and over conventional protein sources for yearling Horro sheep fed a basal diet of fodder oat () hay.

A 90-day feeding trial with 25 yearling Horro lambs (22.6 ± 1.8 kg) was conducted from November 2022 to January 2023. The trial was designed to see how supplementing forage varieties of (Degagsa and Belabas) and (Beresa-55 and Gebis-17) affected the growth performance, feed intake and digestibility of Horro lambs fed a basal diet of fodder oat hay compared to conventional protein supplements. Five experimental sheep per treatment were arranged in a Randomized Complete Blocked Design to receive dietary treatments formulated on an iso-nitrogenous basis which was targeted to provide crude protein (CP) of 64.37 g/h/day. Data were taken on weight gain, feed conversion ratio, feed intake and refusal, and in-vivo digestibility features. All lambs were fed fodder oat hay containing 91.5 % Dry matter, 7.8 % ash, 6.4 % crude protein, 60 % neutral detergent fiber, 42.8 % acid detergent fiber, 13.4 % acid detergent lignin and 65 % in-vitro organic matter digestibility. The dietary treatments were fodder oat hay plus 280.8 g Gebis-17 variety (T1), 274.4 g Beresa-55 variety (T2), 320.9 g Belabas variety (T3), 329.3 g Degagsa variety (T4) and 300 g concentrate mixture (T5). The total dry matter intake (DMI) was higher in T3 and T4 than in the other treatment groups. Except for CP, nutritional consumption differed significantly across treatments. T3 and T4 had higher fiber intakes than the other treatments, while T2 had higher ash intakes and T5 had higher metabolizable energy intakes. Even though there was no significant variation in final body weight, lambs in T5 and T1 showed the greatest weight change and average daily gain. Although the diet in T5 induced the lamb performance in a manner comparable to that of the other dietary supplements, its inaccessibility and high cost would limit the use of such supplements by smallholder farmers. Thus, depending on their availability, either or varieties could be employed as feed supplements in the lambs` diet.