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  • Exploring viral diversity and metagenomics in livestock: insights into disease emergence and spillover risks in cattle

    Vet Res Commun. 2024 Jun 12. doi: 10.1007/s11259-024-10403-2. Online ahead of print.

    ABSTRACT

    Cattle have a significant impact on human societies in terms of both economics and health. Viral infections pose a relevant problem as they directly or indirectly disrupt the balance within cattle populations. This has negative consequences at the economic level for producers and territories, and also jeopardizes human health through the transmission of zoonotic diseases that can escalate into outbreaks or pandemics. To establish prevention strategies and control measures at various levels (animal, farm, region, or global), it is crucial to identify the viral agents present in animals. Various techniques, including virus isolation, serological tests, and molecular techniques like PCR, are typically employed for this purpose. However, these techniques have two major drawbacks: they are ineffective for non-culturable viruses, and they only detect a small fraction of the viruses present. In contrast, metagenomics offers a promising approach by providing a comprehensive and unbiased analysis for detecting all viruses in a given sample. It has the potential to identify rare or novel infectious agents promptly and establish a baseline of healthy animals. Nevertheless, the routine application of viral metagenomics for epidemiological surveillance and diagnostics faces challenges related to socioeconomic variables, such as resource availability and space dedicated to metagenomics, as well as the lack of standardized protocols and resulting heterogeneity in presenting results. This review aims to provide an overview of the current knowledge and prospects for using viral metagenomics to detect and identify viruses in cattle raised for livestock, while discussing the epidemiological and clinical implications.

    PMID:38865041 | DOI:10.1007/s11259-024-10403-2

  • Unraveling the genetic basis of methane emission in dairy cattle: a comprehensive exploration and breeding approach to lower methane emissions

    Anim Biotechnol. 2024 Nov;35(1):2362677. doi: 10.1080/10495398.2024.2362677. Epub 2024 Jun 11.

    ABSTRACT

    Ruminant animals, such as dairy cattle, produce CH4, which contributes to global warming emissions and reduces dietary energy for the cows. While the carbon foot print of milk production varies based on production systems, milk yield and farm management practices, enteric fermentation, and manure management are major contributors togreenhouse gas emissions from dairy cattle. Recent emerging evidence has revealed the existence of genetic variation for CH4 emission traits among dairy cattle, suggests their potential inclusion in breeding goals and genetic selection programs. Advancements in high-throughput sequencing technologies and analytical techniques have enabled the identification of potential metabolic biomarkers, candidate genes, and SNPs linked to methane emissions. Indeed, this review critically examines our current understanding of carbon foot print in milk production, major emission sources, rumen microbial community and enteric fermentation, and the genetic architecture of methane emission traits in dairy cattle. It also emphasizes important implications for breeding strategies aimed at halting methane emissions through selective breeding, microbiome driven breeding, breeding for feed efficiency, and breeding by gene editing.

    PMID:38860914 | DOI:10.1080/10495398.2024.2362677

  • A one health-focused literature review on bovine and zoonotic tuberculosis in Pakistan from the past two decades: challenges and way forward for control

    One Health. 2024 May 23;18:100763. doi: 10.1016/j.onehlt.2024.100763. eCollection 2024 Jun.

    ABSTRACT

    Bovine tuberculosis (bTB), caused by Mycobacterium bovis (M. bovis), is a globally prevalent zoonotic infectious disease. World Organization for Animal Health (WOAH) estimates indicate that up to 10% of the total human TB cases in developing countries are attributed to M. bovis. Pakistan ranks 4th in global milk production with a livestock population of over 212 million animals. Over 8 million families are involved in raising these animals as a means of livelihood. To date, there is an absence of national-level data on the prevalence of bTB and an effective control program is still lacking. The multifaceted impacts and substantial economic losses render addressing bTB a daunting, but highly important challenge. In this review, we summarise all the freely available literature on M. bovis infection from Pakistan using Google scholar and PubMed databases. A total of 40 animal studies were identified using search terms: “bovine tuberculosis in Pakistan, bTB, Pakistan, Mycobacterium bovis in Pakistan, M. bovis in Pakistan”; while seven human studies were identified using the terms: zoonotic tuberculosis in Pakistan’, ‘M. bovis in humans Pakistan’, ‘zTB in TB patients in Pakistan”. We have summarized all these studies to identify critical risk factors involved in transmission of bTB among animals and humans. Despite lack of comprehensive and geographically representative studies, the literature suggests a varying prevalence of bTB in animals, ranging from as low as 2% to as high as 19%. Regarding zTB prevalence in humans, estimates range from 1.5% to 13% in high-risk group of farm and abattoir workers, with notably higher percentages in extra-pulmonary TB cases. The review also addresses the challenges that Pakistan faces in formulating an effective policy for the control and eradication of bTB. We conclude with one-health based recommendations as a way forward for controlling TB caused by M. bovis in cattle and humans.

    PMID:38846704 | PMC:PMC11153871 | DOI:10.1016/j.onehlt.2024.100763

  • Prevalence and associated economic losses of bovine fasciolosis from postmortem inspection in municipal abattoirs in Ethiopia: A systematic review and meta-analysis

    Vet Anim Sci. 2024 May 16;24:100360. doi: 10.1016/j.vas.2024.100360. eCollection 2024 Jun.

    ABSTRACT

    Fasciolosis is a prevalent disease that significantly affects the health and productivity of cattle and causes significant economic loss. Beyond individually available studies with varying prevalence rates, there are no pooled national prevalence studies on bovine fasciolosis. Therefore, the aim of the current study was to determine the combined magnitude and economic significance of fasciolosis among cattle on postmortem examination. Inverse variance (I2), sensitivity analysis, funnel plots, Begg’s test, and Egger’s regression test were used to assess heterogeneity and publication bias. A random-effects model was used to calculate the pooled burden of fasciolosis among cattle. The pooled prevalence of fasciolosis among cattle on postmortem examination was 31.77 % (95 % CI=27.82-35.71). Among a total of 14,965 livers of slaughtered cattle examined in municipal abattoirs, Fasciola hepatica (54.4 %) was the predominant fluke identified compared to F. gigantica (24.6 %). Mixed infections of both species and unidentified immature flukes were detected in 12.4 % and 7.6 %, respectively, of affected livers. Regarding the severity of the pathological lesions observed, 30.5 %, 44.3 %, and 25.2 % of the livers were lightly, moderately, and seriously infested, respectively. The pooled annual economic loss attributed to fasciolosis-associated liver condemnation among cattle in 40 reported studies was approximately 40,833,983.15 ETB (6,417, 847.73 USD). Therefore, bovine fasciolosis requires integrated control methods to address its influence on animal health and economic impact.

    PMID:38831968 | PMC:PMC11145392 | DOI:10.1016/j.vas.2024.100360

  • The biology and development of vaccines for bovine herpesvirus 1

    Vet J. 2024 May 29:106152. doi: 10.1016/j.tvjl.2024.106152. Online ahead of print.

    ABSTRACT

    Bovine herpesvirus type 1 (BoAHV-1) infections lead to compromised herd health and significantly reduced productivity of affected cattle. While BoAHV-1 may cause rhinotracheitis, conjunctivitis, genital infections, and abortions, respiratory tract infections constitute the predominant clinical disease. Immune suppression induced by BoAHV-1 may contribute to co-infections initiating the bovine respiratory disease complex. In this review, the emphasis is to recapitulate the biology and the vaccine technologies currently in use and in development for BoAHV-1, and to discuss the major limitations. Studies on the life cycle and host interactions of BoAHV-1 have resulted in the identification of virulence factors. While several vaccine types, such as vectored vaccines and subunit vaccines, are under investigation, modified live and inactivated BoAHV-1 vaccines are still most frequently used in most areas of the world, whereas attenuated and inactivated marker vaccines are in use in Europe. The knowledge gained from studies on the biology of BoAHV-1 can form a basis for the rational design of future vaccines.

    PMID:38821207 | DOI:10.1016/j.tvjl.2024.106152

  • Fat deposition and partitioning for meat production in cattle and sheep

    Anim Nutr. 2024 Mar 21;17:376-386. doi: 10.1016/j.aninu.2024.03.003. eCollection 2024 Jun.

    ABSTRACT

    In markets for beef and sheep meat, an appropriate level of intramuscular fat (IMF) is highly desirable for meat-eating quality, but strategies to improve it usually lead to an undesirable excess in carcase fat, presenting a major challenge to livestock producers. To solve this problem, we need to understand the partitioning of fat among the major fat depots: IMF, subcutaneous fat (SCF) and visceral fat (VF). In most genotypes of cattle and sheep, the rate of accretion is lower for IMF than for SCF and VF, so genetic selection for a high level of IMF, or the use of an increased dietary energy supply to promote IMF deposition, will increase overall fatness and feed costs. On the other hand, feeding postnatal calves with excessive concentrates promotes IMF deposition, so a nutritional strategy is feasible. With genetic strategies, several problems arise: 1) positive genetic correlations between IMF, SCF and VF differ among genotypes in both cattle and sheep; 2) genotypes appear to have specific, characteristic rates of accretion of IMF during periods of growth and fattening; 3) most breeds of cattle and sheep naturally produce meat with relatively low levels of IMF, but IMF does vary substantially among individuals and breeds so progress is possible through accurate measurement of IMF. Therefore, an essential prerequisite for selection will be knowledge of the genetic correlations and fat accretion rates for each genotype. Currently, selection for IMF is based on existing technology that directly measures IMF in the progeny or siblings, or estimates IMF in live animals. New technology is needed to permit the simultaneous measurement of SCF and IMF in the field, thus opening up the possibility of accurate selection, particularly for fat partitioning in live animals. Specifically, there would be great value in detecting individuals with an IMF advantage at an early age so the generation interval could be shortened and genetic gain accelerated. Genetic gain would also be greatly aided if we could select for genes that control adipogenesis and lipogenesis and are also differentially expressed in the various depots.

    PMID:38812494 | PMC:PMC11134559 | DOI:10.1016/j.aninu.2024.03.003

  • PERSPECTIVE: Semen additives for improving frozen-thawed buffalo and cattle semen – a review

    Cryo Letters. 2024 Jul-Aug;45(4):194-211.

    ABSTRACT

    This comprehensive review delves into the evolving landscape of assisted reproductive technologies (ARTs) in bovine species, particularly focusing on the pivotal roles of semen additives in the cryopreservation of buffalo and cattle semen. In developing nations, where ARTs are still emerging, these techniques significantly influence bovine reproductive strategies. In contrast, developed regions have embraced them as primary approaches for dairy buffalo and cattle breeding. Semen cryopreservation, while offering advantages like extended storage and genetic propagation, also presents challenges. These include diminished sperm quality due to reactive oxygen species (ROS) production, alterations in sperm structure, and temperature fluctuations. Further, the effect of cryopreservation differs between cattle and buffaloes, with the latter exhibiting poorer semen viability and fertility due to inherent lipid composition susceptibilities. The generation and implications of ROS, especially hydrogen peroxide, contribute significantly to sperm DNA damage and functional impairments. To counteract these challenges, research has intensified on semen additives, aiming to bolster semen quality and protect against oxidative stress-induced damage. As the field advances, the review emphasizes the need for optimized cryopreservation techniques and tailored antioxidant strategies to harness the full potential of ARTs in bovine breeding programs. Doi.org/10.54680/fr24410110112.

    PMID:38809784

  • Early prediction of oestrus for herd fertility management in cattle and buffaloes – a review

    Reprod Domest Anim. 2024 May;59(5):e14597. doi: 10.1111/rda.14597.

    ABSTRACT

    Oestrus is defined as a period when a female animal exhibits characteristic sexual behaviour in the presence of a mature male. Oestrous manifestation in dairy animals is due to the oestrogen (E2) effect on the central nervous system (CNS). It is a critical issue to be considered on a priority basis. Inefficient oestrous detection reduces the fertility status of the herd. The primary and most reliable indicator of oestrus is standing to be mounted by a bull or another female herd mate, signalling receptivity and the pre-ovulatory state in dairy cattle. Oestrous detection is primarily a management challenge requiring skill and vigilance. To improve the efficiency of oestrous detection in dairy cattle, visual observation is one of the best methods if done three times a day; however, heat detection aids, if combined, give better results. However, techniques like using teaser bulls, tail painting, chin ball markers, ultrasound (USG) examination, hormonal analysis and examination of cervicovaginal mucus (CVM) improve oestrous detection efficiency. Moreover, the changes in production systems have reduced the expression of oestrous behaviour among cows, due to higher oestrogen (E2) metabolism. Therefore, automated systems, such as pedometers, accelerometers and acoustic sensors like infrared thermography (IRT) and image processing, have significantly enhanced reproductive performance by facilitating oestrous detection and optimizing insemination schedules. From this review, we would conclude that oestrous detection alone contributes considerably to the reproductive status of the herd; therefore, applying different methods of oestrous detection reduces the incidence of missed oestrus and improves the fertility status of the herd.

    PMID:38798195 | DOI:10.1111/rda.14597

  • Zinc about it – zinc and calf immunity

    Front Immunol. 2024 May 10;15:1387950. doi: 10.3389/fimmu.2024.1387950. eCollection 2024.

    ABSTRACT

    Micronutrients, such as vitamins and trace minerals, are critical for supporting growth, performance, health and maintaining redox balance. Zinc (Zn), an essential micronutrient, aids the functioning of innate and adaptive immune cells. This scoping review aims to assemble and evaluate the evidence available for the role of Zn within calf immunity. Relevant literature was identified within Web of Science, PubMed, and CABI using search terms specific to the major innate and adaptive immune cell populations. There was no evidence that Zn supplementation altered neutrophil, natural killer cell, or T-cell functions. However, there was limited evidence to support Zn supplementation with reduced monocyte numbers, but there was no evidence to associate the monocytopenia with improvements in monocyte function. There is moderate evidence to suggest that Zn supplementation was beneficial for maintaining epithelial barriers of integumental and mucosal surfaces. The evidence supports supplementation above the current industry recommendations for improving immunoglobulin (Ig) production, with the strongest results being observed for IgG and IgM. Moreover, Zn supplementation was associated with reduced proinflammatory cytokine production, which may reduce inflammation-associated hypophagia and warrants further investigation. Furthermore, Zn reduced the duration of clinical signs in animals facing respiratory disease and diarrhea. However, consensus is needed about the optimal dose, route, and Zn formulation most appropriate for supporting immunity. In conclusion, while the literature supports that Zn could enhance calf immunity, there is insufficient evidence to adequately determine the extent to which Zn impacts innate immune cell and T-cell functions. Determination of the immune cell functions susceptible to modification by Zn supplementation is an important knowledge gap for enhancing the understanding of Zn and calf immunity.

    PMID:38799472 | PMC:PMC11116585 | DOI:10.3389/fimmu.2024.1387950

  • The welfare of ill and injured feedlot cattle: a review of the literature and implications for managing feedlot hospital and chronic pens

    Front Vet Sci. 2024 May 9;11:1398116. doi: 10.3389/fvets.2024.1398116. eCollection 2024.

    ABSTRACT

    By definition, ill and injured animals are on the negative valence of animal welfare. For beef cattle kept in feedlot settings, advances in cattle health management have resulted in a greater understanding and prevention of illness and injury. However, the management of cattle once they become ill and injured is an understudied area, and there are gaps in knowledge that could inform evidence-based decision-making and strengthen welfare for this population. The aim of this review is to provide a comprehensive overview of the acquired knowledge regarding ill and injured feedlot cattle welfare, focusing on existing knowledge gaps and implications for hospital and chronic pen management and welfare assurance. Ill and injured feedlot cattle consist of acutely impaired animals with short-term health conditions that resolve with treatment and chronically impaired animals with long-term health conditions that may be difficult to treat. A literature search identified 110 articles that mentioned welfare and ill and injured feedlot cattle, but the population of interest in most of these articles was healthy cattle, not ill and injured cattle. Articles about managing ill and injured cattle in specialized hospital (n = 12) or chronic (n = 2) pens were even more sparse. Results from this literature search will be used to outline the understanding of acutely and chronically ill and injured feedlot cattle, including common dispositions and welfare considerations, behavior during convalescence, and strategies for identifying and managing ill and injured cattle. Finally, by working through specific ailments common in commercial feedlot environments, we illustrate how the Five Domains Model can be used to explore feelings and experiences and subsequent welfare state of individual ill or injured feedlot cattle. Using this approach and our knowledge of current industry practices, we identify relevant animal-based outcomes and critical research questions to strengthen knowledge in this area. A better understanding of this overlooked topic will inform future research and the development of evidence-based guidelines to help producers care for this vulnerable population.

    PMID:38799724 | PMC:PMC11117431 | DOI:10.3389/fvets.2024.1398116