Heritabilities of IgA and IgE activities against Teladorsagia and Trichostrongylus L3 larval antigens correlated with traits for faecal worm egg count, health and productivity in Merino sheep

2019 ◽  
Vol 59 (10) ◽  
pp. 1792 ◽  
Author(s):  
Zhongquan Zhao ◽  
Mengzhi Wang ◽  
Shimin Liu ◽  
Dieter Palmer ◽  
Richard Shaw ◽  
...  

Low faecal worm-egg count (FEC) has been used as a phenotypic trait for breeding sheep for resistance to nematode infection. Application of this trait has resulted in a major reduction in worm-egg output in faeces, but in certain environments some of the resistant sheep develop what is believed to be a hypersensitivity-associated diarrhoea, resulting in soiling of the breech area (dags). To avoid breeding sheep with a propensity to scour, it, therefore, seems logical to combine selection for low FEC with selection for a trait based on the immune response to worm infection. We, therefore, investigated the relationships between immunoglobulin A (IgA) and immunoglobulin E (IgE) activities against L3 larval antigens of Teladorsagia circumcincta and Trichostrongylus colubriformis and measured their inheritance and their genetic relationships with FEC, dag traits and measures of production. Total plasma IgE concentrations were also determined and included in the study. We used 762 progeny from 23 Merino sires selected for resistance to helminths (the ‘Rylington Flock’) and to breech flystrike. Total plasma IgE and IgE activities against T. circumcincta were negatively correlated with liveweight, longissimus dorsi muscle depth, and fleece weight, but positively correlated with severity of dags, softer faeces and back-fat depth. The IgA activity against T. circumcincta was negatively correlated with liveweight and clean fleece weight, but positively correlated with back-fat depth and faecal consistency score. The IgA activity against T. colubriformis was not correlated with any measure, except the breeding value for dags around yearling age. The heritability for the IgA activity against T. circumcincta and T. colubriformis was 0.13 and 0.08 respectively. The heritability for both IgE activity against T. circumcincta and total plasma IgE concentration was 0.39. We conclude that it is feasible to combine FEC and dag traits with an immune trait (in this case, helminth-specific IgE activity and total plasma IgE concentration) and, thus, genetically select sheep for resistance to both helminths and diarrhoea. However, under natural worm-challenge conditions, blood sampling protocols need to developed, on the basis of animal age, season and environment, for optimum estimation of the immune trait and its relationships with other traits.


2019 ◽  
Vol 59 (1) ◽  
pp. 35
Author(s):  
S. F. Walkom ◽  
A. N. Thompson ◽  
E. Bowen ◽  
D. J. Brown

There is little evidence to show that mortality rates during the period after weaning are improving over time in Australian sheep. The average mortality rate of Merino lambs during the post-weaning period has been estimated to be 5.2%. The present study explored the potential for producers to breed for improved survival rates during the post-weaning period and the potential impact this would have on key production traits. A total of 122526 weaner survival (mortality) records were obtained from 18 Merino flocks, between 1989 and 2014, encompassing a wide variety of Australian Merino sheep types and production systems. The heritability of weaner survival from a sire model was estimated to be 0.07 ± 0.01 and was significantly greater than zero. The survival of lambs post-weaning was significantly influenced by weaning weight, with higher survival rates observed in the heavier lambs. The phenotypic relationship with weight indicates that selection for heavier weaning and post-weaning weights, and in turn larger growth rates, will improve survival rates. There is genetic variation in weaner survival not explained by the relationship with weaning weight. Weight-corrected weaner survival was antagonistically genetically correlated with fleece weight. Due to these antagonistic genetic relationships selection based on popular MERINOSELECT indexes is leading to a very small reduction in the survival rate of lambs after weaning through to the post-weaning stage. To prevent a decline in weaner survival, producers are advised to record weaner survival and include it in their breeding objective.



2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 206-206
Author(s):  
Tom Murphy ◽  
Jennifer M Thomson ◽  
James Berardinelli ◽  
Brent Roeder

Abstract A long-term selection experiment was conducted in a Rambouillet flock from 1969 to 2017. The high (HL) and low lines (LL) were divergently selected based on a maternal reproductive index, and an unselected control line (CL) was also maintained. Adult ewe traits considered were NLB, greasy fleece weight (GFW), and body weight after fall weaning of their lambs (BW). Results indicated that NLB was greatest for HL (1.67 ± 0.01), intermediate for CL (1.48 ± 0.02), and least for LL (1.28 ± 0.01; P < 0.001). Ewe GFW was greatest for LL (3.9 ± 0.02 kg; P ≤ 0.01) but not different between HL (3.82 ± 0.02 kg) and CL (3.88 ± 0.02 kg; P = 0.08); whereas, BW was least for HL (61.7 ± 0.19 kg; P ≤ 0.01) and not different between LL (62.9 ± 0.21 kg) and CL (62.6 ± 0.25 kg; P = 0.58). Heritability was estimated to be low for NLB (0.13 ± 0.02) and moderate for GFW (0.55 ± 0.03) and BW (0.46 ± 0.04). Genetic correlations were estimated to be near zero between NLB and GFW (-0.07 ± 0.08) and NLB and BW (0.12 ± 0.08) and low between GFW and BW (0.29 ± 0.06). Trends for NLB predicted breeding value differed among all 3 lines (P < 0.01) and was positive for HL (0.012 ± 0.0002 lambs/birth year), negative for LL (-0.005 ± 0.0002), and small but positive for CL (0.002 ± 0.0002). Inbreeding rates were positive in all lines but greatest for HL (0.45 ± 0.005 %/birth year), intermediate in LL (0.37 ± 0.006), and lowest in CL (0.28 ± 0.006). Results indicated long-term phenotypic selection for reproductive rate was effective and not genetically antagonistic with wool production or mature BW.



2008 ◽  
Vol 48 (9) ◽  
pp. 1186 ◽  
Author(s):  
A. E. Huisman ◽  
D. J. Brown

The Australian Merino is the predominant genetic resource for both the prime lamb and sheep meat industries of Australia. There are very few studies that provide good information on the relationships between wool and non-wool traits. The objective of this paper was to describe genetic relationships within bodyweight traits and between bodyweight and other traits recorded in Merino sheep. The genetic correlation between bodyweight, fleece weight and fibre diameter was positive (0.1 to 0.2). While fibre diameter coefficient of variation, staple length, staple strength, mean fibre curvature, and faecal egg count were not correlated with bodyweight. Scrotal circumference (0.4), number of lambs born (0.1), and number of lambs weaned (0.1) were positively correlated with bodyweight. Results indicate that selection for an increase in bodyweight will have a positive effect on eye muscle depth, fleece weight, and reproduction traits, while selection for an increase in bodyweight will have a negative effect on fibre diameter and fibre diameter coefficient of variation.



2009 ◽  
Vol 49 (1) ◽  
pp. 9 ◽  
Author(s):  
G. D. Snowder ◽  
N. M. Fogarty

Reproduction and ewe productivity are complex composite traits that are influenced by several component traits. Genetic improvement by selection for an individual component trait may not always be advantageous because adverse or neutral genetic relationships can exist among the component traits. Selection for an overall composite trait of ewe productivity, defined as litter weight weaned per ewe joined, can result in a balanced biological composite trait with favourable responses in component traits including fertility, number of lambs born, lamb survival, lactation and lamb growth. Selection for litter weight weaned may also overcome adverse genetic relationships among reproductive component traits. This review examines the genetic responses of selecting directly for litter weight weaned, compared with selection responses for one or more of its component traits. It is concluded that selection to improve reproductive efficiency and ewe productivity, under most production and environmental systems, would benefit from selection for a composite trait such as litter weight weaned, rather than for a single component trait.



2000 ◽  
Vol 68 (10) ◽  
pp. 6077-6081 ◽  
Author(s):  
Firdausi Qadri ◽  
Muhammad Asaduzzaman ◽  
Christine Wennerås ◽  
Golam Mohi ◽  
M. John Albert ◽  
...  

ABSTRACT Cholera toxin (CT)-specific antibody responses of the immunoglobulin E (IgE) isotype in the sera of adult patients suffering from infection with either Vibrio cholerae O1, V. cholerae O139, or enterotoxigenic Escherichia coli(ETEC) were analyzed and compared with those in the sera of volunteers immunized with a bivalent B subunit O1/O139 whole-cell cholera vaccine. A significant IgE response to CT was observed in 90% of the patients with V. cholerae O1 infection (18 of 20; P = <0.001) and 95% of the patients with V. cholerae O139 infection (19 of 20; P = <0.001). Similarly, the majority of the patients with ETEC diarrhea (83%; 13 of 15) showed a positive IgE response to CT. Eight of 10 North American volunteers (80%) orally challenged with V. cholerae O1 showed CT-specific IgE responses (P = 0.004). In contrast, Swedish volunteers immunized with the oral cholera vaccine showed no IgE responses to CT (P value not significant). During the study period, total IgE levels in the sera of the diarrheal patients, the North American volunteers, and the Swedish cholera vaccinees alike remained unchanged. However, the total IgE levels in the sera of patients and healthy Bangladeshi controls were on average 89-fold higher than those in the sera of the healthy Swedish volunteers and 34-fold higher than those in the sera of the North American volunteers.



2018 ◽  
Vol 85 (3) ◽  
pp. 355-357
Author(s):  
Coralie Barrera ◽  
Gabriel Reboux ◽  
Audrey Laboissière ◽  
Laurence Millon ◽  
Anne Oppliger

This research communication aimed to evaluate the level of immunoglobulin E from lactic acid bacteria (LAB) that are used in dairy industries. Previous studies have demonstrated that workers report symptoms of irritation and are frequently IgG-sensitised to LAB. Workers (n = 44) from a probiotic production unity and the control lab were seen by a medical practitioner and responded to an occupational questionnaire. Specific IgE by the DELFIA® technique against 6 strains of LAB were measured on 44 exposed workers and 31 controls sera. Levels of specific IgE were low and no difference was observed between the two groups. This lack of IgE response could be explained by a healthy worker effect, an efficient implementation of personal protective equipment or by an absence of allergic mechanisms to account for the self-reported irritative symptoms. Despite the high concentrations of LAB, preventive measures are effective enough to guarantee no allergic effect and to prevent other adverse health effects. The implementation of preventive measures to avoid or reduce exposure to dust of LAB, and more generally to milk powder, is recommended in all dairy industry.



2018 ◽  
Author(s):  
Mitchell H. Grayson ◽  
Peter Mustillo

The incidence of allergic diseases, like asthma, allergic rhinitis, and food allergy, is increasing in Westernized countries. This chapter discusses the importance of taking a careful and focused history and physical examination, as well as the laboratory studies that can be used to demonstrate the presence of allergic sensitization. Treatment for allergic disease is discussed, with an emphasis on new biologic therapies that have been developed. Finally, the chapter explores relatively new studies on the potential for interventions to prevent food allergy.  Allergy is defined as an untoward physiologic event mediated by immune mechanisms, usually involving the interaction between an allergen and the allergic antibody, immunoglobulin E (IgE). Allergic reactions typically occur due to exposure to either airborne allergens, foods, drugs, chemicals, or Hymenoptera (such as wasps, bees and fire ants). Allergies manifest in numerous ways, including allergic asthma, allergic rhinoconjunctivitis, urticaria, eczema, and in its most severe form, anaphylaxis. This review contains 4 videos, 5 figures, 4 tables and 42 references Key Words: Delayed allergic reaction (Alpha-gal), Allergy diagnosis, Measurement of specific IgE, Allergy and asthma therapies, Anticytokine therapy (dupilumab, mepolizumab, reslizumab), AntiIgE therapy (omalizumab), Allergy skin testing, Basophil histamine release assay



2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 494-494
Author(s):  
Desirae Smith ◽  
Kelsey Bentley ◽  
Scott A Bowdridge

Abstract Sheep selected for resistance to gastro-intestinal parasites have been shown to have greater survivability to weaning. Data from Katahdin sheep indicates that selection based on post-weaning fecal egg count estimated breeding values (PWFEC EBV) may further improve generalized immunity. However, no data exists to confirm this increased circulating antibody occurs in breeds genetically unrelated to Katahdins. In the fall of 2020 post-weaning blood and fecal samples were collected from Shropshire sheep (n = 42) and Polypay sheep (n = 91). The blood samples were analyzed for total immunoglobulin-G (IgG) using ELISA. Shropshire sheep were sorted into low (PWFEC EBV &lt; 0) and high (PWFEC EBV &gt; 0) groups based on fecal egg count (FEC), which were analyzed via a modified McMaster’s method. Polypay sheep were sorted into three groups by PWEC EBV; A (&lt; -50) B (&gt;-50 &lt; +50) and C (&gt;+50). In Shropshire group, individuals with low FEC had greater average IgG concentration (87.9 µg/mL) than those with high FEC (62.4 µg/mL) (P &gt; 0.05). In the Polypay group, sheep in PWFEC EBV group A had numerically higher IgG concentration (86.2 µg/mL) than sheep in group B (71.2 µg/mL) and group C (53.1 µg/mL) (P &gt; 0.05). While data in either breed were not significant, the trend observed across breeds indicate that sheep with a lower PWFEC EBV have numerically greater circulating antibody.



PEDIATRICS ◽  
1996 ◽  
Vol 98 (2) ◽  
pp. 329-329
Author(s):  
James E. Gern

RSV bronchiolitis was the most important risk factor for the development of asthma and allergen-specific IgE, although a family history of atopy or asthma further increased the risk.



2010 ◽  
Vol 134 (7) ◽  
pp. 975-982 ◽  
Author(s):  
Robert G. Hamilton

Abstract Context.—The diagnostic algorithm for human allergic disease involves confirmation of sensitization by detection of allergen-specific immunoglobulin E (IgE) antibody in individuals suspected of having allergic disease because of a history of allergic symptoms after known allergen exposure. Previous studies showed wide disparity among clinically reported allergen-specific IgE levels from different serologic assays. Objective.—To validate the relative analytic performance (sensitivity, interassay reproducibility, linearity/parallelism, intermethod agreement) of clinically used total and allergen-specific IgE assays by using College of American Pathologists' Diagnostic Allergy “SE” Proficiency Survey data. Design.—Data from 2 SE survey cycles were used to assess relative analytic performance of the ImmunoCAP (Phadia), Immulite (Siemens Healthcare-Diagnostics), and HYTEC 288 (HYCOR-Agilent Technologies) total and allergen-specific IgE assays. In each cycle, 2 recalcified plasma pools from atopic donors were diluted twice with IgE-negative serum and evaluated in approximately 200 federally certified clinical laboratories for total IgE and IgE antibody to 5 allergen specificities. Statistical analysis evaluated analytic sensitivity, linearity, reproducibility, and intermethod agreement. Results.—Interlaboratory intramethod, intermethod, and interdilution agreement of all 6 clinically used total serum IgE assays were excellent, with coefficients of variation (CVs) below 15%. Interlaboratory intramethod, and interdilution agreement of 3 clinically used allergen-specific IgE assays were also excellent with CVs below 15%. However, intermethod CVs identified between-assay disagreement greater than 20% in 80% of allergen-specific IgE measurements. Allergen reagents and patients' immune response heterogeneity are suggested probable causes. Conclusions.—Clinical total and allergen-specific IgE assays display excellent analytic sensitivity, precision, reproducibility, and linearity. Marked variability in quantitative estimates of allergen-specific IgE from clinically used automated immunoassays is a concern that may be ameliorated with component allergen use.



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