Work

Sunflower seed processing affects nutrient utilization and performance in feedlot ewe lambs fed high-concentrate diets with or without chitosan

Year: 2026

Type: article

Abstract: Oilseed processing can alter lipid accessibility during digestion, potentially affecting microbial activity, nutrient utilization, and animal performance in high-concentrate feeding systems. This study evaluated the effects of sunflower seed processing and chitosan supplementation on nutrient utilization, estimated microbial nitrogen production, growth performance, ingestive behavior, and economic indicators in feedlot ewe lambs. Thirty-two ewe lambs (15.12 ± 3.57 kg BW) were randomly assigned to a 2 × 2 factorial arrangement consisting of two sunflower seed processing methods (whole or ground) and two chitosan levels (0 or 4 g/kg DM). The animals were fed diets with a 25:75 roughage-to-concentrate ratio. Sunflower seed processing did not affect nutrient intake, and no interactions were observed for the intake or digestibility variables. However, lambs fed whole sunflower seeds showed greater apparent digestibility of dry matter, organic matter, non-fiber carbohydrates, and total digestible nutrients than those fed ground seeds (P ≤ 0.007). Whole sunflower seeds also increased nitrogen absorption (+8%), nitrogen retention (+15%), estimated microbial nitrogen production (+41%), and estimated microbial efficiency (+31%) (P < 0.05). These responses were associated with greater average daily gain (254.1 vs. 215.2 g/d) and feed efficiency (P ≤ 0.028), despite similar dry matter intake across treatments. Interactions between sunflower seed processing and chitosan were detected for rumination time and rumination efficiency (P < 0.05), with chitosan reducing the differences between whole and ground seeds. Under the price assumptions used, whole sunflower seeds without chitosan showed the highest descriptive net margin. Overall, whole sunflower seeds improved nutrient utilization and animal performance, whereas chitosan supplementation at 4 g/kg DM provided no additional measurable productive benefits under the conditions evaluated.

Source: Frontiers in Animal Science

DOI: 10.3389/fanim.2026.1903800