Le stress thermique environnemental dans l’espèce bovine : 3. Effets sur la reproduction

Revue d’élevage et de médecine vétérinaire des pays tropicaux, Journal Year: 2025, Volume and Issue: 78, P. 1 - 15

Published: Feb. 28, 2025

Contexte : L’augmentation régulière depuis plusieurs décennies de la température environnementale s’est accompagnée dans l’espèce bovine, notamment d’une diminution fertilité différentes régions du monde. Objectifs Cette revue littérature passe en les divers effets et leurs mécanismes sur aspects reproduction mâle femelle bovine. Méthode À partir base PubMed, cette concentrée un premier temps articles synthèse puis a été complétée par références des identifiés. Résultats La résulte stress thermique croissance folliculaire ovarienne, avec une incidence plus marquée follicules pré-antraux que antraux, l’ovocyte le corps jaune. Ces sont conséquence réduction d’oestradiol, progestérone, l’inhibine l’hormone lutéotrope (LH) ainsi l’augmentation celle folliculostimulante (FSH), modification gradients au niveau système génital n’étant pas non à exclure. Le est également responsable augmentation fréquence mortalité embryonnaire particulièrement durant première semaine gestation. L’exposition vaches gestation raccourcit durée, affecte placenta, modifie métabolisme vache lors sa lactation, altère son immunité exerce négatifs pondérale, développement mammaire folliculaire, longévité performances veau. Chez mâle, se traduit motilité anomalies morphologiques spermatozoïdes. Conclusions reconnaissance croissante reproductives bovins souligne nécessité pour responsables santé animale intégrer approches. Il essentiel mettre place stratégies visant atténuer impacts rentabilité élevages, d’autant influence épigénétique descendance mieux documentée.

---

A Review of the Rumen Microbiota and the Different Molecular Techniques Used to Identify Microorganisms Found in the Rumen Fluid of Ruminants

Animals, Journal Year: 2024, Volume and Issue: 14(10), P. 1448 - 1448

Published: May 13, 2024

Variations in environments, including climate, diet, and agricultural practices, significantly impact the composition microbial activity. A profound understanding of these adaptations allows for improvement nutrition ruminant production. Therefore, this review aims to compile data from literature on rumen microbiota molecular techniques identifying different types microorganisms fluid ruminants. Analyzing microbiology ruminants is complex due interactions, influenced by environment animals. In addition, it worth noting that genera protozoa fungi most evident studies used were Entodinium spp. Aspergillus spp., respectively, Fibrobacter bacteria. About used, can be seen DNA extraction, amplification, sequencing cited evaluated. describes what present provides an overview main agents used.

Language: Английский

---

Thermographic Profiles in Livestock Systems under Full Sun and Shaded Pastures during an Extreme Climate Event in the Eastern Amazon, Brazil: El Niño of 2023

Animals, Journal Year: 2024, Volume and Issue: 14(6), P. 855 - 855

Published: March 11, 2024

The El Niño represents a substantial threat to pastures, affecting the availability of water, forage and compromising sustainability grazing areas, especially in northern region Brazil. Therefore, objective this study was characterize thermographic profile three production systems Eastern Amazon, conducted on rural cattle farm Mojuí dos Campos, Pará, Brazil, between August November 2023. experiment involved livestock systems, including traditional, silvopastoral integrated, with different conditions shade access bathing area. An infrared (IRT) camera used, recording temperatures zones, such as areas trees, pastures exposed pastures. highest mean (p = 0.02) were observed full sun from November. On other hand, lowest average recorded shaded by chestnut trees (Bertholletia excelsa). temperature ranges found sunny areas. pasture sun, while < 0.0001). interaction treatments revealed significant differences 0.0001), native showing an 35.9 °C, lower than grasses soil, which reached 61.2 °C. This research concludes that, under Brazil nut had temperatures, demonstrating effectiveness shade. Native compared showed ability create cooler environments, highlighting positive influence species sheep, goats cattle.

Language: Английский

---

Characterization of Thermal Patterns Using Infrared Thermography and Thermolytic Responses of Cattle Reared in Three Different Systems during the Transition Period in the Eastern Amazon, Brazil

Animals, Journal Year: 2023, Volume and Issue: 13(17), P. 2735 - 2735

Published: Aug. 28, 2023

In the Lower Amazon mesoregion, there are basically three types of production systems: traditional (without shade and no bathing area), silvopastoral (with integrated area). It is considered that type system influences thermal comfort productivity cattle, so this research aims to evaluate influence these systems on thermoregulation Nellore cattle. The experiment was carried out a rural property for raising located in Mojuí dos Campos, Pará, Brazil, during transition period (June/July). Thirty bovine males (not castrated, aged between 18 20 months, average weight 250 ± 36 kg, body condition score 3.5, clinically healthy) were randomly divided into groups: Silvopastoral System-SS (n = 10), Traditional System-TS Integrated System-IS 10). Climate variables collected (air temperature (AT °C), relative humidity (RH %), wind speed (WS, m/s), solar radiation (SR), black globe (BGT physiological parameters, such as respiratory rate (RR) rectal (RT)) at 6 a.m., 12 p.m., a.m. determine situation animals. Thermographic images environment animals captured order obtain surface (BST) through infrared thermography. Benezra Thermal Comfort Index (BTCI), Environmental Stress (ESI), Equivalent Temperature (ETI), Iberian Heat Tolerance (Iberian HTI) used. results showed system, with shading by chestnut trees an ample vegetative area, presented better conditions, 28.98 °C, comparison (35.93 °C) one (34.11 °C). observed cattle did not differ significantly anatomical regions studied (p > 0.05). As rate, registered higher values, 41 movements per minute, indicating possible stress < indices revealed all moderate conditions times intensity. concluded proved be more favorable providing reducing stress, which may have positive impact animal welfare region.

Language: Английский

---

Evaluation of the temperature and humidity index to support the implementation of a rearing system for ruminants in the Western Amazon

Frontiers in Veterinary Science, Journal Year: 2023, Volume and Issue: 10

Published: July 14, 2023

The good productive and reproductive performance of the animals depends on multiple factors, including favorable climatic conditions, which are responsible for causing changes in physiological behavioral responses. Thus, objective this study was to evaluate temperature humidity index (THI) support implementation a rearing system ruminants Western Amazon, Brazil. Monthly relative data were obtained from Database Teaching Research (BDMEP) capitals Manaus (Amazonas), Boa Vista (Roraima), Rio Branco (Acre), considering historical series 27 years (1993 2020), referring January December. In capital Vista, months January, February, May, June, July showed an indication mild stress March, April, August, September, October, November, December had moderate stress. Branco, all year presented average THI with variations lower (73) higher (77). Manaus, signaled stress, but August there December, It is possible observe significant during as well study, under thermal > 72 or warning signal, gradual increase indices over last 10 years. importance breeding consideration environmental such THI, fundamental wellbeing cattle raised field. Our results adoption heat mitigation strategies Amazon.

Language: Английский

---

Reproductive Efficiency of Nelore Cows in Fixed-Time Artificial Insemination Programs with Early Resynchronization

Veterinary Sciences, Journal Year: 2025, Volume and Issue: 12(1), P. 27 - 27

Published: Jan. 8, 2025

We aimed to evaluate the reproductive efficiency of Nelore cows in fixed-time artificial insemination (FTAI) programs with early resynchronization. A total 468 were divided into two experimental groups: R30-conventional resynchronization at 30 days (n = 234); R22-early 22 234). Both groups followed a synchronization protocol using intravaginal progesterone devices combined administration steroids and gonadotropins. The R30 involved after FTAI, while R22 implemented FTAI without prior pregnancy diagnosis. In both groups, one was by resynchronizations. results showed similar rates between rate 1st being 50.85% group 48.72% (p 0.742). During resynchronization, 45.22% 46.67% cumulative 1st, 2nd resynchronizations 80.77% 82.91% 0.643), no significant difference observed. Follicular dynamics also monitored, ovulation occurring 78.95% cases 91.67% 88.98% mean diameter ovulatory follicle 13.64 ± 3.48 mm, largest significantly greater (14.47 2.76 mm) that ovulated compared those did not (11.54 4.24 < 0.05), reinforcing association size likelihood ovulation. These findings indicate conventional protocols perform similarly, offering advantages reducing calving interval. Furthermore, relationship follicular confirms importance as an indicator success.

Language: Английский

---

Ingestive Behavior and Body Development of Backgrounded Heifers From Three Genotypes in the Brazilian Pantanal

Animal Research and One Health, Journal Year: 2025, Volume and Issue: unknown

Published: April 7, 2025

ABSTRACT The aim was to evaluate the ingestive behavior and body development of backgrounded heifers from three genotypes in Brazilian Pantanal. Twenty‐two with an average weight 180 kg 15 months age were used, distributed into genotype groups: eight Nelore (N), seven × Angus (½ Angus, NA), Pantaneiro Pantaneiro, NP). NP exhibited similar grazing times, which higher compared NA heifers. It observed that chest depth, heart girth, rump width between ischia, hook ilia values among other genotypes. total daily gain than N is concluded there are significant differences genotypes, suggesting variations capacity adapt Pantanal environment. These results suggest crossbreeding maximizes benefits derived heterosis, as individuals this cross more efficient have desirable characteristics. breed resulted low heifers, indicating limited heterosis gains cross, even breed's native

Language: Английский

---

Le stress thermique environnemental dans l’espèce bovine : 4. Moyens de lutte

Revue d’élevage et de médecine vétérinaire des pays tropicaux, Journal Year: 2025, Volume and Issue: 78, P. 1 - 15

Published: April 28, 2025

Contexte : Le stress thermique a un impact significatif sur le bien-être des animaux d’élevage, affectant leur santé physique ainsi que paramètres zootechniques tels la productivité et rendement, ce qui conséquences directes rentabilité exploitations. De nombreuses recherches sont menées dans but d’évaluer d’améliorer les méthodes de lutte contre thermique. Objectifs Cette revue littérature récapitule Celles-ci peuvent être regroupées en quatre catégories, l’amélioration l’environnement animaux, gestion l’alimentation, l’approche par sélection génétique reproduction. Méthode s’est d’abord appuyée articles synthèse issus base PubMed, puis été enrichie l’examen références citées ces articles. Résultats Il n’existe pas solution unique pour atténuer effets d’un chez animaux. Au contraire, diverses solutions apparaissent comme étant complémentaires doivent choisies fonction du contexte l’élevage. La première méthode se concentre adaptations ciblant ventilation, choix matériaux construction, systèmes refroidissement. deuxième vise une plus rigoureuse l’alimentation. troisième repose plusieurs approches factorielle, génomique, croisement l’hybridation. Enfin, quatrième catégorie explore l’utilisation biotechnologies reproduction traitements hormonaux. Conclusions recommandation principale est combiner méthodes, privilégiant environnementales nutritionnelles, tout intégrant progressivement stratégie adaptée à chaque système d’élevage.

---

Influence of silvopastoral systems and heat stress on bovine reproduction: Silvopastoral effects on cattle reproduction

Journal of Animal Behaviour and Biometeorology, Journal Year: 2025, Volume and Issue: 13(1), P. 2025010 - 2025010

Published: May 13, 2025

Silvopastoral systems are important tools for bovine production under tropical conditions because of the optimization tree and forage resources. This combination presents productive advantages, such as increasing efficiency environmental effect on system, basis thermoregulation high biomass loads that balance impact system. Animal reproduction depends multiple factors strongly affect nutrition environment. Although reproductive is represented by fertility, there different parameters represent it, intervals between births or open days, which influence generation interval plans genetic improvement. It to understand effects silvopastoral directly indirectly in cattle elucidate construct concepts allow strengthening modifying increase cattle. The objective this review focus heat stress reproduction.

Language: Английский

---

A Review of the Effects of Stress on Dairy Cattle Behaviour

Animals, Journal Year: 2024, Volume and Issue: 14(14), P. 2038 - 2038

Published: July 11, 2024

In this narrative review, the authors summarise relationship between stress and behaviour how dairy cattle cope with stressors. Based on available literature, most common stressors in intensive farming, such as pain, disease, heat stress, poor comfort caused by technology, social are surveyed. The describe these modify of cattle, influencing their feeding patterns, interactions, overall well-being. Additionally, review explores effectiveness various coping mechanisms employed to mitigate including physiological adaptations behavioural responses. This is a valuable resource for understanding grading through reactions. Elucidating intricate interplay offers insights into potential interventions improve animal welfare productivity farming. Furthermore, highlights areas future research, suggesting avenues more comprehensive studies enhance our management strategies cattle.

Language: Английский

---