Concerned about sustainable production in Brazilian, Premix Company in partnership with Phodé, developed a combination of specific natural additives for high production dairy cows. To improve production without affecting the environment, a blend of natural additives (NA) was composed by the association of Fator P (Premix, Brazil) + VeO Premium (Phodé, France). Fator P is composed of amino acids, minerals, probiotics and essential fatty acids. VeO Premium is a neuro-sensory solution mainly composed of a specific extract from the Rutaceae family. The experiment was carried out in a Brazilian farm during spring, where 104 mid-lactation multiparity Holstein cows were used, with a mean production of 38.28 ± 0.355 kg/d. Milk production, dry matter intake, feed efficiency and temperature and humidity index were evaluated over the days. To follow the effects of the use of NA were used 4 periods of 20 d each. For the first 20 d of the evaluation the group did not receive NA (−20 to 0). Then NA was fed for 60 d, divided into 3 periods (0 to 20, 20 to 40, and 40 to 60 d with additives). The average of periods were compared using Tukey test with 5% significance. Supplementation of NA increased milk yield (P < 0.001) and improved feed efficiency (P < 0.001) after 20 d of use. Period 0 to 20 may represent the adaptation time of ruminal microbiota to NA. Dry matter intake decreased (P = 0.005) in period 20 to 40 while THI tended to be higher (P = 0.06; Table 1). The NA can improve milk production even in heat stress. Results suggest that NA has the potential to be a natural alternative to support performance of high-production dairy cows without harming the environment. Table 1. Effect of natural additives on dairy performance

Days with additives	DMI,kg/d	Milk production, kg/d	Feed efficiency	THI1
−20 to 0 (no additive)	25.06a	38.28b	1.53b	73.8
0 to 20	25.14a	38.09b	1.52b	73.7
20 to 40	24.11b	40.54a	1.69a	74.7
40 to 60	25.19a	41.36a	1.64a	71.8
P-value	0.005	<0.001	<0.001	0.06
SEM	0.14	0.328	0.015	0.396

^a,bMeans with different letters are different by Tukey Test (5% significance). ¹THI = temperature-humidity index.