Effect of magnesium sulphate and l-tryptophan and genotype on the feed intake, behaviour and meat quality of pigs

Sixty-nine entire male pigs with different halothane genotype (homozygous halothane positive — nn-, n = 36; and homozygous halothane negative — NN-, n = 33) were fed with a supplementation of magnesium sulphate (Mg) and/or l-tryptophan (Trp) in the diet for 5 days before slaughter. Animals were housed individually and were submitted to stressful ante mortem conditions (mixed in the lorry according to treatments and transported 1 h on rough roads). Individual feed intake was recorded during the 5-d treatment. At the abattoir, pig behaviour was assessed in the raceway to the stunning system and during the stunning period by exposure to CO₂. Muscle pH, colour, water holding capacity, texture and cathepsin activities were determined to assess meat quality. The number of pigs with an individual feed intake lower than 2 kg/day was significantly different among diets (P < 0.05; Control: 8.7%; Mg&Trp: 43.5%; Trp: 17.4%) and they were considered to have inadequate supplement intake. During the ante mortem period, 15.2% of pigs included in the experiment died, and this percentage decreased to 8.7% in those pigs with a feed intake > 2 kg/day, all of them from the stress-sensitive pigs (nn). In general, no differences were observed in the behaviour of pigs along the corridor leading to the stunning system and inside the CO₂ stunning system. During the stunning procedure, Trp diet showed shorter periods of muscular excitation than control and Mg&Trp diets. The combination of a stressful ante mortem treatment and Mg&Trp supplementation led to carcasses with high incidence of severe skin lesions. Different meat quality results were found when considering all pigs or considering only those with adequate supplement intake. In this later case, Trp increased pH₄₅ (6.15) vs Control diet (5.96) in the Longissimus thoracis (LT) muscle (P < 0.05) and pH at 24 h (Trp: 5.59 vs C: 5.47) led to a higher incidence of dark, firm and exudative (DFD) traits in SM muscle (P < 0.05). Genotype affected negatively all the meat quality traits. Seventy-five percent of LT and 60.0% of the SM muscles from nn pigs were classified as pale, soft and exudative (PSE), while none of the NN pigs showed these traits (P < 0.0001). No significant differences were found between genotypes on the incidence of DFD meat.Due to the negative effects observed in the Mg&Trp group in feed intake and carcass quality, the utilization of a mixture of magnesium sulphate and tryptophan is not recommended.     

Sustainable transparent farm animal breeding and reproduction

Farm animal breeders are facing challenges. More and more powerful technologies are at their disposal for creating genetic change. At the same time, society is concerned about the impact of breeding practices and the use to which new technologies are being put. European breeders must compete in a global market. To meet these challenges, European farm animal breeders have conducted three projects to contribute to sustainable and transparent farm animal breeding and reproduction. In “Farm animal breeding and society”, an overview is presented of farm animal breeding in Europe and its technical, ethical, legal and consumer constraints and possibilities. In ‘SEFABAR’, European breeders, scientists and socio-economists have worked towards sustainable breeding and reproduction scenarios. In ‘CODE–EFABAR’, breeders aim to develop, with experts on ethics, communication and certification, and in close contact with NGOs, farmers' organisations and policy makers, a Code of Good Practice for farm animal breeding and reproduction organisations. Along this Code of Good Practice organisations will be able to explain their goals and practices to the public in a transparent way. This paper reviews these projects.     

动物福利法的历史起源、现状及意义

动物福利法的基本出发点是让动物在康乐的状态下生存,即减少其所受的不必要的痛苦,并且针对不同动物采取不同的福利标准,让人与动物和谐相处,从而推动社会的文明进步。本文对动物福利法的历史起源、现状及意义进行了叙述,并对动物福利法的立法宗旨、福利标准、结构框架及对中国法制进程的影响等诸方面进行了讨论。     

层次分析法在畜牧业循环经济综合评价中的应用

对畜牧业实行循环经济的综合评价是衡量畜牧业可持续发展程度的重要措施。采用层次分析法的原理建立畜牧业循环经济综合评价的数学模型,对层次分析法的具体流程进行详细描述,同时对层次分析法存在的一些问题进行总结。通过相应的实例,证明层次分析法在畜牧业循环经济综合评价中应用的可行性,对畜牧业相关部门在制定政策时能起到决策支持的作用。     

Perspective article: The evolving use of stocking rate indices currently based on animal number and type in semi‐arid heterogeneous landscapes and complex land‐use systems

Abstract

Methods of determining stocking rate based on metabolic mass, animal type and biomass are reviewed in the context of equilibrial/disequilibrial paradigms. In South Africa, the calculation of ‘carrying capacity’ is based on conversion of animal species to metabolic mass equivalents. This assumes homogenous systems that tend to some point of equilibrium. It is applied widely in commercial livestock systems involving one or two species. Examination of a case study in the Lowveld of the Northern Province, South Africa, showed that the determination of ‘stocking rate’ in this multi‐herbivore and heterogenous system, overestimated the ‘carrying capacity’ of the reserve over 20 years. The actual animal numbers in the system dropped by approximately 4 000 kg km^?2 after a drought in the early period of the study into the bounds as determined by a model incorporating rainfall and animal biomass. An approach to determine stocking density using animal type, biomass, rainfall and vegetation parameters is suggested. The development of this as a coarse‐scale (regional) and ranch‐specific model to cover a range of scales and heterogeneity in key resources is advocated.     

氯前列烯醇、孕酮阴道栓单独或结合其它激素处理本地母水牛后的发情和受胎情况

本试验研究对比了PGc、CIDR、PGC +PMSG和CIDR +PGc对 2 95头本地母水牛同期发情定时输精的发情率和受胎率。同时对处理后发情的母水牛分别在第一次输精时肌注hCG、LRHA并以不注射的作对照 ,探讨hCG和LRHA对发情母水牛排卵和受胎的效果。也分析了同一处理方法对处女水牛和经产水牛同期发情率和受胎率的差异。结果表明 :采用CIDR +PGc的同期发情率和受胎率最高 (85 .13%、4 6 .0 3% ) ,PGc +PMSG、CIDR和PGc组的发情率和受胎率分别是 73.0 1%和 4 3.4 8%、78.0 2 %和 4 3.6 6 %、6 4 .18%和 4 1.6 8%。CIDR +PG组的发情率极显著高于PGc组 (P <0 .0 1) ,其它各组间无显著差异 (P >0 .0 5 )。各组母牛的受胎率无显著差异 (P >0 .0 5 )。发情的母水牛在第一次输精时肌注hCG或者LRHA3,排卵率为 89.78%和 91.38% ,极显著高于不处理母水牛 (5 9.74 % ) (P <0 .0 1) ;但受胎率与对照组无显著差异 (P >0 .0 5 )。本试验 4种同期发情处理方法在发情率上经产牛 (84 .4 7% )显著高于处女牛 (5 5 .91% ) (P <0 .0 5 ) ;但受胎率 (45 .6 1% :38.4 6 % )无显著差异 (P >0 .0 5 )。     

基于WOS的畜牧兽医学科发文统计分析——以5所211农业院校为例

基于WOS(Web of Science,全球获取学术信息的主要数据库),对我国5所211农业院校的畜牧兽医学科近10年的发文进行统计分析,并以西北农林科大学为例进行了详细分析,展现了我国畜牧兽医学科领域的科研现状与问题。     

几种脲酶抑制剂对大豆脲酶和绵羊瘤胃微生物脲酶的抑制作用

本文研究了脲酶抑制剂乙酰氧肟酸 (AHA)、邻苯二酚、氢醌 (HQ)和硼砂对大豆脲酶和绵羊瘤胃微生物脲酶的抑制作用。结果表明 ,在浓度为 0 .0 0 0 1,0 .0 0 1,0 .0 1和 0 .1mmol/L时 ,4种脲酶抑制剂对大豆脲酶的抑制率分别为 :AHA为 6 % ,6 .2 % ,9.6 6 %和 2 9.79% ;HQ为 8.4 % ,13.0 3% ,19.79%和 4 4 .75 % ;邻苯二酚为 2 0 .34% ,19.12 % ,83.16 %和 93.78% ;而硼砂为 16 .5 5 % ,17.18% ,18.95 %和 35 .5 0 %。在相同浓度下 ,4种脲酶抑制剂对绵羊瘤胃微生物脲酶的抑制率分别为 :AHA为 9.5 8% ,14 .0 4 % ,4 1.30 %和 72 .73% ;HQ为 12 .2 1% ,39.99% ,6 4 .6 2 %和 78.87% ;邻苯二酚为 6 .0 7% ,9.36 % ,31.2 9%和 5 0 .4 4 % ;而硼砂分别为 4 .97% ,8.6 3% ,2 1.78%和 32 .0 2 %。     

Management targets for continuously stocked mixed oat × annual ryegrass pasture in a no-till integrated crop–livestock system

Feeding livestock with cover crops can improve the efficiency and sustainability of integrated crop–livestock systems under no-till. However, no-till systems are based on permanent soil cover by organic material, so grazing livestock can compete for soil cover. Hence, managing stocking rates during the grazing period of the cultivated forage species is a key factor to assure enough herbage mass for maintaining long-term sustainable no-till systems. In this context, the objective of this study was to determine sward management targets for a continuously stocked mixed oat (Avena strigosa) × annual ryegrass (Lolium multiflorum) pasture in rotation with soybean in a no-till integrated crop–livestock system to determine the optimum balance between animal production and herbage mass for soil cover. The effects of sward height management on animal performance and herbage mass covers were evaluated. Treatments corresponded to four sward heights: 10, 20, 30 and 40 cm, maintained throughout the experimental period through continuous stocking and variable stocking rate, plus a no-grazing control area. Treatments were arranged in a randomized complete block design with three replications. Herbage mass and animal performance increased linearly with sward height, but weight gain per hectare decreased. Grazing efficiency fitted to a quadratic regression and conversion efficiency a logarithmic model. Equilibrium between grazing and conversion efficiencies was reached on swards managed at 20 cm, indicating that this sward height provided enough herbage mass to allow both animal performance and no-till crop demand for soil cover.     

气候变化对青海高原及周边地区畜牧业的影响及应对措施

总结了气候变化对青海高原及周边地区畜牧业的影响,并对各地所采取的应对措施进行了评价。结果表明：①1961~2008年青海高原年平均气温和年平均最高气温和年平均最低气温均呈显著增加趋势;年降水量几乎无明显变化,但具有显著的季节变化特点;风速和日照时数逐年减小。②在当前气候变化条件下,草地生产力呈减少趋势,受其影响,草场理论载畜量也呈减小趋势;暖冬较有利于牲畜安全越冬,幼畜成活率维持在一个较高水平;气温升高,降水减少有利于牲畜抓膘育肥,但牲畜产肉量还受草场退化等众多负面因子的影响;家畜疾病与气象条件关系密切,不利的气象条件可引发家畜的许多疾病。③针对当前畜牧业生产所面临的问题,各地采取了草业建设、畜种改良、发展畜牧业新模式、牧业病虫害防治、气象灾害防御等措施,其在提高草地生产力、解决草畜失衡、保护生态环境和提高牲畜性能等方面发挥了重大作用。