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The influence of cow feed enriched with carrots on milk quality and nutritional value
2011
Antone, U., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvia Univ. of Agriculture, Sigulda (Latvia). Research Inst. of Biotechnology and Veterinary Medicine Sigra | Sterna, V., Latvia Univ. of Agriculture, Sigulda (Latvia). Research Inst. of Biotechnology and Veterinary Medicine Sigra | Zagorska, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
β-Carotene (BC) and a-tocopherol in milk fat have positive implications in human nutrition, besides the specifically protecting polyunsaturated fatty acids from oxidation. To determine the possible effect on some milk components, nutritional value and lipid stability of including carrots in the diet of lactating cows, ten cows were selected in a dairy farm and divided into 2 groups (control and experimental) by 5 cows in each. In experimental group's diet additionally 7 kg carrots per cow per day were included. Individual cow milk samples were obtained 1 day before feed enrichment, in days 7, 24, 35, 42 (during the feed enrichment), and 1 week after feed enrichment. Analyses of milk fat, protein content, somatic cell count (SCC), retinol, BC, vitamin C, tocopherols, immunoglobulins (Ig), lysozyme, fatty acids (FA) were made, and milk yield was measured. Supplying cow diet with carrots showed a tendency to improve milk quality by promoting the faster decrease of SCC, and significantly (p is less than 0.05) increasing Ig and lysozyme content, thus potentially improving milk nutritional value. The vitamin content rose significantly (p is less than 0.05) by retinol and tocopherol contents, but b-carotene content increase in milk was not observed. Also milk fatty acid (FA) stability changes during 5 day storage in temperature of 4 - 6 deg C were not observed.
显示更多 [+] 显示较少 [-]Evaluation of quality indices of strawberry mass
2011
Boca, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Skrupskis, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Straumite, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
Colour, texture and aroma are the main quality attributes of food influencing consumer acceptability of food products. Colour of the product is one of the factors affecting hedonic evaluation. Strawberry mass for a consumer is characteristic by its distinct red colour. The stability of anthocyanins becomes most significant in the case of colour quality. To investigate colour quality, it is necessary to measure colour, as well as pigment concentration. Fresh and thermally treated strawberry mass was analyzed. Formation and stability of anthocyanins, which is the main colour formation substance of berries, are determined by different factors. Anthocyanin colors can be enhanced and stabilized by the addition of different natural or artificial acidifiers. Data of the research indicate that anthocyanin amount during storage period decreases. After 2 days storage their amount increased, but afterwards decreased, both, in fresh and thermally treated mass. The taste evaluation of strawberry mass was essentially affected by the enhancers added. The aim of research was to analyze the quality parameter – colour of strawberry mass with added acidifier which further could be used in production of different products for the needs of public catering, e.g. in production of desserts. The anthocyanin content in strawberry mass with acidifiers was determined to see the organic acid impact to colour stability. Research shows, that natural enhancers – quince and sea buckthorn juices used in the research, did not substantially affect each other’s pH in the product.
显示更多 [+] 显示较少 [-]The composition of sugars and sugar-acid ratio of highbush blueberry varieties grown in Latvia
2011
Sne, E., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kampuse, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Berna, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
Highbush blueberries are thought to provide protection against oxidative damage of free radicals and contribute to positive health benefits. They have been studied little in Latvia; therefore, the aim of study was to evaluate the soluble solids content, titratable acidity and sugar content of berries harvested in 2010. Seven varieties of cultivated highbush blueberries (Vaccinium corymbosum L.) grown in Latvia were analysed. Analyses were done for frozen berries of varieties ‘Bluecrop’, ‘Chandler’, ‘Chippewa’, ‘Duke’, ‘Northblue’, ‘Patriot’ and ‘Polaris’. All experiments were performed at the Latvia University of Agriculture, Faculty of Food Technology. The content of titratable acids (TA) was detected using standard method ISO 750:1998 by titration with 0.1N NaOH. Soluble solids content (SSC) was analysed using standard method ISO 2173:2003 by hand refractometer. Sugars (fructose, glucose and sucrose) were analysed by high-pressure liquid chromatography HPLC analysis. Results showed that there are significant differences between varieties (p is less than 0.05) for all parameters. TA content varied from 0.4 – 1.2%, SSC - 8.5 – 10.8 degBrix and total sugars from 7.6 to 9.3 g 100 gE-1. The highest ratio between sugars and titratable acids was for ‘Polaris’ while the lowest – ‘Chandler’ and ‘Bluecrop’.
显示更多 [+] 显示较少 [-]Changes of jelly structural properties depending on different sweet matters
2011
Kronberga, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Karklina, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
There is growing interest in products without added sugar; thus, sugar consumption is directly related to diabetes and other illnesses such as obesity. A change in the type of sugar and content may therefore both change the perception of sweetness and texture of products. The aim of the research work was to evaluate properties of agar-agar jellies prepared with inulin syrup, galactose syrup and malt extract to replace sugar. Agar gels were prepared to substitute sugar with inulin syrup, galactose syrup and malt extract. Texture of experimental samples was determined by using a Texture Analyser (Model TA.XT Plus; Stable Micro Systems). Colour of jellies was evaluated by using Colour Tec-PCM and Jenway 3510 was used for pH measurements. Obtained results showed that different kinds of sugar containing syrups could be used as sugar substitute for production of a new type jellies. Hardness of the experimental samples is influenced by the sugar type containing syrup. The hardness is determined in the experimental samples by replacement of sugar by increasing concentration of inulin syrup. Decreasing hardness values are observed by increase of added malt extract (maltose) and galactose syrup concentration in samples. The pH values of experimental samples ranged between 3.11 and 4.45. Higher L* value of experimental samples are with galactose syrup. Lightness “L” changed between 20.92 and 18.11 increasing inulin syrup concentration. The same situation can be observed using malt extract as sugar substitute.
显示更多 [+] 显示较少 [-]Histological status of lymph nodes for circovirus-2 seropositive and seronegative pigs
2011
Piginka, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Institute of Food Safety, Animal Health and Environment BIOR, Riga (Latvia) | Birgele, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the present study was to investigate the histological status of lymph nodes lnn. inguinales superficiales sinister et dexter, lnn. mesenterici cranial, and lnn. tracheobronchales for porcine circovirus-2 (PCV2) seropositive and seronegative pigs from two Latvian farms. The research was carried out in 2009. Two Latvian farms were investigated – conditional farm A in Latgale, and farm B in Kurzeme. Pigs from farm A had never been vaccinated against PCV2, but on farm B the PCV2 vaccination programme had been stopped six months ago. Ten pigs, 5-15 weeks old, were selected from each farm for investigation. Generally, four lymph nodes were taken from each animal. The blood serum of all 20 pigs was serologically tested for the PCV2 antibody of ELISA Synbiotics, Serelisa PCV2 Ab Mono Blocking kits. Four structural parameters of a lymph node were detected on histological slides: visualization of follicle structure, lymphocyte depletion, amount of histiocytic cell infiltration, and amount of multinucleate giant cell infiltration and localization in the lymph node. Only in lymph nodes of PCV2 seropositive pigs multinucleate giant cells were detected, which is an important additional parameter for serological test and is suggestive of PCV2 infection. As a result, an interrelation between the amount of histiocytic cells and the follicle structure was detected in pigs' lymph nodes: the more histiocytic cells in the lymph node, the greater the loss of the lymphoid follicle structure.
显示更多 [+] 显示较少 [-]Efficacy of the first large-scale rabies oral vaccination campaigns in Latvia
2011
Olsevskis, E., Latvia Univ. of Agriculture, Jelgava (Latvia);Food and Veterinary Service, Riga (Latvia);Institute of Food Safety, Animal Health and Environment BIOR, Riga (Latvia) | Liepins, E., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lamberga, K., Food and Veterinary Service, Riga (Latvia) | Rodze, I., Institute of Food Safety, Animal Health and Environment BIOR, Riga (Latvia)
Rabies is present in the entire territory of Latvia and as a zoonosis poses risk to both human and animal health. The disease is also endemic in countries bordering with Latvia, namely Lithuania, Estonia, Russia and Belarus. Reservoirs for the rabies virus (RABV), the causative agent of the disease in Latvia, are the red fox (Vulpes vulpes) and the raccoon dog (Nyctereutes procyonoides). The first large-scale oral rabies vaccination campaigns using aircrafts were carried out in spring and autumn 2005 using Fuchsoral® SAD B19 oral vaccine baits. In total, 1,894 wild animals (1,366 foxes and 528 raccoon dogs) were hunted in vaccinated areas to evaluate the efficacy of the campaign. After spring and autumn vaccination campaigns, 51.6% of the fox and raccoon dogs were positive for tetracycline. Herd immunity was found in 50.5% of foxes and raccoon dogs using FAVN test and only in 14.8% using ELISA test. After oral vaccination campaigns, rabies incidence decreased in vaccinated area, however, an increase of the incidence was observed in unvaccinated area. Despite the slight increase in rabies incidence in Latvia in 2006 compared to 2005, in 2005 only 141 rabies cases (30%) were found in the vaccinated area whereas 330 cases were detected in the unvaccinated area.
显示更多 [+] 显示较少 [-]The use of black-box modelling in bioprocess scale-up
2011
Mednis, M., Latvia Univ. of Agriculture, Jelgava (Latvia)
Computer models of bioprocesses have become an essential tool in biotechnology. This paper describes various bioprocess scaleup releated problems. The problems at different scales are explained. In this paper the use of computer model in E.coli fermentation scale-up from shake flask to laboratory scale bioreactor is discussed. A black box modelling approach was used. Fermentation results have been visualized and discussed. The computer model created in Matlab environment was used for bioprocess behaviour prediction. Possible bioprocess scale-up software improvements and bioprocess optimization are discussed.
显示更多 [+] 显示较少 [-]Socio-economic characteristics and perceptions of cattle keepers and constraints to cattle production in western Kenya
2011
Amimo, Joshua O. | Thumbi, Samuel M. | Inyangala, B.A.O. | Jung'a, J.O. | Mosi, R.O.
A cross-sectional survey was done in two Districts in Western Kenya to determine the socio-economic characteristics and perceptions of the cattle types kept. This involved socio-economic profiles of households, herd structure, reasons for keeping specific types of cattle and production and marketing constraints together with desired policy interventions to address the constraints. A total of 210 farmers randomly selected were interviewed. The data was analysed using Statistical Analysis System program. The majority of farmers (84%) were males. The households surveyed had an average family size of 8 (± 4.7) members. The mean land holding was 7.8 acres, with 98% of them owning the land. Most of the farmers (64%) in the two districts were literate and were involved in farming (95%) as the primary livelihood. The majority (80%) of the households preferred keeping indigenous zebu cattle over the exotic cattle. The first three reasons for keeping zebu cattle were, in that order, work, especially ploughing (91%), milk (74%) and as a repository for wealth (32%), which accounted for about 62% of the respondents. Diseases (86%), inadequate and low quality feed (12%) and high cost of drugs (2%) were the major constraints to livestock productivity. The farmers also identified lack of market (48%), poor infrastructure (39%) and misuse by the middlemen traders (12%) as main marketing constraints. The survey showed that there is need for the effective implementation of policies on adequate financial aid and regulation of farm input prices to the farmers as well as improved livestock extension services to enhance the production of ruminant livestock.
显示更多 [+] 显示较少 [-]Pastoralists’ perception of the impact of East Coast fever on cattle production under extensive management in Northern Rift Valley, Kenya
2011
Kipronoh, K.A. | Gathuma, J.M. | Kitala, P.M. | Kiara, Henry K.
A study using participatory epidemiology (PE) methodologies was conducted in West Pokot and Baringo districts, Northern Rift Valley, Kenya to assess the status of East Coast Fever (ECF) and obtain livestock keepers’ perceptions of how the disease impacts on their livelihoods. A total of 658 livestock keepers comprising of 480 men and 178 women were invited to participate in community meetings held in twenty two purposively selected locations each in West Pokot and Baringo. Fifty six percent of the livestock keepers were from West Pokot while the remaining 54 percent were from Baringo District. Nearly all the households in both communities depended on cattle keeping as the major source of livelihood. The activity was ranked as priority enterprise by 96.2% and 93.3% of the groups in West Pokot and Baringo district respectively. Cattle diseases were identified as the main constraint affecting production and in particular, ECF and trypanosomosis were reported as the most important compared to other diseases. The informants were relatively consistent in estimating the impact of cattle diseases on derived benefits. There was good agreement among the various groups with coefficient of concordance (W) values ranging between 0.43 and 0.60 (p < 0:05 – p < 0.01). East Coast fever was found to have the greatest impact. Based on the findings from this study, there is need for stakeholders in the livestock industry to develop control strategies for ECF control that are supportive to the production system in a particular the region.
显示更多 [+] 显示较少 [-]Livestock feed resources: Current production and management practices in central and northern rift valley provinces of Kenya
2011
Lukuyu, Ben A. | Franzel, Steven | Ongadi, P.M. | Duncan, Alan J.
Smallholder dairy farmers in developing countries face many feed constraints such as inadequate feed quality and quantity, poor storage facilities for feed conservation as well as insufficient water. However, feeding of livestock continues to pose many problems due to lack of information on composition and utilization of locally available feed resources. These problems are aggravated by lack of access to and high cost of feed inputs. The use of cheap and readily available local feed resources has great potential to increase livestock productivity. The East African Dairy Development project in Kenya, through use of various participatory rapid appraisal tools conducted a rapid appraisal study of three project areas. The objective was to assess feeds and feeding practices in smallholder dairy systems, identify feed resources available year round and where the gaps are as well as to determine what practices are available for improving production and utilization of feed resources in order to raise smallholder dairy production. Established opportunities for improvement include on-farm production and utilization of fodder, efficient storage, processing and utilization of crop residues, pasture improvement, appropriate water harvesting technologies, formulation of feed rations amongst small scale farmers, small scale feed conservation as well as development of fodder markets. Given the complex farming system within which smallholder farmers operate, changes are needed in both the technologies used for improving feeds and feeding systems and in the institutional and policy arrangements surrounding feed supply. In addition, technical interventions need to be developed in a participatory manner along with farmers and other stakeholders within the system to make them relevant and sustainable.
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