Physicochemical characteristics of ewe’s milk following partial substitution of concentrate with Date by–products and Saccharomyces cerevisiae

Abstract

Sustainable feeding strategies are needed to improve the quantity and quality of sheep milk. This study evaluated the impact of partially substituting conventional concentrate with date by– products, with or without the addition of Saccharomyces cerevisiae, on the physicochemical composition of milk produced by Ouled Djellal ewes. 30 ewes were randomly divided into 5 groups. All ewes received wheat straw (1 kg·ewe-1) as roughage (66.66%). In addition to wheat straw, the control group received 33% concentrate (33CON), and the 4 experimental groups received different levels of date by–products and concentrate: 8.33% date by–products + 25% concentrate (8.33 date by–products), 25% date by–products + 8.33% concentrate (25 date by–products), 16.6% date by–products + 16.6% concentrate (16.6 date by– products), and 16.6% date by–products + 16.6% concentrate with Saccharomyces cerevisiae (16.6 date by–products sc). The milk samples were analyzed to determine their fat, protein, lactose, total solids, and non-fat solids content. Milk fat content (P<0.01) and total solids (P=0.025) were significantly higher in the experimental groups than in the control group, particularly in the 25 date by– products and 16.6 date by–products sc rations. Protein and non-fat solids content increased numerically without reaching statistical significance, while lactose levels remained relatively stable in all treatments. Partial substitution of concentrate with date by– products improved milk quality, indicating that date by–products can be a sustainable feed resource for dairy ewes, thereby adding value to their milk products.