used for construction of silo. Farmers were also advised to select the treatment site to be away as much from the reach of poultry. Because poultry like to perch on top of the stacks and peck at the covering layer and thus expose some of the material to air and spoilage. If this is not possible they are advised to use simple protection methods from poultry enrichment. 

Preparation of silo and procedures of straw treatment

Farmers have selected proper site on their backyard and constructed an over-ground silo using local materials like woods and mud. The dimensions of the silo were 2m length, 1m width and 1m height. Each silo had 4 portions and each partition can hold 100 kg straw. The silo was lined with mud. The walls of the silos were devoid of holes protected not allowing air to enter. The floor of the silos was slope gently allowing any excess liquid or solution to sleep to the lowest layer to drain out. Each silo was constructed with shelter to protect the treated feed away from the sun’s direct heat radiation. Then farmers were checked whether they have prepared the facilities used for straw treatment on their site. Facilities and inputs that have been used for straw treatment including plastic sheet, nail, urea, and molasses were asked for purchase on the research side and were collected, transported and distributed to the participating farmers. Farmers were told to decide the amount of barley straw to be treated based on the number of animals to be fed. The detailed procedures of straw treatment and treatment duration were adopted from previous works of Rehrahie mesfin and Inger Ledin (2001).

For the preparation of water-urea-molasses-solution, farmers have been using any container commonly found at home. Some farmers used barrels cut in half and others used cut Jericans in small portion at the top and similar utensils with capacity enough to treat the prepared straw. For spraying the mixture of water-urea-molasses solution, farmers have used any can like utensils mainly with nozzle. For weighing urea, farmers have used a jug measuring 1 kg. For measuring water, they have used plastic buckets. For weighing straw, farmers used certain suck like material commonly found at home of individual farmer which, previously confirmed by weighing certain amount of straw. Fertilizer grade urea was employed for the treatment. The ratio of water-urea-molasses solution to straw was 1:1 (100 liters of solution for 100 kg of straw). To prepare 100 liters of solution, 5kg urea was added to 100 liter of water and stirred very well until urea was dissolved and clump of urea was disappeared from the solution. Then 10-liter of molasses was added and stirred very well until the molasses and the urea solution gets mixed up. The level of urea varies from country to country but is commonly between 4 and 5% of the air dry mass of straws or stovers (Sundst°l and Coxworth 1984; Schiere et al 1988; Dolberg 1992; Chenost 1995 Smith et al 1989). The amount of water used also vary ranging from as low as 0.2 liters per kg of straw in Zimbabwe (Willi et al 2001) to as high as 1 litre per kg of straw in Sri-Lanka (Shiere et al 1988). However, as O’Donovan et al (1997) noted the 1:1 ratio water-urea solution to straw was used for this demonstration because this proportion gave a moist and soft ensiled material. Unfortunately this was appropriate for the prevailing environmental condition of the area under demonstration. The procedure of the treatment was as stated in here. Polyethylene plastic sheet of 0.2 mm thickness was properly lined inside the silo already constructed. Although polyethylene is very effective for this but a number of locally available materials are also used such as banana leaves, soil, jute bags and cow dung in Bangladesh (Sundst°l and Coxworth 1984). Then untreated straw, in batches of 20 kg, was spread in the silo. Twenty L of urea solution was sprinkled uniformly or evenly over the straw layers using a sprinkler. The soaked or treated straw was mixed using local fork-like material. Further batches were treated following similar procedures. After treating one layer of straw, it was pressed by tramping before the next layer was placed on top. As soon as the silo was filled, the stack was covered tightly with the plastic sheet lined previously to exclude the entrance of oxygen, prevent ammonia from evaporating and to protect water from seeping which has paramount importance in obtaining a good quality finished product. The stack finally was loaded with sacks full of sand. The treatment period was 1 month. The treatment period can be as low as 7 days in warm climate and up to 8 weeks in cold climate (Sundst°l and Coxworth 1984; Chenost 1995, Chenost and Kayouli (1997). According to Sundstol et al (1978), recommended treatment periods at different ambient temperatures include: for temperatures below50C, 5-150C, and 15-300C and above 300C, more than 8 weeks, 4-8 weeks, 1-4 weeks less than 1 week of treatment durations respectively are required. To have continued access to the treated straws, the next treatment was done at a minimum of one month after the first treatment.  

Experimental diets and feeding and management

The experimental diets were two: The conventional feeding practice traditionally practiced by farmers which is mainly hay based diet (treatment1) and the intervention diet, urea treated barley straw based diet (treatment2). Individual farmers have used the same type of supplement diets for the experimental cows and were fed at the level required to fulfill the nutrient requirement of lactating cows. Adjustment of the concentrate supplement was made weekly based on the milk yield of each cow at the rate of 0.5kg/kg of milk production/day and fed in the morning and evening which is in the milking time by dividing the daily allowance in to two equal parts. The farmers were followed indoor feeding. Before feeding to the cows, the treated straw was aerated for 12 hours to reduce the concentration of ammonia gas. During the adaptation period, the cows were fed a mixture of the treated straw mixed with other feeds which the cows previously knew it. Both the treated and the conventional roughage feed was given ad libitum to ensure some amounts of refusals (10-15% of the straw offered) in the next morning. Adjustment of both roughages was worked weekly based on the amount of refusals weighed and recorded every morning. The experimental cows had free access to water throughout the experimental duration. Experimental cows were not given more palatable feeds, either as grazing or in confinement.

The study was implemented on farmer’s management with full follow-up on the research side. The study was stayed for one year in the dry season. In the second year farmers were advised to do the treatment by themselves and feed their cattle accordingly. Follow up was undertaken while farmers have been practicing the task by them selves. Finally, the response of framers to the treatment was evaluated.

Measurements and monitoring of the experiment

Data was recorded by a full time employee enumerator and follow up by the researchers was undertaken every week to monitor the feed intake, milk productivity and the entire management of the cows. Experimental cows have been milked with hand, twice a day: during morning and evening. Morning and evening milk right at the time of milking was measured. Farmers recorded the intake of roughage and concentrate as well as the daily milk yield using data recording sheet which previously provided to farmers. The recorded data was checked at each monitoring time for accuracy and consistency. Formal survey was conducted to asses the response of the participating farmers at the end of the experiment. Data on the perception of the farmers towards the practice of feeding urea treated straw to crossbred dairy cows was gathered. 

Statistical analysis

The data were subjected to analysis of variance (ANOVA) following the General Linear Model (GLM) procedures of Minitab statistical software version 12.21 (1998). DM roughage intake, DM concentrate intake and daily milk yield were considered the parameters for analysis. The statistical model is indicated below.

Yij k  =  Á + r i+ c j + t k(ij) + e ij k

Where;   Yij k  =   Dependent variable (dry matter feed intake and milk yield)

                Á   =     Overall mean

                 ri   =     Effect of lactation stage (period effect)

                 c=     Effect of cows                         

                 t k(ij)  =  Effect of diet

                 eij k     =  Random unit variation
 

Results and discussion

Farming system and traditional feeding practice

Livestock production in the demonstration district (Jeldu, West Shoa zone) is an integral component of almost all farming systems. Livestock is mainly used for the supply of draught power and provision of food. Grazing/green feed, crop residues, hay, locally produced by-products and to some extent commercially produced by-products are the feed resources here. Among these, grazing pasture, crop residues and stubble grazing are the major sources of basal diet. 

Daily feed and nutrient intake of experimental cows

The average daily DM and nutrient intake is presented in Table 1. The average daily DM intake of hay (8.7 kg) was significantly (P = 0.001) higher than urea treated barley straw (7.2 kg). Where as, cows fed urea treated barley straw based diet have consumed significantly (P = 0.001) higher average daily DM concentrate feed (5 kg) as compared to those cows that fed the hay based diet which consumed 3.9 kg/day. With regard to total dry matter feed intake, no statistical difference (P = 0.278) was observed between group of cows that fed hay vs. those group of cows that fed urea treated barley straw.

Table 1.Daily dry matter feed intake by crossbred dairy cows (LS-means and SE)

 

Hay diet

Urea treated barley straw diet

SEM

P value

Hay

8.7

-

0.23

0.001

Urea treated barley straw

-

7.2

0.23

0.001

Concentrate

3.9

5.0

0.14

0.001

Total DM feed intake

12.6

12.2

0.28

0.28


 Effect of experimental diets on milk production  

There was an indication (P=0.053) that cows that were fed hay had slightly higher milk yield than those fed urea treated barley straw (Table 2).  Rehraahie and Ledin (2001) reported that there were no significance differences in milk yield of cows that were fed hay based (conventional) diets and urea treated barley straw and urea treated teff straw.

Table 2. Daily milk yield of crossbred dairy cows fed hay or urea treated barley straw based diet (LS-means and SEM)

 

Hay diet

Urea treated barley straw diet

SEM

P

Milk yield, litres/day

11.3

10.5

0.23

0.053


Observed effects of straw treatment

Feeding urea treated straw withstands previous lose of crop residue and consequently save the bulk of feed proper to the feeding calendar. Compared to cows fed the conventional type of feeding, cows fed urea treated straw was observed to drunk more water than before. Urea treated fed cows were observed shiny skin. They were also observed to improve their body condition. Report of Schiere et al (1988) showed similar findings in that urea treatment increased daily live weight gain from -111 on UN treated rice straw to +83 g/day on treated straw when the two were fed as the sole diets. In another trial they observed a daily live weight gain256 g when growing Kilari and Sahiwali bulls were fed on treated rice straw supplemented with rice bran coconut cake compared to 68g on the untreated straw with the same supplement. Findings by Munthali et al (1992) and Hadjipanayiotou et al (1993), and in experiments reviewed by Sundstol et al (1978) and Tengyun (2000), also indicated higher live weight gains in growing animals receiving treated stovers compared to those on untreated straw/stover. Verma and Jackson (1984) reported an experiment where lactating cows on treated straw gained 93g/per day whilst those on untreated straw lost 266 g per day.

Among the model farmers selected for practicing straw treatment, 50% of them have accomplished the task successfully. But the rest of them have started, but interrupted for some reasons. Some farmers refused because they observed some family members frequently working with urea treated straw were exposed to coughing caused from the pungent smell of the non-aerated treated straw. Some believe that the task is labor demanding and others were because of no previous exposure to other agricultural technologies.

Most of the successful farmers are literate (at the level of elementary school) and had exposure to different agricultural technologies. Where as, at the end of the demonstration duration and in the absence of the support from the research side, the successful farmers were checked if they continue practicing the treatment. They were found that less than half of the successful farmers continued practicing it. The rest of them interrupted it mainly because of the inaccessibility of molasses in the vicinity.  

Though the practice of urea treatment is biologically promising and was applicable to the practice of smallholder farmers, it is becoming costly. The price of the raw materials used for the treatment particularly the purchased price of urea is increasing from time to time. The inaccessibility and increased price of molasses from time to time was another problem that restricts farmers from practicing it. Molasses is becoming scarce and inaccessible input in the country due to the additional utilization of it for the production of alcohol as source of fuel. Sometimes, traders/business men have been delivering molasses with prices which was costly and beyond the paying capacity of smallholder farmers. Farmers have to move more far to the source place to purchase it in a reasonable price. For individual farmer in the village, moving from his/her vicinity to the source place to purchase and transport back home is becoming economically challenging. The burden may be easier and simplified with the formation of farmers’ milk producing group. The problem may be simplified for organized farmers in all aspects like easily accessing market information, ease of input delivery in a bulk and sale of milk and milk products in good price which consequently reduce cost and benefit them. 

The long-term success and sustainability of urea treatment in Ethiopia can be attained when the inputs used for preparation of urea treated straw especially urea and molasses becomes affordable and accessible to the smallholder farmer. The rest of inputs and supplies can be used mainly from local materials. Plastic sheet that is required for covering the treated feed/stacks can either be purchased or used ones from urea sacks. If it is purchased ones, it can serve for frequent uses provided that it is handled with good care. Or else, plastic sucks that was coming with fertilizer urea can be used for this purpose. Since the price of the inputs and supplies used for straw treatment are increasing from time to time, continuous check is required for cost benefit issues. O’Donovan et al (1997) noted that the margin between the cost of urea treated straw and alternative roughages must be sufficiently attractive while they are applied at on-farm level. China was one notable exception in treating urea where the treated straw at on-farm level rose from 30,000 tones in 1985 to an estimated 6 million tones by the year 1992 (Dolberg and Finlayson 1995 In: O’Donovan 1997). In here, the treatment procedure differed little from the practice employed in other countries like in Bangladesh. Relatively small lots of straw were treated with urea, using over ground stacks and brick silo, which were covered with plastic and one might justifiably wonder why the adoption rate in China should be so much greater.

In this demonstration, construction of pit or silo which was an initial task in the straw treatment process was discouraging farmers. As a result, four of the participant farmers refused to continue because they felt that the task is labor expensive. In China, site selection and location of straw treatment was receiving more attention. The process of urea treatment was simplified using possible alternatives to minimize the size of plastic sheet used to cover the treated stack. It was reported for example use of the existing walls of farmhouses could be utilized to good effect. Choosing a corner location permitted the use of two walls. Since only the front and one side of the stacks were exposed, these were the only surfaces that had to be covered. In some instances, an existing structure having 3 walls was used, which reduced further the plastic needs (O’Donovan 1997). Thus, utilizing corner locations was considered as easier and simplifies the treatment process. In china, where a corner location was existed, some farmers easily and quickly built a third mud a wall of about 1.25 meters high at minimum cost (using family labor). Such structures were therefore developed to minimize or eliminate completely fixed structures in the form of pits and silos. In addition, over ground squares or rectangular stacks of straw were built, each containing from one-half to two tones of straw. After one or two stacks are built, the under layer of plastic sheeting was dispensed with and no ill effects were noted. Thus it became the standard practice to use only a top sheet of plastic which, when tucked securely under the stack to exclude air, allowed for good quality treated straw to be made and preserved (O’Donovan 1997).

Efforts in Balochistan were focused on testing alternatives and cheaper forms of covering, preferably those readily available on farm. Such tests revealed that plastic sacks, either new or used, cut open to increase surface area, could replace the plastic sheet if the sacks in turn were covered or plastered with a 1-2 cm layer of mud to provide an effective air seal. They also verified that the sack plus mud cover was about one-quarter of the cost of plastic sheet. Subsequently, all straw treatment applications employed this simplified lower-cost procedure. The quality of straw treated by this simplified method was as good as, and in many cases superior to, that achieved through the use of plastic sheet. The later development opened doors to the more rapid uptake and adoption of the technology at peasant farmer level. Other cheaper covering materials, besides plastic sacks, were also tested and adopted; these merely provide a base or holding medium for the layer of mud on top, with which care had to be exercised to ensure a uniform cover over the straw and with no air leaks (O’Donovan 1997).

In the current demonstration task, 16 farmers have been practicing the treatment, out of which eight of them (fifty percent) have properly treated, feeding the treated straw to their animals and accepted the feed technology and continued the practice to the end of the demonstration period. The rest of them interrupted due to different reasons. two farmers refused to continue the practice because they observed some family members frequently working with urea treated straw and feeding to animals were exposed to coughing caused from the pungent smell of the non-aerated treated straw. Four farmers interrupted the task because they believe that the task is labor demanding. The rest two interrupted the task because they seem accumulate very less exposure to agricultural technologies.

The experience of other countries like in Balochistan was; well sealed treated straw can be left for several months without adverse effect. In one instance, ensiled straw in the indicated site, when opened after one year, was found to be of acceptable quality. They were synchronizing the treatment with feeding. As experienced with the farming communities, ample adoption time for animals to become accustomed to the treated straw was series issue during the initial opening of stacks and the feeding of treated straw. More important was that animals were not given to access to more palatable feeds. The practice was mainly cheeped and cost-effective as large cash inputs are disincentives to poor farmers. They had relatively reasonable market for the improved livestock production (O’Donovan 1997). 
 

Conclusions and Recommendations


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Received 8 August 2010; Accepted 3 November 2010; Published 1 February 2011

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