Development and Evaluation of Straw-Based Densified Complete Feed Blocks on the Productive Performances of F1 Freisian-Borena Crossbred Dairy Cattle in the Central Highlands of Ethiopia

The objective of the study was to assess the cureent status on utilization practices of cereal straws, followed by development and evaluation of straw-based densified complete feed blocks (DCFBs) for enhancing the use of wheat straw as feed for dairy cattle. The study assessed the current status of cereal crop residue, management, utilization practices, challenges, and opportunities, and evaluated the effect of DCFBs on feed intake, digestibility, and productive performance of crossbred lactating cows and growing heifer calves. The survey was conducted in the central highlands of Ethiopia in three purposevelly selected woredas (Welmera, Ejere and Degem) to represent wheat, tef and barley production areas, respectively. Data were collected from 180 smallholder dairy farmers (85.6% male and 14.4% female-headed households) using a structured questionnaire and personal observations. For the feeding experiments, four mid lactating multiparous cows with 2-5 parity having similar milk yield (8–10 l/d) and eight post weaned female calves with similar age (5 months) and weight (92.5±27.5 kg) were used from the F1 Friesian x Borena dairy herd found at Holetta Agricultural Research Center. Single and double 4 x 4 Latin Square Design was employed for cow and growing heifer-based experiments, respectively. In both experiments, natural pasture hay (NPH) supplemented with concentrate mix (CM) was used as a control treatment (T1). Cow concentrate mix was supplemented at a rate of 0.5 kg/liter of milk yield and calf CM was fed to cover 50% of the total feed requirement on DM base. The test diets (DCFBs) were prepared from wheat straw and the respective CM of cows and calf’s in the ratio of 50:50 (T2), 40:60 (T3), and 30:70 (T4) for both experiments. The lactating cow-based experiment lasted for 84 days, whereas that of the calves lasted for 240 days. The survey result showed as about 7.4t /HH cereal crop residues were produced per household. The entire respondents practice collection and storage of cereal residues and loose storage system under shelter-shade were practiced by about 83.5% HH. More than 68% of straws collected were used for feeding purpose only. Overall, cereal residues contribute to 75% of the basal feed proportion in the late dry season. Moistening (61.8%) with water and salt, mixing (34.4%) with market-available concentrates, molasses, and local beverage residues xviii (atella), and urea treatment (3.8%) were the common straw treatment methods used during feeding. The cluster-based farming system underway in the areas is an opportunity to increase straw yield. However, lack of appropriate processing, efficient utilization, and absence of regular training supported by practical demonstration were identified as an important challenges in their descending order. The result from the lactating cow experiment revealed that the total DM intake across all dietary treatments was similar except for cows fed with T2 diet. The OM and CP intake was observed higher (P0.05) among the treatment diets but the highest (P