Feeding Sodium Hydroxide-Treated Almond Hulls to Assaf Sheep: Effects on Chemical Composition, Nutrient Digestibility, and Zootechnical Performance

Feeding accounts for approximately 70% of total costs in livestock production, underscoring the need for cost-effective and high-quality alternative feed sources. Almond hulls (AHs), a byproduct of the almond processing industry, represent a promising option due to their availability and potential nutritional value. Moreover, their inclusion in animal diets contributes to a reduction in environmental waste associated with their disposal. This study examined the effects of incorporating 4% sodium hydroxide (NaOH)-treated AHs into the diets of Assaf sheep (rams, ewes, and growing lambs) on feed utilization and animal performance. The experiment evaluated the chemical composition of AHs, nutrient digestibility, sexual behavior and semen quality in rams, milk composition in ewes, and the performance of growing lambs fed diets with increasing levels of inclusion of AHs. A total of 60 ewes and 21 rams were randomly assigned to one of three treatment groups, receiving diets containing 0%, 20%, or 40% AHs. NaOH treatment reduced the concentrations of organic matter and fiber fractions, while increasing the crude protein concentration of AHs (p < 0.01). Diets containing AHs did not affect nutrient digestibility (p > 0.05). Feeding a diet with 40% Na-OH-treated AHs significantly improved the daily weight gain (p = 0.002) of growing lambs up to 70 days after birth, and enhanced (p < 0.05) the libido, scrotal circumference, and semen quality of mature rams. In addition, ewes fed a diet containing 40% AHs showed (p < 0.05) improved fertility, prolificacy, and milk quality. NaOH-treated AHs are a cost-effective and sustainable feed ingredient that can improve reproductive performance and milk production, thereby increasing overall livestock productivity. The 40% inclusion level yielded the most favorable outcomes across all performance parameters evaluated in rams, ewes, and lambs.