A systematic review of disease control strategies in beef cow-calf herds, part 2: preweaned calf morbidity and mortality associated with neonatal calf diarrhea and bovine respiratory disease
Preventing neonatal calf diarrhea (NCD) and bovine respiratory disease (BRD) in cow-calf herds is essential to optimizing calfhood health. Disease control can prevent morbidity and mortality; however, evidence concerning the effectiveness of practices to achieve this is limited. The objective of this systematic review was to assess and summarize the evidence on the effectiveness of management practices to prevent calf morbidity and mortality from NCD and BRD in beef cow-calf herds. The population of interest was preweaned beef calves. The outcomes were calf morbidity and mortality caused by NCD and BRD. Only studies reporting naturally occurring diseases were included. Seventeen studies were deemed relevant, 6 studies of which were controlled trials or randomized controlled trials (RCTs), and 11 were observational studies. Most management practices had some evidence to support their use; however, the certainty of the findings was low to very low. Most of the practices were shown to impact both NCD and BRD. Yet, the different levels of consistency in the directionality of the findings suggest that some outcomes are more affected by some practices than others. More well-designed RCTs and cohort studies are required to provide reliable estimates to support recommended practices for cow-calf herds.
What do we know about the epidemiology of infectious diseases and parasites of free-ranging Neotropical ungulates? Needs and priorities
Our analysis covers 122 scientific publications about health issues in free-ranging Neotropical ungulates produced between 1990 and 2022, with an emphasis on the epidemiology of infectious diseases and parasites. Most studies focus on parasitology (43.4%) and bacteriology (15.6%), while body condition (0.8%), toxicology (1.6%), virology (6.6%), and health assessments (6.6%) are less studied. Brocket deer ( and ), followed by peccaries ( and ), and the lowland tapir () were the most frequent species surveyed (61.4% of all publications). We detected considerably higher numbers of studies and health topics covered in Brazil ( = 64; 52.5% of the total) compared to other Latin American countries. We emphasize the need for further research focused on poorly known health aspects of Neotropical ungulates that have received little attention in the past, especially the Chacoan peccary (), taruca deer (), Northern pudu (), and the least known species. Ecotoxicology and pathology studies are necessary to evaluate the impact of agrochemicals and other human disturbances on Neotropical ungulate populations in the wild. We encourage further research on the human impacts and trends of change in the epidemiology of infectious diseases, parasites, and health status of Neotropical wild ungulate populations.
Recent advances in the use of bacterial probiotics in animal production
Animal husbandry is increasingly under pressure to meet world food demand. Thus, strategies are sought to ensure this productivity increment. The objective of this review was to gather advances in the use of bacterial probiotics in animal production. Lactobacilli correspond to the most used bacterial group, with several beneficial effects already reported and described, as well as the and genera - being the latter expressively used in aquaculture. Research on the genus is mostly focused on human health, which demonstrates great effects on blood biochemical parameters. Such results sustain the possibility of expanding its use in veterinary medicine. Other groups commonly assessed for human medicine but with prospective expansion to animal health are the genera and , which have been demonstrating interesting effects on the prevention of viral diseases, and in dentistry, respectively. Although bacteria from the genera and also have great potential for use in animal production, a complete characterization of the candidate strain must be previously made, due to the existence of pathogenic and/or spoilage variants. It is noteworthy that a growing number of studies have investigated the genus , but still in very early stages. However, the hitherto excellent results endorse its application. In this way, in addition to the fact that bacterial probiotics represent a promising approach to promote productivity increase in animal production, the application of other strains than the traditionally employed genera may allow the exploitation of novel mechanisms and enlighten unexplored possibilities.
A systematic review of disease control strategies in beef herds, part 1: preweaned calf mortality
Calves sold at weaning are the main source of income for cow-calf operations, and their survival should be a priority. Given this, the effective use of management practices for pregnant dams and calves to prevent calf mortality is essential; however, decision-makers often do not have access to information about the effectiveness of many management practices. A systematic review was conducted to summarize the evidence of the effectiveness of biosecurity, vaccination, colostrum management, breeding and calving season management, and nutritional management practices for preventing preweaned beef calf mortality. The population of interest was preweaned beef calves from birth until at least 3 months of age. The outcome of interest was general preweaning calf mortality with stillbirths excluded. Eleven studies were deemed relevant. Ten were observational cross-sectional studies, and one was a randomized controlled trial (RCT). The practices that were statistically significantly associated with calf mortality were intervening with colostrum in case a calf had not nursed from its dam or was assisted at calving, timing and length of the calving season, and injecting selenium and vitamin E at birth. More well-executed RCTs and cohort studies are needed to provide evidence of effectiveness and help support implementation of recommended practices in herds.
Minerals, serum metabolites, hormones, and bovine reproduction: a review
This study aimed to highlight the roles of different minerals, serum metabolites, and hormones related to reproductive health of cattle as these have a significant role in cattle production and reproduction. Minerals are known for their contribution to several physiological processes such as cell formation and are paramount for physiological functions of vitamins, enzymes, and hormones. Evaluations of serum metabolites are good indicators of disease diagnosis and nutritional status in animals. Hormonal imbalance before and during pregnancy can negatively impact an overall bovine reproductive health. Minerals are important for reproduction, serum metabolites are a reliable indicator as their changes have been related to many disorders in reproduction, and hormones are significant indicators in cows presenting different reproductive conditions.
Role of anti-Müllerian hormone in different reproductive aspects of female mammals: women, cow and mare
Anti-Müllerian hormone (AMH) is a dimeric glycoprotein belonging to the superfamily of the transforming growth factor-β. Due to the discovery of AMH functions, relative to the ovarian function, it is being postulated as being a highly important marker in studies on mammalian reproduction. Therefore, the objective of this review was to describe the role of this hormone in different reproductive aspects of female mammals, taking women, cows, and mares as reference species. The relationship between ovarian reserve and AMH was analysed, and it has been verified that there is a relationship between the latter, the antral follicle count, and the number of primary follicles. AMH concentration has been associated with parameters like the age of the individual, fertility, superovulation treatments and embryo production, and to the reproductive hormone concentration. Also, an association between AMH and female reproduction system diseases, and the fact that AMH is a heritable feature in the cow have also been proven. Recent studies have analysed the role of AMH receptor type 2 since it appears that, together with gonadotropin-releasing hormone, it controls the secretion of gonadotropins. Despite the considerable amount of bibliography on AMH, more studies are needed to complete the information that we have on it, in order to reveal the unknown elements in its action mechanisms.
Understanding the global distribution of atypical porcine pestivirus (APPeV)
Atypical porcine pestivirus (APPeV) is a pestivirus affecting pigs, notably causing high mortality in piglets due to neurological issues that impair suckling. This study reviews global literature from 2015 to March 2024, assessing APPeV prevalence. Analysing 40 relevant articles, it finds APPeV widely distributed across Europe, South America, North America, and Asia, with minimal presence in Africa and Australia. The scarcity in these regions might be due to geographical isolation, environmental factors, limited surveillance, diagnostics, or under-reporting. China leads in APPeV prevalence reports, followed by the USA, Germany, Sweden, and other countries. The main diagnostic methods are quantitative reverse transcription polymerase chain reaction (RT-qPCR) and RT-PCR, using tissue and serum samples. APPeV detection in the serum of boars and wild boars suggests possible persistent infections, indicating their role in APPeV epidemiology. Given the global outbreaks, particularly of congenital tremor (CT), the study calls for expanded research, especially in under-studied regions like Africa and Australia, focusing on healthy pigs, CT-affected piglets, and boars to better understand APPeV transmission dynamics.
Essential oils and essential oil compounds in animal production as antimicrobials and anthelmintics: an updated review
Several countries have shown an increased prevalence of drug resistance in animal production due to the indiscriminate use of antibiotics and antiparasitics in human and veterinary medicine. This article aims to review existing methods using naturally occurring essential oils (EOs) and their isolated compounds (EOCs) as alternatives to antimicrobials and antiparasitic compounds in animal production and, consequently, to avoid resistance. The most-reported mechanism of action of EOs and EOCs was cell membrane damage, which leads to the leakage of cytoplasmic content, increased membrane permeability, inhibition of metabolic and genetic pathways, morphologic changes, antibiofilm effects, and damage to the genetic material of infections. In parasites, anticoccidial effects, reduced motility, growth inhibition, and morphologic changes have been reported. Although these compounds regularly show a similar effect to those promoted by traditional drugs, the elucidation of their mechanisms of action is still scarce. The use of EOs and EOCs can also positively influence crucial parameters in animal production, such as body weight gain, feed conversion rate, and cholesterol reduction, which also positively impact meat quality. The application of EOs and EOCs is enhanced by their association with other natural compounds or even by the association with synthetic chemicals, which has been found to cause synergism in their antimicrobial effect. By reducing the effective therapeutical/prophylactic dose, the chances of off-flavors – the most common issue in EO and EOC application – is greatly mitigated. However, there is very little work on the combination of EOs and EOCs in large studies. In addition, research must apply the correct methodology to properly understand the observed effects; for example, the use of only high concentrations may mask potential results obtained at lower dosages. Such corrections will also allow the elucidation of finer mechanisms and promote better biotechnologic use of EOs and EOCs. This manuscript presents several information gaps to be filled before the use of EOs and EOCs are fully applicable in animal production.
Alternatives to antibiotics in veterinary medicine: considerations for the management of Johne's disease
Antibiotic resistance has become a major health concern globally, with current predictions expecting deaths related to resistant infections to surpass those of cancer by 2050. Major efforts are being undertaken to develop derivative and novel alternatives to current antibiotic therapies in human medicine. What appears to be lacking however, are similar efforts into researching the application of those alternatives, such as (bacterio)phage therapy, in veterinary contexts. Agriculture is still undoubtedly the most prominent consumer of antibiotics, with up to 70% of annual antibiotic usage attributed to this sector, despite policies to reduce their use in food animals. This not only increases the risk of resistant infections spreading from farm to community but also the risk that animals may acquire species-specific infections that subvert treatment. While these diseases may not directly affect human welfare, they greatly affect the profit margin of industries reliant on livestock due to the cost of treatments and (more frequently) the losses associated with animal death. This means actively combatting animal infection not only benefits animal welfare but also global economies. In particular, targeting recurring or chronic conditions associated with certain livestock has the potential to greatly reduce financial losses. This can be achieved by developing novel diagnostics to quickly identify ill animals alongside the design of novel therapies. To explore this concept further, this review employs Johne's disease, a chronic gastroenteritis condition that affects ruminants, as a case study to exemplify the benefits of rapid diagnostics and effective treatment of chronic disease, with particular regard to the diagnostic and therapeutic potential of phage.
Evidence that ectoparasites influence the hematological parameters of the host: a systematic review
Ectoparasites are important to the one health concept because their parasitism can result in the transmission of pathogens, allergic reactions, the release of toxins, morbidity, and even death of the host. Ectoparasites can affect host physiology, as reflected in immune defenses and body condition as well as hematological and biochemical parameters. Thus, evidence that ectoparasites influence host hematological parameters was systematically reviewed, and the methodological quality of these studies was analyzed. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed, and the studies included were limited to those that evaluated changes in hematological tests in ectoparasite-infested and non-infested animals, and bias and methodological quality were evaluated using the Animal Research: Reporting of In Vivo Experiments guideline. Thirty-four studies were selected and information about the host, ectoparasite infestation, blood collection, and analysis was collected and compared whenever possible. In this review, the presence of ectoparasites influenced both the red series and the white series of hematological parameters. Among the main parameters analyzed, hematocrit, red blood cells, hemoglobin, and lymphocytes showed reductions, probably due to ectoparasite blood-feeding, while including eosinophils, neutrophils, and basophils increased in infested animals due to the host immune response. However, methodologic improvements are needed to reduce the risk of bias, enhance the reproducibility of such studies, and ensure results aligned with the mechanisms that act in the ectoparasite-host relationship.
Applications of butyric acid in poultry production: the dynamics of gut health, performance, nutrient utilization, egg quality, and osteoporosis - CORRIGENDUM
Internal reference genes with the potential for normalizing quantitative PCR results for oral fluid specimens
In basic research, testing of oral fluid specimens by real-time quantitative polymerase chain reaction (qPCR) has been used to evaluate changes in gene expression levels following experimental treatments. In diagnostic medicine, qPCR has been used to detect DNA/RNA transcripts indicative of bacterial or viral infections. Normalization of qPCR using endogenous and exogenous reference genes is a well-established strategy for ensuring result comparability by controlling sample-to-sample variation introduced during sampling, storage, and qPCR testing. In this review, the majority of recent publications in human ( = 136) and veterinary ( = 179) medicine did not describe the use of internal reference genes in qPCRs for oral fluid specimens (52.9% animal studies; 57.0% human studies). However, the use of endogenous reference genes has not been fully explored or validated for oral fluid specimens. The lack of valid internal reference genes inherent to the oral fluid matrix will continue to hamper the reliability, reproducibility, and generalizability of oral fluid qPCR assays until this issue is addressed.
Applications of butyric acid in poultry production: the dynamics of gut health, performance, nutrient utilization, egg quality, and osteoporosis
Due to the increasing demand for antibiotic-free livestock products from the consumer side and the ban on the use of antibiotic growth promoters, the poultry feed industry is increasingly interested in developing more alternatives to cope with this problem. Organic acids (butyric acid) have many beneficial effects on poultry health, performance, and egg quality when used in their diet, thus they can be considered for the replacement of antibiotics in livestock production systems. Butyric acid is most efficacious against pathogenic bacteria such as spp. and , and stimulates the population of beneficial gut bacteria. It is a primary energy source for colonocytes and augments the differentiation and maturation of the intestinal cells. Collectively, butyric acid should be considered as an alternative to antibiotic growth promoters, because it reduces pathogenic bacteria and their toxins, enhancing gut health thereby increasing nutrient digestibility, thus leading to improved growth performance and immunity among birds. The possible pathways and mechanisms through which butyric acid enhances gut health and production performance are discussed in this review. Detailed information about the use of butyric acid in poultry and its possible benefits under different conditions are also provided, and the impacts of butyric acid on egg quality and osteoporosis are noted.
Biotherapeutic microbial supplementation for ameliorating fish health: developing trends in probiotics, prebiotics, and synbiotics use in finfish aquaculture
Nutrition demands in aquaculture can be realized through quality aquafeeds as compounded diets that contribute to the growth and health of aquaculture species. Functional additives in feed, notably probiotics, prebiotics, and their admixture synbiotics, have been recently recognized for their biotherapeutic role as immunostimulants capable of conferring disease resistance, stress tolerance, and gastrointestinal health; counteracting the negative effects of anti-nutrients, pathogenic prevalence, and antimicrobials in finfish aquaculture. Formulated diets based on probiotics, prebiotics, and as a supplemental combination for synbiotics can significantly influence fish gut microbiomes, establishing the modalities of microbial dynamics to maximize host-associated benefits. These microbial functional-feed supplements are acclaimed to be biocompatible, biodegradable, and safe for dietary consumption as well as the environment. In fed fish aquaculture, prebiotic appended probiotic diet 'synbiotic' has propounded larger attention for its additional health and nutritional benefits. Synbiotic, prebiotic, and probiotic usage as functional feeds for finfish aquaculture thus provides promising prospects. Developing trends in their intended application are reviewed here forth.
Definition of low birth weight in domestic mammals: a scoping review
In people and animals, low birth weight (LBW) is recognized as highly predictive of health trajectory from the neonatal period to elderly ages. Regarding the neonatal period, although LBW is recognized as a major risk factor for neonatal mortality, there does not appear to be a clear definition of 'when a birth weight should be considered low' in all species. The aim of this work was to use the scientific literature available to map the various thresholds proposed to define LBW in domestic mammals. Using a standardized methodology, a scoping review was conducted through a literature search in three different bibliographic databases. After a two-step screening of 1729 abstracts and full-text publications by two independent reviewers, eleven studies met the inclusion criteria. Selected publications represented six mammalian species (rat, mouse, dog, pig, cow, and rabbit). Birth weight thresholds were identified through six different methods. In addition to the scarcity of scientific literature about the definition of LBW, this scoping review revealed the lack of standardization for the description, evaluation or the pertinence these definitions. Because the health consequences of LBW could be preventable, providing early identification of at-risk neonates, a consensus for the standardized definition of LBW is required.
Use of antimicrobials in the treatment of calf diarrhea: a systematic review
The objective of this study was to conduct a systematic review of the scientific literature evaluating the efficacy and comparative efficacy of antimicrobials (AMs) for the treatment of diarrhea in calves. Eligible studies were non- and randomized controlled trials evaluating an AM intervention against a positive and negative control, with at least one of the following outcomes: fecal consistency score, fever, dehydration, appetite, attitude, weight gain, and mortality. Four electronic databases were searched. Titles and abstracts (three reviewers) and full texts (two reviewers) were screened. A total of 2899 studies were retrieved; 11 studies met the inclusion criteria. The risk of bias was assessed. Most studies had incomplete reporting of trial design and results. Eight studies compared AMs to a negative control (placebo or no treatment). Among eligible studies, the most common outcomes reported were diarrhea severity ( = 6) and mortality ( = 6). Eligible studies evaluated very different interventions and outcomes; thus, a meta-analysis was not performed. The risk of bias assessment revealed concerns with reporting of key trial features, including disease and outcome definitions. Insufficient evidence is available in the scientific literature to assess the efficacy of AMs in treating calf diarrhea.
Dietary fiber and its role in performance, welfare, and health of pigs
Dietary fiber (DF) is receiving increasing attention, and its importance in pig nutrition is now acknowledged. Although DF for pigs was frowned upon for a long time because of reductions in energy intake and digestibility of other nutrients, it has become clear that feeding DF to pigs can affect their well-being and health. This review aims to summarize the state of knowledge of studies on DF in pigs, with an emphasis on the underlying mode of action, by considering research using DF in sows as well as suckling and weaned piglets, and fattening pigs. These studies indicate that DF can benefit the digestive tracts and the health of pigs, if certain conditions or restrictions are considered, such as concentration in the feed and fermentability. Besides the chemical composition and the impact on energy and nutrient digestibility, it is also necessary to evaluate the possible physical and physiologic effects on intestinal function and intestinal microbiota, to better understand the relation of DF to animal health and welfare. Future research should be designed to provide a better mechanistic understanding of the physiologic effects of DF in pigs.
Use of cannabis in the treatment of animals: a systematic review of randomized clinical trials
Cannabis is used in the treatment of several human conditions; however, its use is still less explored in veterinary medicine. This systematic review aims to summarize the evidence of efficacy and safety of the use of cannabis for the treatment of animal disease. A literature search was performed for studies published until 16 March 2021 in five databases. Randomized clinical trials (RCTs) that reported the efficacy or safety of cannabis in the treatment of animal disease were included. The RoB 2 Tool was used to assess the risk of bias. A total of 2427 records were identified, of which six studies fully met the eligibility criteria. RCTs were conducted in dogs with osteoarthritis ( = 4), with epilepsy ( = 1), and with behavioral disorders ( = 1). All studies used cannabidiol (CBD) oil in monotherapy or in combination with other drugs. Studies used CBD at 2 or 2.5 mg kg twice daily ( = 4), orally ( = 5), during 4 or 6 weeks ( = 3), and compared CBD with placebo ( = 5). CBD significantly reduced pain and increased activity in dogs with osteoarthritis ( = 3). Moreover, CBD significantly reduced the frequency of seizures in dogs with epilepsy ( = 1) and the aggressive behavior of dogs ( = 1). Although promising results were identified, studies were heterogeneous and presented risks of bias that required caution in the interpretation of findings. Therefore, there was some evidence to support the use of CBD in dogs with osteoarthritis to reduce pain and increased activity, but limited evidence against epilepsy and behavioral problems. In addition, CBD was well tolerated with mild adverse effects. More RCTs with high quality of evidence are needed, including greater numbers of animal subjects, additional species, and clear readout measures to confirm these findings.
Canine leptospirosis in stray and sheltered dogs: a systematic review
The aim of this systematic review was to investigate the prevalence of leptospirosis among stray and sheltered dogs worldwide. Six databases were searched, which resulted in the retrieval of 476 articles. Sixty articles were selected for analysis according to 10 quality criteria. Among the selected papers, 26 papers [43.4% (26/60)] met five of the 10 quality criteria established, 10 papers [16.7% (10/60)] met three criteria, nine papers [15.0% (9/60)] met four criteria, six papers [10.0% (6/60)] met six criteria, four papers [6.7% (4/60)] met eight criteria, and three papers [5.0% (3/60)] met nine of the 10 criteria, whereas two papers [1.7% (1/60)] met two and seven [1.7% (1/60)] criteria. Publications originated mainly from the Americas [45.0% (27/60)] and in the last 16 years (2003-2019) [81.7% (49/60)], and most of the sampled dogs were stray dogs [65.0% (39/60)]. The most commonly used diagnostic test for leptospirosis was the microscopic agglutination test [78.4% (47/60)] followed by polymerase chain reaction [21.7% (13/60)], and the most common serovars were Canicola [71.4% (35/49)], Icterohaemorrhagiae [65.3% (32/49)], Grippotyphosa [40.8% (20/49)], and Pomona [40.8% (20/49)]. In conclusion, our results showed that spp. are present in unowned dogs worldwide; however, the low-methodological quality of the recovered cross-sectional studies precluded a meta-analysis.
Biomarkers of sepsis in pigs, horses and cattle: from acute phase proteins to procalcitonin
Sepsis is a complex clinical syndrome triggered by an inflammatory host response to an infection. It is usually complicated to detect and diagnose, and has severe consequences in human and veterinary health, especially when treatment is not started early. Therefore, efforts to detect sepsis accurately are needed. In addition, its proper diagnosis could reduce the misuse of antibiotics, which is essential fighting against antimicrobial resistance. This case is a particular issue in farm animals, as antibiotics have been traditionally given massively, but now they are becoming increasingly restricted. When sepsis is suspected in animals, the most frequently used biomarkers are acute phase proteins such as C-reactive protein, serum amyloid A and haptoglobin, but their concentrations can increase in other inflammatory conditions. In human patients, the most promising biomarkers to detect sepsis are currently procalcitonin and presepsin, and there is a wide range of other biomarkers under study. However, there is little information on the application of these biomarkers in veterinary species. This review aims to describe the general concepts of sepsis and the current knowledge about the biomarkers of sepsis in pigs, horses, and cattle and to discuss possible advances in the field.
Acute interstitial pneumonia and the biology of 3-methylindole in feedlot cattle
Acute interstitial pneumonia (AIP) of cattle has been recognized for many decades. While the pathogenesis and risk factors for this condition in pastured cattle are relatively well characterized, there remains a poor understanding of the disease as it occurs in intensively fed cattle such as in beef feedlots. Specifically, in pastured cattle, AIP results from excessive ruminal production of the pneumotoxicant 3-methylindole (3-MI). In feedlot cattle, the evidence to substantiate the role of 3-MI is comparatively deficient and further investigations into the cause, pathogenesis, and control are sorely needed. This review highlights our current understanding of AIP with a focus on the disease as it occurs in feedlot cattle. Additionally, it illustrates the need for further work in understanding the specific animal factors (e.g. the ruminal microbiome, and the role of concurrent diseases), management factors (e.g. animal stocking and vaccination protocols), and dietary factors (e.g. dietary supplements) that may impact the development of AIP and which are relatively unique to the feedlot setting. All stakeholders in the beef industry stand to benefit from a greater understanding of what remains a pressing yet poorly understood issue in beef production.
