Ova transport and fertility after resection of the oviductal isthmus in pigs

The effect upon the reproduction of total resection of the oviductal isthmus, including the uterotubal and ampullary-isthmus junctions followed by end-to-end ampullo-cornual anastomosis was studied in pigs. Normal cycling gifts of proved fertility were submitted to bilateral isthmus deletion (Group I). Other gilts were submitted only to unilateral isthmic resection, while their contralateral medial isthmus was transversally cut and reanastomosed (Group II). A significantly lower nidation index was obtained after bilateral isthmic resection. The gilts in Group I which did not become pregnant and those in Group II were successfully mated during forthcoming standing oestruses, and were in association to that slaughtered on days 3, 4, or 5 of the cycle, and the characteristics and location of ova were determined. Spermatozoa fertilized the ova, and those cleaved normally in the isthmic-resected tube as well as in the sham-operated oviducts. The isthmic-resected oviduct, however, did not transport cleaved ova into the uterus at the time expected as normal. The findings suggest that the fertilized pig ova cannot reach the uterus at the normal expected time in case of total absence of the isthmic part of the oviduct, resulting in impaired fertility.     

Production of H2S by Escherichia coli isolated from poultry: an unusual character useful for epidemiology of colisepticemia

Eleven isolates of H2S-producing Escherichia coli were recovered from necropsy materials of chickens with symptoms and lesions of colisepticemia on Saudi Arabian broiler farms. Results of 19 out of 20 biochemical reactions studied were typical for E. coli. Hydrogen sulfide production by the E. coli isolates was used as an epidemiological marker to pinpoint a breeding farm as the probable source of these strains, which were then transferred to progeny farms, where colisepticemia occurred. This finding was confirmed by the presence of the same antigenic structure (O78:H-) and by the same drug-resistance pattern (a multiple resistance to streptomycin, sulfathiazole, and tetracycline) in the isolates.     

Occipito-atlanto-axial malformation with atlanto-axial subluxation in an ataxic calf

Occipito-atlanto-axial malformation with atlanto-axial subluxation was diagnosed radiographically in a 4-day-old Holstein calf with a short neck, symmetric ataxia, and tetraparesis, indicative of a cervical spinal cord lesion. Necropsy confirmed the clinical diagnosis and revealed ribs on C-7, with partial fusion of C-7 and T-1. Histologic examination revealed focal degeneration of the spinal cord in the second cervical segment at the level of the atlanto-axial joint and extensive secondary neuronal fiber degeneration possibly caused by spinal cord trauma that occurred in utero.     

The significance of leptospiral titres associated with bovine abortion

To investigate relationships between serological titres to 2 serovars, pomona (L. pomona) and hardjo (L. hardjo), of Leptospira interrogans and abortions, log linear and logit models were fitted to herd and individual cow data from cattle serologically negative for brucellosis. Serological titres to both serovars were significantly related to abortions in individual cows, with L. pomona having a stronger relationship than L. hardjo. L. hardjo was not significant when herd data were analysed. Differences between dairy and beef cattle in the serological titres found to both L. pomona and L. hardjo were detected when data sets of all cattle or cattle with no history of abortion were analysed. The beef/dairy differences may be due to different management practices and/or to different geographical distributions of both serovars and populations of beef and dairy cattle. If there are no cattle in a herd with a reciprocal titre of 3000 or greater for L. pomona, it is unlikely that L. pomona is associated with the abortion problem. There was no specific L. hardjo titre which separated high and low probabilities that the serum came from a cow or herd with an abortion history.     

Inhibition of phagosome-lysosome fusion in macrophages by soluble extracts of virulent Brucella abortus

Water extracts of virulent Brucella abortus were able to inhibit phagosome-lysosome fusion in unelicited murine peritoneal macrophages following ingestion of yeast. Extracts from an avirulent strain were unable to produce a similar effect. Lipopolysaccharide from B abortus did not appear to be involved with the ability of the extracts to inhibit fusion.     

Response of growing-finishing pigs to decreasing floor space allowance and(or) virginiamycin in diet

Five hundred forty crossbred pigs were utilized in four trials (10 replications) at two stations to determine the separate and interacting effects of decreasing floor space allowance with or without the addition of virginiamycin to the diet on performance of growing-finishing pigs. Pigs were allowed .37, .33 or .28 m2/pig during the growing phase (23 to 55 kg) and .74, .66, .56 m2/pig during the finishing phase (55 to 100 kg) and fed either a corn-soybean meal control diet or the control diet plus 11 mg of virginiamycin/kg of diet. Floor space allowances were achieved by varying pen size, so the number of pigs and feeder space per pig were constant for all pens. During the growing phase, daily gain (P less than .01) daily feed intake (P less than .05) and feed conversion ratio (P less than .05) decreased as floor space allowance decreased. During the finishing phase and for the total test period, daily gain (P less than .01) and feed conversion ratio (P less than .05) were reduced but daily feed intake was not affected (P greater than .05) by restricted floor space allowance. The addition of virginiamycin to the diet had no effect on pig performance. The virginiamycin X floor space allowance interaction was not significant, suggesting that pigs fed a diet with or without virginiamycin responded similarly to restricted floor space allowance. The data suggest that the addition of virginiamycin to the diet was ineffective in overcoming the decrease in performance of growing-finishing pigs caused by crowded conditions.