Serum neutralizing antibodies against Fusobacterium necrophorum leukotoxin in cattle with experimentally induced or naturally developed hepatic abscesses1

Abstract

The relationship between serum-neutralizing antibody against Fusobacterium necrophorum leukotoxin and hepatic abscesses was investigated in cattle fed diets supplemented with or without tylosin. Sixteen cattle (eight each in tylosin and in control groups) were inoculated intraportally with F. necrophorum. Ultrasonographic scanning showed that all control animals developed hepatic abscesses after inoculation. In the tylosin group, two animals were free of abscess by d 7 and one was free by d 14. Leukotoxin-neutralizing antibody titers were low on d 0, but increased (P < .05) markedly after intraportal inoculation in both groups. In a second study, blood was collected at the time of slaughter from 141 feedlot cattle (36 fed diets with tylosin and 105 fed diets without tylosin), and livers were examined for presence or severity of hepatic abscesses at slaughter. The incidences of hepatic abscesses were 32% in the control group and 6% in the tylosin group. Antibody was detected in all animals; however, antibody titers were greater (P < .05) in cattle with abscessed liver than those without, and greater (P < .01) in the nontylosin than in the tylosin group. Abscess score and antibody titer were correlated (r = .34; P < .0001). We conclude that F. necrophorum leukotoxin is highly antigenic and that anti-leukotoxin antibody titer is related to the severity of hepatic abscesses.

Minimum inhibitory concentrations for selected antimicrobial agents against Fusobacterium necrophorum isolated from hepatic abscesses in cattle and sheep

“…It is important to emphasize the good activity of the tylosin, which is used as additive in animal feed for the prophylaxis of hepatic abcessation. These results`in vitro' correspond to those obtained in animals by various authors (Brown et al, 1973;Brown et al, 1975;Galyean et al, 1992;Clary et al, 1993;Tan et al, 1994) in which a significant decrease of hepatic abscesses incidence was observed when tylosin was incorporated together with the feed. This diminution of the incidence of hepatic abscesses is also observed when virginiamycin is supplied in the feed (Skrivanova & Marounek, 1993).…”

Ultrasonography of the Liver in Cattle

“…The ultrasonographic appearance of hepatic abscesses has been described in feedlot cattle [17][18][19][20][21], in cows [22,23] and in a breeding bull [24]. In cattle with experimentally induced hepatic abscesses, the portal vein was inoculated with Fusobacterium necrophorum under ultrasonographic guidance [17,19].…”

Liver abscesses in feedlot cattle: a review.

“…Control Tylosin-fed % Improvement propionate has had no effect on abscess incidence in several studies (Berger et al, 1981;Potter et al, 1985;Tan et al, 1994a;Bauer et al, 1995). Several studies have confirmed that the reduction in abscess incidence from tylosin feeding is 40 to 70% (Brown et al, 1975;Heinemann et al, 1978;Pendlum et al, 1978;Brink et al, 1990;Bartle and Preston, 1991;Tan et al, 1994a). A summary of 40 trials involving a total of 6,971 cattle from all major cattle feeding areas of the United States showed that tylosin (11 g/metric ton of air dry feed or 90 mg·animal −1 ·d −1 ) feeding reduced the incidence of liver abscesses by 73% (Vogel and Laudert, 1994).…”

“…Serum antibodies against F. necrophorum antigens have been detected in healthy and infected animals (Feldman et al, 1936;Simon and Stovell, 1969;Tan et al, 1994a). Several investigators have attempted to induce protective immunity against F. necrophorum by using a variety of antigenic components.…”