Genotype-environment interactions for growth and carcass traits in different pig breeds kept under conventional and organic production systems

The demand for special breeding programmes for organic pig meat production is based on the assumption that pigs kept under organic conditions need different biological properties compared with conventionally kept pigs in order to achieve a good performance. This would mean that genotype-environment interactions exist. Therefore, 682 pigs of seven different genotypes were tested for growth performance and carcass quality under conventional and organic environments at two testing stations to verify genotype-environment interactions. All genotypes achieved significantly better results within the conventional environment and there were significant interactions between genotype and environment for all the criteria of growth performance and carcass quality. The interactions are mainly caused by varying differences between organic and conventional systems within genotypes, but for all traits, except weight gain, no major shift of the ranking order within environment between genotypes. Although statistically significant genotype-environment interactions exist, the modern genotypes selected under conventional conditions are also superior to indigenous breeds under organic conditions in economically important traits. Hence, it can be concluded from these results that no special breeding programme is necessary for organic production systems.     

Assessing the impact of natural service bulls and genotype by environment interactions on genetic gain and inbreeding in organic dairy cattle genomic breeding programs

The objective of the present study was to compare genetic gain and inbreeding coefficients of dairy cattle in organic breeding program designs by applying stochastic simulations. Evaluated breeding strategies were: (i) selecting bulls from conventional breeding programs, and taking into account genotype by environment (G×E) interactions, (ii) selecting genotyped bulls within the organic environment for artificial insemination (AI) programs and (iii) selecting genotyped natural service bulls within organic herds. The simulated conventional population comprised 148 800 cows from 2976 herds with an average herd size of 50 cows per herd, and 1200 cows were assigned to 60 organic herds. In a young bull program, selection criteria of young bulls in both production systems (conventional and organic) were either ‘conventional’ estimated breeding values (EBV) or genomic estimated breeding values (GEBV) for two traits with low (h²=0.05) and moderate heritability (h²=0.30). GEBV were calculated for different accuracies (r_mg), and G×E interactions were considered by modifying originally simulated true breeding values in the range from r_g=0.5 to 1.0. For both traits (h²=0.05 and 0.30) and r_mg⩾0.8, genomic selection of bulls directly in the organic population and using selected bulls via AI revealed higher genetic gain than selecting young bulls in the larger conventional population based on EBV; also without the existence of G×E interactions. Only for pronounced G×E interactions (r_g=0.5), and for highly accurate GEBV for natural service bulls (r_mg>0.9), results suggests the use of genotyped organic natural service bulls instead of implementing an AI program. Inbreeding coefficients of selected bulls and their offspring were generally lower when basing selection decisions for young bulls on GEBV compared with selection strategies based on pedigree indices.     

Comparison of performance and fitness traits in German Angler,Swedish Red and Swedish Polled with Holstein dairy cattle breeds under organic production

Although the use of local breeds is recommended by organic regulations, breed comparisons performed under organic production conditions with similar production intensities are scarce. Therefore, we compared data of local and widely used Holstein dairy cattle breeds from 2011 to 2015 regarding production, fertility and health from German and Swedish organic farms with similar management intensities within country. In Germany, the energy-corrected total milk yield tended to be lower in the local breed Original Angler Cattle (AAZ, 5193 kg) compared to the modern German Holstein Friesian breed (HO, 5620 kg), but AAZ showed higher milk fat and protein contents (AAZ v. HO: 5.09% v. 4.18% and 3.61% v. 3.31%, respectively). In Sweden, the widely used modern Swedish Holstein (SH) breed had the highest milk yield (9209 kg, fat: 4.10%, protein: 3.31%), while the local Swedish Polled (SKB) showed highest milk yield, fat and protein contents (6169 kg, 4.47%, 3.50%, respectively), followed by the local breed Swedish Red (SRB, 8283 kg, 4.33%, 3.46%, respectively). With regard to fertility characteristics, the German breeds showed no differences, but AAZ tended to have less days open compared to HO (−17 days). In Sweden, breeds did not differ with regard to calving interval, but both local breeds showed a lower number of days open (−10.4 in SRB and −24.1 in SKB compared to SH), and SKB needed fewer inseminations until conception (−0.5 inseminations) compared to SH. Proportion of test day records with a somatic cell count content of ≥100 000 cells per ml milk did not reveal breed differences in any of the two countries. German breeds did not differ regarding the proportion of cows with veterinary treatments. In Sweden, SRB showed the lowest proportion of cows with general veterinary treatment as well as specific treatment due to udder problems (22.8 ± 6.42 and 8.05 ± 2.18, respectively), but the local breed SKB did not differ from SH in either of the two traits. In Sweden, we found no breed differences regarding veterinary treatments due to fertility problems or diagnosis of claw or leg problems during claw trimming. Our results indicate a stronger expression of the antagonism between production and functional traits with increasing production intensity. Future breed comparisons, therefore, need to consider different production intensities within organic farming in order to derive practical recommendations as to how to implement European organic regulations with regard to a suitable choice of breeds.     

Evaluation of organic,conventional and intensive beef farm systems: health,management and animal production

The overall aim of the present study was to analyse and compare organic beef cattle farming in Spain with intensive and conventional systems. An on-farm study comparing farm management practices and animal health was carried out. The study also focussed on a slaughterhouse analysis by comparing impacts on the safety and quality of the cattle products. Twenty-four organic and 26 conventional farms were inspected, and farmers responded to a questionnaire that covered all basic data on their husbandry practices, farm management, veterinary treatments and reproductive performance during 2007. Furthermore, data on the hygiene and quality of 244, 2596 and 3021 carcasses of calves from organic, intensive and conventional farms, respectively, were retrieved from the official yearbook (2007) of a slaughterhouse. Differences found between organic and conventional farms across the farm analysis did not substantially reflect differences between both farm types in the predominant diseases that usually occur on beef cattle farms. However, calves reared organically presented fewer condemnations at slaughter compared with intensive and to a lesser extent with conventionally reared calves. Carcass performance also reflected differences between farm type and breed and was not necessarily better in organic farms.     

Genetic and environmental effects on secondary sex traits in guppies (Poecilia reticulata)

Male guppies (Poecilia reticulata) exhibit extreme phenotypic and genetic variability for several traits that are important to male fitness, and several lines of evidence suggest that resource level affects phenotypic expression of these traits in nature. We tested the hypothesis that genetic variation for male secondary sex traits could be maintained by genotype-specific effects of variable resource levels (genotype-environment interaction). To do this, we measured genetic variation and covariation under two environmental conditions--relatively low and relatively high food availability. We found high levels of genetic variation for most traits, but we only found a significant G x E interaction across food levels for one trait (body size) for one population. The across-environment correlations for size were large and positive, indicating that the reaction norms for size did not cross. We also found that male colour pattern elements had nearly an order of magnitude more genetic variation than did male size. Heritability estimates indicated that Y-linked genes are responsible for some of the genetic variation in male size and colour traits. We discuss implications of these results for theories of the maintenance of genetic variation in male secondary sexual traits in guppies.     

Weight and season affects androstenone and skatole occurrence in entire male pigs in organic pig production

To investigate the extent to which the level of androstenone and skatole decreases with a decrease in live weight and/or age at slaughter of entire male pigs produced under organic standards, 1174 entire male pigs were raised in parallel in five organic herds, distributed across four batches in summer and winter. The median androstenone level was high for organic entire male pigs (1.9 µg/g), but varied greatly both within and between herds. Median skatole level was 0.05 µg/g, also with a wide range both within and between herds. Decreasing live weight over the range of 110±15.6 kg s.d. was found to decrease androstenone as well as skatole concentration, however, with different patterns of association. Age did not have significant direct effect on either androstenone or skatole levels. Androstenone levels were higher during winter than summer (P<0.0001), but no difference in skatole was found between seasons. The study concludes that decreasing live weight at slaughter could be an applicable management tool to reduce risk of boar taint and the level of tainted carcasses for a future production of entire male pigs within the organic pig production system, although further studies are needed as great variation in boar taint was found also for low weight animals.     

Methods for assessing phosphorus overfeeding on organic and conventional dairy farms

Phosphorus (P) losses from dairy farms can severely damage aquatic ecosystems, so it is important to have tools to assess overfeeding of P. This study screened P intake and faecal excretion of different P fractions in dairy cows on conventional and organic farms, compared the P feeding level of the herds against the recommendations and analysed different sampling and analysis methods for assessing the general status of P feeding on the farms. The organic (n=14) and conventional farms (n=15) were of comparable size and were located in southern Sweden. On each farm, feed intake was registered for 10 cows representing four different lactation stages and their P intake was calculated and related to current recommendations. Faecal samples taken from the same cows were analysed for total P (TP) and soluble P. Milk production data for the cows were obtained from the Swedish official milk recording scheme. TP was determined in one slurry sample per farm. More than 70% of the cows studied, representing both conventional and organic herds, consumed P in excess of the recommendations. Conventional herds had higher P content in the ration than organic herds, and lactating cows in conventional herds had higher faecal concentrations of total and soluble P than those in organic herds. However in dry cows, the P content of the ration and soluble P and TP in faeces did not differ between the two management systems. Soluble P was well correlated to TP in faeces, and both were good indicators of P overfeeding.     

Evidence for the reproductive isolation of Dermacentor marginatus and Dermacentor reticulatus (Acari: Ixodidae) ticks based on cross-breeding, morphology and molecular studies

The species status of Dermacentor marginatus and Dermacentor reticulatus was evaluated by scanning electron microscope (SEM) examination of adult ticks, cross-breeding experiments and molecular biological analysis of eggs derived from transspecific pairings. The SEM investigations including the morphometric quantification of phenotypic features resulted in an unequivocal differentiation of adult D. marginatus and D. reticulatus ticks. The cross-breeding experiments demonstrated that irrespective of whether female ticks of both species were applied with con- or transspecific male ticks or without males to sheep, they engorged and laid eggs. The larvae, however, developed only in eggs which originated from conspecific matings. A nested polymerase chain reaction (PCR) of the second internal transcribed spacer (ITS2) using the DNA of eggs from transspecific pairings and sequencing of the PCR products revealed two different genotypes. The genotypes of eggs originating from D. marginatus and D. reticulatus females of these pairings differed. However, the eggs deposited by D. marginatus always possessed the same two genotypes as did the eggs produced by D. reticulatus. These results argue for a strict reproductive isolation of D. marginatus and D. reticulatus and, therefore, for a separate species status.     

Impact of cow strain and concentrate supplementation on grazing behaviour,milk yield and metabolic state of dairy cows in an organic pasture-based feeding system

As ruminants are able to digest fibre efficiently and assuming that competition for feed v. food use would intensify in the future, cereals and other field crops should primarily be destined to cover the dietary needs of humans and monogastric animals such as poultry and pigs. Farming systems with a reduced or absent concentrate supplementation, as postulated by organic agriculture associations, require adapted dairy cows. The aim of this experiment was to examine the impact of concentrate supplementation on milk production, grazing and rumination behaviour, feed intake, physical activity and blood traits with two Holstein-Friesian cow strains and to conclude the consequences for sustainable and organic farming. The experiment was a cross-over study and took place on an organic farm in Switzerland. In all, 12 Swiss Holstein-Friesian (HCH) cows and 12 New Zealand Holstein-Friesian (HNZ) cows, which were paired according to lactation number, days in milk and age for primiparous cows, were used. All cows grazed full time and were supplemented either with 6 kg/day of a commercial, organic cereal-grain mix or received no supplement. After an adaptation period of 21 days, a measurement period of 7 days followed, where milk yield and composition, pasture dry matter intake estimated with the n-alkane double-indicator technique, physical activity based on pedometer measurements, grazing behaviour recorded by automatic jaw movement recorder and blood samples were investigated. Non-supplemented cows had a lower milk yield and supplemented HCH cows produced more milk than supplemented HNZ cows. Grazing time and physical activity were greater for non-supplemented cows. Supplementation had no effect on rumination behaviour, but HNZ cows spent longer ruminating compared with HCH cows. Pasture dry matter intake decreased with the concentrate supplementation. Results of blood analysis did not indicate a strong negative energy balance for either non-supplemented or supplemented cows. Minor differences between cow strains in this short-term study indicated that both cow strains are equally suited for an organic pasture-based production system with no concentrate supplementation. Many factors such as milk yield potential, animal welfare and health, efficiency, grazing behaviour and social aspects influence the decision to supplement grazing dairy cows with concentrates.     

Breeding Barn Swallows Hirundo rustica on organic and conventional arable farms in the Netherlands

Populations of farmland birds are under pressure as a result of agricultural intensification. It has been proposed that less intensive approaches to farming, such as organic farming methods, may halt these population declines. In addition, organic farmers may have a more positive attitude towards nature and the environment which can possibly also have positive effects on the populations of breeding birds. We have compared the attitude of conventional and organic farmers towards the presence of Barn Swallows Hirundo rustica and the abundance of breeding Barn Swallows on organic and conventional arable farms in the Netherlands. We found that the abundance of breeding Barn Swallows did not differ between these two types of farms an that both organic and conventional farmers had a positive attitude towards the presence of Barn Swallows on their farms. Our results show that organic farming does not attract more Barn Swallows. However, agricultural intensification could have resulted in lower breeding success and, consequently, population declines, although there may be other contributory factors as well.     

基于知识图谱的植物功能性状与环境研究前沿态势分析

为系统了解国际上植物功能性状与环境的研究进展,该研究基于Web of Science数据来源,采用Web of Science数据库分析工具和Thomson Data Analysis(TDA)进行数据清理和统计分析,并利用Ucinet和Netdraw、Excel等软件进行可视化作图。结果表明:(1)近26年来,植物功能性状与环境研究论文数量呈持续稳步增长态势,尤其近9年来呈加速增长态势。(2)近9年来,研究主题主要围绕比叶面积、叶面积(指数)、光合作用(性能)、叶厚度、叶形态、叶氮含量、叶绿素、叶绿素荧光、比根长等功能指标,及光照、温度、水(水分利用效率、干旱等)、肥(氮、磷为主)、CO2等环境因子展开;化学计量学在该领域应用广泛。(3)2009—2017年间,欧美等发达国家是该领域研究的主要力量。美国发文数量和文献质量均为世界领先。中国在该领域的发文量居第二位,仅次于美国,但文献篇均被引和H指数较低。中国科学院发文量以绝对优势居第一位,但文献质量有待进一步提升。(4)该领域载文量Top10期刊8种为JCR分区Q1区、2种为Q2区。其中,Plant and Soil和Plant Ecology载文量分居第一位和第二位。(5) Top10高被引论文发表于8种期刊,其第一作者分别来自美国、荷兰、加拿大、德国和法国。     

Review: Towards the agroecological management of ruminants,pigs and poultry through the development of sustainable breeding programmes: I-selection goals and criteria

Agroecology uses natural processes and local resources rather than chemical inputs to ensure production while limiting the environmental footprint of livestock and crop production systems. Selecting to achieve a maximization of target production criteria has long proved detrimental to fitness traits. However, since the 1990s, developments in animal breeding have also focussed on animal robustness by balancing production and functional traits within overall breeding goals. We discuss here how an agroecological perspective should further shift breeding goals towards functional traits rather than production traits. Breeding for robustness aims to promote individual adaptive capacities by considering diverse selection criteria which include reproduction, animal health and welfare, and adaptation to rough feed resources, a warm climate or fluctuating environmental conditions. It requires the consideration of genotype×environment interactions in the prediction of breeding values. Animal performance must be evaluated in low-input systems in order to select those animals that are adapted to limiting conditions, including feed and water availability, climate variations and diseases. Finally, we argue that there is no single agroecological animal type, but animals with a variety of profiles that can meet the expectations of agroecology. The standardization of both animals and breeding conditions indeed appears contradictory to the agroecological paradigm that calls for an adaptation of animals to local opportunities and constraints in weakly artificialized systems tied to their physical environment.     

The effectiveness of volunteer nest protection on the nest success of Northern Lapwings Vanellus vanellus on Dutch arable farms

Clutches of ground‐nesting farmland birds are often destroyed by farming operations, resulting in insufficient reproductive success and subsequently declining populations. The aim of this study was to investigate whether volunteer nest protection can enhance nest success of ground‐nesting birds. The study compared nest success of protected and unprotected Northern Lapwing Vanellus vanellus nests over 2 years on arable farms in the Netherlands. Because of different crop management, nest success of ground‐breeding birds might differ between organic and conventional arable farms. The effectiveness of volunteer nest protection was therefore investigated on both farm types. Although nest protection significantly reduced nest loss due to farming operations, there were no significant differences in total clutch survival of protected and unprotected nests. However, sample sizes of unprotected nests, and protected nests on organic farms, were relatively small, which may have reduced statistical power. There were indications that protected nests were predated or deserted more often. We recommend exploring different ways to improve the effectiveness of volunteer nest protection through a further reduction of nest loss due to farming operations and predation.     

Impact of production strategies and animal performance on economic values of dairy sheep traits

The objective of this study was to carry out a sensitivity analysis on the impact of various production strategies and performance levels on the relative economic values (REVs) of traits in dairy sheep. A bio-economic model implemented in the program package ECOWEIGHT was used to simulate the profit function for a semi-extensive production system with the Slovak multi-purpose breed Improved Valachian and to calculate the REV of 14 production and functional traits. The following production strategies were analysed: differing proportions of milk processed to cheese, customary weaning and early weaning of lambs with immediate sale or sale after artificial rearing, seasonal lambing in winter and aseasonal lambing in autumn. Results of the sensitivity analysis are presented in detail for the four economically most important traits: 150 days milk yield, conception rate of ewes, litter size and ewe productive lifetime. Impacts of the differences in the mean value of each of these four traits on REVs of all other traits were also examined. Simulated changes in the production circumstances had a higher impact on the REV for milk yield than on REVs of the other traits investigated. The proportion of milk processed to cheese, weaning management strategy for lambs and level of milk yield were the main factors influencing the REV of milk yield. The REVs for conception rate of ewes were highly sensitive to the current mean level of the trait. The REV of ewe productive lifetime was most sensitive to variation in ewe conception rate, and the REV of litter size was most affected by weaning strategy for lambs. On the basis of the results of sensitivity analyses, it is recommended that economic values of traits for the overall breeding objective for dairy sheep be calculated as the weighted average of the economic values obtained for the most common production strategies of Slovak dairy sheep farms and that economic values be adjusted after substantial changes in performance levels of the traits.     

有机肥对羊草营养生长期功能性状变化的影响

本文研究不同有机肥水平下羊草（Leymus chinensis）营养生长期功能性状的变化规律、响应机制及其相关性的变化,试图为资源环境与植物功能性状的动态研究和草地生态系统的恢复提供参考。结果显示：（1）有机肥会使羊草叶长、叶面为了探讨不同有机肥施用水平下羊草（Leymus chinensis）营养生长期功能性状的变化规律、响应机制及其相关性的变化,为资源环境与植物功能性状的动态研究和草地生态系统的恢复提供参考。选择中国农业科学院呼伦贝尔草原生态系统国家野外科学观测研究站附近,割草利用超过20 a未施用过肥料的固定草场作为试验场地,围封并划分若干小区,设置对照以及低、中、高4个有机肥施用水平（有N效养分用量分别为0、 63、127和 190 kg/hm2）,在羊草主要营养生长的前、中、后期采集样品,测定相关功能性状。分别采用二次曲线方程拟合、单因素多元方差分析、Pearson相关分析和积分（逐步）回归等方法分析羊草功能性状的变化趋势、差异性、相关性及影响系数。结果显示：（1）有机肥会使羊草叶长、叶面积、自然叶宽、展开叶宽、比叶面积、茎长、茎质量、株高由先升后降的变化趋势变为逐渐增加的趋势,同时使叶干物质含量和茎干物质含量有所下降;（2）有机肥会改变羊草功能性状之间的相关性,增强叶面积与比叶面积、茎长与茎质量、茎长与单株质量的相关性,降低叶质量与单株质量、叶宽与株高的相关性;（3）有机肥会改变羊草表型性状（叶、茎、株高）对单株质量的贡献率,随施肥水平的提高,叶、茎、株高的贡献率逐渐趋于均衡。羊草表型性状影响单株质量的大小顺序为叶性状＞株高＞茎性状。研究发现,短期施用有机肥对羊草功能性状变化影响显著,且作用效果主要发生在羊草营养生长后期,尤其对单株质量提升效果显著。叶长、展开叶宽、叶面积、株高对羊草单株质量影响较大,其中株高是驱动羊草单株质量变化的最稳定因子。同时,羊草功能性状之间的相关性也受施肥水平的影响,施肥在增强部分功能性状相关性的同时减弱了其他性状之间的相关性,整体存在着一定的平衡。     

从事有机农业对农民福祉的影响

从事有机农业的农民福祉得到改善是有机农业发展的前提条件。采用Narayan等提出的福祉框架,回顾了有关有机农业行为和支持该行为的公共部门措施对农民福祉影响研究的文献,以厘清从事有机农业与农民福祉间的关系。研究表明,农民有机农业行为对其收入、健康、社会关系、安全和自由与选择等福祉要素产生影响。收入是农民福祉的首要构成要素,但农民有机农业行为究竟是增加还是降低其收入,需要考察具体情境中产量、成本和价格的综合作用,没有一致性结论。农民有机农业行为对其社会关系的影响具有双向性,但它对他们的健康、安全和选择机会的影响是积极的。公共部门通过财政支付、支持合作、建立与完善有机认证制度和采购绿色化等措施支持有机农业,有助于改善有机农民的福祉。其中,财政支付是最重要的支持措施。研究认为不同情境的农民有机农业行为对其福祉影响的综合评价、农民有机农业行为与其福祉间因果关系的检验和公共部门有机农业政策对有机农民福祉贡献的检验,是今后研究的重要选题。