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Frontiers in Veterinary Science 2022The yak () is closely related to common cows (), but is clearly a distinct species. Yaks are of substantial importance to food and leather production in certain...
The yak () is closely related to common cows (), but is clearly a distinct species. Yaks are of substantial importance to food and leather production in certain high-altitude regions of Asia. The animal is increasing elsewhere as well, mainly because of the perceived health benefits of its milk. Like all ruminants, the animal harbors a complex community of microbial cells in its gut, crucial for its physiology. Despite yaks being important domestic animals, the composition of its gut microbiota and how the composition is guided by its specific high-altitude environment remains largely uncategorized. Hence, online databases (Embase, Medline ALL, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and Google Scholar) were searched for articles on yak intestinal microbiota. The pooled taxonomic abundance was compared between regions, sexes, different age groups, and feeding patterns. The gut microbiota distribution across different yak intestinal segments was established through pooled average taxonomic abundance. A total of 34 studies met the inclusion criteria and yielded information on 982 unique yak gut microbiota samples. An analysis of overall pooled microbiota revealed a segmented microbial community composition of the yak gut. Yak rumen microbiota was significantly influenced by difference in region, sex, and feeding patterns, the latter factor being dominant in this respect. Yak microbiome is shaped by the feeding strategy and provides an obvious avenue for improving health and productivity of the animal. More generally, the current segmental description of physiological gut microbiome provides insight into how the microbiology of this animal has adapted itself to help comping yaks with its high-altitude habitat.
PubMed: 35836500
DOI: 10.3389/fvets.2022.889594 -
Animals : An Open Access Journal From... Jul 2021Since the approval by the European Medicines Agency in 2013 of a monensin controlled-release capsule (CRC) for the prevention of ketosis in dairy cows, there has been... (Review)
Review
Since the approval by the European Medicines Agency in 2013 of a monensin controlled-release capsule (CRC) for the prevention of ketosis in dairy cows, there has been widespread use across Europe. In recent decades, several papers have investigated the effects of monensin used as a CRC or as a feed additive to improve cattle energy metabolism and improve feed efficiency. Since the CRC is the only form of monensin permitted in Europe in dairy cows, the objective of this review was to report and summarize observations from the literature on the effects of this treatment in transition cows. The peer-reviewed literature published from 1997 was scanned, and papers written in English were evaluated for eligibility. Only papers evaluating the use of monensin in dairy cows for the prevention of ketosis during the transition period were reviewed. In total, 42 papers met the required criteria and were included in this review. The major findings focused on cow metabolism and health, rumen fermentation and milk production and quality. Overall, the review of the existing literature confirmed that monensin delivered as a CRC during the transition period has effects of different magnitude compared to other forms, doses or durations of administration. Studies agree on the antiketotic effects of this treatment, showing evidence of an increased propionate production in the rumen, reduced blood β-hydroxybutyrate, and improved liver function in treated cows, mainly resulting in reduced incidence of peripartum disease. On the contrary, the effects of CRC on ammonia production and rumen microflora are less robust than those reported for other forms. Of importance for the European market is the well-documented absence of any negative impact on milk and cheese production and composition using the CRC treatment.
PubMed: 34359115
DOI: 10.3390/ani11071988 -
Vaccines Aug 2020Ruminants produce considerable amounts of methane during their digestive process, which makes the livestock industry as one of the largest sources of anthropogenic... (Review)
Review
Ruminants produce considerable amounts of methane during their digestive process, which makes the livestock industry as one of the largest sources of anthropogenic greenhouse gases. To tackle this situation, several solutions have been proposed, including vaccination of ruminants against microorganisms responsible for methane synthesis in the rumen. In this review, we summarize the research done on this topic and describe the state of the art of this strategy. The different steps implied in this approach are described: experimental design, animal model (species, age), antigen (whole cells, cell parts, recombinant proteins, peptides), adjuvant (Freund's, Montanide, saponin, among others), vaccination schedule (booster intervals and numbers) and measurements of treatment success (immunoglobulin titers and/or effects on methanogens and methane production). Highlighting both the advances made and knowledge gaps in the use of vaccines to inhibit ruminant methanogen activity, this research review opens the door to future studies. This will enable improvements in the methodology and systemic approaches so as to ensure the success of this proposal for the sustainable mitigation of methane emission.
PubMed: 32825375
DOI: 10.3390/vaccines8030460 -
Journal of Veterinary Internal Medicine 2006Acupuncture is a popular complementary treatment option in human medicine. Increasingly, owners also seek acupuncture for their animals. The aim of the systematic review... (Review)
Review
Acupuncture is a popular complementary treatment option in human medicine. Increasingly, owners also seek acupuncture for their animals. The aim of the systematic review reported here was to summarize and assess the clinical evidence for or against the effectiveness of acupuncture in veterinary medicine. Systematic searches were conducted on Medline, Embase, Amed, Cinahl, Japana Centra Revuo Medicina and Chikusan Bunken Kensaku. Hand-searches included conference proceedings, bibliographies, and contact with experts and veterinary acupuncture associations. There were no restrictions regarding the language of publication. All controlled clinical trials testing acupuncture in any condition of domestic animals were included. Studies using laboratory animals were excluded. Titles and abstracts of identified articles were read, and hard copies were obtained. Inclusion and exclusion of studies, data extraction, and validation were performed independently by two reviewers. Methodologic quality was evaluated by means of the Jadad score. Fourteen randomized controlled trials and 17 nonrandomized controlled trials met our criteria and were, therefore, included. The methodologic quality of these trials was variable but, on average, was low. For cutaneous pain and diarrhea, encouraging evidence exists that warrants further investigation in rigorous trials. Single studies reported some positive intergroup differences for spinal cord injury, Cushing's syndrome, lung function, hepatitis, and rumen acidosis. These trials require independent replication. On the basis of the findings of this systematic review, there is no compelling evidence to recommend or reject acupuncture for any condition in domestic animals. Some encouraging data do exist that warrant further investigation in independent rigorous trials.
Topics: Acupuncture Analgesia; Acupuncture Therapy; Animals; Cattle; Dogs; Horses; Musculoskeletal Diseases; Pain; Pain Management; Randomized Controlled Trials as Topic; Sheep; Swine; Veterinary Medicine
PubMed: 16734078
DOI: 10.1892/0891-6640(2006)20[480:eoaivm]2.0.co;2 -
PloS One 2020A systematic review and meta-analysis were conducted to predict and identify ways to increase conjugated linoleic acid (CLA) formation in ruminant-derived products to... (Meta-Analysis)
Meta-Analysis
A systematic review and meta-analysis were conducted to predict and identify ways to increase conjugated linoleic acid (CLA) formation in ruminant-derived products to treat human health issues with dietary tannins. The objective was to compare and confirm the effects of dietary tannins on CLA formation by analyzing in vitro and/or in vivo studies. We reported the results of the meta-analysis based on numerical data from 38 selected publications consisting of 3712 treatments. Generally, via multiple pathways, the CLA formation increased when dietary tannins increased. Concurrently, dietary tannins increased Δ9 desaturation and the CLA indices in milk and meat (P < 0.05 and P < 0.001, with average R2 values of 0.23 and 0.44, respectively), but they did not change the rumen fermentation characteristics, including total volatile fatty acids (mmol/L) and their acid components. In vitro observations may accurately predict in vivo results. Unfortunately, there was no relationship between in vitro observations and in vivo results (R2 < 0.10), indicating that it is difficult to predict CLA formation in vivo considering in vitro observations. According to the statistical meta-analysis results regarding animal aspects, the ranges of tannin levels required for CLA formation in vitro and in vivo were approximately 0.1-20 g/kg dry matter (DM) (P < 0.001) and 2.1-80 g/kg DM (P < 0.001), respectively. In conclusion, the in vivo method was more suitable for the direct observation of fatty acid transformation than the in vitro method.
Topics: Animals; Batch Cell Culture Techniques; Bias; Linoleic Acids, Conjugated; Meat; Milk; Regression Analysis; Ruminants; Tannins
PubMed: 32168348
DOI: 10.1371/journal.pone.0216187 -
Animal : An International Journal of... Feb 2014In light of increasing global protein prices and with the need to reduce environmental impact of contemporary systems of milk production, the current review seeks to... (Review)
Review
In light of increasing global protein prices and with the need to reduce environmental impact of contemporary systems of milk production, the current review seeks to assess the feasibility of reducing levels of dietary CP in dairy cow diets. At CP levels between 140 and 220 g/kg DM there is a strong positive relationship between CP concentration and dry matter intake (DMI). However, such effects are modest and reductions in DMI when dietary CP is below 180 g/kg DM can be at least partially offset by improving the digestibility and amino acid profile of the undegradable protein (UDP) component of the diet or by increasing rumen fermentable energy. Level and balance of intestinally absorbable amino acids, in particular methionine and lysine, may become limiting at lower CP concentrations. In general the amino acid composition of microbial protein is superior to that of UDP, so that dietary strategies that aim to promote microbial protein synthesis in the rumen may go some way to correcting for amino acid imbalances in low CP diets. For example, reducing the level of NDF, while increasing the proportion of starch, can lead to improvements in nitrogen (N) utilisation as great as that achieved by reducing dietary CP to below 150 g/kg. A systematic review and meta-analysis of responses to rumen protected forms of methionine and lysine was conducted for early/mid lactation cows fed diets containing ⩽150 g CP/kg DM. This analysis revealed a small but significant (P=0.002) increase in milk protein yield when cows were supplemented with these rumen protected amino acids. Variation in milk and milk protein yield responses between studies was not random but due to differences in diet composition between studies. Cows fed low CP diets can respond to supplemental methionine and lysine so long as DMI is not limiting, metabolisable protein (MP) is not grossly deficient and other amino acids such as histidine and leucine do not become rate limiting. Whereas excess dietary protein can impair reproduction and can contribute to lameness, there is no evidence to indicate that reducing dietary CP levels to around 140 to 150 g CP/kg DM will have any detrimental effect on either cow fertility or health. Contemporary models that estimate MP requirements of dairy cows may require refinement and further validation in order to predict responses with low CP diets.
Topics: Animal Husbandry; Animal Nutritional Physiological Phenomena; Animal Welfare; Animals; Cattle; Dairying; Dietary Proteins; Female; Fertility; Milk; Nitrogen
PubMed: 24290203
DOI: 10.1017/S1751731113002139 -
Journal of Dairy Science Jan 2024To investigate the effects of supplemental monensin administration on the metabolic responses of dairy cows, a systematic review and dose-response meta-analysis were... (Meta-Analysis)
Meta-Analysis
Effects of monensin supplementation on rumen fermentation, methane emissions, nitrogen balance, and metabolic responses of dairy cows: A systematic review and dose-response meta-analysis.
To investigate the effects of supplemental monensin administration on the metabolic responses of dairy cows, a systematic review and dose-response meta-analysis were conducted. Initially, 604 studies were identified through comprehensive database searches, including Google Scholar, Scopus, Science Direct, and PubMed, using key words related to dairy cows, monensin, and metabolic outcomes. After a 2-stage screening process, 51 articles with a total of 60 experiments were selected for meta-analysis based on criteria such as study implementation date between 2001 and 2022, presence of a control group that did not receive monensin supplementation, reporting of at least 1 outcome variable, and presentation of means and corresponding errors. The meta-analysis used the 1-stage random-effects method, and sensitivity analyses were performed to assess the robustness of the results. The results showed that the administration of monensin at a dosage of 19 to 26 mg/kg was inversely related to methane emissions and that the administration of monensin at a dosage of 18 to 50 mg/kg resulted in a significant decrease in dry matter intake. Administration of monensin at doses of 13 to 28 and 15 to 24 mg/kg also resulted in a significant decrease in ruminal acetate proportion and an increase in propionate proportion, respectively, with no effects on ruminal butyrate, NH, or pH levels. We found no effects on blood parameters or nitrogen retention, but a significant negative correlation was observed between monensin supplementation and fecal nitrogen excretion. Based on the analysis of all variables evaluated, the optimal dose range of monensin was estimated to be 19 to 24 mg/kg.
Topics: Female; Cattle; Animals; Monensin; Milk; Fermentation; Methane; Rumen; Nitrogen; Dietary Supplements; Diet; Lactation
PubMed: 37709041
DOI: 10.3168/jds.2023-23441 -
Veterinary and Animal Science Dec 2021Methane (CH) is a greenhouse gas generated during the feed fermentation processes in the rumen. However, numerous studies have been conducted to determine the capacity... (Review)
Review
Methane (CH) is a greenhouse gas generated during the feed fermentation processes in the rumen. However, numerous studies have been conducted to determine the capacity of plant secondary metabolites to enhance ruminal fermentation and decrease CH production, especially those plants rich in tannins. This review conducted a descriptive analysis and meta-analysis of the use of tannin-rich plants in tropical regions to mitigate CH production from livestock. The aim of this study was to analyse the effect of tannins supplementation in tropical plants on CH production in ruminants using a meta-analytic approach and the effect on microbial population. Sources of heterogeneity were explored using a meta-regression analysis. Final database was integrated by a total of 14 trials. The 'meta' package in R statistical software was used to conduct the meta-analyses. The covariates defined in the current meta-regression were inclusion level, species (sheep, beef cattle, dairy cattle, and cross-bred heifers) and plant. Results showed that supplementation with tropical plants with tannin contents have the greatest effects on CH mitigation . A negative relationship was observed between the level of inclusion and CH emission (-0.09), which means that the effect of CH mitigation is increasing as the level of tannin inclusion is higher. Therefore, less CH production will be obtained when supplementing tropical plants in the diet with a high dose of tannins.
PubMed: 34841126
DOI: 10.1016/j.vas.2021.100214 -
Journal of Dairy Science Jan 2024A systematic literature review of in vitro studies was performed to identify methane (CH) mitigation interventions with a potential to reduce CH emission in vivo. Data... (Meta-Analysis)
Meta-Analysis
A systematic literature review of in vitro studies was performed to identify methane (CH) mitigation interventions with a potential to reduce CH emission in vivo. Data from 277 peer-reviewed studies published between 1979 and 2018 were reviewed. Individual CH mitigation interventions were classified into 14 categories of feed additives based on their type, chemical composition, and mode of action. Response variables evaluated were absolute CH emission (number of treatment means comparisons = 1,325); total volatile fatty acids (n = 1,007), acetate (n = 783), propionate (n = 792), and butyrate (n = 776) concentrations; acetate to propionate ratio (n = 675); digestibility of dry matter (n = 489), organic matter (n = 277), and neutral detergent fiber (n = 177). Total gas production was used as an explanatory variable in the model for CH production. Relative mean difference between treatment and control means reported in the studies was calculated and used for statistical analysis. The robust variance estimation method was used to analyze the effects of CH mitigation interventions. In vitro CH production was decreased by antibodies (-38.9%), chemical inhibitors (-29.2%), electron sinks (-18.9%), essential oils (-18.2%), plant extracts (-14.5%), plant inclusion (-11.7%), saponins (-14.8%), and tannins (-14.5%). Overall effects of direct-fed microbials, enzymes, macroalgae, and organic acids supplementation did not affect CH production in the current meta-analysis. When considering the effects of individual mitigation interventions containing a minimum number of 4 degrees of freedom within feed additives categories, Enterococcus spp. (i.e., direct-fed microbial), nitrophenol (i.e., electron sink), and Leucaena spp. (i.e., tannins) decreased CH production by 20.3%, 27.1%, and 23.5%, respectively, without extensively, or only slightly, affecting ruminal fermentation and digestibility of nutrients. It should be noted, however, that although the total number of publications (n = 277) and treatment means comparisons (n = 1,325 for CH production) in the current analysis were high, data for most mitigation interventions were obtained from less than 5 observations (e.g., maximum number of observations was 4, 7, and 22 for nitrophenol, Enterococcus spp., and Leucaena spp., respectively), because of limited data available in the literature. These should be further evaluated in vitro and in vivo to determine their true potential to decrease enteric CH production, yield, and intensity. Some mitigation interventions (e.g., magnesium, Heracleum spp., nitroglycerin, β-cyclodextrin, Leptospermum pattersoni, Fructulus Ligustri, Salix caprea, and Sesbania grandiflora) decreased in vitro CH production by over 50% but did not have enough observations in the database. These should be more extensively investigated in vitro, and the dose effect must be considered before adoption of mitigation interventions in vivo.
Topics: Female; Animals; Diet; Milk; Lactation; Propionates; Methane; Tannins; Rumen; Acetates; Nitrophenols; Fermentation; Digestion; Animal Feed
PubMed: 38353472
DOI: 10.1016/S0022-0302(23)00819-6 -
Journal of Dairy Science Aug 2009The objectives of this paper are to provide an introduction to meta-analysis and systematic review and to discuss the rationale for this type of research and other... (Review)
Review
The objectives of this paper are to provide an introduction to meta-analysis and systematic review and to discuss the rationale for this type of research and other general considerations. We highlight methods used to produce a rigorous meta-analysis and discuss some aspects of interpretation of meta-analysis drawing on examples from the animal and veterinary science literature. Meta-analysis is a rapidly expanding area of research that has been relatively underutilized in animal and veterinary science. It is a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research. Outcomes from a meta-analysis may include a more precise estimate of the effect of treatment or risk factor for disease, or other outcomes, than any individual study contributing to the pooled analysis. The examination of variability or heterogeneity in study results is also a critical outcome. The benefits of meta-analysis include a consolidated and quantitative review of a large, and often complex, sometimes apparently conflicting, body of literature. Meta-analytic methods place less emphasis on dichotomous outcomes from null hypothesis significance testing and greater emphasis on determining the magnitude and the precision of an effect of interest. A substantial benefit of meta-analysis is the potential to investigate new hypotheses using existing data, both through the development of a priori hypotheses and by examination of the heterogeneity in study responses. The specification of the outcome and hypotheses that are tested is critical to the conduct of meta-analyses, as is a sensitive literature search. A failure to identify the majority of existing studies can lead to erroneous conclusions; however, there are methods of examining data to identify the potential for studies to be missing; for example, by the use of funnel plots. Many of the statistical methods to conduct meta-analysis are widely used. Bayesian methods are well suited to meta-analysis. The post-hoc methods used to evaluate heterogeneity and publication bias, which include the I (2) statistic, L'Abbé plots, Galbraith plots, Rosenthal's N, and influential study analysis are exclusively used in meta-analysis. Examples where meta-analyses have been repeated in animal science or veterinary medicine show good consistency in estimates of effect. Findings of studies to date have provided new understandings of rumen modifiers, milk fever, parasite control, mastitis, somatotropin, and reproductive manipulations. Rigorously conducted meta-analyses are useful tools to improve animal well-being and productivity. The need to integrate findings from many studies ensures that meta-analytic research is desirable and the large body of research now generated makes the conduct of this research feasible.
Topics: Animals; Meta-Analysis as Topic; Publication Bias; Reproduction; Review Literature as Topic; Statistics as Topic; Veterinary Medicine
PubMed: 19620636
DOI: 10.3168/jds.2009-2140