Geert Opsomer

During the transition period, cows are confronted with infectious and inflammatory challenges leading to an acute phase response (APR) marked by increased hepatic synthesis of positive acute phase reactants (+AP) and a decrease in negative acute phase reactants (-AP). The aim of this study was to quantify the APR in 21 high-yielding dairy cows studied from 9 days before until 42 days after calving, and to assess the association between the APR, disease incidence and indicators of liver function. Repeated blood samples were analyzed for -AP (retinol, albumin, cholesterol), +AP (haptoglobin, caeruloplasmin), paraoxonase, and liver-associated variables (aspartate aminotransferase, γ-glutamyl transferase, bilirubin). All cows displayed postpartum decreases in -AP and paraoxonase, and increases in +AP and liver variables. When retrospectively categorized, cows presenting a stronger -AP decline displayed higher +AP and liver variables, and a higher disease incidence compared to cows with a milder decline. Altogether, typical changes in -AP and +AP identify the transition period as a time of increased inflammatory load. Group differences in liver variables suggest that a more severe APR may be associated with altered liver function. However, no causal relationship can be proven based on this observational dataset, and results should be interpreted cautiously.

The treatment incidence based on ADDpig for all oral and injectable antimicrobial drugs was 178.1 per 1000 pigs at risk per day. The treatment incidence based on UDDpig shows that in reality fewer pigs were treated, namely 170.3 per 1000 pigs at risk per day. Proportionally, ...

In practice, many veterinarians inseminate cows ‘blindly’ 72 hours following a single injection of prostaglandin F2α (PGF2α). In this paper we describe the results of a study in which we examined follicular growth dynamics following PGF2α induced luteolysis, aiming at a better insight into the chances for pregnancy when cows are inseminated in a timed manner. A total of 62 dairy cows (CL>25 mm and largest follicle >12 mm) were enrolled in the study and divided over three treatment groups. On day 0 (start of the experiment) all animals received an intramuscular injection of 500 μg cloprostenol, while 42 cows were subjected to ultrasound-guided trans-vaginal follicle aspiration of the largest follicle and were further subdivided into ablation ≤8.5 mm (n = 31) and ablation >8.5 mm (n = 11), according to the size (<8.5 vs. 8.5 to 12 mm, respectively) of the second largest follicle present at the moment of aspiration. The remaining cows (n = 20) were allocated as controls, re...