Based on repeatedly reported extensive pantothenic acid disappearance in the rumen, the present study is aimed at examining if pantothenic acid is used for a more efficient ruminal fermentation and microbial growth in an artificial rumen (Rusitec). Three substrates differing in roughage/concentrate ratio were incubated with and without the addition of Ca-D-pantothenate. Pantothenic acid was extensively degraded without notably influencing fermentation, microbial protein synthesis and the status of other B-vitamins such as riboflavin, vitamin B6 and niacin. Therefore, pantothenic acid supplementation cannot be expected to contribute to microbial benefit for the ruminant animal.

Vaginal mucus during estrus was examined with the Metricheck device and the relationship to the reproduction of high-yielding dairy cows was studied. The study was conducted in 99 dairy herds located in Western Germany and 1348 Holstein-Friesian heifers and cows showing spontaneous estrus were examined. Independent of the Metricheck result, the animals were inspected by professional insemination technicians and those suitable for insemination (n = 989) were bred by artificial insemination (AI). Reproductive performance was characterized by non-return rate at 90 days (NRR90). The discharge of the animals predominantly had a clear appearance (70%) and a stringy consistency (80%). Animals with clear vaginal discharge had higher NRR90 (56%; n = 697) than animals with abnormal (turbid, mucopurulent, purulent, sanguineous) vaginal secretion (48%, n = 292; P < 0.05). NRR90 was lower in animals with short calving to AI interval (< 70 days; 39%) than with medium (70-130 days; 54%) or long (> 130 days; 62%) intervals (P < 0.05). NRR90 decreased by 12% from the lowest (< 15 kg) to the highest (> 45 kg) milk yield class. In conclusion, the use of the Metricheck device integrated into the insemination procedure is recommended to identify dairy cows suffering severely from uterine disease.