A herbal feed additive improves udder health of dairy cows in early lactation

Herbal feed additives are frequently used in dairy farms but only little information about their effects is available. The aim of this study was to determine the influence of a commercial herbal feed additive (HFA) containing mainly Urtica dioica L. (herba), Silybum marianum (L.) Gaert. (fructus), Artemisia absinthium L. (herba) and Achillea millefolium L. (herba) on health and performance of dairy cows. A stratified (farm, age, calving date) randomized placebo (PL) controlled field study was conducted including 280 cows (6 – 14 per farm) from 30 German and Swiss farms. From 14 days before calculated calving date until the 300th day of lactation 100 g HFA or 100 g green meal as control (PL) were fed daily to each cow. The amount of concentrate fed (CA) and the milk recording data (milk quantity; content of fat, protein and urea; somatic cell score (SCS)) were monitored for the first four monthly lactation controls of each individual cow. A mixed model was applied whereby study group (HFA and PL) was defined as fixed factor, farm as random effect, and CA as covariate. In the mixed model, cows receiving HFA showed significantly (p < 0.05) lower SCS than placebo while all other parameters were not influenced by the study group (Table 1).

Tab. 1: Effects of a commercial herbal feed additive (HFA) compared to a placebo (PL) on milk parameters including somatic cell score (SCS) calculated in mixed models including farm as random effect and concentrate as covariate. Significance (p-value) and standard deviation (SD)

milk recording	milk parameter	study group		p-value	other significant factors*
		HFA (SD)	PL (SD)
1	Milk (kg)	32 (9)	32 (9)	n.s.	fa, co
	Fat (%)	4.3 (0.9)	4.4 (0.8)	n.s.	fa
	Protein (%)	3.2 (0.4)	3.2 (0.4)	n.s.	-
	Urea (mg/dl	15 (7)	16 (7)	n.s.	fa
	SCS	2.9 (2.0)	3.5 (1.9)	0.007	fa
2	Milk kg	34 (10)	34 (9)	n.s.	fa, co
	Fat	3.9 (0.7)	3.9 (0.7)	n.s.	fa
	Protein	3.0 (0.3)	3.0 (0.3)	n.s.	fa
	Urea	18 (8)	17 (8)	n.s.	fa
	SCS	2.5 (2.0)	3.1 (2.0)	0.001	fa
3	Milk kg	32 (9)	32 (9)	n.s.	fa, co
	Fat	3.8 (0.7)	3.8 (0.7)	n.s.	fa
	Protein	3.1 (0.3)	3.0 (0.3)	n.s.	fa
	Urea	19 (7)	18 (8)	n.s.	fa
	SCS	2.5 (1.9)	3.1 (2.0)	0.016	fa
4	Milk kg	29 (8)	29 (9)	n.s.	fa
	Fat	4.0 (0.7)	3.9 (0.6)	n.s.	fa
	Protein	3.2 (0.3)	3.1 (0.3)	n.s.	fa
	Urea	20 (8)	19 (8)	n.s.	fa
	SCS	2.7 (1.6)	3.3 (1.9)	0.007	fa
*p < 0.05; fa = farm, co = individual amount of concentrate fed

Increased somatic cell scores (SCS > 3), as main sign of udder inflammation and generally linked to bacterial infection, is one of the most important recent health problems and cause for the most antibiotic treatments in dairy cows. Direct anti-inflammatory and immunostimmulative effects of U. dioica and A. millefolium might be a reason for the reduced SCS in the HFA group [1, 2]. Also indirect effects of S. marianum and A. absinthium could play a role: both plants are well known to protect liver cells in vitro and in vivo [3, 4], which is the main producer of proteins for the innate immunity, but highly stressed in early lactation [5]. Further research is needed to clarify the concrete mode of action.

Acknowledgement: Special thanks go to the farmers, who participated at the study and facilitated with their support the collection of data. We gratefully acknowledge funding of this project by Saluvet GmbH.

Keywords: Herbal feed additive, cow, udder health, Urtica dioica, Achillea millefolium, Silybum marianum, Artemisia absinthium.

References:

[1] Hajhashemi V, Klooshani V. Antinociceptive and anti-inflammatory effects of Urtica dioica leaf extract in animal models. Avic J Phytomed 2013; 3: 193 – 200

[2] Pires JM, Mendes FR, Negri G, Duarte-Almeida JM, Carlini EA. Antinociceptive peripheral effect of Achillea millefolium L. and Artemisia vulgaris L.: both plants known popularly by brand names of analgesic drugs. Phytother Res 2009; 23: 212 – 219

[3] Hackett ES, Twedt DC, Gustafson DL. Milk thistle and its derivative compounds: a review of opportunities for treatment of liver disease. J Vet Intern Med 2013; 27: 10 – 16

[4] Amat N, Upur H, Blazeković B. In vivo hepatoprotective activity of the aqueous extract of Artemisia absinthium L. against chemically and immunologically induced liver injuries in mice. J Ethnopharmacol 2010; 131: 478 – 484

[5] Zhou Z, Xu MJ, Gao B. Hepatocytes: a key cell type for innate immunity. Cell Mol Immunol 2015, doi 10.1038/cmi.2015.97

No conflict of interest has been declared by the author(s).