The effects of bovine necrotic vulvo-vaginitis on reproductive and production performance of Israeli 1st calf heifers.
Bovine necrotic vulvovaginitis (BNVV) is a syndrome unique to Israel characterized by necrotic lesion in the caudal vagina mainly in first calf heifers after calving, associated with Porphyromonas levii. The objectives of this study were to analyze the impact of BNVV on reproductive performance, milk production and survival in the heard of first calf dairy heifers in affected farms, and to verify if the effects of BNVV are severity-dependent. For assessment of the severity level a scale of 4 degrees was formed, and cows were scored 4 to 6 d after calving. Data were obtained from two dairy farms during 2006-07, consisting of 603 lactations. The incidence and the severity of BNVV declined between 2006 and 2007, and severe BNVV tended to be more prevalent in the summer. The odds to conceive in the first artificial insemination of BNVV cow tended to be lower than healthy cows (OR = 0.676, P = 0.052). Cows with BNVV had longer empty period (145.8 d vs. 135.1 d of healthy cows, P = 0.031), but only severe BNVV had a negative effect on the odds of the cow to be empty at 150 d in milk (DIM) (OR = 2.05, P = 0.052). Severe BNVV also affected the mean survival time to conception (155.9 d vs. 142.3 d, P = 0.042). All BNVV severity degrees had a negative effect on milk production. The effect on milk production was not limited only to the beginning of the lactation, cows with BNVV produced 338.1 kg milk less than healthy cows (P = 0.016) in 305 d corrected lactation. The effect on milk production was not severity depended. No effect on survival time in the herd was demonstrated.
The Koret School of Veterinary Medicine, the Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel. goshen@agri.huji.acl.il
T
T
Goshen
J
J
Ben-Gera
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O
Koren
T
T
Bdolah-Abram
D
D
Elad
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D007315:Insemination, Artificial / Q000662:veterinary; D008136:Longevity; D008892:Milk; D011247:Pregnancy; D018873:Pregnancy Rate; D012098:Reproduction / Q000502:physiology*; D014848:Vulvovaginitis / Q000150:complications / Q000401:mortality / Q000662:veterinary*