@conference {41559, title = {Immunity in pregnant ewes following a live-dead vaccination and infection with Salmonella Brandenburg}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {65}, year = {2005}, month = {Jan}, pages = {157-162}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = { The aim of this study was to investigate the efficacy of a combined live{\textendash}dead vaccination protocol to protect sheep against Salmonella Brandenburg infection. Thirty ewes were randomly divided into two groups, one of which was vaccinated and the other acted as a control. The vaccinated group received a live modified Salmonella Typhimurium vaccine (given by eye-drop) followed 4 weeks later by a sub-unit preparation derived from S. Brandenburg (given subcutaneously with the adjuvant Quil A). Following challenge with wild type S. Brandenburg (4 weeks after the booster), 43\% of the ewes aborted in the vaccine group as compared with 53\% of the controls. However, a higher mortality rate was found in the vaccine group (43\% vs 20\%). Using an enrichment/selection procedure, S. Brandenburg was detected in the faeces of all challenged animals until 3 weeks post challenge. By 6 weeks and 9 weeks post challenge approximately 50\% and 30\% of animals respectively were shedding, irrespective of treatment. Following administration of the live primary and subunit (secondary) vaccines, levels of total IgG, IgG1 and IgM antibody (measured with an indirect ELISA) were significantly increased in comparison with the control group (P < 0.01). The cell-mediated immune response (interferon gamma from whole blood cultures) was also enhanced following use of the live attenuated vaccine (P < 0.01), but was much less pronounced after boosting with the subunit vaccine and following challenge. In summary, vaccination evoked immune responses but did not give protection to experimental infection with S. Brandenburg.}, issn = {1176-5283}, author = {Li H and McFarlane RG and Amoafo OY and Zhang XZ} } @conference {41251, title = {Experimental infection of pregnant sheep with attenuated Salmonella typhimurium}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {61}, year = {2001}, month = {Jan}, pages = {74-77}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Salmonellosis occurs in many animal species including sheep, and may cause pathology of the gut and possible abortion. If attenuated strains were to be used for future control, their establishment in the host and shedding pattern needs to be determined. Fifty-one pregnant ewes were obtained from the Lincoln University Research Farm and assigned randomly to five treatment groups. At approximately 1 month before lambing, the groups were given attenuated S. typhimurium (cya-, crp-) by different routes and doses as follows: 1010 colony-forming units (cfu) intranasally (i.n.), 109 cfu i.n., 1010 cfu subcutaneously (s.c.), 109 cfu s.c., and control (saline i.n. and s.c.). Selected animals were slaughtered at days 4 and 14 post infection for bacteriological culture from the mesenteric and retropharyngeal lymph nodes, intestinal contents and lamb stomach contents. The experimental organisms were isolated using selective cultures and identified by latex agglutination test and fermentation reactions. Following infection there were no changes in rectal temperature or significant clinical signs except two cases of abortion in the 1010 cfu s.c. group. The number of animals shedding organisms in their faeces decreased with time from 12 ewes at day 1 to one ewe at day 4 and day 7. Most of them were from the 1010 i.n. group. Subcutaneous injection of 1010 cfu induced abortion in two of 11 ewes, as organisms were detected in their faeces and the aborted lambs. However, no organisms were detected in faeces, intestinal contents or the lamb stomach contents of the ewes that were killed at days 4 or 14. In the two ewes that had received 1010 cfu i.n. and were killed at day 4, organisms were detected in the mesenteric and retropharyngeal lymph nodes. In summary, the administration of the attenuated S. typhimurium (cya-, crp-) at 1010 cfu caused asymptomatic short-term faecal shedding and abortion when given i.n. and s.c., respectively. }, issn = {1176-5283}, author = {Khalil AM and McFarlane RG and Shand NA and Leslie SE and Christensen NH} } @conference {40784, title = {The effect of Fenbendazole on the immune system of lambs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {56}, year = {1996}, month = {Jan}, pages = {80-83}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Measurement of lymphocyte blastogenesis and antibody production were used to determine the effect of a benzimidazole anthelmintic on the immune response. Both parasitized and parasite-naive (n=12) lambs, 6 months of age, were treated with fenbendazole (5mg/kgBW) and compared with untreated control animals. All animals (n=24) were given bovine virus diarrhoea (BVD) vaccine the day following anthelmintic treatment. Heparinised blood samples were collected 0,3,7,14 and 21 days after the anthelmintic treatments. The entire treatment regime was repeated at Day 28. No effects on immunity were apparent after the initial dosage with fenbendazole. However, peripheral lymphocytes from lambs (parasitized and parasite-naive) collected 14 days after the second administration of fenbendazole treatment, had significantly lower stimulation indices compared to control animals, when cultured in vitro with concanavalin A (Con A) (P<0.01), phytohaemagglutinin (PHA), and lipopolysacchride (LPS)(P<0.05). In addition, stimulation to Con A was depressed 7 days after the second treatment. The primary and secondary humoral responses to BVD vaccination, as measured by serum neutralisation titre, were similar among groups. The repeated use of anthelmintics from the benzimidazole group may interfere with immune responsiveness in young sheep. }, issn = {1176-5283}, author = {Parish SJ and McFarlane RG and Familton AS and Abell TJ} } @conference {40552, title = {Lamb weight gain and faecal egg count when grazing one of seven herbages and dosed with larvae for six weeks}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {54}, year = {1994}, month = {Jan}, pages = {15-18}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {One hundred and forty Polled Dorset lambs were randomly allocated to graze one of seven herbages (n = 20/herbage) and either trickle dosed (n=12) with a total of 108,000 third stage gastrointestinal nematode larvae (50\% Trichostrongylus colubriformis and 50\% Ostertagia circumcincta) over 6 weeks, or undosed (n=8) and allowed to ingest any nematode larvae on pasture. After 28 days on the trial lambs dosed with larvae had higher (P<0.001) faecal egg counts (FEC{\textquoteright}s) than undosed lambs but after 42 days egg counts did not differ (P>0.05) between dosed and undosed groups. Dosing with larvae did not significantly alter the liveweight gain (LWG). Herbage species affected LWG, being highest on lotus (Lotus pedunculatus cv Maku) and lowest on ryegrass/white clover (Lolium perenne/Trifolium repens), with other treatments being intermediate. Dosed lambs grazing chicory (Chicorium intybus) had more faecal dags than any other group of lambs. Those grazing G27 red clover (Trifolium pratense) were worst afflicted by a dermatitis type condition commonly referred to as trefoil dermatitis. Plasma pepsinogen levels differed significantly (P<0.05) only between dosed and undosed groups grazing pawera red clover, ryegrass/white clover and sulla (Hedysarium coronarium). Worm counts were undertaken on ryegrass/white clover and sulla grazed lambs. Both dosed and undosed groups grazing ryegrass/white clover had higher (P<0.05) abomasal worm counts than sulla grazed lambs, intestinal worm counts were highest in dosed lambs grazing ryegrass/white clover, intermediate in the dosed lambs grazing sulla and in undosed lambs grazing ryegrass/white clover, and lowest in the undosed lambs grazing sulla. }, issn = {1176-5283}, author = {Niezen JH and Waghorn TS and Raufaut K and Robertson HA and McFarlane RG} } @conference {40502, title = {The effects of endophyte ingestion on immune function in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {53}, year = {1993}, month = {Jan}, pages = {255-258}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, abstract = {Midside skin and wool samples were taken at hogget shearing in October 1991 from 58 Perendale ewe hoggets which were the progeny of 2 lines of Perendale sheep selected for, or against, loose wool bulk at hogget shearing. Wool from the high line was 50\% more bulky, with a 17\% lighter clean fleece weight (CFW), 29\% shorter staple length (SL), 25\% shorter fibre length (FL), 14\% greater within sample variation in fibre diameter (SDFD), 72\% higher crimp frequency (CFreq), 61\% higher proportion of paracortex (Para\%), 92\% higher follicle curvature grade (FolC) and 7\% shallower follicle depth (FolD) than the low line. Character grade (Char) was 14\% lower and sulphur content (S) 3\% higher in the high line, each approaching 5\% significance, while there was no significant difference in live weight (LW) or mean fibre diameter (FD). Bulk was most strongly correlated, in decreasing order, with FolC, CFreq, SL, FL, Para\%, CFW, SDFD, Char and FolD. In decreasing order CFreq, Char, FD, SL, FL, Para\% and FolD explained a total of 90\% of the variation in bulk. With deletion of the subjectively assessed characteristics of FolC and Char, CFreq, SL and FL were the only characteristics selected as being significant, explaining a total of 85\% of the variation in bulk. The strong association between bulk and both SL and FL can be considered to be a reflection of associations between the length parameters and other fibre characteristics which impact on bulk rather than a direct effect of the length of fibre being measured for bulk. These data indicate the biological basis of differences in loose wool bulk for coarse wool Perendale sheep are, as for the fine wool Merino, primarily associated with single fibre crimp.}, issn = {1176-5283}, author = {McFarlane RG and Bell TA and Fletcher LR} }