خيارات البحث
النتائج 591 - 600 من 2,008
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.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]Flock structure, level of production, and marketing of three Ethiopian goat types kept under different production systems
2014
Tadesse, D. | Urge, Mengistu | Animut, G. | Mekasha, Yoseph
This study was conducted to characterize three Ethiopian indigenous goat types in terms of their composition and dynamics, productivity, and marketing. A set of semi-structured questionnaire was used to collect information from 155 goat owners based on single-visit-interviews. The study indicates that breeding females constituted the largest average flock composition followed by weaners and kids. Goat owners in the study areas relied mainly on births and purchases to build their flock while sales and deaths were the major routes of disposal. Lower commercial offtake (28%) and higher mortality (24%) rates were estimated for all study areas but the figures were lower in pastoral and agro-pastoral systems. On average, female goats in the study area gave first birth at the age of 1.4 years, kidded every 8.6 months and stayed on production/kidding for about 5 years, giving daily milk yield of 0.37 liter. Based on the estimates given by respondents, Somali and highland goats were characterized to have bigger age at first kidding and longer kidding life time, respectively. For other traits such as kidding interval and daily milk yield, no significant performance difference was observed among the goat types. In all study areas, goats were sold mainly at the farm gate when money is needed to buy grains and other farm inputs. Average age at sale/slaughter of male goats was about 1.4 years. Consumers, producers, traders, butchers and brokers were the major buyers of live goats in the study areas. The participation of goat producers in the market was constrained by seasonality of market, low price, and lack of market information and infrastructure.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]Wool characteristics of Libyan Barbary sheep in north-eastern Libya: I. Fiber diameter and staple length
2008
Akraim, F. | Milad, I.S. | Abdulkarim, A.A. | Ganem, M.
In this study wool characteristics of Libyan sheep in north-eastern Libya were investigated in a coastal region extended from El-Marj (32 25 N and 20 30 E) to Emsaad at the north-eastern border of the country (31 33N, 25 6 E). Twelve locations, one flock per flock were studied. Three sites have been sampled from each animal (Shoulder, mid-side and breech). Mean staple length and fiber diameter were 12.16cm and 38.43 µm respectively. In this study, staple length and fiber diameter didn’t significantly vary between locations studied. Sample site on the body of the animal significantly affect both staple length and fiber diameter, with breech position samples showed the shortest staple length and the thickest fiber diameter (P< 0.05). There was no difference between samples taken from mid-side or shoulder in all measured traits. Results of this study showed that Barbary sheep raised in the eastern part of the country characterized by a long staple and a large fiber diameter, and then confirmed the previous studies studies stated that this breed could be classed as a long carpet wool breed. Samples taken from mid-side position could be representative of Barbary sheep fleece
اظهر المزيد [+] اقل [-]Productivity and Natural Disease Resistance Potential of Free-ranging Local Chicken Ecotypes in Tanzania
2002
Msoffe, P.L.M. | Mtambo, M.M.A. | Minga, U.M. | Gwakisa, P.S. | Mdegela, R.H. | Olsen, J.E.
This study was carried out to investigate the productivity and the natural disease resistance potential of free-ranging local chickens in Tanzania. A total of 84 adult free-ranging local chicken ecotypes were studied, namely: Mbeya, Morogoro-medium, Ching’wekwe, Kuchi and Singamagazi. Adult body weight, body length, shank length and egg weight were assessed and compared. Average body weight for hens and cocks was 1441g (800 to 2,300g) and 2261g (1000 to 3500g), respectively. Egg weight averaged 41.6g (27 to 72g). Mean body length for hens and cocks was 21.6cm (17 to 26cm) and 24.6cm (21 to 29cm), respectively, and mean shank length 9.7cm (7 to 12cm) and 12.7cm (8.5 to 15cm), respectively. Between ecotypes significant differences were seen in the above parameters. The disease resistance potential was tested on 10 offspring of each ecotype, excluding the Mbeya. Twenty chickens (five from each of the four ecotypes) aged 12 weeks were inoculated with Newcastle disease virus while another 20 aged 20 weeks were inoculated with Salmonella gallinarum. Five chickens per group that were not challenged were used as controls. Following oral, ocular and nasal drop inoculation with Newcastle disease virus, the chickens developed clinical signs of Newcastle disease as from day three after infection. Mortality started on day five after infection, and all but one chicken were dead by day seven after infection. The 20 chickens, infected orally with S. gallinarum, showed clinical signs of fowl typhoid on day three after infection. Mortalities started on day seven after infection and by day 12 after infection 13 chickens had died. Seven birds survived without visible signs of the disease, including all five from the Kuchi ecotype and one each of the Morogoro-medium and Ching’wekwe ecotypes. At necropsy enlarged and congested liver and spleen, and catarrhal enteritis of the small intestines were seen. The surviving birds were sacrificed on day 14 after infection. Neither the sacrificed surviving birds nor the controls showed the above necropsy picture. It was concluded that free-ranging local chicken ecotypes in Tanzania differ in both productivity and disease resistance potential.
اظهر المزيد [+] اقل [-]Productivity of Abergelle, Central Highland and Woyto-Guji goat breeds in Ethiopia
2020
Jembere, Temesgen | Haile, Aynalem | Dessie, Tadelle | Kebede, Kefelegn | Mwai, Ally Okeyo | Rischkowsky, Barbara
The objective of this paper was to evaluate the productivity of three indigenous goat breeds from Ethiopia namely Abergelle (AB), Central Highland (CH) and Woyto-Guji (WG) based on their kids’ total live weight at three months (LWW), survival rate to three months (S3M) and average daily milk yield (ADM, for AB only). The LWW were standardized by year and post partum weight (ppw) of does. In addition, productivities expressed as the body weight of three months old kids produced per doe per year (index I) and per kg ppw per year (Index II) were also assessed. The overall least squares means of LWW for AB, CH and WG were 7.6, 15.3 and 10.2 kg, respectively. The overall mean of the ADM for AB was 367.10±139.79 ml. The S3M was 76.30%, 78.50% and 77.70%, for AB, CH and WG, respectively. Overall means of index I and index II were 14.7 kg and 0.50, respectively. Year of birth affected (p<0.05) LWW and S3M of AB, CH and WG as well as the indices. The ADM and S3M of AB and LWW of WG were also influenced ( p<0.001) by village of kidding. The LWW and S3M of the three breeds were not influenced (p>0.05) by sex of lambs. On the other hand parity of birth had clear influence (p<0.05) on ADM and S3M of AB and index I. Season of birth also had influence (p <0.001) on LWW of AB only. The CH does produce about 200% LWW of AB does and about 150% LWW of WG does. The CH was found to be the most productive breed in terms of all assessed parameters followed by WG. The AB was best suited for dual services (meat and milk). Hence, goat meat investment priorities in Ethiopia could target Central Highland goats. However, the productivity of these goat breeds should be improved in their respective localities by minimizing possible factors hampering their productivity
اظهر المزيد [+] اقل [-]Participatory approaches to investigate breeding objectives of livestock keepers
2010
Duguma, G. | Mirkena, T. | Haile, Aynalem | Iñiguez, L. | Okeyo Mwai, Ally | Tibbo, Markos | Rischkowsky, Barbara A. | Sölkner, Johann | Wurzinger, Maria
There are distinct breeds suitable for diverse purposes in the different production environments or ecological zones. Farmers in different production systems have different trait preferences and the strategies followed by them are also as diverse as the agro-environments within which they operate. In order to design a viable breeding plan, farmers’ preferences for the different traits need to be investigated. In this paper available tools and methods for defining livestock breeding objective traits are described, discussed and comparisons among them are made. The reviewed tools were: participatory rural appraisal (PRA), choice experiments, ranking of animals from own flock/herd and ranking of others animals. Each methodology may be appropriate to specific situation; however, it is recommended that a combination of approaches be used to precisely capture the breeding objective traits of livestock producers. Elucidation of objective traits using the tools with active involvement of producers can result in appropriate livestock genetic improvement that is well grounded in practical reality and truly reflects owners’ preferences.
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