Influence of the herbal component of a commercial feed additive on serum parameters, fertility and longevity of dairy cows

Fertility dysfunction is a main culling reason for dairy cows [1]. A randomized placebo controlled trial investigates a herbal mixture containing mainly Urtica dioica L. (herba), Trigonella foenum-greacum L. (semen), Silybum marianum (L.) Gaert. (fructus) and Achillea millefolium L. (herba). It was fed cows daily (50g per cow and day) about 60d from dry off to calving date. 63 dairy cows (32 in the herb-(h)- and 31 in the placebo-(p)-group) of one Swiss organic dairy farm were included in the study. Cows were differentiated depending on their lactation number (L); L1: first lactating cows (h: n=10, p: n=9), L2–4: cows of second to fourth lactation (h: n=11, p: n=12) and L>4: cows with more than four lactations (h: n=11, p: n=10). Blood samples were taken and a rectal palpation according to Rosenberger [2] of uterus and ovaries was done once between day 21 and 35 after calving. Furthermore all cows were observed until culling or next calving. Table 1 shows the significant differences (p<0.05) between the herb and placebo group. The fed herbal mixture seems to have an impact on the postpartal metabolic status of dairy cows which is a main factor influencing fertility [3]. The herbs seem to prolong the postnatal anoestrus but also to decrease the culling rate particularly for fertility reasons. Overall the prolonged intercalving period had a lower economic effect than the decreased culling rate.

Table 1: Significant differences (p<0.05) between herb and placebo group

	herb fed group	placebo group
abnormalities in at least one of 7 tested serum parameters (glucose, bilirubin, aspartate aminotransferase, glutamate dehydrogenase, calcium, phosphate, magnesium) in the lactating group L1	0%	44%
serum phosphate contents in the lactating group L >4	7.2mg/dl	5.9mg/dl
ovaries with palpable follicles in the lactating group L >4	18%	63%
uterus dimension score in the lactating group L >4	3	2
intercalving period	387 days	344 days
overall culling rate	17%	50%
culling rate for fertility reasons	3%	23%

References: 1. Seegers, H. et al. (1998) Prev Vet Med. 9:257–271.

2. Rosenberger, G. (1990) Die klinische Untersuchung des Rindes. Verlag Paul Parey. Berlin und Hamburg.

3. Westwood, C. T. et al. (2002)J. Dairy Sci. 85:3225–3237.