Milk production, composition and milk fatty acid profile from grazing ewes fed diets supplemented with Acacia cyanophylla leaves as tannins source and whole or extruded linseed

Abstract This experiment was conducted to investigate the effects of two different forms of linseed (whole or extruded) and only leaves of Acacia cyanophylla as tannins source on milk yield and fatty acid (FA) profile in dairy ewes. Tannins are secondary compound able to interfere with protein and lipid metabolism in the rumen. For this trial, an experimental flock of forty ewes, conducted on triticale pasture, and receiving 250g of Soya bean meal a day, was divided into four groups. Such diet was complemented by 70g of whole linseed for the first group (SW), 70g of extruded linseed for the second (SE), 70g of whole linseed together with 100g of leaves of Acacia cyanophylla for the third group (SWA) and 70g of extruded linseed with 100g Acacia leaves for the last one (SEA). Daily milk production varied between 628 and 692 ml/ewe without significant difference. Fat and protein percentages did not differ between groups while milk urea content (mg/dl) was much lower (P Acacia cyanophylla leaves only (SWA and SEA). Odd FA, undecyclic acid (C11:0) and tridecyclic acid (C13:0) increased while pentadecyclic acid (C15:0) decreased significantly with extruded linseed intake. Extruded linseed and Acacia intake (P Acacia cyanophylla leaves also reduced oleic acid, but increased minor (n-6) fatty acids as γ-linolenic acid (C18:3 cis6 cis9 cis12 (n-6)) and docosapentaenoic acid (C22:5 cis4 cis7 cis10 cis13 cis16 (n-6)). The effect of Acacia cyanophylla leaves with extruded linseed amplified oleic, and docosapentaenoic acid levels.