The significance of N‑carbamoylglutamate in ruminant production

Improving the efficiency and production of grazing ruminants to support food and fiber production,while reducing the environmental footprint and meeting the welfare needs of the animals,is important for sustainable livestock production systems.Development of new technologies that can improve the efficiency of nitrogen(N)utilization in ruminants,and that are effective and safe,has important implications for ruminant livestock production.N-carbomoylglutamate(NCG)is a functional micronutrient that stimulates endogenous synthesis of arginine,which can improve survival,growth,lactation,reproductive performance,and feed efficiency in mammals.There is a growing body of evidence to support the potential of dietary NCG supplementation to improve the productive capacity and N utilization efficiency of ruminants.This review summarizes the current literature on the effects of dietary supplementation with NCG in ruminants and impacts on production and potential to reduce the environmental footprint of farmed ruminant livestock.The current literature highlights the potential for commercial application in ruminant livestock to improve productivity and N utilization efficiency.

The glutamate metabotropic receptor 5(GRM5)gene is associated with beef cattle home range and movement tortuosity

Background:The grazing behaviour of herbivores and their grazing personalities might in part be determined genetically,but there are few studies in beef cattle illustrating this.In this study,we investigated for first time the genetic variation within a candidate‘grazing gene',the glutamate metabotropic receptor 5 gene(GRM5),and tested associations between variation in that gene and variation in grazing personality behaviours(GP-behaviours)displayed by free-ranging cows during winter grazing in the steep and rugged rangelands of New Zealand.Mature beef cows(n=303,from 3 to 10 years of age)were tracked with global positioning system(GPS)and,with 5-minutes(min)relocation frequency,various GP-behaviours were calculated.These included horizontal and vertical distances travelled,mean elevation,elevation range,elevation gain,slope,home range and movement tortuosity,variously calculated using daily relocation trajectories with repeated measurements(i.e.,7 to 24 days(d))and satellite-derived digital elevation models(DEM).The different GP-behaviours were fitted into mixed models to ascertain their associations with variant sequences and genotypes of GRM5.Results:We discovered three GRM5 variants(A,B and C)and identified the six possible genotypes in the cattle studied.The mixed models revealed that A was significantly associated with elevation range,home range and movement tortuosity.Similarly,GRM5 genotypes were associated(P<0.05)to home range and movement tortuosity,while trends suggesting association(P<0.1)were also revealed for elevation range and horizontal distance travelled.Most GP-behaviour models were improved by correcting for cow age-class as a fixed factor.The analysis of GP-behaviours averaged per cow age-class suggests that grazing personality is fully established as beef cows reached 4 years of age.Home range and movement tortuosity were not only associated with GRM5 variation,but also negatively correlated with each other(r=-0.27,P<0.001).Conclusions:There seems to be a genetically determined trade-off between home range and movement tortuosity that may be useful in beef cattle breeding programmes aiming to improve the grazing distribution and utilisation of steep and rugged rangelands.

Single nucleotide polymorphism in the tumor necrosis factor-alpha gene affects inflammatory bowel diseases risk

AIM: To investigate the role that single nucleotide polymorphisms (SNPs) in the promoter of the tumour necrosis factor-alpha (TNF-α) gene play in the risk of inflammatory bowel diseases (IBDs) in a New Zealand population, in the context of international studies. METHODS: DNA samples from 388 patients with Crohn's disease (CD), 405 ulcerative colitis (UC), 27 indeterminate colitis (IC) and 201 randomly selected controls, from Canterbury, New Zealand were screened for 3 common polymorphisms in the TNF-α receptor: -238 G→A, -308 G→A and -857C→T, using a TaqmanR assay. A meta-analysis was performed on the data obtained on these polymorphisms combined with that from other published studies. RESULTS: Individuals carrying the -308 G/A allele had a significantly (OR = 1.91, χ2 = 17.36, P < 0.0001) increased risk of pancolitis, and a 1.57-fold increased risk (OR = 1.57, χ2 = 4.34, P = 0.037) of requiring a bowel resection in UC. Carrying the -857 C/T variant decreased the risk of ileocolonic CD (OR = 0.56, χ2 =4.32, P = 0.037), and the need for a bowel resection (OR = 0.59, χ2 = 4.85, P = 0.028). The risk of UC was reduced in individuals who were smokers at diagnosis, (OR = 0.48, χ2 = 4.86, P = 0.028). CONCLUSION: TNF-α is a key cytokine known to play a role in inflammatory response, and the locus for the gene is found in the IBD3 region on chromosome 6p21, known to be associated with an increased risk for IBD. The -308 G/A SNP in the TNF-α promoter is functional, and may account in part for the increased UC risk associated with the IBD3 genomic region. The -857 C/T SNP may decrease IBD risk in certain groups. Pharmaco- or nutrigenomic approaches may be desir- able for individuals with such affected genotypes.

Technological,environmental and biological factors:referent variance values for infrared imaging of the bovine

Background： Despite its variety of potential applications, the wide implementation of infrared technology in cattle production faces technical, environmental and biological challenges similar to other indicators of metabolic state. Nine trials, divided into three classes （technological, environmental and biological factors） were conducted to illustrate the influence of these factors on body surface temperature assessed through infrared imaging. Results： Evaluation of technological factors indicated the following： measurements of body temperatures were strongly repeatable when taken within ]0 s; appropriateness of differing infrared camera technologies was influenced by distance to the target; and results were consistent when analysis of thermographs was compared between judges. Evaluation of environmental factors illustrated that wind and debris caused decreases in body surface temperatures without affecting metabolic rate; additionally, body surface temperature increased due to sunlight but returned to baseline values within minutes of shade exposure. Examination/investigation/exploration of animal factors demonstrated that exercise caused an increase in body surface temperature and metabolic rate. Administration of sedative and anti-sedative caused changes on body surface temperature and metabolic rate, and during late pregnancy a foetal thermal imprint was visible through abdominal infrared imaging. Conclusion： The above factors should be considered in order to standardize operational procedures for taking thermographs, thereby optimizing the use of such technology in cattle operations.

Use of stochastic simulations to investigate the power and design of a whole genome association study using single nucleotide polymorphism arrays in farm animals

This paper presents a quick, easy to implement and versatile way of using stochastic simulations to investigate the power and design of using single nucleotide polymorphism (SNP) arrays for genome-wide association studies in farm animals. It illustrates the methodology by discussing a small example where 6 experimental designs are considered to analyse the same resource consisting of 6006 animals with pedigree and phenotypic records: (1) genotyping the 30 most widely used sires in the population and all of their progeny (515 animals in total), (2) genotyping the 100 most widely used sires in the population and all of their progeny (1102 animals in total), genotyping respectively (3) 515 and (4) 1102 animals selected randomly or genotyping respectively (5) 515 and (6) 1102 animals from the tails of the phenotypic distribution. Given the resource at hand, designs where the extreme animals are genotyped perform the best, followed by designs selecting animals at random. Designs where sires and their progeny are genotyped perform the worst, as even genotyping the 100 most widely used sires and their progeny is not as powerful of genotyping 515 extreme animals.

Using genetic markers in unpedigreed populations to detect a heritable trait

Before a breeder invests selection pressure on a trait of interest, it needs to be established whether that trait is actually heritable. Some traits may not have been measured widely in pedigreed populations, for example, a disease or deformity may become more prevalent than previously, but is still relatively rare. One approach to detect inheritance would be to screen a commercial population to obtain a sample of "affecteds" (the test group) and to also obtain a random control group. These indi- viduals are then genotyped with a set of genetic markers and the relationships between individuals within each group estimated. If the relatedness is higher in the test group than in the control group, this provides initial evidence for the trait being heritable. A power simulation shows that this approach is feasible with moderate resources.

Studies on Methane Emissions from Pastoral Farming in New Zealand

The aim of this paper was to give a basic understanding of studies on methane emissions of New Zealand, as we know the agriculture of New Zealand is pastoral farming, most livestock animals are grazed in pasture, and quantities of methane were released from the digestive tract and animals excreta. In New Zealand some 50% greenhouse gases （GHG） sources are attributed to agriculture and one third is methane from livestock enteric formation. For many years, many researchers have been exploiting the techniques and methods to measure the emission of methane of New Zealand, further more studing the available options to alleviate the methane emissions. Their pioneering work and successful experiences including the determined methods and mitigation strategies are worth learning for scholars around the world. Some of their approaches were not only suitable for New Zealand grazed livestock, but for many other countries, even the animals are intensively bred in pen. The calorimeter/respiration chamber is the most exactly method in present, but it needs expensive equipments and skilled manipulators, so there are still some difficulty in applying this approach extensively in practice. Sulfur hexafluoride （SF6） trace technique is much adopted for grazed livestock evaluating the methane emission, though its veracity was doubted by some researchers, it is still a good option in present for studying the GHG emissions for grazing animals. By measuring the rumen volatile fatty acid （VFA） concentration to estimate the methane emission is a relatively simple approach, it is just only a rough evaluation, and it is unsuitable for exact study, but this method may be used in China for extensively raised ruminant. In present China, the ruminants are fed in an extensively managed state, the diversities of roughage and animals varieties caused difficult to exactly estimate the methane emission. So exploiting the available options is much important for constituting the exhaustive emission inventory. This review just maybe a good reference for researchers to carry out their studies in years and acquired great achievements in methane mitigation area. outline some practical techniques of New Zealand, those this field, after all New Zealand have been persisting many

The Use and Exchange of Biological Control Agents for Food and Agriculture

The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories of biological control:classical and augmentative.Allowing access to BCAs for use inanother country imposes no risk of liability to the source country.Local scientific knowledge abouthabitats,fauna andflora,can be

Toward to agricultural green development by multi-objective zoning and nitrogen nutrient management:a case study in the Baiyangdian Basin,China

Although China has achieved great advancements toward national food security,the country is still confronted with a range of challenges,including natural resource stress,imbalanced diets and environmental pollution.Optimized management of crop–livestock systems is the key measure to realize agricultural green transformation.However,optimized management of crop–livestock systems that use multi-objective zoning is lacking.This study employed a multi-objective zoning management approach to comprehensively analyze four indicators:ammonia volatilization,nitrogen surplus,soil carrying capacity and ecological red line area.With its significant ecological integrity and a strong emphasis on sustainability,the Baiyangdian Basin serves as a unique and suitable test case for conducting analyses on multi-objective nutrient optimization management,with the aim to facilitate the agricultural green transformation.This study finds that less than 8%of the area in the Baiyangdian Basin meet the acceptable environmental indicator standard,whereas around 50%of the area that had both nitrogen surplus and ammonia volatilization exceeded the threshold.Implementation of unified management,that is,the same management technique across the study areas,could result in an increase of areas meeting environmental indicator thresholds to 21.1%.This project developed a novel multi-indicator partition optimization method,in which distinct measures are tailored for different areas to satisfy multiple environmental indicators.Implementation of this method,could potentially bring more than 50%area below the threshold,and areas with ammonia emissions and nitrogen surplus could be reduced to 15.8%.The multi-indicators partition optimization method represents a more advanced and efficiency-oriented management approach when compared to unified management.This approach could be regarded as the best available option to help China achieve agricultural transformation to improve efficient production and reduce environmental pollution.It is recommended that current policies aimed at nutrient management toward sustainable agricultural development should shift toward the application of multi-indicators partition optimization.

Sodium butyrate promotes gastrointestinal development of preweaning bull calves via inhibiting inflammation,balancing nutrient metabolism,and optimizing microbial community functions

Butyrate promotes the growth and gastrointestinal development of calves.But,the mechanisms behind its effects on signaling pathways of the gastrointestinal tract and rumen microbiome is unclear.This study aimed to reveal transcriptomic pathways of gastrointestinal epithelium and microbial community in response to butyrate supplementation in calves fed a high fiber starter.Fourteen Holstein bull calves(39.9±3.7 kg,14 d of age)were assigned to 2 groups(sodium butyrate group,SB;control group,Ctrl).The SB group received 0.5%SB supplementation.At d 51,the calves were slaughtered to obtain samples for analysis of the transcriptome of the rumen and jejunum epithelium as well as ruminal microbial metagenome.Sodium butyrate supplementation resulted in a higher performance in average daily gain and development of jejunum and rumen papillae.In both the rumen and jejunum epithelium,SB downregulated pathways related to inflammation including NF-κB(PPKCB,CXCL8,CXCL12),interleukin-17(IL17A,IL17B,MMP9),and chemokine(CXCL12,CCL4,CCL8)and up-regulated immune pathways including the intestinal immune network for immunoglobulin A(IgA)production(CD28).Meanwhile,in the jejunum epithelium,SB regulated pathways related to nutritional metabolism including nitrogen metabolism(CA1,CA2,CA3),synthesis and degradation of ketone bodies(HMGCS2,BDH1,LOC100295719),fat digestion and absorption(PLA2G2F,APOA1,APOA4),and the PPAR signaling pathway(FABP4,FABP6,CYP4A11).The metagenome showed that SB greatly increased the relative abundance of Bacillus subtilis and Eubacterium limosum,activated ruminal microbial carbohydrate metabolism pathways and increased the abundance of carbohydrate hydrolysis enzymes.In conclusion,butyrate exhibited promoting effects on growth and gastrointestinal development by inhibiting inflammation,enhancing immunity and energy harvesting,and activating microbial carbohydrate metabolism.These findings provide new insights into the potential mechanisms behind the beneficial effects of butyrate in calf nutrition.

Elevated and atmospheric-level methane consumption by soil methanotrophs of three grasslands in China

Background:Methane(CH4)oxidation driven by soil aerobic methanotrophs demonstrates the capacity of grassland as a CH4 sink.Methods:In this study,we compared the oxidation characteristics of atmospheric-level and elevated concentration(10%)CH4 in a typical grassland(steppe)on the Loess Plateau,an alpine meadow(meadow)on the Qinghai-Tibet Plateau,and an inland arid-area artificial grassland(pasture)in northwest China and investigated the communities of active methanotrophs and their contribution to CH4 oxidation using DNA-based stable-isotope probing and Illumina Miseq sequencing.Results:The results showed that the oxidation of atmospheric CH4 only occurred in steppe and meadow soils where the USCγgroup of methanotrophs was numerically dominant in the methanotroph community.Pasture soils,with their very low relative abundance of USCγ,did not show atmospheric CH4 oxidation.However,a DNA-stable isotope probing experiment with 10%CH4 indicated that conventional CH4 oxidizers(Methylocaldum and Methylocystis)rather than USCγcommunities assimilated significant amounts of 13CH4 for growth.Conclusions:The CH4 oxidation mechanisms in the three experimental grassland soils varied significantly.The USCγgroup may be obligate oligotrophic microorganisms or their growth requires specific unknown conditions.

The scarab gut： A potential bioreactor for bio-fuel production

Cellulose and hemicelluloses are the most prevalent sources of carbon in nature. Currently many approaches employ micro-organisms and their enzyme products to degrade plant feedstocks for production of bioenergy. Scarab larvae are one such model. They consume celluloses from a variety of sources including plant roots, soil organic matter and decaying wood, and are able to extract nutrients and energy from these sources. In this paper, we review the physicochemical properties of the scarab larval gut, the diversity and digestive role that microflora play in the scarab gut and discuss the potential for applying these digestive processes in bioreactors for improving bio-fuel production. Scarab larvae are characterised by their highly alkaline midgut which is dominated by serine proteinase enzymes, and a modified hindgut which harbors the majority of the intestinal microbiota under anaerobic conditions. Evidence suggests that digestion of recalcitrant organic matter in scarab larvae likely results from a combination of endogenous gut proteinases and cellulolytic enzymes produced by symbiotic micro-organisms. Most of the easily digestible proteins are mobilized and absorbed in the midgut by endogenous proteinases. The hindgut contents of scarab larvae are characterized by high concentrations of volatile fatty acids, the presence of fermenting bacteria, and typical anaerobic activities, such as methanogenesis. The hindgut typically contains a wide diversity of micro-organisms, some of which appear to be obligate symbionts with cellulolytic potential. As a result, the scarab larval gut can be regarded as a small bioreactor resembling the rumen of sheep or cattle, where solid food particles composed of cellulose, hemicellulose, pectin and polysaccharides are degraded through enzymatic and fermentation processes. Together these observations suggest scarab larvae have potential to assist the bio-fuel industry by providing new sources of （hemi）cellulolytic bacteria and bacterial （hemi）cellulolytic enzymes.

Responses of soil microbial communities and functions associated with organic carbon mineralization to nitrogen addition in a Tibetan grassland

Alpine grasslands with a high soil organic carbon(SOC)storage on the Tibetan Plateau are experiencing rapid climate warming and anthropogenic nitrogen(N)deposition;this is expected to substantially increase the soil N availability,which may impact carbon(C)cycling.However,little is known regarding how N enrichment influences soil microbial communities and functions relative to C cycling in this region.We conducted a 4-year field experiment on an alpine grassland to evaluate the effects of four different rates of N addition(0,25,50,and 100 kg N ha^-1 year^-1)on the abundance and community structure(phospholipid fatty acids,PLFAs)of microbes,enzyme activities,and community level physiological profiles(CLPP)in soil.We found that N addition increased the microbial biomass C(MBC)and N(MBN),along with an increased abundance of bacterial PLFAs,especially Gram-negative bacterial PLFAs,with a decreasing ratio of Gram-positive to Gram-negative bacteria.The N addition also stimulated the growth of fungi,especially arbuscular mycorrhizal fungi,reducing the ratio of fungi to bacteria.Microbial functional diversity and activity of enzymes involved in C cycling(β-1,4-glucosidase and phenol oxidase)and N cycling(β-1,4-N-acetyl-glucosaminidase and leucine aminopeptidase)increased after N addition,resulting in a loss of SOC.A meta-analysis showed that the soil C/N ratio was a key factor in the response of oxidase activity to N amendment,suggesting that the responses of soil microbial functions,which are linked to C turnover relative to N input,primarily depended upon the soil C/N ratio.Overall,our findings highlight that N addition has a positive influence on microbial communities and their associated functions,which may reduce soil C storage in alpine grasslands under global change scenarios.

Yield-scaled nitrous oxide emissions from nitrogen-fertilized croplands in China: A meta-analysis of contrasting mitigation scenarios

Nitrogen(N) losses in cropland resulting from the application of synthetic fertilizers decrease crop productivity and exacerbate environmental pollution.Mitigation measures, such as reduction in N fertilizer application rates, can have unintentional adverse effects on crop yield. We conducted a meta-analysis of soil N_(2)O emissions from agricultural fields across China under contrasting mitigation scenarios as a novel approach to identify the most effective strategy for the mitigation of emissions of N_(2)O derived from N fertilizer use in China. Current standard agricultural practice was used as a baseline scenario(BS), and 12 potential mitigation scenarios(S1–S12) were derived from the available literature and comprised single and combinations of management scenarios that accounted for crop yield. Mitigation scenarios S6(nitrification inhibitor 3,4-dimethylpyrazole phosphate) and S11(20% reduction in N application rate plus nitrification inhibitor dicyandiamide) in maize, rice, and wheat crops led to an average 56.0% reduction in N_(2)O emissions at the national level, whereas scenario S4(nitrification inhibitor dicyandiamide) led to yield optimization, with a 14.0% increase for maize and 8.0% increase for rice as compared to the BS. Implementation of these most effective mitigation scenarios(S4, S6, and S11) might help China, as a signatory to the 2015 United Nations Framework Convention on Climate Change(Paris Agreement), to achieve a 30% reduction in N_(2)O emissions by 2030.

A mathematical model to describe the diurnal pattern of enteric methane emissions from non-lactating dairy cows post-feeding

Enteric methane emission is not only a source of energy loss in ruminants, but also a potent contributor to greenhouse gas production. To identify the nature and timing of interventions to reduce methane emissions requires knowledge of temporal kinetics of methane emissions during animal husbandry.Accordingly, a mathematical model was developed to investigate the pattern of enteric methane emissions after feeding in dairy cows. The model facilitated estimation of total enteric methane emissions（V,g） produced by the residual substrate（V1, g） and newly ingested feed（V2, g）. The model was fitted to the10 h methane emission patterns after morning feeding of 16 non-lactating dairy cows with various body weights（BW）, and the obtained parameters were used to predict the kinetics of 24 h methane emission for each animal. The rate of methane emission（g/h） reached a maximum within 1 to 2 h after feeding,followed by a gradual post-prandial decline to a basal value before the next feeding. The model satisfactorily fitted curves for each cow according to the criterion of goodness-of-fit, and provided biological descriptions for fluctuations in methane emissions based on basal V1 and feeding V2 in response to the changes in BW and dry matter intake（DMI） of different dairy cows. The basal V1 and feeding V2 are probably maintained by slow-and readily-degradable substrates, respectively. The former contributed at least 0.6 of methane production. In summary, the model provides a means to separate basal V1 and feeding V2 within V, and can be used to predict 24 h emission from a single feeding period.

Sheep numbers required for dry matter digestibility evaluations when fed fresh perennial ryegrass or forage rape

Research trials with fresh forages often require accurate and precise measurement of digestibility and variation in digestion between individuals, and the duration of measurement periods needs to be established to ensure reliable data are obtained. The variation is likely to be greater when freshly harvested feeds are given, such as perennial ryegrass(Lolium perenne L.) and forage rape(Brassica napus L.),because the nutrient composition changes over time and in response to weather conditions. Daily feed intake and faeces output data from a digestibility trial with these forages were used to calculate the effects of differing lengths of the measurement period and differing numbers of sheep, on the precision of digestibility, with a view towards development of a protocol. Sixteen lambs aged 8 months and weighing 33 kg at the commencement of the trial were fed either perennial ryegrass or forage rape(8/treatment group) over 2 periods with 35 d between measurements. They had been acclimatised to the diets, having grazed them for 42 d prior to 11 days of indoor measurements. The sheep numbers required for a digestibility trial with different combinations of acclimatisation and measurement period lengths were subsequently calculated for 3 levels of imposed precision upon the estimate of mean dry matter(DM) digestibility. It is recommended that if the standard error of the mean for digestibility is equal to or higher than 5 g/kg DM, and if sheep are already used to a fresh perennial ryegrass or forage rape diet,then a minimum of 6 animals are needed and 4 acclimatisation days being fed individually in metabolic crates followed by 7 days of measurement.

Potential probiotic and health fostering effect of host gut-derived Enterococcus faecalis on freshwater prawn,Macrobrachium rosenbergii

The present study investigated the potential probiotic effect of Enterococcus faecalis against a pathogenic microorganism,Vibrio harveyi occurring in the giant freshwater prawn(Macrobrachium rosenbergii).V.harveyi was isolated from the intestine of M.rosenbergii through biochemical tests and PCR-based molecular assays.An in-vitro challenge was conducted by mixing isolated probiotic(5.12 log CFU/g)and V.harveyi(3.09 log CFU/g).Feeds incorporated with E.faecalis(9.02 log CFU/g)were applied to the treatment group during in vivo test in the aquarium and earthen pond(70 m^(2),1 m depth).Pathogenic bacteria were found to be reduced after 8 h(from 5.02 to 3.62 log CFU/g)and 60 days(from 5.44 to 2.15 log CFU/g)of probiotic administration in the in vitro and in vivo test,respectively.The E.faecalis mixed feed also showed higher weight gain(WG%,481.22%±17.71%;SGR%,2.93%±0.18%)and digestive enzymes activities(amylase,1.26±0.08 unit/mg;protease,2.78±0.02 unit/mg)compared to control group(WG%,371.31%±13.35%;SGR%,2.30%±0.32%;amylase,0.7±0.03 unit/mg;protease,1.82±0.02 unit/mg).Furthermore,the probiotic also improved the immune response by augmenting NGH(from 73.33%±0.23%to 74.63%±0.11%)and SGH(from 22.24%±0.06%to 23.13%±0.08%)in the treatment group.Therefore,E.faecalis could be recommended to use against bacterial infections of the M.rosenbergii.