Table 8.

Summary of studies in periparturient dairy cows investigating the effects of supplemental phytoproducts on cow metabolism

Nutraceutical	Treatment	Period	Tissue/Cells	Main outcome	Reference
EO mix (thymol, eugenol, vanillin, guiacol, limonene	1 g/cow/d	From −21 d to 42 d relative to calving	Blood	γ-glutamyltransferase increase	[137]
EO (curcum oleoresin or garlic excract or capsicum oleoresin)	2 g/cow/d	9 d treatment	Blood	Subtle or no effect on blood cells, nutrient digestibility, antioxidant status and mRNA liver enzymes expression. Immune-stimulatory effect by CD4 cells activation and expansion	[142]
EO (allicin or pinene)	5 g/cow/d Allium sativum standardized at 1.5% of allicin; 2 g/cow Juniper communis standardized at 35% pinene	21 d	Rumen	DM, OM and CP ruminal truly digestibility increase	[143]
Quebracho tannin	90 g/cow/d	6 weeks (− 3 before and + 3 after calving)	Blood	Antiketogenic effect decreasing BHB	[144]
Tea saponin	20, 30, 40 g/cow/d	8 weeks treatment		Tea saponin may reduce oxidative stress and improve immune system	[140]

EO essential oil, DM and DMI dry matter and dry matter intake, respectively, CD4 cluster differentiation-4, OM organic matter, CP crude protein, BHB beta-hydroxybutyrate