Advances in pasture plant breeding for animal productivity and health

Plant breeding has had a substantial effect on the productivity and health of ruminant animals in New Zealand by improving the quantity, quality and reliability of grazed temperate pastures. Genetic changes have affected annual pasture productivity, seasonal growth, digestibility, protein/energy balance, level of rumen undegradable protein, leaf properties affecting intake, resistance to foliar diseases, and reductions in compounds that have an adverse impact on the health, welfare and reproductive fertility of ruminant animals. Most plant improvement programmes have achieved genetic gains in excess of 1% per year for a variety of target traits, and these gains are likely to continue given the high genetic variation available within forage plants. Significant heritable variation exists to improve forage quality, particularly for soluble carbohydrate and fibre fractions in grasses, and in the rate at which these change during the season. Deleterious animal health and welfare effects can be alleviated through the use of non-toxic endophytes in grasses, that do not produce lolitrem B and ergovaline. Use of improved cultivars, with the appropriate management, can add value to animal products.     

Advances in pasture management for animal productivity and health

A wide range of management techniques is available to enhance quantity and quality of forage supply to grazing animals throughout the annual production cycle. Within broad limits, dry matter (DM) production is relatively insensitive to management of defoliation frequency, severity and duration. However defoliation management has effects on feed quality which can be enhanced, in particular, by control of pasture growth in the spring through maintenance of relatively low average pasture masses. Treading damage can have significant immediate and ongoing effects on pasture production and farmers can use a range of management techniques to minimise these. Fertiliser application practices have a potent influence on pasture production and seasonality of that production. Available soil nitrogen is the primary nutrient deficiency limiting production in New Zealand's characteristically grass-dominant pastures. Nitrogen fertiliser usage has increased markedly in recent years, particularly to grow substantially greater amounts of forage during the cool season, and this trend looks set to continue. However, the use of nitrogen fertiliser has important environmental implications. Pasture renewal and forage crop use has also increased in recent years. Care needs to be taken in conducting cost-benefit analyses, selecting the options that best meet the needs, and in establishment and subsequent management practices. Ryegrass (perennial and hybrids) and white clover remain the primary choice for permanent pasture renewal, the availability of safe endophytes having largely alleviated effects of endophyte toxicosis. Special-purpose mixtures are used, especially in dry environments. Italian ryegrasses, brassicas and chicory are common choices for forage crops. A range of management techniques can be used to alleviate deleterious effects of some forages, including ryegrass endophyte toxicosis, facial eczema, and toxins associated with Fusarium fungi. Generally these techniques are not totally effective. More research is required to increase our understanding of these disorders, and in order to develop more effective and reliable management practices.     

Advances in pasture plant breeding for animal productivity and health

Plant breeding has had a substantial effect on the productivity and health of ruminant animals in New Zealand by improving the quantity, quality and reliability of grazed temperate pastures. Genetic changes have affected annual pasture productivity, seasonal growth, digestibility, protein/energy balance, level of rumen undegradable protein, leaf properties affecting intake, resistance to foliar diseases, and reductions in compounds that have an adverse impact on the health, welfare and reproductive fertility of ruminant animals. Most plant improvement programmes have achieved genetic gains in excess of 1% per year for a variety of target traits, and these gains are likely to continue given the high genetic variation available within forage plants. Significant heritable variation exists to improve forage quality, particularly for soluble carbohydrate and fibre fractions in grasses, and in the rate at which these change during the season. Deleterious animal health and welfare effects can be alleviated through the use of non-toxic endophytes in grasses, that do not produce lolitrem B and ergovaline. Use of improved cultivars, with the appropriate management, can add value to animal products.     

建立中国的牧草病害可持续管理体系

根据从事牧草病理学研究的实践和当今社会与科技的发展,作者提出了建立中国的牧草病害可持续管理体系,这一体系以信息技术,生物技术和经济学与社会学的知识为技术支撑。通过抗病品种的利用和对草地的持续管理,并辅以杀菌剂拦种和生物防治等措施,将病害控制在经济阈值水平之下,达到提高草地农业生态系统整体生产力和稳定性的目的。     

Recent progress in the study of behavior and management in grazing cattle

Recent progress in studies concerning behavior of, and management for, grazing cattle are reviewed. Since 1950, much study has been conducted on ‘How’, ‘When’, ‘Where’ and ‘How long’ regarding grazing. After the 1980s, grazing ecology introduced the concept of hierarchy at different spatial and temporal scales, and since then grazing behavior has been investigated on the foraging hierarchy of large grazing herbivores: bite, feeding station (FS), patch, feeding site, camp and home range. From the sequence of activities, FS is grouped within a feeding patch, and movement of grazing cattle has been studied between FSs, feeding patches, feeding sites and between camps. Grazing behavior and production relates closley with defoliation, and grazing management should control both grazing behavior and vegetation according to three rules: planning, operational and adaptation rules. Planning rules relate the stocking rate of cattle; operational rules relate to defoliation; and adaptation rules vary with regional situations. Recent studies on grazing have been carried out in the fields of animal diversity and welfare. Future studies in this field should be conducted on the ecology, neurophysiology and psychology of grazing. Nonlinear analysis will also be significant in this field. Grazing cattle production should also utilize supplementation by roughage and/or grains.     

垂穗披碱草/星星草混播草地优化牦牛放牧强度的研究

以植被和牦牛生产力变化为目标研究草地不退化的最大放牧强度,在垂穗披碱草/星星草高寒混播草地3年的牦牛放牧试验结果表明,1)优良牧草比例和牦牛个体增重的平均年度变化随放牧强度的增加而减小,牦牛个体增重和优良牧草比例的平均年度变化之间存在着正相关,因此确立了不同放牧强度下优良牧草比例的年度变化是评价高寒混播群落放牧价值的直接度量指标.2)虽然群落相似性系数和草地质量指数可以评价草场的相对变化,但相似性系数的变化与牦牛个体生产力没有显著关系,因而不能反映草场放牧价值的变化,而计算草地质量指数时,不同植物类群盖度的测定和适口性的判别受人为因素的干扰较大,因此它也不是一个很客观的指标.3)当放牧强度为9.97头/hm2时,优良牧草比例和牦牛个体增重的年度变化能维持基本不变,因此,可以认为该放牧强度是高寒人工草地生长季放牧不退化的最大放牧强度.     

关键场与季节放牧及草地畜牧业的可持续发展

基于季节畜牧业和草地农业生态系统的思想,提出了关键场的新概念;基于3S技术的应用和草业发展的需要,提出了关键场载畜量计算的新方法,为草地退化的防治和草地畜牧业的可持续发展,提供一个新的视角和可操作的评价指标;这些新的概念、指标、方法和程序,已经在<中国西部阿勒泰地区草地生产力变化及对策研究>中得到验证;草地畜牧业的核心问题,就是全年放牧的草畜平衡问题,这一点已列入草原法.因此,这些成果,可为新形势下正在起步的我国草原监理事业,提供必要的技术支撑.     

Managing Grazing Intensity Linked to Forage Quantity and Quality Trade-off in Semiarid Rangelands

Knowledge of herbivory tolerance of dominant plant species and their responses to varying grazing intensity is required for sustainable grazing management in semiarid rangeland ecosystems. In a field experiment, we studied the effects of simulated grazing 0%, 30%, 50%, and 80% leaf removal (control, partial, intermediate, and heavy leaf removal) of three dominant perennial legumes: Astragalus cyclophyllon, Astragalus effuses, and Hedysarum criniferum in semiarid rangelands of southwestern Iran for 2 yr and tested 1) differential herbivory tolerance in terms of regrowth ability of belowground and aboveground biomass (AGB), fecundity, and nonstructural carbohydrate reserves; and 2) trade-off between forage quantity and quality—less defoliated plants produce larger amount of biomass with less forage quality and vice versa. The results showed a reduction in AGB and reproduction in each of the three plants. However, three forbs exhibited some sort of variations in shoot and root growth, reproduction and forage quality under intermediate and heavy leaf removal. Leaf removal in individuals of A. effusus and H. criniferum are more likely to compensate for tissue loss by allocating the available resources to the expansion of root biomass, at the cost of AGB and reproductive effort. Leaf removal also led to an increase in forage quality in each of the three forb species, depending on the level of height removal. The control plant had a higher amount of biomass production and lower amount of crude protein compared with heavy leaf removal treatments (i.e., 80%), by contrasting responses of acid detergent fiber and neutral detergent fiber, indicating a trade-off between forage quality and forage quantity. The results indicate that there is a balance among forage quantity, quality, and regrowth ability of belowground and aboveground tissues in intermediate leaf removal treatments of these forb species. This balance is used to develop principles for grazing management of steppe rangelands because such a regime meets different criteria including forage quantity, quality, and nonstructural carbohydrate reserves.     

新疆退牧还草工程建设与管理的探讨

草地是发展畜牧业的重要基础,退牧还草工程是恢复、更新天然草地和保护生态环境的重要手段。本文就新疆实施退牧还草工程中所出现的一些问题进行了探讨。     

Imbedding HACCP principles in dairy herd health and production management: case report on calf rearing

Driven by consumer demands, European legislation has suggested the use of HACCP (Hazard Analysis Critical Control Point) as the quality risk management programme for the whole dairy chain. Until now, an exception has been made for primary producers, but as regulations evolve, on-farm HACCP-like programmes should be ready to assure food safety as well as animal health and animal welfare. In our field experiment, the HACCP-concept was used to combine both optimal farm management and formalisation of quality assurance in an on-farm situation in the Netherlands. The process of young stock rearing was chosen, since its importance for the future of the farm is often underestimated. Hazards and their associated risk factors can be controlled within the farm-specific standards and tolerances, as targets can be controlled by corrective measures and by implementation of farm-specific worksheets. The veterinarian is pivotal for the facility-based HACCP team, since he/she has knowledge about on-farm risk assessment and relations between clinical pathology, feed and farm management. The HACCP concept in combination with veterinary herd health and production management programmes offers a promising approach to optimise on-farm production processes (i.e., young stock rearing) in addition to a structural approach for quality risk management on dairy farms.     

The effect of dietary supplementation with Aurantiochytrium limacinum on lactating dairy cows in terms of animal health,productivity and milk composition

The aim of this study was to investigate the effect of dietary supplementation with the docosahexaenoic acid (DHA )‐rich microalgae, Aurantiochytrium limacinum (AURA ), on a variety of health and productivity parameters in lactating cows. Twenty‐four cows were blocked by parity and number of days in milk and then randomly assigned to a control (CON ; n  = 12) group with no algal supplementation, or a treatment group (AURA ; n  = 12) provided with 100 g AURA  cow^?1 day^?1 or 16 g DHA  cow^?1 day^?1. A variety of health and productivity measurements were taken, and results indicated that supplementation had no negative effects on animal health in terms of somatic cell count, haematological and biochemical blood parameters, while body condition was marginally improved by algal supplementation. No differences were found for the various production parameters measured; however, a tendency towards increased milk production was observed for the AURA group during the final stage of the study (+4.5 kg cow^?1 day^?1, day 78–84). The fatty acid profile of milk was improved by supplementation, with significantly lower saturated fatty acids, significantly higher omega‐3 fatty acids and an improved omega‐3/omega‐6 ratio observed when compared to the control group. The amount of DHA in the milk of cows provided 105 g AURA  head^?1 day^?1 was 4.7 mg/100 g milk with a peak transfer efficiency from feed to milk at day 49 of 8.3%. These results indicate that supplementation with 105 g AURA  head^?1 day^?1 resulted in the successful enrichment of milk with DHA without negatively impacting the health or productivity of the animals.     

红三叶和鸭茅混播草地综合管理优化模式的研究

选择牧草播种期、混播草地中禾本科和豆科牧草混合比例、施氮肥量、施氮肥量和刈割次数5个管理因子，建立红三叶和鸭茅混播草地参数回归模型，并由引进行产量分析和计算机仿真寻优，建立该草地综合管理优化模式，确定最佳的管理因子和水平。分析结果表明，该草地以3月份播种、禾草混播比例75％、施氮肥和磷肥量分别为0．15t/hm^2、刈害3次效果较好。     

红三叶和鸭茅混播草地综合管理优化模式的研究

选择牧草播种期、混播草地中禾本科和豆科牧草的混合比例、施氮肥量、施磷肥量和刈割次数五个管理因子 ,建立红三叶和鸭茅混播草地参数回归模型 ,并由此进行产量分析和计算机仿真寻优 ,建立该草地的综合管理优化模式 ,确定最佳的管理因子和水平。分析结果表明 ,对于该草地在 3月份播种、禾草混播比例 75%、施氮肥和磷肥量分别为 0 1 5t/hm2 、刈割 3次效果较好     

甘南高寒草地放牧系统生态风险的AHP决策分析及管理对策

本研究从生态经济学角度,系统探讨了制约高寒草地畜牧业可持续发展的主要风险因素及其时空变化特征,剖析了生态风险分析内涵,应用多层次的AHP(analytichierarchyprocess)决策分析方法,对甘南玛曲高寒草地放牧系统的生态风险进行了综合评价分析。结果表明,在导致高寒草地植被退化、土地沙漠化的诸风险因素中,长期超载放牧是主要风险因素,其权重达0.4803;其次是全球气候变化造成的降水减少风险和鼠害、虫害风险,其权重分别为0.2902和0.1558;人类其他不当活动(挖药材、采矿等)的风险影响较小,其权重仅为0.0737。在研究区风险防范的诸管理措施中,围栏轮牧(降低放牧强度)措施和针对严重退化草地实施的补播、施肥、封育等综合措施的效果最佳,其相应组合权重分别为0.3060和0.2661;灭鼠和建植人工草地等措施均有一定的效果。基于上述风险评价分析,提出了高寒草地放牧系统生态风险防范的主要管理对策与措施,为草地资源保护与可持续利用提供定量依据。     

新版兽药GMP检查常见问题分析及改进建议

自2020年6月实施新版兽药GMP验收标准以来,对山东省验收兽药企业中发现的常见缺陷项,从质量管理、机构人员、厂房与设施、设备、物料与产品、确认与验证、文件管理、生产管理、质量控制与质量保证、产品销售与召回、自检共11个部分给予总结和归纳,对问题产生原因进行了分析,并提出改进建议,以期为兽药生产企业更好地实施GMP工作提供借鉴和参考。