Effect of dietary Conocarpus erectus leaves and branches on milk yield, quality, antioxidant activity and fatty acid profile, and blood parameters of Najdi dairy goats

To investigate the effect of Conocarpus erectus tree leaves and branches as a partial replacement of forage on milk yield and components, blood and rumen parameters of goats, 16 Najdi goats were used in a completely randomized design with 2 treatments (CON, without C. erectus; CE, contains C. erectus). The basic ratio consisted of 60% concentrate and 40% forage. In treatment CE, 22.5% of the forage (alfalfa hay and wheat straw) was replaced with C. erectus leaves and branches. The lowest amount of dry matter intake and digestibility were observed in the treatment CE (P < 0.05). The amount of milk production significantly increased (P = 0.01) in the treatment CE. The total count did not differ between treatments, but the highest amount of Lactobacillus spp. (P = 0.01) and the lowest amount of mold (P = 0.01) were observed in the treatment CE. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity decreased on days 15 (P = 0.02) and 31 (P = 0.01) of the experiment in treatment CE. The highest amount of short-, medium-, and long-chain fatty acids and also conjugated fatty acids were observed in the treatment CE (P < 0.05). Also, the concentration of fatty acids C16:0 and C18:0 was lower in the treatment CE (P < 0.05). The lowest amount of triglycerides, blood urea nitrogen, cholesterol, low-density lipoprotein, high-density lipoproteins, serum glutamic pyruvic transaminase, and serum glutamic oxaloacetic transaminase were observed in the treatment CE (P < 0.05). Ruminal pH and ammonia-N concentration were not affected by experimental treatment (P > 0.05). According to the results, the use of C. erectus leads to improved milk production and fatty acid profile, antioxidant activity, and microbial load.