Goat production is widespread in the tropics. Goats are very susceptible to gastrointestinal nematode infection, but there is less evidence of their genetic resistance. Genetic resistance of Creole goats to gastrointestinal nematodes has been studied at Guadeloupe in the French West Indies since 1995. The objective of this research was to investigate genetic variation for resistance to gastrointestinal nematode infection, in order to introduce this trait into breeding schemes. Genetic variability was assessed within a Creole experimental flock. Forty-nine sire groups were characterized at weaning and 55 during fattening after weaning. Kids were naturally infected, mainly by Haemonchus contortus and Trichostrongylus colubriformis. Fecal egg counts were determined once at weaning and every 6 and 7 wk after drenching during fattening. Blood samples were collected every 7 wk during fattening for determination of packed cell volume. Live weights were recorded at weaning and at the beginning and middle of every infection period during fattening. Genetic parameters were estimated using the REML for multivariate animal models. The heritability estimate for transformed fecal egg count was 0.37+/-0.06 at weaning. During fattening, it increased from 0.14+/-0.05 at 4 mo to 0.33+/-0.06 at 10 mo. Heritabilities of packed cell volume ranged from 0.10 to 0.33. At weaning, maternal heritability of fecal egg count reached 0.26 and direct heritability 0.20. After 6 mo of age, maternal effects were found to be unimportant for fecal egg count and packed cell volume. Live weights presented significant genetic variability. Genetic relationships between fecal egg counts and live weight in infected pastures were never significant. Genetic correlations between packed cell volume and live weight decreased from 0.47 to 0.10 from weaning to 10 mo of age. These results demonstrated the feasibility of breeding for improved resistance to nematodes in Creole kids.
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http://dx.doi.org/10.2527/2001.7971706x | DOI Listing |
J Integr Plant Biol
January 2025
State Key Laboratory of Rice Biology and Breeding & Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences, Zhejiang University, Hangzhou, 310058, China.
Upon recognizing elicitors derived from herbivores, many plants activate specific defenses. Most of the elicitors identified thus far are from the oral secretions and egg-laying fluids of herbivores; in contrast, herbivore fecal excreta have been sparsely studied in this context. In this study, we identified elicitors in the frass of the striped stem borer (SSB; Chilo suppressalis) larvae using a combination of molecular and chemical analyses, bioactivity tests and insect performance bioassays.
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December 2024
University of Molise, Department of Agricultural, Environmental and Food Science, Campobasso, Italy.
In sheep, gastrointestinal nematodes (GINs) can cause disease, reduced feed intake, and nutritional deficiencies. To counteract GINs, anthelmintics are widely used although it is well known they may enter the environment impacting ecosystems. In addition, anthelmintics resistance has rapidly developed and consequently, alternative approaches are crucial for profitable and sustainable sheep production.
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January 2025
Science Center of Chapadinha, Federal University of Maranhão, Chapadinha, Maranhao, Brazil.
This study investigated the modulation of Eimeria spp. parasite load and its impact on productivity parameters in lambs fed varying levels of babassu by-product (BBP). Twenty-four Dorper × Santa Inês lambs naturally infected with Eimeria spp.
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Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André 09280-560, SP, Brazil.
In the present study, the hexane extract from branches of (Winteraceae) displayed potent activity against parasites (100% mortality of the worms at 200 μg/mL). Bioactivity-guided fractionation afforded, in addition to the previously reported bioactive sesquiterpene 3,6-epidioxy-bisabola-1,10-diene, two chemically related drimane sesquiterpenes-polygodial () and 9-deoxymuzigadial (). The anti- effects for compounds and were determined in vitro, with compound demonstrating significant potency (EC value of 10 μM for both male and female worms), while was inactive.
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Melbourne Veterinary School, The University of Melbourne, Werribee, VIC, 3030, Australia.
Background: Gastrointestinal parasites such as nematodes and coccidia are responsible for significant economic losses in the goat industry globally. An indiscriminate use of antiparasitic drugs, primarily registered for use in sheep and cattle, in goats has resulted in drug-resistant gastrointestinal parasites. Very little is known about the gastrointestinal parasite control practices used by Australian dairy goat farmers that are pivotal for achieving sustainable control of economically important parasites.
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