Genetic resistance of different genotypes of sheep to natural infections with gastro-intestinal nematodes

1997 ◽  
Vol 64 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Endang Romjali ◽  
V. S. Pandey ◽  
R. M. Gatenby ◽  
M. Doloksaribu ◽  
H. Sakul ◽  
...  
Keyword(s):  
First Generation ◽  
Genetic Resistance ◽  
The Body ◽  
Birth Season ◽  
Weaning Weight ◽  
Intestinal Nematode ◽  
Faecal Samples ◽  
Breeding Programmes ◽  
Nematode Eggs ◽  
Mcmaster Method

AbstractDuring a 3-year period, from April 1991 to December 1993, in a flock with four lambing periods annually, faecal samples from lambs at weaning at the age of 3 months (no. = 1756), were examined for gastro-intestinal nematode eggs by the McMaster method. Faecal samples were also examined at the age of 9 (no. = 170), 12 (no. = 157), 15 (no. = 253) and 18 (no. = 85) months from the females only. From June to December 1993 packed cell volume (PCV) was also examined from lambs at weaning. Seven genotypes were used in this study.The faecal egg counts were affected by genotype, birth season, type of birth and rearing, sex and age. First generation cross of Sumatra × Barbados Blackbelly had lowest eggs per g of faeces (EPG) followed by Sumatra, St Croix, Sumatra × St Croix Fl and F2 and Sumatra × Java Fat tail. Lambs born in February-March when rainfall was low had lower EPG (V < 0·05) than those born in May-June or August-September. The EPG of lambs born and reared singly were significantly lower (P < 0·001) than those born twin, triplet or quadruplet. Female lambs had lower EPG than male lambs (P < 0·001). The EPG of lambs at 3 months were higher than at 9, 12, 15 or 18 months (P < 0·001).PCV was affected by genotype, sex, type of birth and rearing and season of birth. There was a positive correlation between PCV and weaning weight of lambs and a negative correlation between EPG and weaning weight. These results show that the crosses of St Croix and Barbados Blackbelly with local Sumatra sheep are at least as resistant or more resistant to gastro-intestinal nematodes than pure Sumatra breed and therefore these breeds can be used in cross breeding programmes to improve the body size of local Sumatra sheep.

scholarly journals Heligmosomoides bakeri: a model for exploring the biology and genetics of resistance to chronic gastrointestinal nematode infections

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1565-1580 ◽  
Author(s):  
J. M. BEHNKE ◽  
D. M. MENGE ◽  
H. NOYES
Keyword(s):  
Genetic Resistance ◽  
Gastrointestinal Nematode ◽  
Chromosome 1 ◽  
Laboratory Model ◽  
Production Traits ◽  
Wood Mice ◽  
Intestinal Nematode ◽  
Domestic Livestock ◽  
Breeding Programmes ◽  
Heligmosomoides Bakeri

SUMMARYThe intestinal nematodeHeligmosomoides bakerihas undergone 2 name changes during the last 4 decades. Originally, the name conferred on the organism in the early 20th century wasNematospiroides dubius, but this was dropped in favour ofHeligmosomoides polygyrus, and then more recentlyH. bakeri, to distinguish it from a closely related parasite commonly found in wood mice in Europe.H. bakeritypically causes long-lasting infections in mice and in this respect it has been an invaluable laboratory model of chronic intestinal nematode infections. Resistance toH. bakeriis a dominant trait and is controlled by genes both within and outside the MHC. More recently, a significant QTL has been identified on chromosome 1, although the identity of the underlying genes is not yet known. Other QTL for resistance traits and for the accompanying immune responses were also defined, indicating that resistance toH. bakeriis a highly polygenic phenomenon. Hence marker-assisted breeding programmes aiming to improve resistance to GI nematodes in breeds of domestic livestock will need to be highly selective, focussing on genes that confer the greatest proportion of overall genetic resistance, whilst leaving livestock well-equipped genetically to cope with other types of pathogens and preserving important production traits.

scholarly journals Parasites of Myocastor coypus – a Comparison in Farm Animals and Their Feral Counterparts

2018 ◽  
Vol 49 (1) ◽  
pp. 21-25
Author(s):  
S. Nechybová ◽  
I. Langrová ◽  
E. Tůmová
Keyword(s):  
Czech Republic ◽  
Nematode Species ◽  
Farm Animals ◽  
Myocastor Coypus ◽  
Free Living ◽  
The Czech Republic ◽  
Faecal Samples ◽  
Nematode Eggs ◽  
Mcmaster Method ◽  
Feral Animals

Abstract The parasitic status in the coypus (nutrias) Myocastor coypus, both farm-bred or free-living on river banks in the Czech Republic, was determined. Faecal samples were collected from 200 coypus originating from 11 farms (farm-bred animals) and from 20 individuals living at 14 natural localities (feral animals). Faeces were examined for nematode eggs and coccidian oocysts using the McMaster method. The evaluation of faeces from farm-bred coypus indicated infection with the following parasites: Trichuris sp., Strongyloides sp., Trichostrongylus sp., Eimeria seidelli, Eimeria nutriae, Eimeria coypi, and Eimeria myopotami. Free-living feral rodents harboured Eimeria nutriae, E. coypi, Strongyloides sp. and in one case also Trichuris sp. An additional visceral examination of 20 coypus originating from five farms revealed two nematode species in the gastrointestinal tracts, namely Trichuris myocastoris and Strongyloides myopotami. The study indicated that feral coypus are far less parasitized than their captive counterparts.

A novel method for the isolation of gastro-intestinal nematode eggs that allows automated analysis of digital images of egg preparations and high throughput screening

Parasitology ◽  
2001 ◽  
Vol 123 (3) ◽  
pp. 309-314 ◽  
Author(s):  
T. H. M. MES ◽  
H. W. PLOEGER ◽  
M. TERLOU ◽  
F. N. J. KOOYMAN ◽  
M. P. J. VAN DER PLOEG ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Digital Images ◽  
Automated Analysis ◽  
Accurate Analysis ◽  
Counting Procedure ◽  
Intestinal Nematode ◽  
Large Numbers ◽  
Fold Reduction ◽  
Faecal Samples ◽  
Nematode Eggs

A simple and robust method for the isolation of gastro-intestinal nematode eggs from faeces is described that uses both salt- and sugar solutions for flotation. Application of this ‘salt–sugar’; isolation method to large numbers of faecal samples of adult dairy cows indicates a 3- or 4-fold reduction in the proportion of e.p.g.-negative cows relative to studies that used other techniques for egg isolation. The procedure detects more eggs than the Wisconsin flotation method in replicate samples and in spiked egg-free faeces. The number of recovered eggs in spiked faecal samples is linear over a range of egg concentrations, and the transparent faecal preparations that result from the protocol can be stored as digital images which can be used as input for an efficient automated egg-counting procedure. The increased rate of processing of faeces combined with the large reduction of the percentage of e.p.g.-negative cows allows more accurate analysis of large numbers of adult or resistant animals for studies of nematode parasitism.

scholarly journals Genetic Basis of Mastitis Resistance in Dairy Cattle – A Review / Podstawy Genetyczne Odporności Krów Mlecznych Na Zapalenie Wymienia – Artykuł Przeglądowy

2013 ◽  
Vol 13 (4) ◽  
pp. 663-673 ◽  
Author(s):  
Grażyna Sender ◽  
Agnieszka Korwin-Kossakowska ◽  
Adrianna Pawlik ◽  
Karima Galal Abdel Hameed ◽  
Jolanta Oprządek
Keyword(s):  
Dairy Cattle ◽  
Association Studies ◽  
Genetic Resistance ◽  
Clinical Mastitis ◽  
Future Research ◽  
Complex Nature ◽  
Candidate Gene Approach ◽  
Genome Wide Association Studies ◽  
Polygenic Control ◽  
Breeding Programmes

Abstract Mastitis is one of the most important mammary gland diseases impacting lactating animals. Resistance to this disease could be improved by breeding. There are several selection methods for mastitis resistance. To improve the natural genetic resistance of cows in succeeding generations, current breeding programmes use somatic cell count and clinical mastitis cases as resistance traits. However, these methods of selection have met with limited success. This is partly due to the complex nature of the disease. The limited progress in improving udder health by conventional selection procedures requires applying information on molecular markers of mastitis susceptibility in marker-assisted selection schemes. Mastitis is under polygenic control, so there are many genes that control this trait in many loci. This review briefly describes genome-wide association studies which have been carried out to identify quantitative trait loci associated with mastitis resistance in dairy cattle worldwide. It also characterizes the candidate gene approach focus on identifying genes that are strong candidates for the mastitis resistance trait. In the conclusion of the paper we focus our attention on future research which should be conducted in the field of the resistance to mastitis.

Fabrication and Electrical Characterization of Ultra-Thin Body and BOX (UTBB) Back Enhanced SOI (BESOI) pMOSFET

2020 ◽  
Vol 15 (1) ◽  
pp. 1-6
Author(s):  
Ricardo Cardoso Rangel ◽  
Katia R. A. Sasaki ◽  
Leonardo Shimizu Yojo ◽  
João Antonio Martino
Keyword(s):  
First Generation ◽  
Electrical Characterization ◽  
Current Drive ◽  
The Body ◽  
Silicon On Insulator ◽  
Oxide Semiconductor ◽  
Thin Body ◽  
Back Gate ◽  
Buried Oxide ◽  
Complementary Mos Technology

This work analyzes the third generation BESOI MOSFET (Back-Enhanced Silicon-On-Insulator Metal-Oxide-Semiconductor Field-Effect-transistor) built on UTBB (Ultra-Thin Body and Buried Oxide), comparing it to the BESOI with thick buried oxide (first generation). The stronger coupling between front and back interfaces of the UTBB BESOI device improves in 67% the current drive, 122% the maximum transconductance and 223% the body factor. Operating with seven times lower back gate bias, the UTBB BESOI MOSFET presented more compatibility with standard SOI CMOS (Complementary MOS) technology than the BESOI with thick buried oxide.

Genetic analyses of piglet survival and individual birth weight on first generation data of a selection experiment for piglet survival under outdoor conditions

2007 ◽  
Vol 2007 ◽  
pp. 65-65
Author(s):  
R. Roehe ◽  
N. P. Shrestha ◽  
W. Mekkawy ◽  
P. W. Knap ◽  
K. M. Smurthwaite ◽  
...  
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Genetic Improvement ◽  
First Generation ◽  
Genetic Parameters ◽  
Selection Experiment ◽  
Postnatal Mortality ◽  
Breeding Programmes ◽  
Potential Benefits ◽  
Piglet Survival

Peri- and postnatal mortality of piglets is reported to be around 20% and genetic improvement in piglet survival has great potential benefits in terms of animal welfare, economics and the environment. The indication of an unfavourable genetic correlation between litter size and survival in particular points to the importance of including piglet survival in those pig breeding programmes that currently only aim to increase litter size. Phenotypically, individual birth weight is closely associated with piglet survival (Roehe and Kalm, 2000). Genetic parameters for piglet survival traits and individual birth weight therefore need to be estimated in order to genetically improve piglet survival efficiency

scholarly journals The point prevalence of gastro-intestinal parasites in calves, sheep and goats in Magadi division, south-western Keny

2004 ◽  
Vol 71 (4) ◽  
Author(s):  
M.W. Maichomo ◽  
J.M. Kagira ◽  
T. Walker
Keyword(s):  
Animal Species ◽  
Intestinal Parasites ◽  
Economic Loss ◽  
Parasite Control ◽  
Sheep And Goats ◽  
Internal Parasite ◽  
Faecal Samples ◽  
Parasite Infections ◽  
Mcmaster Method ◽  
Semi Arid

Helminths cause great economic loss in livestock in Africa, and can be categorized as either direct or indirect losses. Arid and semi-arid lands (ASAL) in Kenya comprise 71 % of total land area and harbour the largest population of cattle, sheep and goats. However, little information on the distribution and impact of gastro-intestinal (GIT) parasitism in these animals is available. This survey was conducted to establish the prevalence of GIT parasites infecting calves, sheep and goats and their relative importance in Magadi division, which is semi-arid. Faecal samples were obtained directly from the rectum of 109 calves, 133 goats and 20 sheep and submitted to the laboratory for faecal worm egg counts, and coccidial oocysts examination using a modified McMaster method. The significance of differences in mean egg count per gram (epg) between animal species and herds (farms) were assessed using analysis of variance. The overall prevalence of nematodes in the calves, sheep and goats was 69.2 %, 80 % and 82 %, respectively. About 10 % of sheep and goats had epgs higher than 1 000, the remainder having light to moderate infections. The overall prevalence of coccidial oocysts in calves, sheep and goats was 30 %, 44 % and 45 %, respectively. Poor productivity in ASAL areas, where nutrition is often poor, is likely to be pronounced in the presence of parasite infections. These findings indicate that viable internal parasite control should be implemented in the study area in order to increase the productivity of the livestock there.

Steinernema apuliae sp. n. (Rhabditida: Steinernematidae): a new entomopathogenic nematode from southern Italy

Zootaxa ◽  
2004 ◽  
Vol 460 (1) ◽  
pp. 1 ◽  
Author(s):  
ORESTE TRIGGIANI ◽  
ZDENEK MRÁ»EK ◽  
ALEX REID
Keyword(s):  
First Generation ◽  
Southern Italy ◽  
Entomopathogenic Nematode ◽  
Rflp Analysis ◽  
Tail Length ◽  
Its Region ◽  
The Body ◽  
Steinernema Glaseri ◽  
Pcr Rflp ◽  
H 41

Steinernema apuliae sp. n. has been found in soil samples collected along a saltpan border habitat in southern Italy characterized by a salted silt soil. This species belongs to the long-IJ nematode group represented by Steinernema glaseri (Steiner, 1929) and Steinernema arenarium (Artyukhovsky, 1967) among others. However, it differs from these taxa in some morphometric values such as V%, H%. Females possess asymmetrical, oblique slit vulva, slant vagina and small flap in the vulval opening. These characteristics are more distinct in second generation females which is different from most other steinernematids; the vulva position is behind the mid-body about 57% to 61% of the body length. First-generation females have a conical-like tip bearing 2 to 3 papilla-like protuberances. Male mucron is absent in both generations. Lightly brown spicules have bluntly pointed tip and elongated manubrium. Third-stage infective juveniles are on average over 1000 m long; the position of the excretory pore is posterior (D% 66) and the hyaline layer is less than half the tail length (H% 41 42). Lateral fields are formed by 8 equally distributed ridges. S. apuliae differs from S. glaseri and S. arenarium and is separated by PCR-RFLP analysis of the ITS region. There were no positive cross-breedings among these species.

Gastrointestinal parasites as a possible threat to an endangered autochthonous Portuguese sheep breed

2019 ◽  
Vol 94 ◽  
Author(s):  
Z.M. Ruano ◽  
A. Cortinhas ◽  
N. Carolino ◽  
J. Gomes ◽  
M. Costa ◽  
...  
Keyword(s):  
Fasciola Hepatica ◽  
Gastrointestinal Parasites ◽  
Sheep Breed ◽  
Parasitic Infections ◽  
Factors Affecting ◽  
Feed Management ◽  
Faecal Samples ◽  
High Prevalence ◽  
Protozoan Infections ◽  
Mcmaster Method

Abstract Helminth and protozoan infections are responsible for important diseases in grazing sheep, which can be especially threatening in an autochthonous breed at risk of extinction like the Churra Galega Mirandesa Portuguese sheep breed. The aim of the present study was to determine the diversity, prevalence and burden of gastrointestinal parasites in these sheep and to assess the effects of deworming practices, cohabiting animals on the farm and feed management. Coprological qualitative and quantitative analysis (flotation, natural sedimentation and McMaster method) were used to identify and quantify gastrointestinal parasites and a questionnaire was designed and applied. A total of 512 faecal samples were collected from 49 flocks, and 49 replies to the questionnaire were received. Parasites were identified in 100% of the flocks, and in 97% of the samples. The genera or species that have been morphologically identified were: strongyle-type, Nematodirus spp., Skrjabinema spp., Moniezia expansa, Moniezia benedeni, Trichuris spp., Capillaria spp., Eimeria spp., Dicrocoelium spp. and Fasciola hepatica. This is the first report in Portugal of Skrjabinema spp. The burden of parasites’ oocysts and eggs per gram in faecal samples ranged, respectively, from 50 to 17,550 for Eimeria spp., and from 50 to 6250 for strongyle-type eggs. Factors affecting parasitic infections were evaluated using a multivariate logistic regression. Grazing time and a lack of anthelmintic treatment were positively associated with Nematodirus spp. infection. This study showed that there is a high prevalence and diversity of gastrointestinal parasites in the Churra Galega Mirandesa sheep breed.

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