Heterosis effects in a black and white dairy cattle population under different production environments

The effect of the environmental level of production (ENV) on the expression of heterosis for 305-day milk, fat, protein, and fat plus protein (FP) yields, lactation average somatic cell score (LSCS), and age at first calving (AFC) was investigated in first lactation Black and White dairy cows in the Netherlands, and officially enrolled in the Dutch herd-book. Holstein Friesian (HF), Dutch Friesian (DF), and first generation (F₁) crosses obtained from the mating of HF sires and DF dams (HD) were involved in the study, and data from animals with a calving date between 1990 and 2000 were used. A total of 22,930 cows with production and AFC information distributed in 3549 herds and 11,055 cows with LSCS information distributed in 2071 herds, were available. Adjusted lactation yield of milk for each herd was obtained using a model that accounted for fixed effects of herd, year and month of calving, genotype, and AFC. The overall mean of all adjusted data was computed, and 3 ENV were defined on the basis of the overall mean ± 0.5 standard deviations. Once ENV was defined, traits were analysed with a model that included fixed effects of ENV, herd nested within ENV, AFC (only production traits and LSCS), year and month of calving, genotype, and the interaction between ENV and genotype. Least squares means for the interaction effect were used to estimate heterosis and to evaluate its magnitude across ENV. Holstein Friesian achieved higher productions than DF. First generation crosses showed productions close to HF, especially in the low ENV. Estimates of heterosis for yield traits ranged from 2.4% (milk) in the high to 5.3% (fat) in the low ENV, and reduced with increasing ENV. Estimates for LSCS and AFC were low, with the exception of LSCS in the high ENV. Results suggest that the highest non-additive genetic effects for yield traits and LSCS were expressed in the most stressful ENV, i.e., the low one for production and the high one for LSCS.     

Starch granule size distribution of hard red winter and hard red spring wheat: Its effects on mixing and breadmaking quality

Starch was isolated from 98 hard red winter (HRW) wheat and 99 hard red spring (HRS) wheats. Granule size/volume distributions of the isolated starches were analyzed using a laser diffraction particle size analyzer. There were significant differences in the size distribution between HRW and HRS wheats. The B-granules (<10 μm in diameter) occupied volumes in the range 28.5–49.1% (mean, 39.9%) for HRW wheat, while HRS wheat B-granules occupied volumes in the range 37.1–56.2% (mean, 47.3%). The mean granule sizes of the distribution peaks less than 10 μm in diameter also showed a significant difference (HRW, 4.32 vs. HRS, 4.49 μm), but the mean sizes of the distribution peaks larger than 10 μm were not significantly different (21.54 vs. 21.47 μm). Numerous wheat and flour quality traits also showed significant correlation to starch granule size distributions. Most notably, protein content was inversely correlated with parameters of B-granules. Crumb grain score appeared to be affected by starch granule size distribution, showing significant inverse correlations with B-granules. Furthermore, the linear correlations were improved when the ratio of B-granules to protein content was used, and the polynomial relation was applied. There also appeared to be an optimum range of B-granules for different protein content flour to produce bread with better crumb grain.     

Effect of nitrogen and potassium fertilization on mineral and amino acid content of colored flesh potato cultivar Blue Congo

The purpose of this study was to determine optimum rates of soil dressing with nitrogen (N) and potassium (K) fertilization in the cultivation of potato with purple–blue peel and flesh, affecting the qualitative composition of tubers of a less known potato cultivar called Blue Congo.

The experimental results proved that the optimum rates of fertilizers applied to soil for the cultivar Blue Congo are 80 kg N ha^?1 and 150 kg K ha^?1. Application of 120 kg N ha^?1 caused a decrease in the content of all macro- and micro-nutrients. In contrast, the content of all macronutrients was observed to increase up to the rate of 150 kg K ha^?1.

Micronutrients responded to the increase in the K rate in different ways. No effect of the differentiated rates of K was noted in the case of iron. Vitamin C responded by its lower content to the increased rates of both N and K. It was determined that isoleucine was the limiting amino acid for the cv. Blue Congo potato. The highest level of isoleucine was found at the N rate of 80 kg ha^?1.     

不同填料对纤维素丝力学及热稳定性能的影响

以微晶纤维素、N,N-二甲基乙酰胺(DMAc)、无水氯化锂(Li Cl)为原料制备纤维素凝胶。为探究不同填料对纤维素丝力学及热稳定性能的影响,通过加入氧化石墨烯(GO)、纳米纤维素(NCC)、无水氯化钙(Ca Cl2)等对其进行补强,并将其制备成纤维素丝。用万能试验机、热重分析(TGA)分别对纤维素丝力学性能及热稳定性能进行研究;用红外光谱、原子力显微镜等分析方法对其结构进行表征。结果表明,GO、Ca Cl2和NCC等填料可以增强纤维素丝的力学强度,但GO和NCC会使纤维素丝的热稳定性能稍有降低。其中采用无水Ca Cl2补强纤维素丝的性能最为优越。此时的纤维素丝表面光滑,存在的缺陷少,其拉伸强度和断裂伸长率分别为125.2 MPa、6.3%。     

党参产地加工方法对有效成分的影响

为优选出党参的产地加工方法,以多糖、党参炔苷、醇溶性浸出物和水溶性浸出物为考察指标,采用综合评分法对党参产地加工方法进行研究。结果表明:清洗、白矾浸润、干燥、失重发汗方式及揉搓次数均对党参主要化学成分有显著影响。其中,清洗以1倍水量抢水清洗为佳、白矾浸润以1%用量浸润5min最佳、干燥以阴干法最佳、发汗方式以晾晒至失重60%发汗3d最佳、揉搓次数以1次最佳,其综合评分分别为0.797分、0.522分、0.700分、0.692分和0.601分。     

壳聚糖对断奶仔猪生长性能、粪便评分及血清激素和T淋巴细胞亚群的影响

本试验旨在研究壳聚糖对断奶仔猪生长性能、粪便评分及血清激素和T淋巴细胞亚群的影响。选取28日龄断奶的杜×大×长三元杂交仔猪60头,随机分为5组(每组12头):对照组饲喂基础饲粮,试验组分别饲喂在基础饲粮中添加250、500、1 000和2 000 mg/kg壳聚糖的试验饲粮。试验期14 d。结果表明:1)饲粮添加250~2 000 mg/kg壳聚糖显著提高断奶仔猪的平均日增重(ADG)(P0.05),显著降低料重比(F/G)(P0.05);2)饲粮添加250~2 000 mg/kg壳聚糖显著降低试验第11天断奶仔猪的粪便评分(P0.05);3)饲粮添加适宜剂量的壳聚糖显著提高断奶仔猪的血清促生长激素释放激素(GHRH)(250~2 000 mg/kg)、生长激素(GH)(500~1 000 mg/kg)和瘦素(LP)(2 000 mg/kg)的浓度(P0.05),显著降低血清促肾上腺皮质激素释放激素(CRH)(250~2 000 mg/kg)、促肾上腺皮质激素(ACTH)(500~1 000 mg/kg)、皮质醇(COR)(250~2 000 mg/kg)和可溶性CD8(sCD8)(500~2 000 mg/kg)的浓度(P0.05)。由此可见,饲粮中添加适宜剂量的壳聚糖能够促进断奶仔猪的生长,降低腹泻,缓解断奶应激。     

Ultraviolet resistance and other physical properties of softwood polymer nanocomposites reinforced with ZnO nanoparticles and nanoclay

Wood polymer nanocomposites (WPNCs) based on nano-ZnO and nanoclay were prepared by impregnation of melamine formaldehyde–furfuryl alcohol copolymer, 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU), a cross-linking agent and a renewable polymer obtained as a gum from the plant Moringa oleifera under vacuum condition. Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD) studies were employed for the characterization of modified ZnO and WPNCs. The change in crystallinity index (CrI) value of the cellulose in wood and the distribution of ZnO nanoparticles in composites were determined using FTIR and XRD. Scanning electron microscopy and Transmission electron microscopy showed the presence of nanoparticles and nanoclay in the cell lumen or cell wall of wood. An enhanced UV resistance property was shown by the treated wood samples as judged by lower weight loss, carbonyl index, lignin index, cellulose CrI values, and mechanical property loss compared to the untreated wood samples. Wood polymer composites treated with 3 phr each of nanoclay, ZnO, and the plant gum showed an improvement in mechanical properties, flame-retarding properties, thermal stability, and lower water uptake capacity.     

Agroforestry Practices among Male and Female Farmers in South–South, Nigeria

Perceptions of the benefits of agroforestry practices (AFPs) and the level of utilization of these practices by male and female participants were examined in the agroforestry programs of the Akwa Ibom and Cross River State Governments of the South–South region of Nigeria. Responses were derived from 250 randomly selected respondents. Overall, respondents perceived the major benefit of agroforestry practices as enhancement of environmental conservation. Female respondents however perceived increased income as the major benefit of agroforestry practices. A composite perception index revealed that women farmers were more favourably disposed than male respondents to the utilization of agroforestry practices. The farmers were favourably disposed to the utilization of only five of the 16 identified AFPs in the study area, including ‘leaving of isolated woody trees on farmlands’, ‘utilizing woody trees as windbreaks’ and to ‘demarcate farm boundaries’, ‘planting of woody trees in combination with fruit trees’, and ‘planting of woody trees in combination with vegetable crops’. Male and female responses were generally similar although a major difference was observed with regard to ‘planting of trees for fuel wood’. The composite index, however, revealed a general low level of utilization of AFPs, although female farmers were relatively more disposed to the utilization of AFPs. The key policy implication of the study is the necessity to embark on sustained education and environmental awareness campaign, with a focus on presenting AFPs as livelihood sustaining and risk mitigation activities, against its present misperception as simply a government strategy to increase the stock of woody trees in the environment. This policy should endeavour to target landless women farmers who have been found to be more interested in the adoption of AFPs into their farming system.     

Refined mapping of quantitative trait loci for somatic cell score on BTA02 in the German Holstein

The aim of this study was to more precisely map a previously reported quantitative trait locus (QTL) affecting somatic cell score on Bos taurus autosome 2 by increasing the number of markers fourfold, analysing more families and exploiting within‐population linkage disequilibrium (LD). A granddaughter design of 10 German Holstein grandsire families with 1121 progeny tested sons was used. Twenty‐six markers with an average marker spacing of 3.14 cM were genotyped along 81.6 cM. Linkage analysis (LA) was performed using variance‐component methodology. The incorporation of LD was first done using variance‐component methods followed by regression on marker alleles. LA revealed genome‐wide significance (LOD > 3) at 15 contiguous marker‐intervals, with the maximum test‐statistic between DIK2862 and BMS778 and a 1‐lod drop‐off interval of 38 cM. While the variance‐component methods could not detect any LD, two individual markers with a significant effect (ILSTS098, p < 0.05; BMS778, p < 0.01) were found by regression analysis. Compared with previous results QTL‐localisation was substantially narrowed; further fine‐mapping should focus on the close vicinity of BMS778.     

Illness Severity Scores in Veterinary Medicine: What Can We Learn?

Illness severity scores are gaining increasing popularity in veterinary medicine. This article discusses their applications in both clinical medicine and research, reviews the caveats pertaining to their use, and discusses some of the issues that arise in appropriate construction of a score. Illness severity scores can be used to decrease bias and confounding and add important contextual information to research by providing a quantitative and objective measure of patient illness. In addition, illness severity scores can be used to benchmark performance, and establish protocols for triage and therapeutic management. Many diagnosis‐specific and diagnosis‐independent veterinary scores have been developed in recent years. Although score use in veterinary research is increasing, the scores available are currently underutilized, particularly in the context of observational studies. Analysis of treatment effect while controlling for illness severity by an objective measure can improve the validity of the conclusions of observational studies. In randomized trials, illness severity scores can be used to demonstrate effective randomization, which is of particular utility when group sizes are small. The quality of veterinary scoring systems can be improved by prospective multicenter validation. The prevalence of euthanasia in companion animal medicine poses a unique challenge to scores based on a mortality outcome.