A novel intervention based on Browse-aid to prevent animals from dying during droughts in Ethiopia and beyond: A game changer

By Harinder Makkar, Abay Bekele, Yosef Seyoum Mulugeta, Andinet Adamu, Redwan Getachew Asfaw, Wesinew Adugna Bekele, Abdinur Ali Warfa, Degefa Wayessa, Merkeb Belay & Genene Regassa

Introduction

During droughts the only greens available on the rangelands are browses, shrubs and trees; generally termed as browses. The grass disappears. Notably, even under normal conditions, the biomass from browses is 4-5 times greater than that from grasses on the soil. Browses can be good feed resources during dry and drought seasons. However, animals do not consume them due to the presence of tannins. The consumption of browses produces dry, puckerish and bitter tastes in the animal mouth. Additionally, their consumption can cause digestive problems. These effects are attributed to the high affinity of tannins for proteins. They bind membrane proteins and inhibit enzymes. Tannin-protein complexes are poorly degraded in the gastrointestinal tract, decreasing protein availability. Tannins also bind to minerals and decrease their availability to animals. The crude protein content of browses is very high (15-23% on a dry matter basis), but the presence of tannins decreases their availability to animals.

In droughts, large amounts of feed are transported from the Ethiopian highlands to drought areas in the lowlands of Ethiopia. The high transport cost of feed makes feed provision to affected areas very expensive. In addition, the emergency feed provided to farmers for their animals is not sufficient for all the animals, and the emergency feed does not reach all the pastoralists. A large number of animals die because of feed shortage. Utilization of browses present in situ in drought areas can save animals from dying, provided tannins present in these browses can be neutralized. The use of this in situ feed by ruminant animals could help reduce the amount of feed transported into the affected areas. The provision of feed in affected areas is expensive, mainly due to high transport cost. Several studies have been conducted at research stations showing the benefits of the inclusion of the Browse-aid (polyethylene glycol 4000) in diets containing high amounts of tannins.

The approach used at farmers’ farms

Polyethylene glycol 4000 as Browse-aid

Among PEGs of various molecular weights, PEG 4000 has the highest ability to neutralize tannins. The PEG has several applications in the cosmetic, pharmaceutical and food industries and hence is available in abundance on the market. PEG is a synthetic compound and is inert, water soluble and tasteless; therefore, animals can easily consume it. Because of their inertness and lack of skin irritation, PEGs are widely used in pharmaceuticals, e.g., in the preparation of ointments, suppositories, tablets, and solvents for injection, as well as in cosmetics, e.g., creams, lotions, powders, cakes, and lipsticks. PEG 4000 is a laxative available over-the-counter and is named Miralax. PEGs have low toxicity, are miscible with aqueous fluids in all proportions, and dissolve many poorly soluble aqueous compounds. PEG is also a part of several medicines.

Browse-aid levels

In our study we evaluated the effects of dietary inclusion of the Browse-aid (polyethylene glycol, PEG-4000) on animals at two different sites during the peak dry spell, where feed and water were very scarce. The field trials were conducted in the second half of 2023. During the trials, the sites were devoid of any grasses. Browses were present at both sites. We postulated that the Browse-aid at low levels of inclusion in diet would be effective at enhancing the consumption of browses present in the rangeland and providing nutrients to animals from these in situ present feed resources. In on-station research, inclusion of PEG-4000 or PEG-6000 in diets was at high levels, with the aim to neutralize most of the dietary polyphenolics/tannins; however, in the field trials conducted in this study the aim was to evaluate whether low levels of PEG-4000 could prevent death of animals during droughts. Studying low levels of PEG-4000 was important for decreasing the cost of the treatment and for providing benefits to a large number of animals, thus helping to save the livelihood of a large number of pastoralists and agro-pastoralists during droughts. 

Field trial locations

The field trials were conducted at two different sites: Nakiya Kebele, Dassenech District, in the former South Omo zone, Southern National Nationalities and People (SNNP) region state of Ethiopia; and Anokulul kebele of Gode Woreda. The trial was conducted in the field using farmers’ animals and under natural conditions in which the animals are reared.

Figure 1. Site 1: Nakiya Kebele, Dasenech District, SNNP, Ethiopia Region

Figure 2. Site 2: Anokukul Kebele of Gode Woreda, Somali Region

Animal species and treatment protocols used in the trials

The study was conducted on sheep and cattle at Site 1 and on sheep, goat and cattle at Site 2; and the duration of the trial was 45 days and 50 days respectively.

Wheat bran (WB) was used as a vehicle for administration of the Browse-aid. The Control group was given 100 g of WB. Sheep and goats were given 5 g and 10 g of the Browse-aid along with 100 g WB; while for cattle 15 g and 30 g were given along with 100 g of WB.

Findings

At site 1 the incorporation of the Browse-aid increased the percent gain in body weight of sheep by up to 32% and in cattle by up to 19%. The increase was concentration dependent (Tables 1 & 2). The progression of the body weight changes is given in Figures 3 and 4.

Trial Group	Initial	Final (on day 45)
Control Group
Absolute body weight, kg	20.3 + 4.97	22.05 + 4.67
ABW change (Final minus Initial) in kg	1.8
ABW, % change in live animal body weight, SD	10.0 ± 0.10a
Daily dose of Browse-aid: 5 g
Absolute body weight, kg	24.4 + 6.87	28.65 + 6.77
ABW change (Final minus Initial) in kg	4.3
ABW, % change in live animal body weight, SD	20.0 ± 0.16b
Daily dose of Browse-aid: 10 g
Absolute body weight, kg	22.79 + 5.54	29.53 + 5.84
ABW change (Final minus Initial) in kg	6.7
ABW, % change in live animal body weight, SD	32.0 ± 0.116c

^a,b,c Means with different superscripts differ at P<0.05 (values are mean + SD)

Table 1. Change in average body weight gain (ABW) gain in sheep 

Figure 3. Change in sheep weight during trial

Trial Group	Initial	Final ( on day 45)
Control Group
Absolute body weight, kg	232.3 + 8.68	212.9 + 8.97
ABW change (Final minus Initial) in kg	-19.4
ABW, % change in live animal body weight, SD	-1.0 ± 0.04a
Level-1 (15 g Browse-aid) Group
Absolute body weight, kg	152.6 + 8.04	172.9 + 8.24
ABW change (Final minus Initial) in kg	20.3
ABW, % change in live animal body weight, SD	13.0 ± 0.06b
Level-2 (30 g Browse-aid) Group
Absolute body weight, kg	181.1 + 11.70	212.1 + 12.23
ABW change (Final minus Initial) in kg	31
ABW, % change in live animal body weight, SD	19.0 ± 0.06c

^a,b,c Means with different superscripts differ at P<0.05 (values are mean + SD)

Table 2. Change in average body weight (ABW) gain in cattle

Figure 4. Change in cattle weight during trial

The qualitative parameters, with respect to hair coat appearance, shine in the eyes and body condition score were also better in the Browse-aid fed group. The changes in body weight gain and in the qualitative parameters were similar at site 2.

Foraging frequency, defined as the frequency of foraging during the day (when the animal browsed for a certain time and then rested under tree shade, ruminated and started foraging), also increased in the Browse-aid group. Besides for both sheep and cattle, the Browse-aid induced voracious browsing behaviour for the browses and shrubs that are normally not eaten (see videos, the links of which are given at the end). The animals fed the Browse-aid started consuming Abutilon Indicum, Arctostaphylos patula, Calotropis gigantea and Acacia spp., which are shrub species widely found in the East African Rangelands (Figures 5,6 & 7).

Figure 5. Sheep browsing Calotropis gigantea. Photo credit: Eneyew Tesfaye, VSF-Germany

Figure 6. Sheep browsing Abutilon indicum. Photo credit: Eneyew Tesfaye, VSF-Germany

Figure 7. Cattle browsing "Alegn" (Arctostaphylos patula). Photo credit: Eneyew Tesfaye, VSF-Germany

It is worth noting that these positive changes were observed at very low levels of the Browse-aid incorporation in the diet (daily dose of 5 g for small ruminants and 15 g for cattle).

Almost 100% of the Browse-aid comes out in animal faeces and is deposited in the soil. However, a number of studies have shown that Browse-aid is degradable both in the soil and in other environments. The delivery of the Browse-aid to soil through animal faeces is not expected to have any adverse effects on the environment.

The livestock farmers who participated in the field trials at both sites were overwhelmed by the growth response and overall conditions of the animals. Initial scepticism about the effectiveness of a small amount of the Browse-aid turned into excitement and happiness when the body weights and body condition scores improved, while animals of neighbours that did not participate in the trial lost weight and were in poor body condition. All the livestock farmers in the villages where this trial took place and those in the surrounding villages showed keen interest in using this technology in the future.

Learning from the study for practical application of the Browse-aid intervention

For future application of the Browse-aid at livestock farmers’ doorsteps, the following may be considered.

Amounts of the Browse-aid and wheat bran.

The Browse-aid inclusion in the diet should be at a level of 5 g/day for sheep and goats and 15 g/day for cattle to prevent deaths of animals during severe droughts. For sheep and goats, a daily dose of 5 g of the Browse-aid would also lead to an increase in body weight, while a daily dose of 15 g of the Browse-aid would maintain the body weight in cattle. A higher level of the Browse-aid (10 g/day for sheep and 30 g/day for cattle) would further increase the body weight gain; however, it would incur an additional cost. However, this approach would enable livestock farmers to sell animals during droughts, dry spells or just after droughts at a higher price. An economic evaluation that considers the additional cost of the Browse-aid inclusion at higher levels and additional monetary gains from selling livestock is needed.

The daily amount of wheat bran, used as a carrier for the Browse-aid, can be reduced to 50 g. This would reduce the cost of feeding. Since wheat bran is only a vehicle for the administration of the Browse-aid, any other locally available cheaper feed ingredient could also be offered inplace of wheat bran to reduce the cost of the Browse-aid administration to animals. Water could also be a potential vehicle because the Browse-aid is highly soluble in water and is tasteless. However, during droughts, water is a scarce commodity and is available to livestock farmers at a cost. Additionally, the inclusion of the Browse aid in water decreases its retention time in the rumen, which might decrease its effectiveness.

Preparation and provision of the Browse-aid containing wheat bran (or any other locally available feed ingredient) in the field.

Two approaches could be considered: a) preparation of the Browse-aid containing wheat bran (or any other feed ingredient), e.g., for a one-month period, and b) the desired amount of the Browse-aid to be offered on a daily basis. For the former, the approach described below is for 100 sheep and goats.

Suggested Browse-aid incorporation rate = 5 g/day/small ruminants (sheep or goat)

For 100 small ruminant, Browse-aid requirement would be 500 g/day

For 100 small ruminants, Browse-aid requirement for 30 days would be 15 kg  ……… (A)

Similarly, wheat bran requirement @ 50 g/day, for 30 days would be 150 kg ……… (B)

Mix A and B thoroughly and advise farmers to administer @ 55 g of this mixture per sheep or gooat daily. A container with a mark or when full that delivers 55 g of the mixture can be given to the farmer. This approach could also be adopted by drought-managing organizations.

For approach b), in which the Browse-aid can be given on a daily basis, a suitable size spoon can be used to deliver 5 g of the Browse-aid. Similarly, a container with a mark (or when full) to deliver 50 g of the wheat bran (or any other feed ingredient) could also be provided to the farmers.

A similar approach could be used for cattle.

Dissemination

The Farmer (pastoralist) Field School could be used to further promote the Browse-aid approach and to test the appropriateness of strategies to deliver the Browse-aid to animals. Short video clips demonstrating cattle and sheep browsing extensively on browses and shrubs have been prepared[1] and presented to community members, government experts (federal, regional, zonal, and woreda levels), research centers (Somali Livestock and Pastoral Research Institute (SOLPARI) and Jinka Research Center (JRC)) and non-governmental organization and donor communities such as the European Commission of Humanitarian Aid (ECHO), the United States Agency for International Development (USAID)-Bureau of Humanitarian Assistance (BHA), and the Office for the Coordination of Humanitarian Affairs (OCHA).

Browse-aid as a complementary drought management strategy.

The drought risk management strategy employed in arid and semiarid lands (ASLs) by communities involves the segregation of herds into homestead herds, which include breeding animals (such as pregnant cows/ewes, lactating cows/ewes and calves/lambs); and satellite herds (comprising nonbreeding animals such as dry cows/ewes and bulls/rams).

The satellite herds in the dry season/in drought conditions move away from residential areas to dry season grazing areas found around permanent water points to avoid competition with homestead herds. These animals scavenge available palatable grasses, and at times, they are supplemented with crop by-products or share grazing with wild animals in/near national parks. When the rains start, the satellite herds return to residential areas (wet season grazing areas) so that the dry season grazing areas recover for the next dry season. The Browse-aid provision to animals could be an important strategy aimed at preventing noncore breeding stock (satellite herd) from dying during droughts, which constitute almost 70% of the herd. In the event of droughts, a large number of these animals die due to starvation.

The homestead animals remain behind, around residential areas during the dry season and during droughts. Homestead animals are allowed to feed on enclosures. Since the 2005 drought, large quantities of hay and concentrated livestock feed have been transported from the highland region of Ethiopia to drought-affected areas, primarily to protect core breeding stocks. This approach is costly, can introduce parasitic infestations (e.g., liver flukes) to drylands and can have unintended negative impacts on the dairy and beef industries in highlands, mainly due to an insufficient supply of feeds. Furthermore, the feed provided by NGOs and governmental agencies to these breeding animals during droughts is insufficient. During dry seasons and during droughts, grazing land around residential areas also contains browses and shrubs. The inclusion of the Browse-aid into the diets of these animals would also improve the production and health of homestead animals.

Many studies have estimated that the cost of transport of feed from the highlands to the drought-affected areas to protect core breeding stocks is 4 to 5 times the price of livestock feed. The Browse-aid strategy is cheaper by approximately 60% for sheep and 90% for cattle compared to the available emergency livestock feed options, as shown in this study. It may be noted that the animals that are not allowed free access to browses in the rangeland will not benefit from the Browse-aid. In addition, the Browse-aid will not benefit the animals under conditions where grass is available on the rangelands.

Takeaways

From the results obtained in Ethiopia, it can be concluded that the inclusion of the Browse-aid improved:

• body weights of both the sheep and goats and cattle;
• hair coat appearance and softness;
• shine in the eyes;
• browsing behaviour, leading to increased consumption of shrubs and browses; 
• the body condition score;
• consumption of in situ browses and shrubs when the rangeland is depleted of grasses and other normally consumed browses on rangelands during dry seasons and during droughts; and
• use of the Browse-aid is cheaper than other options currently used during droughts

Provision of the Browse-aid to animals during the drought/dry season is a promising strategy not only for preventing deaths during meagre availability of feed but also for maintaining the body weight of the animals. This strategy would decrease the amount of feed needed at drought sites to prevent animal deaths and body weight loss and to maintain the productivity of breeding stocks during these critical periods. This study has implications for all countries in the Horn of Africa and for areas in other countries that face droughts.