IJAFR, Volume 57, 2018
Recent Submissions
-
The fatty acid profile and stable isotope ratios of C and N of muscle from cattle that grazed grass or grass/clover pastures before slaughter and their discriminatory potentialConsumption of grazed pasture compared to concentrates results in higher concentrations, in beef muscle, of fatty acids considered to be beneficial to human health. Little information is available on the influence of the type of grazed forage. Our objectives were to determine 1) the effect of inclusion of white clover in a grazing sward on the fatty acid profile of beef muscle and 2) the potential of the fatty acid profile and stable isotope ratios of C and N to discriminate between beef from cattle that grazed grass-only or grass/clover swards before slaughter. A total of 28 spring-born Charolais steers grazed from March until slaughter in October, either on a perennial ryegrass (Lolium perenne L.) sward that received approximately 220 kg N/ha or a perennial ryegrass–white clover (Trifolium repens L.) sward that received 50 kg N/ha. The longissimus muscle from cattle finished on grass/clover had a higher (P < 0.05) proportion of C18:2 and C18:3 but a lower (P < 0.05) proportion of conjugated linoleic acid and δ15N value than animals finished on the grass-only sward. Discriminant analysis using the fatty acid data showed that, after cross-validation, 80.7% of grass/clover and 86.1% of grass-only muscle samples were correctly classified. Discriminant analysis using the stable isotope data showed that, after cross-validation, 95.7% of grass/clover and 86.5% of grass-only muscle samples were correctly classified. Inclusion of white clover in pasture is likely to have little effect on healthiness of meat for consumers. However, changes in fatty acids and stable isotopes can be used to distinguish between grass/clover-fed and grass-only-fed beef.
-
Effects of mycorrhizal inoculation and digestate fertilisation on triticale biomass production using fungicide-coated seedsCrop fertilisation management using organic wastes and arbuscular mycorrhizal fungi (AMF) inoculation can play a crucial role in the sustainability of agroecosystems. However, in conventional agricultural systems, agrochemicals like fungicides could reduce the positive effect of AMF. The aim of this study was to evaluate the agronomic (biomass production) and environmental (soil CO2 emission) effects of AMF inoculation and digestate spreading on triticale cultivation using commercial seeds coated with fungicide. The field experiment was conducted in 2014–2015 at the University of Padua’s experimental farm (Italy), adopting a split-plot design, where the main plot factor was AMF inoculation (inoculated vs. uninoculated) and the subplot factor was fertilisation treatment (no fertilisation (NF), digestate liquid fraction (DL), digestate solid fraction (DS), mineral fertilisation (MF)). Low AMF root colonization was observed, likely due to the effect of fungicide; the only significant effect of AMF inoculation was a lower shoot density. Dry biomass production was significantly higher in the MF treatment (21.8 ± 1.04 Mg/ha) and lower in the NF treatment (14.5 ± 0.73 Mg/ha) compared to DS and DL treatments, which were not significantly different with an average yield of 17.2 ± 2.10 Mg/ha. During the cropping season, soil CO2 emissions were not significantly affected by either AMF inoculation or fertilisation treatment. The median value of soil CO2 emissions was 447.3 mg/m2 per hour.
-
Evaluating the effect of storage conditions on milk microbiological quality and compositionIn this study, the effect of storage temperature (2 or 4°C) on the composition of milk and microbiological load was investigated over 96 h. Milk samples were collected from farm bulk milk tanks after one complete milking and stored at 2 or 4°C over 96 h. Total bacterial count (TBC), psychrotrophic bacterial count (PBC) and proteolytic bacterial count (PROT) were affected by storage time and temperature and varied significantly between farms (P < 0.05). The levels of TBC, PBC and PROT bacterial count increased from 4.37 to 6.15 log cfu/mL, 4.34 to 6.44 log cfu/mL and 3.72 to 4.81 log cfu/mL, respectively, when the milk was stored for 96 h at 2°C. The milk samples stored at 4°C had higher increases in these bacterial counts after 72 h in comparison to milk samples stored at 2°C. The casein fraction content was lower in milk samples stored at 4°C, which could be due to high levels of PROT bacteria or enzyme activity in these samples. Milk stored for 96 h at 2°C has less impact on composition or processability parameters compared to milk stored at 4°C.
-
Effect of biostimulants on cold resistance and productivity formation in winter rapeseed and winter wheatThe aim of the study was to investigate the effects of biostimulants on the resistance to freezing under laboratory-controlled cold conditions and on the growth, development, overwintering and productivity of winter rapeseed and winter wheat in natural field experiments. The effect of free amino acids, macroelements and microelements that contain biostimulants Ruter AA, Terra Sorb and Razormin was tested on cultivars of rapeseed, ‘Hornet H’, and winter wheat, ‘Skagen’ and ‘Kovas’, applying morphometrical methods. We found that biostimulants applied to rapeseed at BBCH 13–14 stage and to wheat at BBCH 14–15 stage under controlled cold stress conditions increased the freezing tolerance of seedlings. Biostimulants more actively increased the freezing resistance of rapeseed seedlings at –5°C compared to that of wheat seedlings. The temperature of –7°C was mortal to rape seedlings, while the resistance of wheat seedlings increased under the influence of the tested biostimulants compared to that of the control seedlings. In natural field experiments, these biostimulants produced a significant effect on plant growth in autumn, acclimation to the cold, plant overwintering, vegetation renewal and, due to this, formation of productivity elements. The effects of Razormin (200 mL/ha), Terra Sorb (2 L/ha) and Ruter AA (1 L/ha) were significantly higher on growth parameters of winter wheat compared to the productivity of winter rapeseed.
-
Fortification of milk with phytosterol and its effect on sensory and physicochemical propertiesPhytosterols are a group of lipophilic steroid alcohols found in plants, which have been shown to lower cholesterol when supplemented in the diet. A commercial phytosterol preparation was added to milk in the form of an oil-in-water emulsion. For the preparation of an emulsion, diacetyl tartaric acid ester of mono- and diglycerides was used as an emulsifier and butteroil was used as a source of fat. Three emulsion formulations, i.e. A (8% phytosterols), B (10% phytosterols) and C (12% phytosterols), were prepared in which the levels of emulsifier (6.5%) and butteroil (10%) were kept constant, and each emulsion was added to milk at a rate of 5% (w/w). Based on sensory evaluation, B-emulsion formulation was selected for fortification of milk. The phytosterol content of the fortified milk determined by reverse-phase high-performance liquid chromatography was 410.8 mg/100 g. No significant loss in the initial content of phytosterol was observed after 1 week of storage. Sensory and physicochemical analyses indicated that significant differences were not observed between control and fortified milk samples up to 7 days of refrigerated storage. The present study suggests that it is feasible to add phytosterol as a functional ingredient in milk in the form of water-soluble emulsion to enhance health benefits of consumers. Two servings of such fortified milk per day provide almost the entire recommended daily requirement of phytosterol.
-
A critical review of integrated grass weed management in IrelandGrass weeds affect arable crops throughout the world, inflicting yield penalties, reducing crop quality and taking available nutrients away from the growing crop. Recently in Ireland, the presence of herbicide resistance in grass weeds has been noted. In order to preserve the sustainability of crop production in Ireland, an integrated pest management approach must be implemented. How this applies to control grass weeds was the focus of this review. Here we examined the state of current research into grass weed biology and the nature of herbicide resistance, identifying gaps in research in the Irish context. We identified a number of cultural grass weed control techniques, as being relevant to the Irish mode of crop production. Crop rotation, cultivation techniques, manipulation of sowing dates and increased crop competition were recognised as useful strategies. Combining these strategies to provide effective grass weed control may be key to reduce dependence on herbicides.
-
A comparison of husked and naked oats under Irish conditionsDuring the harvesting of husked oats (Avena sativa L.), the kernel remains tightly enclosed by a lignified lemma and palea, collectively termed the husk or hull. In naked oats, which are the same species as husked oats, the lemma is much less lignified and the kernel threshes free during harvesting. The absence of the largely indigestible husk increases the nutritive value of naked oats compared to that of husked oats, particularly for non-ruminants and poultry. There is little information regarding the potential of naked oats as an arable crop in Ireland. The objective of this study was to determine the productivity of naked oats under Irish conditions. Field experiments were carried out in the south east of Ireland to compare the grain yield and grain quality of both autumn-sown and spring-sown naked and husked oat cultivars. Grain yield of naked oat cultivars was significantly lower than that of husked oat cultivars, irrespective of whether they were autumn sown or spring sown. However, when the kernel yield of husked oat cultivars was estimated, differences in yield between the two types were much smaller, and in some cases, kernel yield of naked oat cultivars exceeded that of husked oat cultivars. Grain quality, as indicated by hectolitre weight and grain N concentration, was generally greater for naked oat cultivars than for husked oat cultivars. It is concluded that under Irish conditions, naked oats have the potential to produce kernel yields equivalent to husked oats. The grain produced is of high quality and may be particularly suited for the nutrition of non-ruminants.
-
Ethical, moral and social dimensions in farm production practices: a segmentation study to assess Irish consumers’ perceptions of meat qualityGrowing consumer concerns with modern farming and food production systems indicate a significant market opportunity for meat production practices that consider ethical, moral and social value traits. In the current study, we aimed to identify and characterise distinct segments of Irish consumers based on their perceptions of the quality of meat from different farm-level production practices (organic farming, high animal welfare standards, free range farming, and “natural”, treatment-free feeding regimes). An online survey was carried out with 251 Irish meat consumers. Using cluster analysis, we identified three distinct segments: “Target consumers”, “Purist consumers” and “Disinterested consumers”. Chi-square analyses revealed differences between the segments based on gender, age and meat-purchasing motivations. The results provide insight into the opportunities that exist for exploring new viable market segments as well as for engaging Irish consumers and empowering them with information around the ethical, social and moral aspects of farm-level practices related to meat production.
-
Insect assemblages and their preference for Lupinus albus and L. luteusWhile lupin has undergone extensive research to ascertain its suitability for growth as forage or grain legume crop, the present trend is for research to be centered on its applicability in the seed protein and oil industry. Study of the literature showed that no intensive study of the lupin insect fauna had been carried out in Bulgaria. The purpose of this study was to identify the insect assemblages associated with Lupinus albus and L. luteus, as well as the insect preference for them. Thrips sampling was made by the tapping-method, aphids were directly counted on the plants and the composition and population density of other species were recorded by sweepings. Insect fauna was studied for the first time in Bulgaria. The fauna was represented on L. albus by 64 species, belonging to eight orders, 28 families and 57 genera, including 23 beetles, 25 hemipteras, five thrips, three butterflies, three bees, one leaf aphid, two grasshoppers, one leafminer and one green lacewing. L. luteus had similar species composition but was less preferred by insects. The use of lupin cultivars with shorter and intense reproductive periods, with a lower content of crude protein and phosphorus, would give an environmentally friendly protection against insect pests, which would be suitable for an organic production system.