Australian Journal of Experimental Agriculture最新文献_第5页

Dietary cation–anion differences in some pasture species, changes during the season and effects of soil acidity and lime amendment 牧草品种饲粮正负离子差异、季节变化及土壤酸度和石灰改良剂的影响

Australian Journal of Experimental Agriculture Pub Date : 2008-08-04 DOI: 10.1071/EA08121

S. Pelletier, R. Simpson, R. Culvenor, G. Bélanger, G. Tremblay, G. Allard, J. Braschkat, P. Randall

{"title":"Dietary cation–anion differences in some pasture species, changes during the season and effects of soil acidity and lime amendment","authors":"S. Pelletier, R. Simpson, R. Culvenor, G. Bélanger, G. Tremblay, G. Allard, J. Braschkat, P. Randall","doi":"10.1071/EA08121","DOIUrl":"https://doi.org/10.1071/EA08121","url":null,"abstract":"The difference between cation and anion concentrations is an important property when assessing feed for dry dairy cows in order to avoid hypocalcaemia following calving. Dietary cation–anion difference (DCAD) is used to assess suitability of feed and predict the risk of milk fever; a value of –5 cmol(+)/kg dry matter (DM) or less is desirable. This work has examined the DCAD of 16 field-grown species found in pasture in southern Australia. The DCAD [cmol(+)/kg DM] at the flowering stage varied from 7 to 32 for grasses, 21 to 72 for legumes and 72 to 99 for dicot weeds. The average DCAD for legumes was 50 cmol(+)/kg DM, over 2-fold higher than the 20 cmol(+)/kg DM average for grasses. There was a substantial decline in DCAD of herbage as the season progressed. In a glasshouse experiment with five grass species in an acid soil, lime application increased yield and tended to lower the DCAD. Lime decreased uptake per unit root length of potassium and chlorine and increased uptake of calcium by phalaris and timothy. While DCAD is an important attribute of herbage for assessing its suitability for prepartum diets of dairy cows, the present data indicate that it would be prudent to also consider concentrations of calcium and other mineral nutrients in herbage, particularly when examining less familiar plant species or the effects of different cultural practices on the composition of herbage for such diets.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"1143-1153"},"PeriodicalIF":0.0,"publicationDate":"2008-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58805214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Designing complex research projects to estimate genetic parameters plus treatment and other effects – optimising the experimental design 设计复杂的研究项目来估计遗传参数加上治疗和其他影响——优化实验设计

Australian Journal of Experimental Agriculture Pub Date : 2008-08-04 DOI: 10.1071/EA07356

D. L. Robinson

{"title":"Designing complex research projects to estimate genetic parameters plus treatment and other effects – optimising the experimental design","authors":"D. L. Robinson","doi":"10.1071/EA07356","DOIUrl":"https://doi.org/10.1071/EA07356","url":null,"abstract":"There is an increasing trend towards integrated research, in which several individuals or institutions pool their expertise and make use of common resources, collaborating towards a common set of scientific goals. Integrated research enables a larger number of factors to be investigated, and the most influential or important ones identified, providing information on how the different factors interact or fit together. Good experimental design is, however, required to ensure the aims can be achieved and resources spent wisely. Issues involved in the experimental design of the Australian Beef Cattle Cooperative Research Centre for Meat Quality are discussed. Theoretical results and simulation studies were used to determine optimal numbers of progeny per sire for estimating genetic parameters. For heritabilities of 0.2 and 0.5, the optima are respectively 21 and 9 progeny with recorded measurements. The curves surrounding the optima are quite flat, so aiming for 10–15 progeny with measurements per trait should provide reasonable accuracy in many situations. Estimates of heritabilities, genetic correlations and phenotypic variances have lower sampling correlations than genetic variances and covariances, suggesting that when results are pooled over different breeds or trials, it is better to pool estimates of heritabilities and genetic correlations than (co)variances. Using sires in more than one year increases the robustness of estimated sire effects and increases the accuracy of genetic parameter estimates for hard-to-measure traits (e.g. feed efficiency) that are not recorded on all animals. Unless sires can be chosen as a true random sample of the population, arrangements of link sires (and other effects such as treatments) should be chosen to provide accurate estimates when all terms in the model are fitted as fixed.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"1110-1117"},"PeriodicalIF":0.0,"publicationDate":"2008-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58797673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Application of rumen microbial genome information to livestock systems in the postgenomic era 后基因组时代瘤胃微生物基因组信息在家畜系统中的应用

Australian Journal of Experimental Agriculture Pub Date : 2008-06-18 DOI: 10.1071/EA07408

G. Attwood, W. Kelly, E. Altermann, C. Moon, S. Leahy, A. Cookson

{"title":"Application of rumen microbial genome information to livestock systems in the postgenomic era","authors":"G. Attwood, W. Kelly, E. Altermann, C. Moon, S. Leahy, A. Cookson","doi":"10.1071/EA07408","DOIUrl":"https://doi.org/10.1071/EA07408","url":null,"abstract":"Sequencing the genomes of individual rumen microbes and determining the function of their encoded genes promises to transform our understanding of the microbiology of the rumen. The diversity and density of microbes in the rumen, and our inability to culture the majority of rumen microbes, limit current genome studies to only a small fraction of the microbes present in this environment. Nevertheless, genomes of fibre-degrading organisms are beginning to reveal a previously unexpected abundance of genes encoding glycosyl hydrolases and carbohydrate esterases, which could be used to enhance fibre digestion in the rumen. Additionally, genome sequencing of a rumen methanogen is identifying conserved genes within the methanogenic archaea that may serve as targets for their inhibition and therefore reduction of methane emissions from ruminants. The problem of rumen microbe culturability can be overcome by a new approach called metagenomics, in which microbial DNAs are extracted from rumen samples and sequenced independent of cultivation. In the future, sequencing individual genomes and metagenomic libraries is likely to capture much more of the microbial DNA in the rumen and, coupled with postgenomic studies on gene and protein expression, is likely to enhance our knowledge of the microbial component of ruminant digestion.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"467 1","pages":"695-700"},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58798588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

In utero effects on livestock muscle development and body composition 子宫内对家畜肌肉发育和体成分的影响

Australian Journal of Experimental Agriculture Pub Date : 2008-06-18 DOI: 10.1071/EA08017

J. Brameld, Z. Daniel

引用次数: 24

The effect of finishing diet and meat cuts on the attributes of four processed products from bull beef 肥育日粮和切肉对4种牛肉制品性状的影响

Australian Journal of Experimental Agriculture Pub Date : 2008-06-18 DOI: 10.1071/EA07395

M. Farouk, C. Podmore, C. Boom, G. Sheath

引用次数: 0

Development and validation of a simple technique for logging body temperature in free-ranging cattle 开发和验证一种简单的技术来记录自由放养的牛的体温

Australian Journal of Experimental Agriculture Pub Date : 2008-06-18 DOI: 10.1071/EA07422

J. Lea, D. Niemeyer, M. Reed, A. Fisher, D. Ferguson

引用次数: 25

Genotype and age effects on sheep meat production. 5. Lean meat and fat content in the carcasses of Australian sheep genotypes at 20-, 30- and 40-kg carcass weights 基因型和年龄对羊肉产量的影响。5. 20、30和40公斤胴体体重时澳大利亚绵羊基因型胴体的瘦肉和脂肪含量

Australian Journal of Experimental Agriculture Pub Date : 2008-06-18 DOI: 10.1071/EA08054

E. Ponnampalam, K. Butler, D. Hopkins, M. Kerr, F. Dunshea, R. Warner

{"title":"Genotype and age effects on sheep meat production. 5. Lean meat and fat content in the carcasses of Australian sheep genotypes at 20-, 30- and 40-kg carcass weights","authors":"E. Ponnampalam, K. Butler, D. Hopkins, M. Kerr, F. Dunshea, R. Warner","doi":"10.1071/EA08054","DOIUrl":"https://doi.org/10.1071/EA08054","url":null,"abstract":"Leanmeatand fat content of Australiansheep genotypes were comparedat20-,30- and 40-kg carcass weights. Sheep comprised Poll Dorsetgrowth ·Border Leicester Merino (PDg ·BLM), Poll Dorsetgrowth ·Merino (PDg ·M), Poll Dorsetmuscling ·Merino (PDm ·M), Border Leicester ·Merino (BL ·M) and Merino ·Merino (M ·M) genotypes. Lambs wereraisedasamixedflockundergrazingandslaughteredat4,8,14and22monthsofagewitheachslaughtertimeinvolving ~150mixed sex animals. At 24h after slaughter, chilled carcasses were halved along the backbone and the right sides were usedfordeterminationoflean,fatandashpercentagesusingdualenergyX-rayabsorptiometry.Withinaparticularagegroup andgenotype,animalsgrowingatfasterratesandreachingheaviercarcassweightshadlowercarcassleanmeatcontentthan slowergrowinganimals.Merinocarcassesweighing20and30kghadsimilarlevelsofleanmeattoPD ·Mgenotypes,which wasgreaterthanthatfromtheBL ·Mgenotype.Second-crossPD ·BLMcarcassesweighing20kgat4monthsand30kgat 8monthshadsimilarcarcassfatandleanpercentagesto20-kgMerinocarcassesat8monthsandfirst-crossPD ·Mcarcasses weighing30kgat14 months, respectively. At40-kgcarcass weight, 22-month-oldMerinoshad similarlevelsofleannessto carcasses from 22-month-old PD ·M animals and carcasses from 14-month-old second-cross PD ·BLM animals. Carcass leanmeatcontentdecreasedwithincreasingcarcassweightandfirst-crossBL ·Manimalshadthelowestcarcassleanacross allweightcategories.Therewasamajoraccelerationincarcassfatnessbetween14and22monthsassociatedwithareduction inmuscle deposition.Results indicatethatage ofthe animalshouldbe taken intoaccount whencarcass leanand fat contents are compared at a particular carcass weight. Merinos will achieve weight/composition specifications at least equally well to crossbreds but will take longer with a likely increase in production costs.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"893-897"},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08054","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58803061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 33

Manipulating dietary preference to improve animal performance 操纵饮食偏好以提高动物生产性能

Australian Journal of Experimental Agriculture Pub Date : 2008-06-18 DOI: 10.1071/EA08006

G. Edwards, A. Parsons, R. Bryant

{"title":"Manipulating dietary preference to improve animal performance","authors":"G. Edwards, A. Parsons, R. Bryant","doi":"10.1071/EA08006","DOIUrl":"https://doi.org/10.1071/EA08006","url":null,"abstract":"This paper reviews opportunities to improve the diet quality, intake and performance of animals through manipulation of the partial preference commonly shown by grazing animals for different pasture components. Using evidence from the well-worked example of grass–legume pastures, potential opportunities to manipulate preference are highlighted, including: (i) altering plant characteristics to change the relative preference of alternative species or cultivars; (ii) utilising variation in preference among and within animal species; and (iii) working with, rather than against, known preference patterns, by offering forages as spatially separated monocultures within the same paddock or at different times of the day. In all cases, it is argued that is important to consider the full complexities of pasture–animal interactions, in particular, how current diet choices feed back to determine choices available subsequently in the pasture. To develop feeding systems where desirable pasture traits for animal performance are sustained at a high abundance in the diet, plant and animal breeding selection practises and grazing management systems should take greater account of the existence of partial preferences.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"773-779"},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58800485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24

Application of gene expression studies in livestock production systems: a European perspective 基因表达研究在畜牧生产系统中的应用:欧洲视角

Australian Journal of Experimental Agriculture Pub Date : 2008-06-18 DOI: 10.1071/EA08018

I. Cassar-Malek, B. Picard, C. Bernard, J. Hocquette

{"title":"Application of gene expression studies in livestock production systems: a European perspective","authors":"I. Cassar-Malek, B. Picard, C. Bernard, J. Hocquette","doi":"10.1071/EA08018","DOIUrl":"https://doi.org/10.1071/EA08018","url":null,"abstract":"In the context of sustainable agriculture and animal husbandry, understanding animal physiology remains a major challenge in the breeding and production of livestock, especially to develop animal farming systems that respond to the new and diversified consumer demand. Physiological processes depend on the expression of many genes acting in concert. Considerable effort has been expended in recent years on examining the mechanisms controlling gene expression and their regulation by biological and external factors (e.g. genetic determinants, nutritional factors, and animal management). Two main strategies have been developed to identify important genes. The first one has focussed on the expression of candidate genes for key physiological pathways at the level of both the transcripts and proteins. An original strategy has emerged with the advent of genomics that addresses the same issues through the examination of the molecular signatures of all genes and proteins using high-throughput techniques (e.g. transcriptomics and proteomics). In this review, the application of the gene expression studies in livestock production systems is discussed. Some practical examples of genomics applied to livestock production systems (e.g. to optimise animal nutrition, meat quality or animal management) are presented, and their outcomes are considered. In the future, integration of the knowledge gained from these studies will finally result in optimising livestock production systems through detection of desirable animals and their integration into accurate breeding programs or innovative management systems.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"701-710"},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58800739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 46

Effectiveness of non-steroidal anti-inflammatory drugs and epidural anaesthesia in reducing the pain and stress responses to a surgical husbandry procedure (mulesing) in sheep 非甾体类抗炎药和硬膜外麻醉在减轻绵羊外科饲养过程(除鼠)的疼痛和应激反应中的有效性

Australian Journal of Experimental Agriculture Pub Date : 2008-06-18 DOI: 10.1071/EA08050

Paull, I. Colditz, Caroline Lee, S. Atkinson, A. Fisher

{"title":"Effectiveness of non-steroidal anti-inflammatory drugs and epidural anaesthesia in reducing the pain and stress responses to a surgical husbandry procedure (mulesing) in sheep","authors":"Paull, I. Colditz, Caroline Lee, S. Atkinson, A. Fisher","doi":"10.1071/EA08050","DOIUrl":"https://doi.org/10.1071/EA08050","url":null,"abstract":"In this study, we examined the potential of several widely used non-steroidal anti-inflammatory drugs (NSAIDs) and other analgesics to reduce pain and stress in sheep after surgery. Because mulesing involves a greater degree of tissue trauma than other surgical husbandry procedures such as castration or tail-docking, it provides a more rigorous and conservative test to identify potentially useful analgesic strategies in sheep. Merino lambs (5 weeks of age) were randomised into eight treatment groups: (1) carprofen; (2) flunixin; (3) ketoprofen; (4) buprenorphine; (5) xylazine; (6) lignocaine epidural; (7) saline control; (8) sham control. The NSAIDs were administered 1.5 h before mulesing, buprenorphine 0.75 h and xylazine and lignocaine 0.25 h before mulesing. Pain- and discomfort-related behaviours were recorded for 12 h after mulesing, and plasma cortisol concentrations were measured before mulesing and 0.5, 6, 12, 24 and 48 h after mulesing. The results indicated that no single analgesic treatment provided satisfactory analgesia during both the surgical mulesing procedure and the ensuing period of pain associated with the inflammatory phase. However, there were indications that two NSAIDs (carprofen and flunixin) showed good potential as analgesics during the inflammatory phase. A combination of short- and long-acting analgesics may be needed to provide more complete pain relief. In conclusion, the administration of some NSAIDs offers the potential for good analgesia in sheep for the inflammatory phase following the tissue trauma of surgical husbandry procedures. Other analgesic options need to be considered if the acute stress response to the procedure is to be reduced.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"1034-1039"},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58803115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13