Selection of enterococci for potential canine probiotic additives

Enterococci are important inhabitants of animal intestine and are widely used in probiotic products. A potentially successful probiotic strain is expected to have several desirable properties in order to be able to exert its beneficial effects. Forty enterococcal isolates from dog faeces were tested for characters believed to be important for probiotic strains; bacteriocin production, resistance or tolerance to antibiotics, low pH, bile tolerance and adhesive activity. The total count of enterococci was found to be 3.3-7.3log(10)CFU/g of faeces. Most identified strains were Enterococcus faecium. All strains were sensitive to vancomycin, ampicillin, penicillin and chloramphenicol. Thirty-three percentage of strains were resistant to erythromycin and 28% to tetracycline. Among 40 isolates, 75% showed a broad inhibitory spectrum only against Gram-positive indicator bacteria. Seven strains with broad bacteriocin activity were selected for further assays. In the presence of 1% bile, the survival rate of selected strains ranged between 72 and 98%. Survival of strains at pH 3.0 was found in the range between 76 and 87% after 3h. The adhesion of the tested strains to intestinal mucus ranged from 4 to 11% for canine mucus and from 5 to 8% for human mucus. E. faecalis EE4 and E. faecium EF01 showed the best probiotic properties. It indicates that they could be used as new candidate probiotic strains after in vivo testing.     

Preweaning efficiency for mature cows of breed crosses from tropically adapted Bos indicus and Bos taurus and unadapted Bos taurus breeds

Production data were collected on mature cows produced by mating Angus and Hereford (pooled AH), Brahman (Bh) and Boran (Br), and Tuli, a tropically adapted Bos taurus, sires by AI or natural service to Angus and Hereford cows. These cows were mated to Charolais bulls for the purpose of this study. Within each sire breed of cow, cows were assigned randomly to one of three feeding rates, 49 or 76 g of DMI/ BW0.75 or ad libitum (10 to 12 cows/feeding rate group), with weekly individual animal feed consumption recorded. Lactation yields were recorded via the weigh-suckle-weigh protocol at approximately 14, 28, 56, 84, 112, 140, 168, and 196 d postpartum for each cow/calf pair. Means for milk yield at peak lactation, total milk yields, calf birth weight, age-adjusted weaning weights, preweaning daily gain, and feed efficiency were estimated. Peak yield (kg/d) for Bh (10.3 +/- 0.36) was greater (P < 0.05) than for Tuli (9.0 +/- 0.31). Total yield (kg, 212 d) for Bh (1802 +/- 68) was greater (P < 0.05) than for Tuli (1532 +/- 59). Birth weight of AH (44 +/- 0.9) was heavier than for Bh and Br (P < 0.05). Preweaning daily calf gain (g/d) and adjusted weaning weight (kg) of Bh (813 +/- 28, 212 +/- 6.1) and Br (766 +/- 24, 202 +/- 5.1) differed (P < 0.05) from AH (589 +/- 24, 169 +/- 5.2) and Tuli (634 +/- 24, 176 +/- 5.3). Efficiency estimates (grams of adjusted weaning weight/kilograms DMI of the cow) for Bh (88 +/- 2.5) and Br (85 +/- 2.1) exceeded (P < 0.05) those for Tuli (74 +/- 2.1) and AH (73 +/- 2.1). Bos indicus breed crosses exhibited greater peak and total yield, lower birth weight, greater daily gain and adjusted weaning weight, and higher feed efficiency than did Bos taurus breed crosses (P < 0.05). Total yield, daily gain, adjusted weaning weight, and feed efficiency were higher (P < 0.05) for cows sired by bulls from tropically adapted breeds, and the peak yield was less (P < 0.10). Tuli exhibited lower total yield and birth weight than did Angus/Hereford (P < 0.05). The efficiency of crossbred Tuli cows did not differ from Angus/Hereford F1 females, but neither equaled the efficiency of crossbred cows produced using Bos indicus breeds.     

The use of vitamin D3 and its metabolites to improve beef tenderness

Three experiments were conducted to determine whether feeding 25-hydroxyvitamin D3 (25-OH D3) or 1,25-dihydroxyvitamin D3 (1,25-(OH)2 D3) improves the tenderness of longissimus dorsi (LD), semimembranosus (SM), and infraspinatus (IF) muscles similar to supplemental vitamin D3 without leaving residual vitamin D3 and its metabolites in muscle. In the first two experiments, 24 crossbred steers were used to determine the effects of different oral amounts of 1,25-(OH)2 D3 (Exp. 1; n = 12) and 25-OH D3 (Exp. 2; n = 12) on plasma Ca2+ concentrations. In the third experiment, crossbred steers were allotted randomly to one of four treatments: 1) control placebo (n = 7); 2) 5 x 10(6) IU of vitamin D3/d (n = 9) for 9 d and harvested 2 d after last treatment; 3) single, 125-mg dose of 25-OH D3 (n = 8) 4 d before harvest; or 4) single, 500-microg dose of 1,25-(OH)2 D3 (n = 9) 3 d before harvest. The LD and SM steaks from each animal were aged for 8, 14, or 21 d, whereas steaks from the IF were aged for 14 or 21 d. All steaks were analyzed for tenderness by Warner-Bratzler shear force and for troponin-T degradation by Western blot analysis. Supplementing steers with vitamin D3 increased (P < 0.01) the concentration of vitamin D3 and 25-OH D3 in all muscles sampled. Feeding steers 25-OH D3 increased (P < 0.05) the concentration of 25-OH D3 in meat, but to an amount less than half that of cattle treated with vitamin D3. Supplemental 1,25-(OH)2 D3 did not affect (P < 0.10) shear force values; however, there was a trend (P < 0.10) for supplemental vitamin D3 and 25-OH D3 to produce LD steaks with lower shear values after 8 and 14 d of aging, and lower (P < 0.10) shear force values for the SM aged for 21 d. Analysis of Western blots indicated that LD steaks from cattle supplemented with vitamin D3 and 25-OH D3 had greater (P < 0.05) troponin-T degradation. Antemortem supplementation of 25-OH D3 seems to increase postmortem proteolysis and tenderness in the LD and SM without depositing large concentrations of residual vitamin D3 and its metabolite 25-OH D3.     

Risk factors associated with porcine cysticercosis in selected districts of Eastern and Southern provinces of Zambia

To determine the risk factors associated with Taenia solium transmission in humans and pigs in the rural areas of Eastern and Southern provinces of Zambia, a questionnaire was administered in 788 households from 155 villages. Pigs were examined from 800 households. Tongue examination and enzyme-linked immunosorbent assay (Ag-ELISA) for the detection of circulating antigens of T. solium cysticerci were used to measure infection in pigs. A snowballing technique was utilised to select households with pigs. Prevalence of households with pigs infected with T. solium on tongue examination by district ranged from 12.7% to 32.1% with Ag-ELISA having a range of 30.0-51.7%. Of the total number of households visited, 18.8% and 37.6% had at least one pig positive for porcine cysticercosis on tongue examination and Ag-ELISA, respectively. Risk factors associated with T. solium infection were lack of pork inspection at slaughter (96.7%), consumption of pork with cysts (20.1%), selling of pork infected with T. solium cysticerci (18.3%), free-range husbandry system (83.2%) and absence of latrines (58.0). Free-range husbandry system (OR=1.68; 95% CI=1.36-2.07) was a significant risk factor for porcine cysticercosis in the surveyed areas. The result that pigs were mostly kept on free-range and semi-intensive husbandry systems may have permitted them to have access to eating human faeces that could be contaminated with tapeworm eggs. This study has shown that T. solium infection poses a high public health risk in the study areas and urban areas as well. We recommend that a human survey be conducted to verify the human exposure to taeniasis and/or cysticercosis in Zambia.     

Multilocus-sequence typing analysis reveals similar populations of Streptococcus uberis are responsible for bovine intramammary infections of short and long duration

Multilocus-sequence typing (MLST) was used to analyse Streptococcus uberis isolates from a single herd associated with long duration (50-260 days) and rapidly cleared (less than 1 month) bovine intramammary infections to determine whether the bacterial type had any impact on the duration of infection. Most chronic infections (24 of 33) were due to continuous infection of the mammary quarter with the same sequence type, and infections were found to persist for many months. The remaining quarters were re-infected with a different sequence type within a single lactation. No particular sequence type or clonal complex (lineage) was associated with persisting infections, indicating that the outcome of intramammary infections with S. uberis is more likely to be dependent on host factors than on inter-strain differences. Analysis of these strains alongside others obtained from the same herd at a later date revealed the shift in the predominant genotypes with time.     

Genetic characterisation of African swine fever viruses from outbreaks in southern Africa (1973-1999)

African swine fever (ASF) is a highly lethal and economically significant disease of domestic pigs in the southern African sub-region, where outbreaks regularly occur. There is anecdotal evidence suggesting that trans-boundary movement of infected animals may have played a role in precipitating widespread outbreaks in the past, however, since the 1970s outbreaks have generally been more localised, particularly in those countries where control of animal movement is strictly regulated. The origin and relatedness of regional ASF outbreaks was investigated here by means of a two-step genetic characterisation approach whereby p72 gene sequencing was used to delineate genotypes, prior to intra-genotypic resolution of viral relationships by central variable region (CVR) characterisation of the 9RL ORF. In this manner, regional virus heterogeneity and epidemiological links between outbreaks could be assessed for the first time through phylogenetic analysis of the C-terminal end of the p72 gene of viruses recovered from domestic pig outbreaks in southern Africa between 1973 and 1999. The phylogeny revealed the presence of 14 distinct p72 genotypes of which 6 (genotypes XVII-XXII) were considered novel. Eight of these were country-specific with the remaining six having a trans-boundary distribution. CVR products were heterogeneous in size ranging from 377bp to 533bp across the 14 southern African genotypes. Within-genotype CVR comparisons revealed the presence of a genotype XIX virus with an extended field presence in South Africa (1985-1996) and permitted discrimination between three genotype VII viruses that were identical across the p72 gene.     

Antiapoptotic activity of bovine herpesvirus type-1 (BHV-1) UL14 protein

Viruses have evolved different strategies to interfere with apoptotic pathways in order to halt cellular responses to infection. One previous study showed that transient transfection of bovine herpesvirus type-1 (BHV-1) UL14 protein is efficient in protecting Madin Darby kidney (MDBK) and human chronic myelogenous leukemia (K562) cells from sorbitol-induced apoptosis. This protein corresponds to a putative protein of BHV-1, which shares aminoacid sequence with a part of the peptide-binding domain conserved in human heat shock protein (HSP70) family. The pBK-CMV-UL14 plasmid transfected MDBK cells treated with sorbitol did not show caspase-3 and caspase-9 activation with respect to non-transfected MDBK cells (UL14 negative). Furthermore, we report that the expression of the full length sequence of BHV-1 UL14 is evident after 7 h of infection of BHV-1 on MDBK cells which were then treated with sorbitol. These results indicate that UL14 gene product has important implications to enhance cell survival in response to apoptotic stimuli.     

Importance of the rearing period for laying hens in alternative systems

Feather pecking and cannibalism are still major problems in alternative systems for laying hens. Literature and practical experience indicate that unfavourable rearing conditions might be important risk factors for the occurrence of these behavioural disturbances during the laying period.Typical rearing conditions of laying hens from 50 rearing units in Germany and Austria are presented. Obvious risk factors during rearing for feather pecking and cannibalism during the laying period were found. Most flocks were kept under high stocking density (mean: 15 pullets per m' useable area) and some flocks had access to litter only after the second week of life or access to raised perches after the fourth week of life. Plumage condition of pullets and laying hens varied widely in non-beak-trimmed as well as in beak-trimmed flocks.The percentage of pullets with damaged plumage was higher in beak-trimmed than in non-beak-trimmed flocks (medians: 53 % versus 30 %, p = 0,022). In laying hens there was a higher percentage of hens with plumage damage in non-beak-trimmed flocks compared to beak-trimmed flocks (medians: 23 % versus 50 %, p = 0,007). Data analysis will be continued, especially with regard to particular risk factors.