Projecten per jaar
Materials and Methods: In the present paper, an assessment was made of the risk factors in the management of the BB breed on calf mortality. For 2 years, calf mortality until 6 months on 19 selected BB farms was followed up and autopsies were performed. Furthermore, the following samplings were implemented on each farm. A colostrometer was used on 10 BB heifers and cows to assess the quality of the colostrum. The amount of immunoglobulin’s transferred from the colostrum to the blood was determined on 5 calves at 2-3 days of age by the zinc sulfate turbidity test (ZST). Fecal sampling was done in clinically healthy calves from different age categories (2-3, 7-14, 15-21 days and 6-8 weeks) to search for the presence of specific diarrhea pathogens. As Selenium status is known to be related with an increased calf mortality and reduced calf weaning weights, 10 heifers and cows were blood sampled in the last stage of their gestation and the blood was pooled in two groups (heifers and cows). Finally the IBR and BVD status of the farms was checked by serology in different age categories (young stock [+/-1 year], heifers and older cows).
Results: Results from the first year revealed a calf mortality until 6 months of age of 3.3% with a range from 0-8.7% between the different herds. Autopsies revealed that within the first week of age the most common causes of death were heart defects and inadequate ventilation of the lungs whereas later on (> 1 weeks - 6 months) mostly enteritis and pneumonia could be indicated as cause of death. No significant difference was seen in calf mortality between individual rearing and suckling calves. Concerning the transfer of immunity, only 10% of the calves had ZST levels less than 20 grams per liter. Fecal sampling in the younger calves (< 21 days) showed 18% samples being positive for Cryptosporidiosis, 12% for Coronavirus and 4% for Rotavirus. In older calves (6-8 weeks), 49% revealed Giardia and only 9% were positive for Coccidiose (E. bovis and/or zuernii).
Conclusions: Whether there is an association with clinical disease still has to be investigated. When taken the level of >80µg/l for Selenium, only 1 of the 19 farms (5.3%) reached the threshold. Serological sampling showed 18% positive samples and 73.7% of the farms having one or more samples being positive for IBR (IBR gE [ELISA Idexx®]). 33.3% of the farms showed a negative serology for BVD (BVD Asn [ELISA Idexx®]), whereas 66.7% had one or more positive samples, indicating a recent contact with the virus.
VingerafdrukBekijk de onderzoeksthema's van 'Field study on the risk factors of calf mortality in the double-muscled Belgian Blue breed.'. Samen vormen ze een unieke vingerafdruk.
- 1 Afgerond
KALFSTER: Verbetering van de rendabiliteit in de vleesveehouderij door beperking van de kalversterfte
1/04/10 → 31/03/12