Brucellosis associated with stillbirth in a bottlenose dolphin in Australia

A captive adult female bottlenose dolphin presented with stillbirth. The placenta appeared oedematous. No other gross lesions were evident in the placenta or the stillborn calf. Histopathology revealed mild multifocal placentitis and foetal encephalitis. Brucella sp. was isolated from lung, liver, spleen and kidney. Sequence and phylogenetic analysis demonstrated this organism to be most similar to Brucella ceti sequence type (ST) 27. Brucella sp. DNA was detected in formalin-fixed paraffin-embedded placenta and brain by real-time PCR using primers targeting the IS711 gene. Immunohistochemical staining revealed Brucella sp. antigen in placental inflammation. This is the first report of isolation of Brucella sp. from a marine mammal in the Southern Hemisphere and the first report of marine Brucella-associated disease in Australia.     

Cocomposting of Crawfish and Agricultural Processing By-Products

Disposal of crawfish processing residuals (hereinafter, referred to as crawfish residuals) poses a challenging problem to the rapidly expanding crawfish industry. Cocomposting is examined as a waste management alternative to landfill disposal. Four agricultural processing by-products were evaluated for use as bulking agents in composting crawfish residuals: wood chips, rice hulls, bagasse, and bark. Approximately 5 to 6.5 volumes of each bulking agents were mixed with one volume of crawfish residuals in 0.3-m³ composting reactors. Compost temperature was continuously monitored, and moisture content was maintained within a desirable range. Samples were collected twice weekly throughout the 50-d composting process. Use of bagasse as a bulking agent led to the largest reduction in volatile solids (27.6 percent), organic C (55.3 percent), particle size (64.7 percent), and compost volume (52.8 percent). Finished compost using bagasse contained the greatest concentration of N (18.4 g N/kg and 160 mg NH₄-N/kg). Self-heating patterns and decomposition of crawfish residuals were satisfactory using all four bulking agents, and no odor, insect or other nuisance problems were detected. The finished products of all compost mixtures were suitable for use as mulch or reuse as bulking agents.     

Alternative pathway of bovine complement: concentration of factor B, hemolytic activity and heritability

Concentrations of bovine factor B (Bbov) were determined by radial immunodiffusion in sera of 46 Holstein cows and heifers aged one to nine years. Mean values were 34.2 +/- 5.3 mg/100 ml. A hemolytic diffusion plate assay in agarose gel in presence of 10 mM EGTA and 5 mM Mg accurately measured concentrations of purified Bbov but gave higher mean values, i.e. 47.8 +/- 10.2 mg/100 ml, for concentrations of Bbov in whole sera. Hemolytic values obtained by the hemolytic diffusion plate assay, however, weakly correlated (r = .4539, p less than 0.01) with the serum concentration of Bbov measured by radial immunodiffusion. It was concluded that the hemolytic diffusion plate assay was not an accurate technique for the quantitative measurement of Bbov but a good assay for quantitation of the total hemolytic activity mediated via activation of the alternative complement pathway. It is suggested that the difference between the values obtained by the two tests for one particular serum is, to some degree, an expression of the ratio of amplification and restriction of the alternative pathway activity. No significant heritability (offspring and one parent) was detected for the hemolytic activity of serum. A heritability of 0.93 at a significance level of p less than 0.1 was determined for the serum concentration of Bbov.     

A comparison of Dorset and Finnish Landrace crossbred ewes

Data from 644 exposures and 552 lambings were used to analyze reproductive traits of 1/2-Finnish Landrace, 1/2-Dorset ewes (1/2 Finn); 1/4-Finnish Landrace, 3/4-Dorset ewes, (1/4 Finn) and Dorset ewes. Ewes were exposed to Hampshire or Suffolk rams for spring lambing from 1973 to 1978. The analytical model included fixed effects of ewe birth year (EBY), ewe breed (BR), lambing year within EBY and EBY X BR interaction and random effects of ewe within EBY and BR. Conception rate differed (P less than .01) for 1/2-Finn (.94), 1/4-Finn (.88) and Dorset (.80) ewes. Litter size was highest (P less than .01) for 1/2-Finns (1.97), followed by 1/4-Finns (1.74) and Dorsets (1.44). The 1/2-Finn ewes ranked first for number and weight of lambs weaned, and for number and weight marketed as feeder lambs. Birth weights were heavier (P less than .001) for lambs with Dorset dams (3.88 kg) than for lambs with 1/4-Finn (3.24 kg) or 1/2-Finn (3.08 kg) dams. Preweaning average daily gains and adjusted 90-d weights were also larger (P less than .001) for lambs with Dorset dams (.26 kg/d and 28.3 kg, respectively) than for lambs with 1/4-Finn (.24 kg/d and 25.4 kg) or 1/2-Finn (.24 kg/d and 25.1 kg) dams. However, Dorset ewes lambed an average of 10.5 d later than Finn-cross ewes, and actual weaning weights (unadjusted for age) did not differ significantly among lambs from Dorset (27.2 kg), 1/4-Finn (26.9 kg) and 1/2-Finn ewes (26.7 kg).(ABSTRACT TRUNCATED AT 250 WORDS)     

Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations

AIMS: To investigate the seroprevalence of antibodies to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure.

METHODS: Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was?>30%), and latex agglutination test (LAT; with titres ≥1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples.

RESULTS: Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive.

CONCLUSIONS: Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.     

Effect of supplementation frequency and supplemental urea level on dormant tallgrass-prairie hay intake and digestion by beef steers and prepartum performance of beef cows grazing dormant tallgrass-prairie

Effect of supplementation frequency and supplemental urea level on forage use (Exp. 1) and performance (Exp. 2 and 3) of beef cattle consuming low-quality tallgrass-prairie were evaluated. For Exp. 1 and 2, a 2 x 2 factorial treatment structure was used, such that two supplements (30% CP) containing 0 or 30% of supplemental degradable intake protein (DIP) from urea were fed daily or on alternate days. In Exp. 1 and 2, supplement was fed at 0.41% BW daily or at 0.83% BW (DM basis) on alternate days. For Exp. 3, a 2 x 4 factorial treatment structure was used, such that four supplements (40% CP) containing 0, 15, 30, or 45% of supplemental DIP from urea were fed daily or 3 d/wk. Supplements were group-fed at 0.32% BW daily or at 0.73% BW (DM basis) 3 d/wk. In Exp. 1, 16 Angus x Hereford steers (initial BW = 252 kg) were blocked by BW and assigned to treatment. Urea level x supplementation frequency interactions were not evident for forage intake, digestion, or rate of passage. Forage OM intake (OMI) and total digestible OMI (TDOMI) were not significantly affected by treatment. Total-tract digestion of OM (P = 0.03) and NDF (P = 0.06) were greater for steers supplemented daily. In Exp. 2, 48 Angus x Hereford cows (initial BW = 490 kg) grazing winter tallgrass prairie were used. Significant frequency x urea interactions were not evident for BW and body condition (BC) change; similarly, the main effects were not substantive for these variables. In Exp. 3, 160 Angus x Hereford cows (initial BW = 525 kg) grazing dormant, tallgrass prairie were used. Supplement refusal occurred for cows fed the highest urea levels, particularly for cows fed the supplement with 45% of the DIP from urea 3 d/wk, and supplement refusal increased closer to calving. A frequency x urea interaction (P = 0.02) was observed for prepartum BW changes. As supplemental urea level increased, prepartum BW loss increased quadratically (P = 0.02); however, a greater magnitude of loss occurred when feeding supplements containing > or = 30% of DIP from urea 3 d/ wk. Cumulative BC change followed a similar trend. In conclusion, moderate protein (< or = 30% CP) supplements with < or = 30% of supplemental DIP from urea can be fed on alternate days without a substantive performance penalty. However, infrequent feeding of higher protein (> 30% CP) supplements with significant urea levels (> 15% of DIP from urea) may result in decreased performance compared with lower urea levels.     

Effect of increasing proportion of supplemental N from urea in prepartum supplements on range beef cow performance and on forage intake and digestibility by steers fed low-quality forage

Four experiments were conducted to evaluate the influence of changing the proportion of supplemental degradable intake protein (DIP) from urea on forage intake, digestion, and performance by beef cattle consuming either low-quality, tallgrass prairie forage (Exp. 1, 2, and 4) or forage sorghum hay (Exp. 3). Experiments 1, 2, and 3 were intended to have four levels of supplemental DIP from urea: 0, 20, 40, and 60%. However, refusal to consume the 60% supplement by cows grazing tallgrass prairie resulted in elimination of this treatment from Exp. 1 and 2. Levels of supplemental DIP from urea in Exp. 4 were 0, 15, 30, and 45%. Supplements contained approximately 30% CP, provided sufficient DIP to maximize digestible OM intake (DOMI) of low-quality forage diets, and were fed to cows during the prepartum period. In Exp. 1, 12 Angus x Hereford steers (average initial BW = 379) were assigned to the 0, 20, and 40% treatments. Forage OM intake, DOMI, OM, and NDF digestion were not affected by urea level. In Exp. 2, 90 pregnant, Angus x Hereford cows (average initial BW = 504 kg and body condition [BC] = 5.0) were assigned to the 0, 20, and 40% treatments. Treatment had little effect on cow BW and BC changes and calf birth weight, ADG, or weaning weight. However, pregnancy rate tended to be lowest (P = 0.13) for the greatest level of urea. In Exp. 3, 120 pregnant, crossbred beef cows (average initial BW = 498 kg and BC = 4.6) were assigned to the 0, 20, 40, and 60% treatments. Prepartum BC change tended (P = 0.08) to be quadratic (least increase for 60% treatment), although BW change was not statistically significant. Treatment effect on calf birth weight was inconsistent (cubic; P = 0.03), but calf ADG and weaning weight were not affected by treatment. Pregnancy rate was not affected by prepartum treatment. In Exp. 4, 132 pregnant, Angus x Hereford cows (average initial BW = 533 and BC = 5.3) were assigned to the 0, 15, 30, and 45% treatments. Prepartum BC loss was greatest (quadratic; P = 0.04) for the high-urea (45%) treatment, although BW loss during this period declined linearly (P < 0.01). Prepartum treatment did not affect pregnancy rate, calf birth weight, or ADG. In conclusion, when sufficient DIP was offered to prepartum cows to maximize low-quality forage DOMI, urea could replace between 20 and 40% of the DIP in a high-protein (30%) supplement without significantly altering supplement palatability or cow and calf performance.