The effects of first calving (FC) in Holstein heifers on their first lactation, second lactation and lifetime milk production were examined from an initial database of 459 743 animals that first calved between 1 January 1990 and 31 July 2010 in Wallonia, Belgium. The FC age class (18 to 22, 22 to 26, 26 to 30, 30 to 34, 34 to 38 and 38 to 42 months), the FC season and FC year class (1990 to 1994, 1995 to 1999, 2000 to 2004 and 2005 to 2010) were considered when analysing the first and second lactation data. Lifetime data were similarly analysed, but did not include animals that calved after 2005 because many of them were still lactating. Only 24% of animals had their FC before 26 months of age. Animals that first calved between 22 and 26 months of age had more lactations and productive days during their life. They also had higher first and second lactation milk production and lifetime milk production. Summer or autumn FC improved first lactation, second lactation and lifetime milk production, as well as production per day of lactation, compared with winter or spring FC. Compared with animals that calved for the first time in 1990 to 1994, animals with a FC in 2000 to 2004 had a longer calving interval (0.5 months), fewer lactations per animal (−0.6) and fewer days in their lifetime lactation (a reduction of 144 days). As a result, the animals’ lifetime production did not increase between 1990 to 1994 and 2000 to 2004, although milk production per day of lactation (22.85v.20.49 l/day) and per day of life (11.49v.10.78 l/day) improved. Milk fat content was lower in 2000 to 2004 than in 1990 to 1994, but protein content remained relatively constant, probably because of the cows’ higher production level and increased dietary concentrate supplementation.

The occurrence of Fusarium species in winter wheat in southern Belgium (Wallonia) and the deoxynivalenol content in 692 samples collected in commercial fields in the region's main cereal growing area were investigated. The main Fusarium species associated with head blight in wheat were identified at levels that varied from year to year. Interactions between fungal species causing head blight in wheat were detected, most of them positive. The years 2007 and 2008 were very conducive to the disease and there was a strong correlation between mean annual deoxynivalenol content and number of days with a mean relative humidity above 80% over a period starting from 7 days before the mean flowering date and ending 16 days after this date. A two-stage approach, based on type of year (at risk or not) and agricultural practices during risk years has been developed to help cereal storage companies reduce the risk of mixing sound and deoxynivalenol-contaminated lots at harvest and to limit the number of analyses.

Cow's milk can be used as a potential source of equol in the human diet. In order to study human intake, however, it is necessary to develop a reliable and sensitive analytical method. This paper reports on the validation of an analytical method using ultra-performance liquid chromatography coupled with a tandem mass spectrometry detector to quantify the equol in commercial milks (raw, whole, semi-skimmed, and skimmed milk). The equol was initially released using enzymatic hydrolysis, and it was then extracted using a double liquid/liquid extraction. The analytical method produced a linear calibration curve with a high correlation coefficient (R 2 ≥0.996) between 5 and 1,000 ng.mL -1 . Good intra-and inter-day precision (≤5.3% and≤5.2%, respectively) and accuracy (≤8.6%) were achieved. The recovery rate differed slightly among the different types of milk, ranging between 60.6± 1.09% and 82.3±5.21%. Good method repeatability was observed (≤15%). There was neither matrix effect nor carry-over effect, and the sample extracts were stable for at least 7 days of storage at -21 °C and 5 °C. The method proved to be specific, sensitive, precise, and accurate and was used for the first time to quantify the equol content in Belgian commercial cow's milk. In all the samples analyzed, equol was present at a concentration ≥10 ng.mL -1 and had a significantly higher content in organic than in conventional milk. The study also found that the mean concentrations of equol were similar for each type of commercial conventional cow's milk.

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