Ruminant Health Research Articles

From Chilean saltpeter to modern agriculture: navigating nitrate toxicity in ruminants through compartmental modeling

Nitrate/nitrite poisoning is a significant issue in ruminant livestock health, with historical roots pre-dating the widespread use of nitrogen fertilizers. This review explores the various factors contributing to nitrate toxicity, including natural and anthropogenic sources, metabolic pathways, mechanisms of action, and the variability in reported data. The importance of compartmental modeling in under-standing nitrate metabolism dynamics is emphasized. These models provide a framework for simu-lating the complex processes involved in nitrate intake, conversion, absorption, distribution, and ex-cretion, ultimately informing effective mitigation strategies. The goal of this article is to provide a comprehensive overview of nitrate/nitrite poisoning in ruminants and highlight the role of compart-mental modeling in safeguarding animal health, optimizing agricultural practices, and ensuring food safety in the context of modern agriculture.

Phytochemical Study of the Anthelminthic Potential of Guadeloupean Plant Biodiversity.

Gastrointestinal parasitism is a major health and welfare problem in ruminants. Synthetic chemical anthelmintic drugs have led to the emergence of resistance in gastrointestinal strongyles, inducing the search for alternatives to control the infections that affect ruminants. The objective of this work was to evaluate the anthelmintic potential of plant extracts against Haemonchus contortus Rudolphi. Three plants of the Guadeloupean biodiversity, Momordica charantia L., Carica papaya L. and Sargassum spp., were selected based on their high polyphenolic content and natural abundance. The phytochemistry of plants was explored, a biological assay against the parasite H. contortus was carried out, and several hypotheses about the way of action were proposed by an innovative electrochemical screening method.

Usability of Postbiotics in Ruminant Nutrition and Health

Since the ban on the use of antibiotics to promote growth in animal production in 2006, there has been a growing interest in alternative feed additives for animal production. Postbiotics, which have been utilized for this purpose in recent years, are highly promising feed additives that substitute banned substances like antibiotics. In recent years, there have been numerous studies on the utilization of postbiotics in ruminant animal nutrition. This article includes the definition of postbiotics, their properties, methods of obtaining them, and their potential applications in ruminant animal nutrition and health.

Basic dairy and beef nutrition principles for the new graduate

Ruminant nutrition is often considered a difficult and complex subject in the minds of veterinary students. This may be due to the lack of nutritional training in veterinary colleges, the lack of exposure to agriculture, or because nutrition is considered a separate career practiced by a nutritionist. Nutrition doesn’t have to be complicated. The purpose of the nutritional program is to provide safe feed that meets the cow’s nutritional require­ments. Veterinarians have an intricate knowledge of ruminant health and a well-developed problem-solving skillset. These at­tributes make the veterinarian highly capable of consulting with clients regarding nutritional concepts. The goal of this session is to demonstrate to aspiring veterinarians that nutrition is simple in concept and can be easily implemented in clinical practice.

Saponin Extracts Utilization as Dietary Additive in Ruminant Nutrition: A Meta-Analysis of In Vivo Studies.

The present meta-analysis aimed to determine the underlying effects of different saponins extracted from different sources on the production performance, milk yield, digestibility, rumen fermentation, blood metabolites, and nitrogen utilization of ruminants. A total of 26 papers comprising 66 in vivo studies (148 data points of dietary treatments) were evaluated in the present study. The databases were statistically analyzed using the mixed model procedure of SAS, where experiments considered random effects and tannin-related factors were treated as fixed effects. Statistical procedures were then continued in comparing different sources of saponin extract through Mixed Model analysis, where experiments were also random factors and sources of saponin extract were fixed factors. The evidence revealed in the present meta-analysis that saponin supplementation of up to 40 g/kg DM appears to have no detrimental impact on feed intake across ruminant types, suggesting that it does not significantly affect diet palatability. However, the results indicated that there are species-specific responses to saponin supplementation, particularly in relation to palatability and nutrient absorption efficiency, with larger ruminants being better able to tolerate the bitterness induced by saponin extracts. Furthermore, the study found that saponin extracts can influence nutrient digestibility and rumen fermentation dynamics, with different effects observed in large and small ruminants. While some saponin extracts can enhance average daily weight gain and milk yield, others can have adverse effects, highlighting the importance of considering both saponin sources and animal physiological condition when developing nutritional strategies. Additionally, optimization of ruminant production by utilizing saponin extracts is necessary to avoid negative health implications, such as increased blood creatinine levels. Different saponin extracts utilization in ruminant nutrition and environmental management, have a distinct understanding associated to their various bioactive properties. However, among the saponin sources, saponin extracted from Quilaja saponaria is more likely to improve large ruminant production performance while maintaining ruminant health and metabolism, but negatively affect small ruminants. Further research is needed to unravel the intricate effects of different saponin sources on ruminant health and productivity, emphasizing the importance of tailored dietary strategies that consider the unique physiological and metabolic characteristics of the target livestock.

Chamomile: functional properties and impacts on poultry/small ruminant health and production – A Review

Abstract Chamomile oil or extract, derived from the chamomile flower, is a natural remedy with various therapeutic properties. This review summarizes the current knowledge regarding the medicinal properties of chamomile oil or extract including its antimicrobial, antidiabetic, antitumor, and anti-inflammatory activities. Chamomile oil has exhibited antibacterial and antifungal properties against various microbes, involving Escherichia coli, Candida albicans, Pseudomonas aeruginosa, and Staphylococcus aureus. It has also been found to regulate blood sugar levels in animal and human studies, making it a potential candidate for diabetes treatment. Moreover, chamomile oil has antitumor properties, as it can induce apoptosis in cancer cells and inhibit their growth. In addition, chamomile oil has anti-inflammatory features, making it a possible option for treatment under inflammatory circumstances such as eczema, arthritis, and inflammatory bowel diseases. Chamomile oil has also been found to have valuable impacts on poultry farming due to its antimicrobial properties. It may be utilized as an organic substitute for antibiotics in chicken production. It is effective against common poultry pathogens, including Salmonella and E. coli, and can also improve poultry growth and feed conversion rate. In conclusion, chamomile oil or extract are promising natural remedy with various therapeutic properties and useful impacts on poultry and small ruminants.

Epidemiology and field efficacy of anthelmintic drugs associated with gastrointestinal nematodes of sheep in Nejo district, Oromia, Ethiopia

Gastrointestinal nematodes (GINs) are major constraints to health and productivity of small ruminants. Methods of their control relies mainly on anthelmintic drugs; however, the indiscriminate use of these drugs could lead to the development of anthelmintic resistance (AR). This study aimed to investigate the epidemiology of GINs infection, and field evaluation of anthelmintic efficacy in sheep. The epidemiological data were collected using a cross-sectional study design while a farm-based field study design was employed for the evaluation of anthelminthic efficacy. Furthermore, standard parasitological techniques were employed for qualitative and quantitative worm identification. The overall prevalence indicated 50.3%. Six genera of GINs (Haemonchus, Trichostrongylus, Oesophagostomum/Chabertia, Trichuris, Teladosargia/Ostertagia and Nematodirus) were identified. Among the identified genera, Haemonchus (25.4%) and Trichostrongylus (24.8%) were the dominant genera followed by mixed infection (21.8%), Oesophagostomum/Chabertia (10.4%), Trichuris (7.8%), Teladosargia (Ostertagia) (5.7%) and Nematodirus (4.1%). Mixed infections consisted either of double infections with Haemonchus and Trichostrongylus, or triple infections with Haemonchus, Trichostrongylus and Trichuris. The McMaster egg counting results showed that the mean EPG of infected sheep was 845.6. The results also showed 66 (34.2%), 101 (52.3%) and 26 (13.5%) sheep had low, moderate and heavy worm burden, respectively. Albendazole and Ivermectin showed low efficacy (percentage reductions = 90% and 92%; 95% lower confidence limit = 82.1% and 83.6% respectively) whereas Tetramisole was effective (FECR% = 96.8%; 95% LCL = 93.4%). Factors such as age, body condition, management system and past deworming history of sheep were found to have a statistically significant (p < 0.05) influence on the occurrence and burden of the worms. This is further explained as the highest prevalence and worm burden was detected in sheep of young age (p = 0.008; OR = 0.58; 95% CI = 0.39–0.87), poor body condition (p = 0.001; OR = 0.08; 95% CI = 0.04–0.16) and sheep kept under semi-intensive (p = 0.04; OR = 1.53; 95% CI = 1.02–2.29) with no deworming history for the last two months (p = 0.001; OR = 2.97; 95% CI = 1.94–4.56). The study results revealed that nematode infections were among sheep health constraints that could hurt their productivity while low efficacy of Albendazole and Ivermectin were detected. Therefore, the appropriate management techniques of GIN infections should be designed and implemented. Moreover, a further study involving more sensitive techniques (e.g. Mini-FLOTAC, molecular, and serological techniques) should be conducted by considering different host and environmental risk factors such as production level and seasons.

The effects of including sprouted barley with alfalfa hay in the diet on ruminal health and performance of cow-calf pairs.

The world population is growing exponentially, increasing demand to produce high-quality protein for human consumption. Changes in weather patterns, drought, and decreased land resources due to urbanization have increased thestrain on the agriculture sector to meet world demands. An alternative method to combat these issues and continue to produce high-quality livestock feed would be through a controlled environment vertical farming system. Commonly, cereal grains, such as barley, are used in these systems to produce livestock feed. However, there is little information on the viability of feeding sprouted grains to beef cattle. Two diets of either feeder-quality alfalfa hay (n = 10 pairs; ALF) or the same alfalfa hay and sprouted barley (SB; 12.6% dry matter [DM]; n = 10 pairs) were fed for 90 d to Angus pairs with a steer calf during mid to late lactation. On days 0 and 90, body weight (BW), milk, rumen fluid, and body condition score were collected from cows and hip height and BW were recorded for calves. On day 10, BW was recorded for cows and calves and rumen fluid was collected from cows. Rumen fluid was also collected from cows on day 45. On day 55, BW was collected for both cows and calves and milk from cows. Intake was recorded throughout the trial via bunks with Vytelle technology. The PROC MIXED procedure of SAS was used to analyze all data with the day as a repeated measure to determine the main effect of diet. Individual volatile fatty acids (VFA) were measured as a percent of total VFA. No differences (P ≥ 0.16) were observed in calf BW, hip height, milk protein, fat, lactose, calf DM intake (DMI), or cow DMI. Cows fed SB tended (P = 0.08) to have a decreased somatic cell count compared to ALF. Percent butyrate was impacted by diet × day (P = 0.02), but no difference (P > 0.09) at any time points were detected. Additionally, a diet × day effect (P = 0.001) on rumen pH demonstrated that both groups stayed consistent until day 45 and then SB pH decreased the last 45 d. There was a day effect for total VFA (P = 0.0009), acetate:propionate (Ac:Pr; P < 0.0001), acetate (P < 0.0001), and propionate (P < 0.0001) demonstrating that total VFA, acetate, and Ac:Pr all increased throughout the trial, while propionate decreased. These results indicate that SB can be a potential alternative feed at this stage of production as it does not negatively impact health or production, but does affect the rumen pH and proportion of some VFA.

YAP1/TAZ Mediates Rumen Epithelial Cell Proliferation but Not Short-Chain Fatty Acid Metabolism In Vitro.

Promoting rumen development is closely related to the health and efficient growth of ruminants. The transcriptional co-activators Yes1-associated protein (YAP1) and WW domain-containing transcription regulator protein 1 (TAZ) are key regulators of the mammalian epithelium. In the present study, we assessed the impact of YAP1/TAZ on rumen epithelial (RE) cell proliferation using their activator GA-017 (GA) and inhibitor verteporfin (VP). We also investigated whether YAP1/TAZ-dependent alteration was involved in the RE developmental process induced by sodium butyrate (SB). The results indicated that GA promoted RE cell proliferation, while VP disrupted RE cell proliferation. The Hippo, Wnt, and calcium signaling pathways were altered following the regulation of YAP1/TAZ. Upon YAP1/TAZ activation, the expression of CCN1/2 increased. However, when YAP1/TAZ was inhibited, the expression of BIRC3 decreased. In the SB-treated cells, YAP1/TAZ-induced changes were not observed. SB increased the expressions of differentiated cell marker genes and genes involved in short-chain fatty acid (SCFA) metabolism, while YAP1/TAZ did not. Thus, YAP1/TAZ could be potential targets for regulating RE cell proliferation but not for SCFA metabolism. SB could not affect YAP1/TAZ. These findings broaden our understanding of the role of YAP1/TAZ and their regulators in RE development.

Accumulative Heat Stress in Ruminants at the Regional Scale under Changing Environmental Conditions

Environmental heat stress is implicated in various animal health issues in ruminants, including reproduction rates, mortality rates, and animal physical quality. During extremely hot weather, there is often no overnight equilibration of animal temperature with its cooling effect, and the accumulated heat load becomes an important factor in animal health for ruminants such as sheep. Using the heat load index (HLI), a heat load model is used as an indicator of heat stress on an hourly basis and annually, using downscaling models for temperature, humidity, solar radiation, and wind speed, in both spatial and temporal cases, across several example sites in regional Victoria. Analysis is provided on the performance of the downscaling models and various adaptation and mitigation options are discussed and tested. These options include using different tree planting patterns to modify solar radiation exposure and wind effects, with mixed results because adding shading structures may also diminish the effect of wind-based cooling. The modelling experiments indicated that (1) heat stress is likely to increase under future climate conditions and could represent a serious threat to the health of small ruminants; (2) adaptation measures by means of tree planting to provide shade may not be sufficient to alleviate projected heat stress; and (3) other adaptation measures will need to be considered. Indicative results for heat stress under potential future environments are provided for 2030, 2050, and 2070. Also discussed is the performance of wind speed modelling, and the effect of heat stress on animal growth and ram fertility.

Fecal microbiota colonization dynamics in dairy heifers associated with early-life rumen microbiota modulation and gut health.

Early-life modulation of rumen microbiota holds promise for enhancing calf growth, health, and long-term production in ruminants. However, limited attention has been given to the impact of rumen microbiota modulation on the establishment of hindgut microbiota. In this study, fecal microbiota development was examined in identical twin calves for 12 months. The treatment group (T-group) received adult cow fresh rumen liquid inoculum during the pre-weaning period, while the control group did not (C-group). The effects of inoculum were assessed on calf gut health and as microbial seeding route into the hindgut. The early rumen modulation had no effect on age-related fecal microbiota development. The fecal bacterial community evolved gradually following dietary changes and categorized into pre-weaning and post-weaning communities. Bacterial richness increased with age and stabilized at month 9, while between-sample variation reduced in post-weaning samples. Archaeal load in fecal samples increased after month 4, while archaeal richness increased and stabilized in both groups by month 9. Between-sample similarity was higher during the pre-weaning period, with increased dissimilarity from month 4 onward. Anaerobic fungi were detected in feces at month 4, with richness peaking at month 7. Before month 6, fungal community composition distinctly differed from mature communities. When colostrum, calf rumen, and donor inoculum were evaluated as seeding sources for hindgut colonization, the calf's own rumen was identified as the primary seeding source for fecal bacteria and fungi. Colostrum was a source for several bacteria detected in feces, but these were of temporary importance until weaning. The donor inoculum had limited impact on gut health as diarrhea rates were similar between the T-group and C-group. In conclusion, early-life microbiota modulation shows potential in ruminant development. However, a more targeted approach with bacteria adapted to the hindgut environment may be necessary to modulate hindgut effectively. This research contributes to our understanding of the complex relationship between gut microbiota and calf health and growth.

Distance examination of livestock with drones - an effective method for assessing health and welfare.

Distance examination is an important part of veterinary investigation into ruminant herd health and welfare. The Department of Primary Industries and Regional Development (DPIRD) explored the use of drones to conduct assessments of the health and welfare status of sheep and cattle. Three methods of distance examination were compared comprising observations; from a vehicle, a "micro" category drone and a "very small" category drone. The disturbance and behavioural reactions caused by the methods were compared. Assessments of adverse health and welfare conditions by each method were compared to observations made at yarding. The preferred method was the use of the very small drone which had the best sensitivity for detection of conditions potentially associated with adverse health or welfare and the best optics at a distance that did not disturb the animals. The optics of the very small drone enabled distance examination without disturbance in both cattle and sheep. Cattle were more sensitive to the presence of the drones than sheep. The micro drone was unable to approach cattle close enough to allow undisturbed distance examination. All methods had similar specificity, however, sensitivity varied markedly. The very small drone had the best sensitivity 86% which was statistically greater than the micro drone (44%, P = 0.05) and better than the vehicle observations, which had sensitivity of 77% (not statistically significant). The selection of an appropriate drone model is essential for accurate distance examination. Distance examination of livestock with drones of suitable optic quality and resolution represents an effective method for assessing animal health and welfare.

Prevalence Study on Gastrointestinal Helminthic Infections in Ruminants of Hassan and Chikkamagalur Districts of Karnataka State, India

A prevalence study on gastrointestinal parasites in ruminants was undertaken in Hassan and Chikkamagalur districts of Karnataka state to observe the current infection status in the region. The faecal samples were collected from the animals and processed as per the standard procedures. A total of 354, 46, 212 and 138 faecal samples from cattle, buffalo, sheep and goats were screened, of which 92 cattle, 13 buffalo, 79 sheep and 58 goat samples were positive for parasitic infection, respectively. The coprological examination of cattle and buffaloes revealed the highest infection of Amphistome spp. (20.3% &amp; 28.3%) followed by strongyles (2.8% &amp; 2.2%) and Schistosoma spindale (0.6%). Buxtonella sulcata cysts were found in nine cattle samples. Mixed infection of Amphistome spp. and strongyle followed by Amphistome and Fasciola spp.; Amphistome spp. and Schistosoma spindale were also observed. The highest infection of strongyle (25.5% &amp; 24.6%) was followed by Amphistome spp. (2.4% &amp;0.7%) and Fasciola spp. (0.9%) in sheep and goats, mixed infection of strongyle with Amphistome spp. and Fasciola spp.; strongyle and Trichuris spp., Amphistome spp. and Trichuris spp. were observed in the faecal samples. Gastrointestinal parasitic infections cause considerable economic loss by way of reduced weight, decreased milk yield, debilitation and morbidity in livestock, besides causing major health problems in domestic animals. The study helps to understand parasitic infection in ruminants, which could greatly help in understanding the management strategies necessary for the health of domestic ruminants, thereby safeguarding the economic impact.

Treatment of corn with lactic acid delayed in vitro ruminal degradation without compromising fermentation: a biological and morphological monitoring study.

Grain processed by lactic acid (LA) is known to improve ruminant growth and health. However, the exact mechanism regarding rumen hydrolysis of LA-treated grain is still ambiguous. This experiment was designed to compare the effects of 5% LA treatment on the trophic and morphological variations in corn and to discover the alternations in ruminal hydrolysis between LA-treated and untreated corn macroscopically and microscopically using in vitro fermentation method. The results showed that, compared with untreated corn (CN), corn treated with 5% LA for 48 h (CNLA) experienced a decrease in the dry matter, albumin fraction, aNDFom, and water-soluble carbohydrate content but an increase in the resistant starch content. The in vitro fermentation showed that the pH of CNLA was higher, but dry matter disappearance was lower than that of CN. Most of the fermentation indices were unaffected, except for decreased iso-butyrate and iso-valerate. The abundances of total bacteria, Prevotella spp., Streptococcus bovis, and Selenomonas ruminantium were higher, but those of Ruminococcus flavefaciens and Ruminococcus albus were lower in CNLA than in CN. There were differences in the scanning electron micrographs between CNLA and CN after 3 h of fermentation. This study suggests that treating corn with LA for 48 h can induce changes in its nutrient composition and alter the bacterial flora during subsequent in vitro fermentation. These changes appeared to be crucial contributors to the beneficial effects observed in rumen fermentation.

The feeding of heather (Calluna vulgaris) to Teladorsagia circumcincta infected lambs reduces parasitism but can detrimentally impact performance

Gastrointestinal nematode (GIN) infections impact small ruminant health, welfare, and production across farming systems. Rising anthelmintic resistance and regulation of synthetic drug use in organic farming is driving research and development of sustainable alternatives for GIN control. One alternative is the feeding of plants that contain secondary metabolites (PSMs) e.g., proanthocyanidins (PA, syn. condensed tannins) that have shown anthelmintic potential. However, PSMs can potentially impair performance, arising from reduced palatability and thus intake, digestibility or even toxicity effects. In this study, we tested the trade-off between the antiparasitic and anti-nutritional effects of heather consumption by lambs. The impact of additional feeding of a nematophagous fungus (Duddingtonia flagrans) on larval development was also explored. Lambs infected with Teladorsagia circumcincta or uninfected controls, were offered ad libitum heather, or a control chopped hay for 22 days during the infection patent period. Eight days into the patent period, parasitised lambs were supplemented (or remained unsupplemented) with D. flagrans for a 5-day period. Performance and infection metrics were recorded, and polyphenol levels in the heather and control hay were measured to investigate their association with activity.The lambs consumed heather at approximately 20% of their dry matter intake, which was sufficient to exhibit significant anthelmintic effects via a reduction in total egg output (P = 0.007), compared to hay-fed lambs; the magnitude of the reduction over time in heather fed lambs was almost 10-fold compared to control lambs. Negative effects on production were shown, as heather-fed lambs weighed 6% less than hay-fed lambs (P < 0.001), even though dry matter intake (DMI) of heather increased over time. D. flagrans supplementation lowered larval recovery in the faeces of infected lambs by 31.8% (P = 0.003), although no interactions between feeding heather and D. flagrans were observed (P = 0.337). There was no significant correlation between PA, or other polyphenol subgroups in the diet and egg output, which suggests that any association between heather feeding and anthelmintic effect is not simply and directly attributable to the measured polyphenols. The level of heather intake in this study showed no antagonistic effects on D. flagrans, demonstrating the methods can be used in combination, but provide no additive effect on overall anthelmintic efficacies. In conclusion, heather feeding can assist to reduce egg outputs in infected sheep, but at 20% of DMI negative effects on lamb performance can be expected which may outweigh any antiparasitic benefits.

Effect of feeding hydroponic barley seedlings to lactating ewes on blood biochemical indexes and growth performance of lambs.

The aim of this study was to investigate the effects of replacing different ratios of basal diets with hydroponically barley seedlings (HBS) on the serum biochemical indexes and growth performance of lambs. It provides a theoretical basis for the use of HBS in ruminant health and scientific feeding management. In total, 30 ewes were randomly categorized into six groups (two control groups, 4 treatment groups, and 8 replicates in each group). All experiments were conducted under the same feeding and management conditions, on this basis the control group was CK1 and CK2 groups, which CK1 group added 15% corn silage, the treatment groups replacing 5% (group A), 10% (group B), 15% (group C) and 20% (group D) of the basal diet (dry matter basis) with HBS, and the experimental period lasted for 36 days, and the lambs were lactating with their mothers throughout the experimental period. Key results. The contents of total protein (TP), albumin (ALB), milk fat percentage and total solids (TS) in group C were significantly higher than CK1 and CK2 groups (p < 0.05) in milk samples; malondialdehyde (MDA) content in groups A and C was significantly lower than groups CK1 and CK2 (p < 0.05), alanine aminotransferase (ALT) and azelaic transaminase (AST) contents in groups A and B were significantly higher than CK1 group (p < 0.05), TC content in groups A and D was significantly higher than CK1 and CK2 groups (p < 0.05), high-density lipoprotein (HDL-c) content in group D was significantly higher than CK1 and CK2 groups (p < 0.01) in blood samples; Body height in C group was significantly higher than CK2 group (p < 0.05), ear width in group B was significantly higher than CK1 group (p < 0.05). In conclusion, under the conditions of this experiment, HBS instead of 5-15% of the basal diet could improve the milk quality of lactating Hu ewes and alleviate the oxidative stress of the body.

A novel bluetongue virus serotype 2 strain isolated from a farmed Florida white-tailed deer (Odocoileus virginianus) arose from reassortment of gene segments derived from co-circulating serotypes in the Southeastern USA.

Bluetongue disease is a reportable animal disease that affects wild and farmed ruminants, including white-tailed deer (WTD). This report documents the clinical findings, ancillary diagnostics, and genomic characterization of a novel reassortant bluetongue virus serotype 2 (BTV-2) strain isolated from a dead Florida farmed WTD in 2022. Our analyses support that this BTV-2 strain likely stemmed from the acquisition of genome segments from co-circulating BTV strains in Florida and Louisiana. In addition, our analyses also indicate that genetically uncharacterized BTV strains may be circulating in the Southeastern USA; however, the identity and reassortant status of these BTV strains cannot be determined based on the VP2 and VP5 genome sequences. Hence, continued surveillance based on complete genome characterization is needed to understand the genetic diversity of BTV strains in this region and the potential threat they may pose to the health of deer and other ruminants.

A Review on Metacestode Influence in the Case of Public Health and Economic Manners in Small Ruminants

A Review on Metacestode Influence in the Case of Public Health and Economic Manners in Small Ruminants

The effect of reducing starch bioavailability using organic acids on rumen fermentation and ruminant performance: A meta-analysis

Starch is an important nutrient in ruminants as an energy source. Utilizing organic acids to reduce starch bioavailability offers a safer approach to sustainable ruminant health and productivity. However, the inconsistent results obtained from published studies necessitate integration through meta-analysis to determine the actual effects. This study aimed to evaluate the effect of reducing starch bioavailability using organic acids on rumen fermentation and ruminant performance by meta-analysis. Hedges’ meta-analysis was conducted by using a random effect. A total of 14 articles were selected from the Scopus platform, with 23 comparative studies. This meta-analysis revealed that starch modification using organic acids influenced rumen fermentation. In vitro studies demonstrated a significant increase (p<0.01) in rumen pH and a reduction in ammonia (NH3) and total volatile fatty acids (VFA) levels (p<0.01). Partial VFA components, including butyrate, iso-butyrate, valerate, and iso-valerate, also showed significant decreases (p<0.01). Total protozoa also obtained a significant decrease (p<0.001). Moreover, in vivo trials indicated ruminant performance with increased milk fat content (p<0.05). In conclusion, the intervention of organic acids for reducing the bioavailability starch in rumen is effectively optimizes rumen health by maintaining fermented products within the normal range and increasing ruminant productivity.

Multiple bHLH/MYB-based protein complexes regulate proanthocyanidin biosynthesis in the herbage of Lotus spp.

Main conclusionThe complexes involving MYBPA2, TT2b, and TT8 proteins are the critical regulators of ANR and LAR genes to promote the biosynthesis of proanthocyanidins in the leaves of Lotus spp.The environmental impact and health of ruminants fed with forage legumes depend on the herbage's concentration and structure of proanthocyanidins (PAs). Unfortunately, the primary forage legumes (alfalfa and clover) do not contain substantial levels of PAs. No significant progress has been made to induce PAs to agronomically valuable levels in their edible organs by biotechnological approaches thus far. Building this trait requires a profound knowledge of PA regulators and their interplay in species naturally committed to accumulating these metabolites in the target organs. Against this background, we compared the shoot transcriptomes of two inter-fertile Lotus species, namely Lotus tenuis and Lotus corniculatus, polymorphic for this trait, to search for differentially expressed MYB and bHLH genes. We then tested the expression of the above-reported regulators in L. tenuis x L. corniculatus interspecific hybrids, several Lotus spp., and different L. corniculatus organs with contrasting PA levels. We identified a novel MYB activator and MYB-bHLH-based complexes that, when expressed in Nicotiana benthamiana, trans-activated the promoters of L. corniculatus anthocyanidin reductase and leucoanthocyanidin reductase 1 genes. The last are the two critical structural genes for the biosynthesis of PAs in Lotus spp. Competition between MYB activators for the transactivation of these promoters also emerged. Overall, by employing Lotus as a model genus, we refined the transcriptional network underlying PA biosynthesis in the herbage of legumes. These findings are crucial to engineering this trait in pasture legumes.