Effect of corn and millet silage and their particle size on feed intake, digestibility, rumen parameters, and feed intake behavior in Kermani sheep

The purpose of this experiment was to study the effects of silage type (ST) and levels of silage particle size (SPS) on feed intake, digestibility, rumen parameters, and feed intake behavior in Kermani sheep. Corn and millet crops were cultivated in May and harvested into coarse and fine forages in mid-September. Four rams (two years old, BW 39.2±3.1 kg) were randomly assigned to four treatments in a 2×2 factorial arrangements in a Latin square design. The experimental diets were coarse corn silage diet; short corn silage diet; coarse millet silage diet and short millet silage diet. Diets were iso-nitrogenous and iso-energetic, and the ratio of forage to concentrate was 50:50. The potential of gas production was higher in corn silage (CS) than millet silage (MS) (P<0.03) and coarse SPS than short SPS (P<0.02). The dry matter (DM), organic matter (OM) and crude protein (CP) intakes were higher in short SPS diets while DM, OM and neutral detergent fiber (NDF) digestibility were higher in CS diets (76.26, 73.43 and 58.71%, respectively), while the CP digestibility was higher in short SPS diets (74.98%). The mean ruminal pH value was lower in CS diets (P<0.05). The mean ruminal ammonia nitrogen (NH3-N) concentration was higher in CS and short SPS diets. Microbial protein (MP) synthesis was higher in short SPS diets (P<0.05). Chewing activity was higher in MS and short SPS diets (P<0.05). The results indicated the higher quality of CS, although MS can be safely fed to small ruminants such.