A novel method for the estimation of the relative importance of breeds in order to conserve the total genetic variance

The need for conservation of farm animal genetic resources is widely accepted. A key question is the choice of breeds to be conserved. For this purpose, a core set of breeds was introduced in that the total genetic variance of a hypothetical quantitative trait was maximised (MVT core set). For each breed the relative contribution to the core set was estimated and the breeds were ranked for conservation priority according to their relative contribution. The method was based on average kinships between and within breeds and these can be estimated using genetic marker data. The method was compared to a recently published core set method that maximises the variance of a hypothetical population that could be obtained by interbreeding the conserved breeds (MVO core set). The results show that the MVT (MVO) core set favours breeds with a high (low) within breed kinship that are not related to other breeds. Following this, the MVT core set method suggests conserving breeds that show a large difference in the respective population mean of a hypothetical quantitative trait. This maximises the speed of achieving selection response for this hypothetical selection direction. Additionally, bootstrap based methods for the estimation of the breed''s contribution to the core sets were introduced, substantially improving the accuracy of the contribution estimates.     

基于国家生态足迹账户的海陆养殖产品研究

海陆养殖产品是人类蛋白质营养摄取的重要来源, 而生态足迹是评价评估人类在获取蛋白质对地球生态系统和环境的影响的重要方法。本文运用国家生态足迹账户分析法核算了我国海水养殖产品和畜牧业产品2009—2014年的生态足迹及2014年的单位蛋白质生态系数。结果表明: 2009—2014年我国海水养殖产品中扇贝的人均生态足迹最高, 从0.0005 hm2增长到0.0007 hm2; 2009—2014年畜牧产品中猪肉的人均生态足迹最高, 从1.2 hm2增长到1.4 hm2; 畜牧产品的人均生态足迹普遍高于海水养殖产品, 畜牧产品人均所需的生物生产性面积是海水养殖产品的2000倍; 由2014年的单位蛋白质生态系数核算得知, 畜牧产品的平均单位蛋白质生态系数为0.1381 hm2•kg–1, 其中羊肉的蛋白质生态系数最高, 达到0.1595 hm2•kg–1, 海水养殖产品的平均单位蛋白质生态系数为0.0020 hm2•kg–1, 其中海水鱼的单位蛋白质系数仅为0.0004 hm2•kg–1。因而在获取同等条件的蛋白质营养供给时, 我们可以优先考虑海水养殖产品, 这样既能改善国民蛋白质营养供给结构, 又能降低生态环境的生态负荷, 同时也是我们发展海洋经济、经略海洋的节点。     

A decision-tree model to detect post-calving diseases based on rumination,activity, milk yield,BW and voluntary visits to the milking robot

Early detection of post-calving health problems is critical for dairy operations. Separating sick cows from the herd is important, especially in robotic-milking dairy farms, where searching for a sick cow can disturb the other cows’ routine. The objectives of this study were to develop and apply a behaviour- and performance-based health-detection model to post-calving cows in a robotic-milking dairy farm, with the aim of detecting sick cows based on available commercial sensors. The study was conducted in an Israeli robotic-milking dairy farm with 250 Israeli-Holstein cows. All cows were equipped with rumination- and neck-activity sensors. Milk yield, visits to the milking robot and BW were recorded in the milking robot. A decision-tree model was developed on a calibration data set (historical data of the 10 months before the study) and was validated on the new data set. The decision model generated a probability of being sick for each cow. The model was applied once a week just before the veterinarian performed the weekly routine post-calving health check. The veterinarian’s diagnosis served as a binary reference for the model (healthy–sick). The overall accuracy of the model was 78%, with a specificity of 87% and a sensitivity of 69%, suggesting its practical value.     

Hydroponic method for ramie and removal of nitrogen and phosphorus from livestock wastewater

By using a hydroponic culture system, the terrestrial fiber crop ramie can growth optimally in aquatic environment and enhance exponentially quantities of high quality seedlings for subsequent field cultivation. In this study, the survival rate of ramie seedling was more than 97% when cultured using the novel hydroponic method. Further physiological analysis of the hydroponic ramie to different concentration of livestock wastewater demonstrated that all of these ramies can survival in livestock wastewater, but the 4 times diluted livestock wastewater (total N: 100.9 mg L^?1, total P: 2.69 mg L^?1) was more appropriate for ramie growth. The nutrients N and P in livestock wastewater were significantly decreased by the growth of ramie, and the removal efficiency of total N and total P in the 4 times diluted livestock wastewater achieved 78.1% and 43.1% respectively within 5 weeks. In conclusion, our studies highlight that the combination of ramie and the hydroponic technology resulted to be effective in the phytoremediation of livestock wastewater.     

Livestock exclusion alters plant species composition in fen meadows

Questions

Our study evaluated how species composition and plant traits that indicate functioning condition in fens responded to grazing cessation over time in an arid ecosystem of the western US. The specific questions addressed were: (i) how does livestock exclusion influence species composition in fens; (ii) is grazing cessation associated with shifts in species functional traits that indicate fen condition; and (iii) what is the pattern of response to livestock exclusion over time?

Location

Plumas National Forest, California, US.

Methods

We studied paired fenced and unfenced study sites in two fens to examine the effects of livestock exclusion. Parallel transects were established at each site, and plant species and ground cover were repeatedly surveyed, once prior to and multiple times following treatment, using 0.01 m² frequency frames. We used NMDS to analyse species composition, RLQ and fourth‐corner analysis to evaluate species functional traits and environmental variables, and linear mixed effects models to examine differences in responses between fenced and unfenced study sites over time.

Results

After fencing, we observed unexpected shifts in species composition and plant functional traits. Grazed sites were associated with peat‐forming obligate wetland, moss and sedge species, while fenced sites were characterized by non‐peat‐forming facultative upland, and upland forb, grass and early seral species. Species composition also varied between sites and sample years.

Conclusions

We found that livestock exclusion strongly affects plant species composition in fens, including promoting species with functional traits that indicate a loss of functioning condition, such as ruderal and upland species. Possible explanations for these observed shifts include: (1) biomass accumulation in the absence of herbivory, (2) competitive exclusion in fenced sites, (3) succession, (4) the abiotic conditions of our study sites, particularly hydrology and nutrient status, and (5) interactions among these factors. We conclude that degradation of fen wetlands caused by livestock grazing in the arid western US may not be reversed by excluding livestock alone.     

Introduced and native herbivores have different effects on plant composition in low productivity ecosystems

Questions

Understanding how livestock grazing alters plant composition in low productivity environments is critical to managing livestock sustainably alongside native and introduced wild herbivore populations. We asked four questions: (1) does recent livestock and rabbit grazing reduce some plant attributes more strongly than others; (2) does grazing by introduced herbivores (i.e. livestock and rabbits) affect plants more strongly than native herbivores (i.e. kangaroos); (3) do the effects of recent livestock grazing differ from the legacy effects of livestock grazing; and (4) does the probability of occurrence of exotic plants increase with increasing net primary productivity (NPP)?

Location

South‐eastern Australia.

Methods

We measured the recent grazing activity of co‐occurring livestock (cattle, sheep, goats), rabbits and kangaroos by counting faecal pellets; historic grazing activity by measuring livestock tracks; and derived NPP from satellite imagery. We used a hierarchical GLMM to simultaneously model the presence or absence (i.e. probability of occurrence) of all plant species as a function of their attributes (growth form, lifespan and origin) to assess their average response to recent grazing, historic grazing and productivity in a broad‐scale regional study.

Results

Recent and historic livestock grazing, rabbit grazing and increasing NPP reduced the average probability of occurrence of plant species, although responses varied among plant attributes. Both recent and historic livestock grazing strongly reduced the average probability of occurrence of native species, and forbs and geophytes, but differed in their relative effects on other growth forms. Recent livestock grazing, rabbit grazing and NPP had similar effects, strongly reducing native species and forbs, geophytes, shrubs and sub‐shrubs. The overall effects of recent kangaroo grazing were relatively weak, with no clear trends for any given plant attribute.

Conclusion

Our results highlight the complex nature of grazing by introduced herbivores compared with native herbivores on different plant attributes. Land managers need to be aware that domestic European livestock, rabbits and other free‐ranging introduced livestock such as goats have detrimental impacts on native plant communities. Our results also show that kangaroo grazing has a relatively benign effect on plant occurrence.     

The impact of livestock grazing on the spatial pattern of vegetation in north-eastern Patagonia,Argentina

Background: The occurrence of shrub patches, alternating with either bare soil or low herbaceous cover, is a common feature in arid and semi-arid shrublands throughout the world. This patchy pattern of vegetation may result from water limitation, modulated by plant interactions; grazing (offtake and tramping) by livestock may cause further patchiness vegetation structure.

Aims: We hypothesised that vegetation patchiness in the semi-arid shrublands of north-eastern Patagonia would be increased by livestock grazing, but not by positive interactions between adult plants of shrubs and grasses.

Methods: We compared vegetation cover and pattern at three grazing intensities (exclosure, light and heavy grazing) and measured the growth of a representative shrub and grass in the presence and absence of the other to quantify the role of plant-to-plant interactions and its interaction with grazing for vegetation structure.

Results: In the grazing exclosure and in moderately grazed areas, vegetation cover among shrub patches was larger, whereas the top cover of shrubs was lower than in the heavily grazed areas. We did not find any evidence of positive interactions between shrub and grass life forms.

Conclusions: Our results were consistent with the hypothesis that livestock grazing increased the formation of patchy vegetation cover in arid and semi-arid shrublands.     

Latency in response of barn swallow Hirundo rustica populations to changes in breeding habitat conditions

Inclusion of past, in addition to current ecological conditions can improve the realism of animal‐habitat models, because populations may show delayed responses to changing environments. We studied the relationships between the distribution of barn swallows (Hirundo rustica L.) in 2001 and ecological factors between 1986 and 2001. Livestock farming was the best predictor of swallow distribution. Maximum predictive power of swallow abundance was achieved by livestock farming data 7 years before the census and significantly earlier than 2001, as shown by a bootstrap analysis. Breeding philopatry, social facilitation of breeding habitat choice may delay response of barn swallow populations to rapidly changing ecological conditions in anthropogenic habitats. By bootstrapping the set of farms and applying our predictive distribution models to livestock farming data in the past and those predicted for the near future we forecast no significant change in swallow populations until 2015. This study suggests that population studies should incorporate historical ecological data.     

Nitrogen and carbon isotope responses of Chinese cabbage and chrysanthemum to the application of liquid pig manure

The effects of the liquid pig manure (LM) used in organic farming on the natural abundance of ¹⁵N and ¹³C signatures in plant tissues have not been studied. We hypothesized that application of LM will (1) increase δ¹⁵N of plant tissues due to the high δ¹⁵N of N in LM as compared with soil N or inorganic fertilizer N, and (2) increase δ¹³C of plant tissues as a result of high salt concentration in LM that decreases stomatal conductance of plants. To test these hypotheses, variations in the δ¹⁵N and δ¹³C of Chinese cabbage (Brassica campestris L.) and chrysanthemum (Chrysanthemum morifolium Ramatuelle) with two different LMs (with δ¹⁵N of +15.6 and +18.2‰) applied at two rates (323 and 646 kg N ha^-1 for cabbage and 150 and 300 kg N ha^-1 for chrysanthemum), or urea (δ¹⁵N = -2.7‰) applied at the lower rate above for the respective species, in addition to the control (no N input) were investigated through a 60-day pot experiment. Application of LM significantly increased plant tissue δ¹⁵N (range +9.4 to +14.9‰) over the urea (+3.2 to +3.3‰) or control (+6.8 to 7.7‰) treatments regardless of plant species, strongly reflecting the δ¹⁵N of the N source. Plant tissue δ¹³C were not affected by the treatments for cabbage (range −30.8 to −30.2‰) or chrysanthemum (−27.3 to −26.8‰). However, cabbage dry matter production decreased while its δ¹³C increased with increasing rate of LM application or increasing soil salinity (P < 0.05), suggesting that salinity stress caused by high rate of LM application likely decreased stomatal conductance and limited growth of cabbage. Our study expanded the use of the δ¹⁵N technique in N source (organic vs. synthetic fertilizer) identification and suggested that plant tissue δ¹³C maybe a sensitive indicator of plant response to salinity stress caused by high LM application rates.