Associations between lamb growth to weaning and dam udder and teat scores     

KJ Griffiths  AL Ridler  CWR Compton  RA Corner-Thomas  PR Kenyon 《New Zealand veterinary journal》2013,61(4):172-179

ABSTRACT

Aims: To investigate associations between lamb growth to weaning and dam udder and teat scores measured at pre-mating, pre-lambing, docking and weaning.

Methods: Mature Romney ewes (n?=?1,009) were enrolled from a commercial sheep flock located near Masterton, in the Wellington region of New Zealand in 2017. A range of udder and teat traits were scored in all ewes, using visual assessment and palpation, at pre-mating, pre-lambing, docking and weaning. During the lambing period, each newborn lamb was matched to its dam and lamb sex, birthweight and birth-rank were recorded. A rearing rank was allocated to each live-lamb at weaning, when all lambs were weighed (n?=?1,570), allowing calculation of daily growth rates (g/day). Associations between udder and teat scores and lamb growth rates to weaning were examined using multivariable models for each udder-scoring time.

Results: Growth rates of lambs whose dams had udder palpation scores of hard, or both teats recorded as abnormal, pre-mating were lower than lambs whose dams had normal scores (229.9 (95% CI?=?213.2–246.6) vs. 254.5 (95% CI?=?245.6–263.5) g/day; p?=?0.011) and (227.4 (95% CI?=?208.3–246.6) vs. 247.9 (95% CI?=?235.7–260.2) g/day; p?=?0.024), respectively. Growth rates of lambs whose dams had clinical mastitis at docking or weaning were lower than those without mastitis (215.8 (95% CI?=?199.9–231.7) vs. 235.4 (95% CI?=?225.4–255.0) g/day; p?=?0.007) and (220.0 (95% CI?=?205.2–234.8) vs. 254.7 (95% CI?=?248.9–260.5) g/day; p?<?0.001), respectively. Growth rates of lambs whose dams had asymmetrical udders at docking or weaning were lower than lambs whose dams had symmetrical udders (204.6 (95% CI?=?189.7–219.5) vs. 240.2 (95% CI?=?225.4–255.0) g/day; p?<?0.001) and (223.3 (95% CI?=?213.9–232.7) vs. 242.2 (95% CI?=?229.4–255.0) g/day; p?=?0.014), respectively.

Conclusions and Clinical Relevance: Pre-mating udder palpation and teat palpation scores can be used to identify ewes whose lambs are predicted to have lower growth to weaning. Assuming a mean lamb age at weaning of 84.4 days, lambs born to ewes with a pre-mating score of hard would be expected to have a mean weaning weight that was 2.1?kg less than those whose dams had normal scores. Udder palpation, udder symmetry and clinical mastitis scores during lactation were also associated with lamb growth rates.

Abbreviation: CALW: Conceptus-adjusted liveweight  相似文献   

Mycobacterium avium subsp. paratuberculosis infection in wildlife on three deer farms with a history of Johne's disease     

G Nugent  EJ Whitford  JC Hunnam  PR Wilson  ML Cross  GW de Lisle 《New Zealand veterinary journal》2013,61(6):293-298

Abstract

AIM: To determine the prevalence of Mycobacterium avium subsp. paratuberculosis (Map) infection in wildlife, in pastoral landscapes with a recent history of clinical Johne's disease in livestock.

METHODS: A total of 449 wild mammals and birds from three farms in the South Island of New Zealand with recent histories of clinical Johne's disease in their deer herds were trapped and examined for gross pathological changes in the gastrointestinal tract. Additionally, individual mesenteric lymph nodes from 380 mammals, and segments of gastrointestinal tract from 32 birds were excised, homogenised and cultured for viable Map bacilli. The prevalence of Map infection was then calculated for the various species. Faecal samples from those mammals which had culture-positive tissues were further cultured for the presence of Map.

RESULTS: Gross pathological changes were identified in the gastrointestinal tract of four brushtail possums, one cat, six ferrets, 12 hares, six hedgehogs, three rabbits, one stoat, and one paradise shelduck. Infection with Map in the gastrointestinal tract was confirmed in only three of these cases, one each of brushtail possums, hares and hedgehogs. In contrast, Map infection in the absence of gross pathological changes was frequently recorded in enteric tract tissues of mammals and birds. Among mammals, Map infection was recorded in 18/73 (25%) brushtail possums, 4/23 (17%) cats, 15/42 (36%) hedgehogs and 29/113 (26%) rabbits. Among birds, intestinal tract tissue Map infection was recorded in 3/17 (18%) paradise shelducks. Among 64 of the 74 mammals which had Map culture-positive tissues, 38% (n=5) of hedgehogs and 11% (n=3) of rabbits also had culture-positive faecal samples.

CONCLUSIONS: This study is the first to identify that Map infection can be prevalent in wildlife in New Zealand. There was a high prevalence of Map infection among both scavenging and grazing wild animals. Both mammals and birds are capable of harbouring viable Map organisms in their gastrointestinal tract; further, viable Map was excreted into the environment via faeces by hedgehogs and rabbits.

CLINICAL RELEVANCE: Previous studies overseas have postulated a role of wildlife as reservoirs of Map infection and possible vectors of Johne's disease to livestock. Here, brushtail possums, hedgehogs and rabbits and in particular were identified as potential wildlife hosts for Map infection in NewZealand. This suggests that several wildlife species could contribute to the persistence of Map infection within a wildlife/livestock complex, and potentially, perhaps more importantly, to the spread of infection between farms.  相似文献   

Serological patterns,antibody half-life and shedding in urine of Leptospira spp. in naturally exposed sheep     

E Vallée  C Heuer  JM Collins-Emerson  J Benschop  PR Wilson 《New Zealand veterinary journal》2013,61(6):301-312

Abstract

AIMS: To determine within-farm prevalence, longitudinal pattern of exposure measured by serology, antibody titre longevity and point prevalence of shedding in urine of Leptospira borgpetersenii serovar Hardjo and L. interrogans serovar Pomona in naturally infected sheep on a sample of commercial farms in New Zealand.

METHODS: On eight commercial sheep farms, between September 2011 and January 2014, blood samples were collected from 115–217 ewe lambs on each farm, at intervals of 2–11 months. They were analysed by microscopic agglutination test (MAT) for antibodies to L. borgpetersenii serovar Hardjo and L. interrogans serovar Pomona, using a titre cut-point of 48. Urine from 98 animals was tested by quantitative PCR (qPCR). The half-life of antibodies was estimated in 185 sheep for serovar Hardjo and 21 for Pomona, and the seroprevalence and mean titre of animals lost to follow-up was compared with those remaining in the study.

RESULTS: Within-flock seroprevalence for serovar Hardjo reached a maximum at 17–22 months of age, ranging from 79 to 100%. Seroprevalence for serovar Pomona rose above 10% on three farms and increased to 21–54% by 4–14 months. Seroconversions occurred mainly from late autumn to early summer at 7–15 months of age. Seroprevalences ranging from 3 to 76% for serovar Hardjo and 0.5 to 15% for serovar Pomona were observed up to 3 months of age, likely due to maternally derived immunity. The half-life of antibody in response to infection was estimated to be 6.7 (95% CI=5.8–7.9) months for serovar Hardjo and 6.3 (95% CI=4.8–9.0) months for Pomona. The prevalence of sheep with urine positive for leptospires on qPCR on each farm ranged from 11 to 88%. All but one of the qPCR-positive animals were seropositive for serovar Hardjo. On two farms where Pomona exposure was observed, animals that were lost to follow-up had a higher geometric mean titre for serovar Pomona than those remaining in the study.

CONCLUSIONS: This study demonstrated seasonal exposure from autumn to early summer in young sheep, a wide range of within-flock serological and shedding prevalence, and gives an estimation of the half-life of MAT titres in sheep. More extensive data are needed to fully understand the epidemiology of leptospirosis in sheep flocks across New Zealand and, along with economic analysis, to justify and design cost-effective and efficient control measures to protect human and animal health.  相似文献   

Re: Journal standards     

PR Wilson 《New Zealand veterinary journal》2013,61(5)

Abstract

Extract

I refer to the correspondence by Dr Jackson (2003) Jackson, R. 2003. Journal standards. New Zealand Veterinary Journal, 51: 199–199. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar] in the August 2003 issue of the New Zealand Veterinary Journal, regarding citation of articles published in non-peer reviewed publications in this journal.  相似文献   

The effect of individual liveweight and condition scores of ewes at mating on reproductive and scanning performance     

PR Kenyon  PCH Morel  ST Morris 《New Zealand veterinary journal》2013,61(5):230-235

Abstract

AIMS: To determine the effects of liveweight (LW) and condition score (CS) of ewes at mating on both mating performance and scanning percentage, and to determine if effects of CS were independent of LW.

METHODS: Two groups of ewes, comprising 1,780 mixedaged Romney (Rom MA) and 692 composite two-tooth (? East Friesian 1/16 Finn 13/16 Romney, Comp TT) ewes were grazed separately with harnessed rams for two reproductive cycles. Romney rams were used for the first 17 days of mating and then replaced on the morning of Day 18 by Suffolk rams. Ewes were weighed and CS assessed on a scale of 0–5 before the introduction of the rams. Ewes were identified as having been mated during the first cycle only, during both cycles, during the second cycle only, or not mated. All mated ewes were scanned using ultrasound, 50 days after the end of mating, and identified as being either non pregnant, single-, twin- or triplet-bearing.

RESULTS: Linear relationships (R²=0.99) between mean LW and CS at mating were evident for both Rom MA and Comp TT ewes and the mean increase in LW per unit increase in CS was greater in the Rom MA ewes (7.88 kg) than the Comp TT (4.78 kg) ewes (p<0.05). Ewes mated in the second cycle only were significantly (p<0.05) lighter than those mated in the first cycle only. In Rom MA ewes, a greater proportion were mated in the first cycle only if CS was .2.0 than if CS was <2.0, and the proportions of ewes mated in the first cycle only or in both cycles did not differ if CS was ≥2.5. In Comp TT ewes, there was no difference in the proportions mated in the first cycle or both cycles, if CS was ≥2.0. Triplet-bearing ewes were heavier than twin-bearing ewes, which were in turn heavier than both singleton-bearing and non pregnant ewes. Twin-bearing ewes had higher CS than both single-bearing and non pregnant ewes (p<0.05) but differences were not significant if LW was included as a covariate. In both Rom MA and Comp TT ewes, greater proportions were non pregnant and lower proportions had twins if CS was <2.0 than if CS was ≥2.0. In Rom MA ewes only, a greater proportion again had twins and a lower proportion had singletons if CS was ≥3.0 than if CS was <3.0. In Comp TT ewes, the proportion that were non pregnant or twin-bearing did not vary with CS if CS was ≥2.0. Reproductive performance was maximal for Rom MA and Comp TT ewes that had CS at mating ≥3.0 and ≥2.0, respectively, equating to LW of 62.6 and 48.5 kg, respectively.

CONCLUSIONS: In both groups of ewes, CS and LW at mating positively affected reproductive performance measured at the time of mating and at scanning, however, no reproductive advantage was evident above a minimum CS of 3.0 and 2.0, equating to LW of 62.6 and 48.5 kg, for Rom MA and Comp TT ewes, respectively. Sheep farmers should direct management to ensure that no ewes are below these minimum targets rather than ensuring high average LW and/or CS of a mob.  相似文献   

Identifying factors which maximise the lambing performance of hoggets: a cross sectional study     

PR Kenyon  GL Pinchbeck  NR Perkins  ST Morris  DM West 《New Zealand veterinary journal》2013,61(6):371-377

AIM: To identity perceptions of farmers with respect to advantages of hogget lambing and to identify optimal management strategies for hogget lambing used in New Zealand.

METHODS: A questionnaire was sent to 1,038 sheep farmers in New Zealand who had indicated their hoggets would be lambing in 2002. Information was gathered on the practice of hogget lambing in New Zealand, in particular on the numbers and breeds of hoggets and rams used, selection criteria used for hoggets, use of teasers (vasectomised rams), length of mating period, use of mating crayons, vaccinations, medications and mineral supplements given, level of feed offered, use of pregnancy scanning, management during pregnancy and lambing, number of lambs present at docking, and shearing policies for hoggets. Farmers were also asked to indicate the relative importance of five stated reasons for choosing to have their hoggets mated in 2002.

RESULTS: A total of 629 (60.6%) responses were incorporated in the analysis, and the average percentage of hogget lambing was 60%. Use of vaccinations, length of the mating period, number of rams used, breed of hogget, weight at mating, management during lactation, and shearing policy were associated (p<0.05) with the lambing performance of hoggets, in the multivariate analysis.

CONCLUSIONS: This study indicated that to ensure high lambing percentages (LP) in hoggets in New Zealand, sheep farmers should: vaccinate hoggets against toxoplasmosis and campylobacteriosis; utilise a 40-day mating period; use 2.6–3.5% of rams during mating; incorporate Finn or East Friesian genetics; ensure liveweights at mating are as high as possible; manage single- and multiple-bearing/-rearing hoggets separately during the lambing and lactation periods; and shear hoggets pre-mating.  相似文献   

The effect of time between doses on serological response to a recombinant multivalent pilus vaccine against footrot in sheep     

CL SCHWARTZKOFF  PR LEHRBACH  ML NG  A. POI 《Australian veterinary journal》1993,70(4):127-129

SUMMARY The response of sheep to a recombinant multivalent footrot vaccine containing pilus antigens was examined after the administration of two doses of vaccine at Intervals ranging from 2 to 52 weeks. Agglutinating antibody titres were measured 3 weeks after the second vaccination and showed that lengthening of the interdose interval results in higher agglutinin titres. The capability of sheep to mount an increasingly strong immune response as the interval between doses is increased provides an opportunity to maximise the usefulness of vaccination by administering the first dose well before an expected footrot transmission period. This advantage of increasing the interdose interval has not been reported for traditional, whole-cell footrot vaccines, and use of the new pilus vaccine in this manner may improve prospects for disease control. Furthermore, sheep given a third dose either 6 or 12 months after their initial two-dose vaccination program achieved significantly higher titres than those elicited after the second dose, suggesting the likelihood of further improvement in disease control in successive seasons.  相似文献   

Detection of Border disease virus in cattle   总被引：1，自引：0，他引：1  

Cranwell MP  Otter A  Errington J  Hogg RA  Wakeley P  Sandvik T 《The Veterinary record》2007,161(6):211-212

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Rapid detection of Escherichia coli virulence factor genes using multiplex real-time TaqMan PCR assays   总被引：1，自引：0，他引：1  

West DM  Sprigings KA  Cassar C  Wakeley PR  Sawyer J  Davies RH 《Veterinary microbiology》2007,122(3-4):323-331

Three multiplex real-time TaqMan PCR assays were developed for the detection of Escherichia coli virulence factor genes in veterinary samples. Target virulence factors chosen were the fimbriae K88 (F4), K99 (F5), F41, F17, F18 and 987p (F6) and the toxins LT, STa and CDT IV. Detection of genes coding GAD were included in each assay as an internal control. These assays allow rapid identification of virulence factor genes using identical cycling conditions on an Mx3000Ptrade mark real-time PCR machine with the capacity to test up to 20 strains for 9 virulence genes in 1h.  相似文献   

Associations between liveweight,body condition score and previous reproductive outcomes,and the risk of ewes bred at 18-months of age being dry at docking     

KJ Griffiths  AL Ridler  C Heuer  RA Corner-Thomas  PR Kenyon 《New Zealand veterinary journal》2018,66(6):290-296

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