In Ethiopia, atella is part of the farmers’ practice aiming at enhancing the energy and/or protein status of diets based on crop residues and low-quality roughages (Mekasha et al., 2003). Atella is mixed with other feeds and fed to livestock. Supplementing low-quality residues with green feed and providing mixtures of oil cakes and wheat bran soaked with water and atella is a common strategy to improve the edibility of crop residues, and the whole nutritional quality of the diet (Yayneshet Tesfay et al., 2016). In Ethiopia, when atella is available during the dry season, it can be used as a major protein source for ruminants (Yenesew Abebe et al., 2013) and can be fed at low cost (Mekasha et al., 2003).
Atella is widely used in dairy farms of Ethiopia, in particular in the Addis Ababa area (Mekasha et al., 2000), in Tigray (Alemayehu Tadesse et al., 2016) and in Amhara (Ayenew et al., 2009). Atella is used as a supplementary feed throughout the year (Mekasha et al., 2000). In dairy cows, atella is mostly offered in association with niger cake, which has a higher OM digestibility and protein content, and with wheat bran (Mekasha et al., 2000). Tela-atella can be included at 9-20% in dairy cows diet in association with niger cake, wheat bran and barley straw, resulting in increased milk yield (+114%) (Alemayehu Tadesse et al., 2016).
A study conducted in the town of Arsi-Negle, 225 km south of Addis Ababa, showed that 70% of households producing katikala were engaged in cattle fattening and they used the atella produced with crop residues to feed the cattle (Bekele et al., 2005).
Atella can be used as a protein supplement in sheep diets during the dry season (Yenesew Abebe et al., 2013). The protein and energy contents of atella are high enough to greatly increase the intake, digestibility, N retention and performance of growing sheep fed diets based on low quality forage (Mekasha et al., 2003; Ajebu Nurfeta, 2010; Ajebu Nurfeta et al., 2014).
Supplementing diets with 25-50% (DM) atella ensures that the dietary protein is able to support an acceptable rumen microbial activity, meeting the maintenance protein requirement (Mekasha et al., 2003; Ajebu Nurfeta, 2010; Ajebu Nurfeta et al., 2014). Supplementation of wheat straw with atella resulted in weight gains similar to those observed in sheep supplemented with concentrates (Ajebu Nurfeta, 2010). Supplementation of low protein hay (crude protein 5.5% DM) with atella improved total intake, without affecting the intake of the basal forage, and greatly improved protein and energy intake (Mekasha et al., 2002). However, this result depended on the protein content of the basal forage. With a hay containing 4.1% DM protein, a significant substitution between atella and hay was observed (Ajebu Nurfeta et al., 2014).
Atella is often associated with other supplements in sheep diets. Atella, and especially katikala-atella, may be less palatable than other supplements, such as malt sprouts. The heating applied during alcoholic fermentation may make proteins more resistant to rumen degradation and reduce digestibility by the formation (Maillard reactions) of a nutritionally unavailable dark-coloured amino-sugar complex. A 50:50 mixture of katikala-atella and malt sprouts included at 40% dietary level optimized digestibility, growth performance and feed conversion efficiency in sheep (Ajebu Nurfeta et al., 2014).
In urban and peri-urban areas, with growing sheep fed on a straw based diet, katikala-atella in combination with poultry litter and coffee pulp, instead of atella alone, improved nitrogen digestibility, nitrogen retention and basal forage intake, without impairing performance. This combination could save concentrate feeds (Ajebu Nurfeta, 2010). Supplementation of atella with niger cake is commonly practiced for sheep fattening (Yenesew Abebe et al., 2013). Sheep supplemented with atella had a higher digestibility of N than those supplemented with faba bean, field pea, and rough pea hulls (Mekasha et al., 2002). The type of the atella (katikala or tella) does not affect intake or N retention in sheep (Mekasha et al., 2002). However, sheep fed on katikala-atella had a higher level of rumen ammonia and volatile fatty acids concomitant with lower microbial N supply and efficiency. This could be due to the fact that katikala-atella is extensively fermented during brewing, and thus yields less energy during rumen fermentation (Mekasha et al., 2003).