Livestock feed potential of mango (Mangifera indica Linn) seed kernel

Abstract

Mango (Mangifera indica Linn) fruits weigh from small to large about 1 kg in some cultivars. It easily ripens within 6 months, turn reddish and ready for consumption. Most of the produced mango fruit can be consumed fresh and less amount (less than 2%) of it become processed to different products including juice. During processing of mango fruit for consumption, large quantity of mango by- products which can be used as animal feeds and some important antioxidants can be produced. Mango seed kernel (MSK) is a by-product of mango used for both human and animal consumption after several treatment options. In mango fruit, MSK constitutes about 45% to 75% of the whole seed. Mango seed kernel composes greater amount of carbohydrate, protein, fiber, fat, amino acids, important anti-oxidants and minerals comparable to maize. Mango seed kernel contains some important acids which can be fractionated in to the different oils and used in chocolate making by replacing some forms of butter in developed countries. Although MSK is cheap and contains high amount of metabolizable energy, MKS is rich in anti-nutritional factors like tannin which is difficult for animals to consume. However, research reports showed that effective treatment methods like boiling, soaking and drying reduced the anti-nutrient to the level safe for both ruminants and monogastric animals. It is concluded that MKS is a potential energy feed resource for farm animals and inclusion of mango seed kernel up to 25% in layer, up to 30% in broiler nutrition and up to 40-60% in ruminants nutrition has no detrimental effect, profitable and can be best alternative feed sources if well treated by using the best technical methods of anti-nutritional factors reduction like boiling.

IMPACT STATEMENT

Mango seed kernel, which is the byproducts of Mango fruit, can be obtained during processing of mango fruit either for industrial in factory or direct use at home. Although different countries have been producing large amount of mango fruit, there is a huge MSK which is about 60% of the whole fruit weight. So these huge amount of by products are left at vicinity without any use and causing environmental pollution, which is a health hazards for human life in general. On another hand there is increasing human population in the world and these demands animal products like meat, milk, egg and the like, but there is shortage of conventional feed resources for feeding these demands and needs additional sources like using MSK after treating it by using recommended technologies. So mobilizing of such wastes has beneficial for public interest in that, it can fill the feed scarcity gap and also minimize environmental pollution as waste disposal mechanism.

Keywords:

• Livestock feed
• anti-nutritional factors
• boiling
• mango seed kernel

SUBJECTS:

• agriculture & environmental sciences
• plant & animal ecology
• soil sciences

REVIEWING EDITOR:

• Pedro González-Redondo, Senior Editor University of Seville, Seville, Spain

Introduction

Ethiopia stands first in largest livestock population in Africa and seventh in the world and owns about 70 million cattle, 42.9 million sheep, 52.5 million goats, 2.15 million horses, 10.80 million donkeys, 0.38 million mules and about 8.1 million camels and 57 million chickens (CSA, 2021). In spite of these huge livestock number and kind in the country, the productivity per head including chicken and the contribution of this sector to the national economy is relatively low and is limited to farm to fork of their products. The prime factor is the feed scarcity in quality as well as quantity especially the conventional energy and protein source ingredients in spite of the animal type and the consequence in high price of the products (meat, milk and eggs) (Aberra et al., 2011, Nigussu et al., 2019, Yasin et al., 2022).

In many situations, there is also increasing competition between humans and animals for the same products especially for maize that aggravate the food security problem in the country (Nigussu et al., 2019, Yasin et al., 2022). To break and minimize this pressure, there is a need to focus on and mobilizing the use of non-conventional feed resources which are cheap, simple and best alternative. One of the non-conventional feed resources might be mango seed kernel (MSK) and other similar fruits by-products in line with reduction of their negative impact on the environment and human health when left as wastes (Yasin et al., 2022).

The potentials of MSK as animal feed, especially for the chicken feed have been elaborated and discussed in detail so that it can help to solve the scarcity created between animal and man in general and poultry sector in particular (Das et al., 1988; Dhingra & Kapoor, 1985; El Alaily et al., 1976; Yibrehu et al., 2012). Mango seed kernel has been studied and found having a high amount of energy, fat and minerals but has a lesser percent of crude protein (CP) (El Alaily et al., 1976) and has 77% NFE (nitrogen free extractives) (Patel et al., 1971, Dakare et al., 2012). Mango seed kernel can easily be processed and contained in nutrients like carbohydrate, protein, fiber, ash, calcium and phosphorus that is comparable to maize depending on varieties (Table 1 and 2) (Patel et al., 1971, Diarra, 2014). The MSK is also balanced in the limiting amino acids like lysine and methionine (Table 3) (Abang et al., 2023a,b; Fowomola, 2010).

Table 1. Proximate analysis values of mango seed kernel.

Characteristic	Reported values (mean)
	Znikou et al., 2010; Yasin et al.,2022 ;Dhingra & Kapoor, 1985; Changso, 2008
Moisture content %	38.55-45.20
Crude protein %	5.34-6.36
Fats (oil) %	7.82-13.00
Crude fiber %	2.02-3.96
Ash content %	2.75-3.20
ME (kcal/kg)	3275-3400
NFE%	67-70

ME: metabolizable energy; NFE: nitrogen free extractives.

Table 2. Important minerals in mango seed kernel mg/100g.

	Znikou et al., 2010; Fowomola, 2010
Calcium (Ca)	110-111
Magnesium (Mg)	85-95
Potassium (K)	18-22
Sodium (Na)	21-26
Phosphorus (P)	19-20
Iron (Fe)	12
Manganese (Mn)	1

Table 3. Essential amino acid profile in mango seed kernel (g/100g protein).

Essential amino acids	Reported values (mean)
	Arogba, (1999), Dakare et al., 2012, Yasin et al., 2022)
Lysine	3.13-5.5
Methionine	1.02-2.3
Threonine	2.03-3.38
Arginine	5.2-8.86
Valine	3.90-5.0
Histidine	2.29-2.65

Although MSK is selected and used as chicken feed having that huge potential in it, it also contains anti-nutrients like tannins and trypsin inhibitors that makes it unsafe feed prior to further processing and removal of the anti-nutrients (Abang et al., 2023a, Dakare et al., 2012). Different processing methods have been suggested to remove these toxic substances from MSK and some of them are soaking, boiling, leaching fermentation and others (Dakare et al., 2012, Yasin et al., 2022). Several researchers reported the treated (de-oiled, soaked or boiled) MSK has been successfully used to replace maize in levels up to 15-20% in poultry diets (Abang et al., 2023b, Archibong & Shien, 2023, Odunsi, 2005; Yasin et al., 2022). The general objective of the current study is to explore and review the potentials of MSK as an alternative livestock feed resource in the country.

Origin, distribution and production potential of mango fruit

Mango (Mangifera indica) tree is originated from Southeast Asia and distributed across all regions of tropical and subtropical areas (Orwa et al., 2009). Mango belongs to fruits of the family Anacardiaceae and species Mangifera (Mangifera indica L) (Farag, 2001). This fruit is ranked as the 3^rd most important tropical fruit crop after banana and plantains (FAO, 2021) and with its estimated production potential of 57 million tons in 2021 (Jedele et al., 2003; FAO, 2021). Mango fruit can grow and establish at optimum temperature and rainfall across the regions ranging from 24-30 °C and rainfall between 750-2500 mm, respectively and reaches its pick during dry period. It can tolerate drought and flood but performs poorly in frosty areas especially during young shoot development and flowering time especially when temperature is below 4 °C. It cannot stand acidic and saline soils and can easily be killed and cannot be productive (Sukonthasing et al., 1991). More than the 80% of the world’s mango production came from Asian countries while small amount from an African country, Nigeria (Orwa et al., 2009).

The World’s mango fruits production reached more than 57 million tons in 2021 and Egypt contributed about 1.40 million tons (FAO, 2021). The production of mango fruit became more popular and increased from time to time and doubled within a short period of time. At the same time the export of mango fruit becomes increased and it was about 2.1 million 2021 (Jedele et al., 2003, FAO, 2021). Mango is one of the most widely grown fruits among the fruit crops cultivated in Ethiopia preceded only by the banana in terms of economic importance (Fita, 2014).

A total of 105,379.375 tons of mango is produced from 16,363.48 ha of land (CSA, 2020). It is grown in several parts of the country where the western and eastern Ethiopia are among the major producing belts that accounts >50% of the total mango production in Ethiopia (CSA, 2015). Mango fruit size ranges from small to large weighing about 1 kg in some cultivars and can easily ripens within 6 months and turns reddish during that time and becomes ready for consumption.

The world’s top ten mango producers with their main varieties were identified and provided in Table 4. In the context of Ethiopia, mango is produced in the southern and eastern parts of the country. The total production of mango in Ethiopia is about 142,630 tons in 2022 Ethiopian fiscal year (CSA, 2022). The production of mango at Arba Minch and around Woredas was 126,800 quintal with the total area coverage of 634 hectares. Mango farmsteads in Asossa produce an average of 13,500 mangoes per farmstead (James et al., 2008).

Table 4. World’s top ten mango producers, 2021.

No	Country	Variety	Production (tons/year)
1	India	Alphonso, Badami, Chaunsa, Dasheri, Kesar, Jauhari, Lucknowi, Fazli, Totapuri, Banganapalli, Sindhuri, Kalmi, Neelam, Langra	25,337,400
2	China	Zillate, Mallika, Deshehari, Edward, Saigon, R2E2, Spooner, Bambaroo	4,351,593
3	Thailand	Brahm Kai Meu	2,550,600
4	Pakistan	Anwar Ratol, Langra, Sindhri, Chaunsa, Fajri, Samar Bahist, Dasehri, Saroli	2,784,300
5	Mexico	Ataulfo, Haden, Tommy Atkins, Kent, Keitt	2,632,650
6	Indonesia	Arumanis, Gedong	3,613,540
7	Brazil	Espada, Rosa, Bourbon, Uba	1,188,910
8	Bangladesh	Gopalbhog, Himsagar, Khirsapat, Langra, Fasli, Ashwina, Amropali	1,547,850
9	Philippine	Champagne mangoes	852,576
10	Nigeria	Kerosene, Sherri	927,200

Source: FAOSTAT (2021).

The production of mango fruits in Ethiopia (CSA, 2003–2022) is summarized and presented below in Table 5. The production increased from time to time, but the postharvest loss reached at 26.3% due to the perishability nature of mango fruit. There is not only a need but also a potential for the fruit to be processed into various product types, consequently increasing the market potential of mango fruit (Kader, 2009). Industrial processing opportunities, to increase the market value of the initial fruit, may lead to the potential development of the following products: - Food (mango juice and fizzy drinks, canned fruits and pulp, fruit leather, dried pieces, jam and chutney), domestic (mango detergent and cleaning agents), beauty (as an applied product in skin creams), animal feed (MSK, Mango Peel, Saponin) (Table 6).

Table 5. Estimated area of production and yield of mango fruits in Ethiopia during the Meher season for the last three years (2020-2022).

Year	Area in hectare	Production in quintal (qt)	Yield in (qt/ha)
2019/20	16,340.92	1,051,660.85	64.36
2020/21	20,783.10	1,513,312.40	72.81
2021/22	24,153.55	1,426,301.14	59.05

Source: CSA, (2020, 2021, 2022); and FAOSTAT (2021).

Table 6. Estimated area of production and yield of mango fruits for three high producing regions of Ethiopia during the Meher season (2020-2022).

Amhara region
Year	Area in hectare	Production in quintal (qt)	Yield in (qt/ha)
2019/20	–	82,940	–
2020/21	295.20	–	–
2021/22	2,321.70	115,239.16	49.64
Oromia region
2019/20	–	389,554	–
2020/21	244.43	10,857.87	44.42
2021/22	10,240.90	619,888.07	60.53
SNNP region
2019/20	–	502,925	–
2020/21	313.16	21,275.81	67.94
2021/22	7,520.90	557,527.62	74.13

Source: CSA, (2020, 2021, 2022); and FAOSTAT (2021).

Table 7. Estimated by product yield of mango fruits for three high producing regions during the Meher season during the last three years (2020-2022).

Amhara region
Year	Area in hectare	Production in quintal (qt)	Yield in (qt/ha)	Peal production(qt)	MSK production(qt)
2019/20	–	82,940	–	12441	49764
2020/21	295.20	–	–	–	–
2021/22	2,321.70	115,239.16	49.64	17285.874	69143.49
Oromia region
2019/20		389,554	–	58433.1	233732.4
2020/21	244.43	10,857.87	44.42	1628.68	6514.72
2021/22	10,240.90	619,888.07	60.53	92983.21	371932.85
SNNP region
2019/20	–	502,925	–	75438.75	301755
2020/21	313.16	21,275.81	67.94	3191.37	12765.49
2021/22	7,520.90	557,527.62	74.13	83629.14	334516.57

Source: CSA, (2020, 2021, 2022); and FAOSTAT (2021).

Table 8. MSK toxic substances and handling process.

MSK toxic substances	Handling process
	Yasin et al., 2022; Dakare et al., 2012; Odunsi, 2005; Ramteke et al., 2019, Rehman and Shah, 2005
Tannin	Sundried + Boiled; Sundried + Boiled + Ca(OH)2; soaking + cooking + sundried + milling
Cyanogenic glucosides	Boiled + Ca(OH)2; Sundried + Boiled; Sundried + Boiled + Ca(OH)2
Oxalates	Sun dried + Boiled, boiled + HCI
Trypsin inhibitors	boiled + HCI; Boiled + Ca(OH)2; Sun dried + Boiled ; Sun dried + Boiled + Ca(OH)2

By product production potential of mango fruit

Mango processing industries utilize up to 25% of the mangoes produced, equivalent to about 10 million metric tons per year worldwide and during its processing, huge amounts of peels and seeds are generated as by-products, which are often times regarded as wastes. It can be estimated that during mango processing in different products it yields between 150,000 and 400,000 metric tons of wastes as by-products in the world per year, causing environmental pollution in the vicinity of the processing plants as well as increasing labor requirements in the cities and towns (Beyene, 2015).

Its disposal is a major problem among many fruit processing industries because such wastes are easily spoiled, degraded and is a potential hazard to both people and the environment. The waste peels and seeds of mango amount to 35 - 60% of the total fruit weight, of which mango peels form about 15-20% of whole mango fruit and the remaining 20-40% may be composed of the mango seeds. This invention attempts to exploit such fruit wastes in order to recover more valuable compositions or products from such seemingly worthless by-products in fruit processing (Evelyn, 2013). So, to minimize this environmental crisis and pollution there must be utilization options for reducing environmental pollution and keeping the vicinity clean and safe (Jedele et al. 2003; El-Kholy et al., 2008) (Table 7).

Definition and concepts of mango seed kernel

Mango contains larger sized seed between 10 to 20% of the fruit weight (Palaniswamy et al., 1974). There may be differences in the composition and contents of mango fruits by-products depending on variety of the fruit, stage of maturation, way of processing and storage and environmental conditions (Mustefa et al., 2018). Mango fruit comprises the skin, pulp and seed kernel. During mango processing, peel and kernel constitute about 17-22% of the fruit (Mustefa et al., 2018). Mango seed kernel is the inner most parts and by-product of mango (Mangifera indica Linn) used for both human and animal consumption after several treatment options. Mango seed is a single flat oblong seed and its coat is about 1 - 2 mm thick lining covering a single embryo, 4 - 7 cm long, 3 - 4 cm wide, and 1 cm thick. Mango seed consists of a tenacious coat enclosing the kernel and the kernel content of the seed ranges from 45.7% to 72.8% (Hemavathy et al., 1988). In countries such as in India, Pakistan and Bangladesh where mangoes are abundant, these by-products are also available in quite large quantities. India alone produces an estimated >1.5 million tons of MSK annually (FAOSTAT, 2015). In Ethiopia also about 7219 tons of mango seed kernel, was produced annually (CSA, 2014). But this number is increased to 10538 ton annually by 2020 in Ethioipia (CSA, 2020).

Nutritional composition of mango seed kernel

Mango seed kernel composes greater amount of carbohydrate, protein, fiber, fat, acids, amino acids, important anti-oxidants and minerals equivalent to that of maize and other feed sources (Anon, 1967; Kiftewahid et al., 1982). Due to the presence of phenolic compounds, mango seed kernel is a potential source of natural antioxidants. Major phenolic components in mango seed kernel are tannins and flavonoids (Maisuthisakul, 2009). Other constituents of antioxidants present in mango seed kernel are ellagic acid, gallic acid, coumarin, ferulic acid, vanillin and cinnamic acid (Abdalla et al., 2007). It contains tannin 20.7, gallic acid 6.0, cinnamic acid 11.2, ferulic acid 10.4, mangiferin 4.2, vanillin 20.2 and caffeic acid 7.7 mg per 100 gram of dry mango seed kernel weight (Ahmed et al., 2007). Antioxidant activity of mango seed kernel is higher among variety of fruit seeds such as jackfruit, tamarind and avocado due to its high polyphenolic content (Soong and Barlow, 2004). Schieber et al. (2003) and Nunez-Selles (2005) reported that mango seed kernel showed antioxidant effect due to polyphenols, phytosterols and microelements such as zinc, copper and selenium. Therefore, it is the reason for industrial utilization of mango seed kernel as a functional food ingredient. Early work by Kehar and Chandra (1945–1946) indicated that mango seed kernel had a digestible crude protein (DCP) content of 6.1% and a total digestible nutrient (TDN) content of 50.0%. Mango seed kernel contains some important acids which can be fractionated in to different oil and used in chocolate making by replacing some forms of butter in developed countries (Gunstone, 2006) (Table 8).

Potassium is an essential nutrient and has an important role in the synthesis of amino acids and proteins (Malik & Srivastava, 1982). Calcium and magnesium plays a significant role in photosynthesis, carbohydrate metabolism, nucleic acids and binding agents of cell walls (Scalbert, 1991). Calcium assists in teeth development (Brody, 1994). Magnesium is essential mineral for enzyme activity, like calcium and chloride; magnesium also plays a role in regulating the acid-alkaline balance in the body. Phosphorus is needed for bone growth, kidney function and cell growth. It also plays a role in maintaining the body’s acid-alkaline balance (Fallon & Enig, 2001). Fowomola (2010) reported that mango seed kernel contains higher amount of vitamins and important anti-oxidants which are the backbone of the feed components around the world which are used for the health and good performance of both ruminants and non-ruminant animals including the chicken (Table 9).

Amino acid profile of mango seed kernel

The amino acids content of mango seed kernel are demonstrated in different journals and it contains both essentials and non-essential amino acids which are important in animal feeding. Mango seed kernel has higher percent of valine and phenylalanine content followed by threonine, lysine and tyrosine (WHO (World Health Organization), 1985 and Arogba, 1999).

Challenges and limitations of using mango seed-kernel as animal feed:- toxic substances of mango seed kernel

One limiting factor in this feed is the presence of about 5 - 10% of tannins (Table 6). There is information gap on the use of MSK for livestock feeding and its use is limited in poultry sectors also due to anti-nutritional factors which reduces chicken growth (Odunsi, 2005; Teguia, 1995). Since MSK contains some toxic substance like tannin, it will reduce the growths of chicken and pigs if fed untreated (Moore, 2004). Mango Seed Kernel also contains cyanogenic glucosides (64 mg/kg DM), oxalates (42 mg/kg DM) and trypsin inhibitors (20 TIU/g DM) (Ravindran & Sivakanesan 1996). These anti-nutrients chelate divalent ions like Ca²⁺, Mg²⁺, Fe²⁺ and Zn²⁺. It also reacts with the charged groups of protein and polysaccharides thereby forming indigestible complexes while the toxic substances interfere with nutrient bioavailability and utilization (Dakare et al., 2012).

Processing and handling of mango seed kernel for animal feeds purpose

Different processing methods such as soaking, drying, heating and the combination of one of them have been used to remove the anti-nutritional factors in MSK either partially or in full Table 6 (El Boushy & Vander Poel 2000). Compared to a raw mango seed kernel, boiling have improved the nutrient contents of mango seed kernel and improved the growth and performance of animal (Diarra & Usman, 2008; Joseph & Abolaji 1997). Through using boiling, only as treatment option, it reduced the tannin and trypsin contents below 5% and was recommended (Farag, 2001). The combination of soaking and boiling brought better performances of broiler chickens than soaking only (Ravindran & Sivakanesan 1996).

Mango Seed Kernel can be boiled in tap water at 100 °C for 20 minutes and again washed with cold water then sun dried until it has become completely dried to minimize its tannin and related factors for feeding to both ruminants and chickens (Dakare et al., 2012, Yasin et al., 2022; Mbajunwa, 1995; Teguia & Beynen, 2005). Generally treatment of soaked and boiled MSK with Ca(OH)₂ was found to effectively enhance the reduction of antinutritional factors to barest minimum, if not complete removal and implies that this processing method had greatly detoxified the MSK, thereby enhancing better utilization of the MSK in livestock and poultry nutrition (Dakare et al., 2012).

Mango seed kernel application in animal feed

The inclusion levels for both raw and treated mango seed kernel were presented in Table 9 below. Through boiling of raw MSK, there is an increase in the energy and other nutrients contents of MSK that capacitates the use and it’s potentials for animal feeds rather than feeding raw MSK and retard the growth and performances of animals (Ravindran & Sivakanesan 1996). Raw MSK meal included at 5 - 10 percent in the diet depressed feed intake and growth in broiler chicks (Dakare et al., 2012). The same amount of inclusion of raw MSK decreased laying rate and increased the weight losses in layers (Odunsi, 2005). Augustin and Ling (1987) reported a significant decrease of feed intake in chickens as the level of mango fruit waste increases.

In other experiments (Dakare et al., 2012; Diarra & Usman, 2008; Teguia, 1995) even lower inclusion (< 5%) of raw MSK retarded the growth and performances of the chickens. Diarra and Usman, (2008) also recommended that treated MSK inclusion of <5% in broiler chicks during the starter phase (0 − 28 days) and 10 - 20% during the grower and finisher phases (28 − 35 and 35-42 days), respectively with no harmful effect on chicken’s performances. Similarly, Diarra et al. (2010) reported that the replacement of 20 and 30% of dietary maize with boiled MSK in broiler starter and finisher diets respectively significantly reduced feed cost without adverse effects on growth and feed utilization. Sundried mango fruit waste was also incorporated up to 20% in broiler feed without any adverse effect on feed intake and growth performance (Yibrehu et al., 2012).

Broiler birds can use up to 30% processed MSK throughout their growth phase without any problem as energy and protein source when properly boiled, dried and processed (Faniyi, 1997). Teguia (1995) and Odunsi (2005) reported a significant increase of BW gains in broiler chickens that fed up to 10% MFW and then declined. Putting the cost of cereal-based poultry rations in considerations, boiled and sundried MSK could substitute up to 15 of maize in broilers ration without affecting their performances (Yasin et al., 2022). Feeding trials with Kankrej and Surti buffalo calves for 12 weeks indicated that the optimum level of incorporation in concentrate diets was 20% (Patel et al., 1971).

Larger animals can consume MSK in larger amount than poultry and it is safe up to 60% in cattle when mixed with other feed when controlled in known extent (Diarra & Usman, 2008; Odunsi & Farinu 1997; Gohl, 1982). With working bullocks, Patel et al. (1972) found a 40-60% inclusion level to be satisfactory. A concentrate mixture made up of tomato waste, MSK and Cassia tora seed in the ratio 4:3:2 yielded live weight gains at reduced feed costs (Patel & Patel, 1971).

Conclusion and recommendation

Mango seed kernel is the most appreciable and nutrient full product if well treated and managed with care for feeding of livestock. MKS is rich in carbohydrate, starch, protein, amino acids, fatty acids and minerals. However, it contains some anti-nutritional factors that affect the bio availability of nutrients as well as digestibility of same. The effect is severe in non-ruminant (eg. Poultry) because of the absence of rumen microbes .Raw MSK is not recommended at more than 5-10% replacement rates for maize in layer and broiler diets, but processed kernels can be included at the rates of 25 and 30% as replacements for maize in layers and broilers diets, respectively while 40-60% inclusion of MSK is recommended for ruminants. Processing methods such as; fermentation, boiling, autoclaving, sun drying, soaking etc. have been used to reduce the effect of these anti nutrients to a more tolerable level. As value addition to the horticultural products in general and mango fruit in particular, there must be a technology that ease the processing of these by-products with minimum labor and cost to different products including animal feed specially poultry so that the income from both mango and livestock sector will increase. In addition to minimizing feed scarcity issue through effective processing and using MSK for feeding of livestock, it will also create job for those participating people on collecting and processing of these wastes to use it in such important sector and feeding themselves and improve their life.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Table 9. Inclusion level of MSK in animal feeds.

Animal type	Recommended level of RMSK	Recommended level of Treated MSK
	Morton, 1987; Gohl, 1982; Yasin et al., 2022; Dakare et al., 2012; Odunsi, 2005
Broiler	Less than 10% of total feed	Up to 30% of total feed
layer	Less than 10% of total feed	Up to 25% of total feed
Ruminants	Less than 50% of total feed	40-60% of total feed

Additional information

Notes on contributors

Yasin Beriso

Yasin Beriso completed his first degree in Animal and range sciences from Hawassa University. He also completed his master’s degree in Animal production from Addis Ababa University. He is a researcher and program leader of Animal feeds and nutrition at Ethiopian institute of agricultural research Debrezeit agricultural research center.

Etalem Tesfaye

Etalem Tesfaye (Ph.D.) is a senior researcher of Animal Nutrition at Ethiopian institute of agricultural research Debrezeit agricultural research center, Ethiopia. She obtained her Ph.D degree in animal nutrition from Haramaya University. She is serving as an editorial member and reviewer of several international reputed journals. Etalem has successfully completed her Administrative responsibilities. She has authored of many research articles/books related to Animal science.