Utility of pearl millet landraces in breeding dual-purpose hybrids for arid zone environments of India

In pearl millet (Pennisetum glaucum (L.) R. Br.), single cross hybrids based largely on exotic germplasm, have found very limited adoption in drought-prone arid regions mainly due to their inadequate adaptation to prevalent extremely harsh agro-climatic conditions. This study tested the hypothesis that the use of restorer parents derived from adapted landrace germplasm could be an alternative strategy in developing suitable hybrids for arid regions. Forty inbred restorer lines developed from two phenotypically diverse landraces were used to develop hybrids evaluated in this study for their performance in five typical arid zone environments between 2003 and 2007. Inbred lines from both landrace populations differed significantly in their combining ability for biomass, harvest index and grain and stover yields. A larger proportion of experimental hybrids, based on selected inbred lines, significantly outperformed the commercial checks for grain and stover yields. Increase in grain and stover yields was achieved primarily due to their higher biomass productivity, with no decline in harvest index. Choice of landrace determined the relative grain and stover productivity of their hybrids. Phenotypic differences observed in parental landraces in tillering and panicle length were also visible in their respective hybrids, indicating that characteristics of landrace parental populations were transmitted in their hybrids.     

Impact of reader antenna polarisation, distance, inlay design, conveyor speed, tag location and orientation on the coupling of UHF RFID as applied to modified atmosphere packaged meat

Undetected RFID tags make the potential benefits of RFID unattainable. This study aimed to determine the most significant factors that affect RFID and particularly its application to the traceability of meat. Experimental parameters included five RFID tag inlays, two levels of conveyor speeds, five variations of beef sample and an empty container, 12 tags per test sample, three distances and two types of reader antenna polarisations. Tag detection rates were determined in three replicates per combination of test parameters. A GLM ANOVA was carried out on tag detection rate. In decreasing order of significance in terms of the effect on mean tag detection rate were distance, sample, inlay design, conveyor speed and reader antenna polarisation. Interaction of these factors also proved significant, in decreasing order of importance were reader antenna * inlay, sample type * distance, inlay * distance, sample type * inlay, sample type * reader antenna, distance * speed, sample type * speed and finally sample type * distance * speed. Linearly polarised antenna preformed better overall at detecting tags, with 63% mean detection rate compared with circularly polarised antenna with 57% mean detection rate. Varying the tag inlay resulted in mean detection rates of between 62% and 88%. Ideal transponder location on package was reader antenna polarisation dependent, but generally tags facing reader antennas exhibited better detection rate. Results revealed that the under side of the package was the most un-detectable transponder location, considering the placement of reader antennas on top, left and right sides of the sample. Conveyor speed also proved significant with a variation from 0.5 to 1.0 m/s resulting in an average detection rate ranging from 62% to 57%, respectively. Circularly polarised antennas are believed to perform better in cases of random tag orientation on products. It can be concluded that RFID systems implementation in the meat supply chain requires a holistic approach where distances, polarisations, inlay type, meat composition and conveyor speed need to be considered.     

n-3 LC-PUFA deposition efficiency and appetite-regulating hormones are modulated by the dietary lipid source during rainbow trout grow-out and finishing periods

Largely attributable to concerns surrounding sustainability, the utilisation of omega-3 long-chain polyunsaturated fatty acid-rich (n-3 LC-PUFA) fish oils in aquafeeds for farmed fish species is an increasingly concerning issue. Therefore, strategies to maximise the deposition efficiency of these key health beneficial fatty acids are being investigated. The present study examined the effects of four vegetable-based dietary lipid sources (linseed, olive, palm and sunflower oil) on the deposition efficiency of n-3 LC-PUFA and the circulating blood plasma concentrations of the appetite-regulating hormones, leptin and ghrelin, during the grow-out and finishing phases in rainbow trout culture. Minimal detrimental effects were noted in fish performance; however, major modifications were apparent in tissue fatty acid compositions, which generally reflected that of the diet. These modifications diminished somewhat following the fish oil finishing phase, but longer-lasting effects remained evident. The fatty acid composition of the alternative oils was demonstrated to have a modulatory effect on the deposition efficiency of n-3 LC-PUFA and on the key endocrine hormones involved in appetite regulation, growth and feed intake during both the grow-out and finishing phases. In particular, n-6 PUFA (sunflower oil diet) appeared to ‘spare’ the catabolism of n-3 LC-PUFA and, as such, resulted in the highest retention of these fatty acids, ultimately highlighting new nutritional approaches to maximise the maintenance of the qualitative benefits of fish oils when they are used in feeds for aquaculture species.     

Crop loss and control of Pseudocercospora fruit and leaf spot of citrus in Ghana

Pseudocercospora fruit and leaf spot (PFLS) of citrus, caused by Pseudocercospora angolensis, was recently described in Ghana and has spread in most citrus-growing areas of the country. A survey of PFLS incidence was conducted in the Eastern Region. Orchards were georeferenced and data on altitude, annual mean temperature, and annual precipitation were obtained from the WorldClim database. Fruit drop due to PFLS and other pests and diseases was evaluated in three orchards. Field efficacies of 4-week, 6-week and 8-week schedules with carbendazim + mancozeb were evaluated in the major and minor fruit production seasons. Ordinal logistic regression and generalized linear models were fitted in each case according to the nature of the data and possible overdispersion. Disease incidence in the sweet orange orchards surveyed was 25–100 %, with higher values in higher altitude areas exposed to lower temperatures and higher rainfall. PFLS was the main problem causing yield losses, associated with 84–87 % of fruit dropped on the orchard floor. PFLS severity on shoots and incidence on fruit 12 weeks after full bloom was significantly reduced by all fungicide schedules evaluated. The effects of fungicides on PFLS severity in fruit at harvest were not substantial because of intense fruit drop. The 8-week schedule showed the lowest effectiveness in reducing fruit drop and thus the 6-week schedule is preferred. Further research is needed for an integrated management of PFLS in Ghana.     

Foraging wireworms are attracted to root-produced volatile aldehydes

Soil-dwelling insects are known to react to chemical cues they encounter in the rhizosphere. Whether wireworms (Coleoptera, Elateridae) use root-emitted volatile organic chemicals to localize their host plant remains, however, poorly understood. Here, we aimed at identifying chemical cues released by barley roots that attract Agriotes sordidus. In a first behavioral experiment, we assessed the ability of wireworms to orient towards live barley roots, using dual-choice olfactometers suitable for belowground insects. Then, we collected the volatile organic compounds (VOC) produced by barley roots using a dynamic head-space sampling approach. VOC were quantified and identified using gas chromatography—mass spectrometry (GC–MS). The odorant blend is composed of four aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-2-enal, and (E,Z)-nona-2,6-dienal. In a second set of dual-choice bioassays, wireworms were attracted towards a synthetic blend of these four major compounds. However, the synthetic blend was not as attractive as live roots, which is partially explained by the absence of CO₂, commonly known as a strong attractant for soil-dwelling insects. While CO₂ indicates the presence of living material in the vicinity, we hypothesize that additional VOC inform about the plant suitability. A better understanding of these belowground signals would contribute to the development of new integrated control strategies against wireworms.     

Characterization of broiler poultry production system in Rwanda

A study was conducted on 37 randomly selected broiler poultry farmers in Rwanda to characterize the production system using pre-tested semi-structured questionnaires. The data were processed in SPSS and presented as means, percentages and ranges in tables and text. All respondents kept Cobb breed and young stock was mainly (73 %) imported from abroad. The majority of respondents were males (68 %) and most farmers had attended only primary level of education (40.5 %). Most of the farms were in the peri-urban (48.6 %) and urban (37.8 %) areas and hired male youth (62.2 %) mainly aged 19–35 years. The majority of respondents (68 %) kept less than 500 birds per batch. Recordkeeping was well practiced (91.9 %) and (62.6 %) had permanent poultry houses and all farmers used deep litter system. Purchased feedstuffs were reportedly (92 %) mixed at farm level as the main feed resource. Maize bran was reported (97.06 %) the main, basal feedstuff. The mortality rates of chick and growers were 12.3 and 9.4 %, respectively. The slaughter age was reportedly 60 days with an average dressing percentage of 75.67 %. The main challenges reported were scarcity and unaffordability of quality feeds (59.5 %), lack of market access (45 %) and lack of credit (21 %). The farmers had various views on improving broiler production in Rwanda ranging from establishing feed processing industries 62.2 %, improving marketing facilities 35.1 %, increasing availability of day-old chick and access credit 27 %, to intensification of farmer training 16.2 %.     

Current status of cattle production system in Nyagatare District-Rwanda

A study was conducted to characterize the cattle production systems in Nyagatare District, Eastern Province of Rwanda using pre-tested questionnaires, interviews with key informants as well as focus group discussions in a period of 2 months. The respondents were selected by multi-stage sampling at sector and cell levels. Based on the procedure of Krejcie and Morgan (Educational and Psychological Measurement 30:607–610, 1970) to determine the overall sample size, the result indicated that the majority (98.3%) of farms were privately owned by large families of five to seven members, and most farmers (53.9%) had only primary education. Most respondents (52.6%) were in the age bracket of 41–50 years and were mainly (48.3%) located within 3 km from trading centers. The farm size averaged 6.5 ± 0.8 ha and most farms (64.7%) were fenced except in Rukomo Sector (50%) where zero grazing prevailed. Natural pastures (savanna grass land) were the main feed resource; tethering (9%) and communal grazing had diminished. Napier grass was the main planted forage (93.2%), followed by Chloris guyana (3.1%) and Brachiara (1.2%). Leguminous forages were rarely (2.5%) reported. Vita-mineral and salt block supplements, hay, and crop residues were the predominant supplementary feed stuffs used except in Karangazi and Rwemiyaga Sectors where only vita-mineral block predominated. However, maize and rice brans were reported to be the main feed stuffs used in supplementary feeding of lactating cows. Most farmers (89.7%) reported shortage of water as most of the farmers trekked their cattle to the nearest valley dams (59.2%), rivers (21.1%), and a few 6% had water on farms. Indigenous cattle were predominant (67.03%) followed by cross-breeds (28.37%) and exotics (4.6%) while all farmers kept small ruminants. Natural breeding predominated (74.9%) and most farms (60.6%) had animal houses most of which were temporary (52.8%). The reported mean age at first calving (AFC) was highest (40.2 ± .33) for Ankole and the lowest (29.1 ± .50) months for exotic cattle. Calving interval was shorter in local breeds than 65.7 ± 3.0 in exotic. The mean dairy milk yield was lowest for Ankole cattle 2.4 ± .08 as compared to the exotics (10.42 ± .36) and their crosses (7.2 ± .34). The main challenges were diseases, shortage of water, feeds, and inadequate extension services. Same observation was reported by Okello (African Journal of Range and Forage Science 22(3), 2005) in Uganda.     

Methionine oxidation enhances κ-casein amyloid fibril formation

The effects of protein oxidation, for example of methionine residues, are linked to many diseases, including those of protein misfolding, such as Alzheimer's disease. Protein misfolding diseases are characterized by the accumulation of insoluble proteinaceous aggregates comprised mainly of amyloid fibrils. Amyloid-containing bodies known as corpora amylacea (CA) are also found in mammary secretory tissue, where their presence slows milk flow. The major milk protein κ-casein readily forms amyloid fibrils under physiological conditions. Milk exists in an extracellular oxidizing environment. Accordingly, the two methionine residues in κ-casein (Met(95) and Met(106)) were selectively oxidized and the effects on the fibril-forming propensity, cellular toxicity, chaperone ability, and structure of κ-casein were determined. Oxidation resulted in an increase in the rate of fibril formation and a greater level of cellular toxicity. β-Casein, which inhibits κ-casein fibril formation in vitro, was less effective at suppressing fibril formation of oxidized κ-casein. The ability of κ-casein to prevent the amorphous aggregation of target proteins was slightly enhanced upon methionine oxidation, which may arise from the protein's greater exposed surface hydrophobicity. No significant changes to κ-casein's intrinsically disordered structure occurred upon oxidation. The enhanced rate of fibril formation of oxidized κ-casein, coupled with the reduced chaperone ability of β-casein to prevent this aggregation, may affect casein-casein interaction within the casein micelle and thereby promote κ-casein aggregation and contribute to the formation of CA.